No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Prevalence of glaucoma in the Australian National Eye Health Survey
Abstract
Aim
To estimate the prevalence of glaucoma in Australia.
Methods
This was a population-based study of 3098 non-Indigenous Australians (50–98 years) and 1738 Indigenous Australians (40–92 years) stratified by remoteness. Each participant underwent a standard examination that included visual field assessment, tonometry and non-mydriatic fundus photography. Two fellowship-trained glaucoma specialists independently assessed relevant case notes (past ocular history, best-corrected visual acuity, frequency doubling technology visual fields, Van Herick grade, intraocular pressure and optic disc-centred photographs) and assigned a diagnosis ranked on a scale of certainty: none, possible, probable or definite glaucoma.
Results
A total of 4792 (99.1%, 3062 non-Indigenous and 1730 Indigenous) participants had retinal photographs in at least one eye that were gradable for glaucoma. The weighted prevalence of glaucoma (definite) in non-Indigenous Australians and Indigenous Australians was 1.5% (95% CI 1.0 to 2.2) and 0.6% (95% CI 0.4 to 1.1), respectively. When definite and probable cases of glaucoma were combined, rates were 3.4% (95% CI 2.7 to 4.3) among non-Indigenous and 1.6% (95% CI 1.1 to 2.3) in Indigenous Australians. Only 52.4% of non-Indigenous Australians and 28.0% of Indigenous Australians with glaucoma self-reported a known history of glaucoma.
Conclusion
We estimate that 198 923 non-Indigenous Australians aged 50 years and over and 2139 Indigenous Australians aged 40 years and over have glaucoma. Given the high rates of undiagnosed glaucoma coupled with a significant ageing of the Australian population, improvements in case detection and access to low vision rehabilitation services may be required to cope with the growing burden of glaucoma.
... 1,2 Because glaucoma is asymptomatic until advanced stages, many people with glaucoma remain undetected; a proportion which ranges from 50% in the developed world to 90% in the developing world. 3,4 However, early detection and rigid surveillance are imperative to prevent glaucoma blindness and reduce the rate of disease progression. 4,5 Visual field (VF) testing with a standard automated perimeter (SAP) is the clinical standard for the diagnosis and monitoring of glaucoma. ...
... 3,4 However, early detection and rigid surveillance are imperative to prevent glaucoma blindness and reduce the rate of disease progression. 4,5 Visual field (VF) testing with a standard automated perimeter (SAP) is the clinical standard for the diagnosis and monitoring of glaucoma. VF testing in glaucoma typically involves the evaluation of the central 24 degrees of monocular vision with 6-degree spaced targets (24-2 perimetry). ...
... As one of the leading causes of irreversible blindness, glaucoma remains alarmingly underdiagnosed; even in developed nations, the rate of undiagnosed glaucoma exceeds 50%. 4 The reasons contributing to this are multifactorial. Diagnosing and managing glaucoma requires healthcare infrastructure. ...
Purpose
To establish a normative database using a central 10-degree grid pattern for the online circular contrast perimetry (OCCP) application.
Participants
Fifty participants with mean age 65 ± 13 years were selected for this study. One eye from each participant that met inclusion criteria was randomly included in the cohort.
Methods
The web-application delivered online 52-loci perimetry in a central 10-degree pattern using circular flickering targets. These targets consist of concentric sinusoidal alternating contrast rings. Users were guided by the application to the correct viewing distance and head position using in-built blind spot localization and webcam monitoring. A spinning golden star was used as the fixation target and patients performed the test in a darkened room following standard automated perimetry (SAP).
Results
The reliability rates and global indices for OCCP were similar to SAP. OCCP mean sensitivity reduced with age at a similar rate to SAP. Mean sensitivity per loci of 10-degree OCCP was greater than SAP by 1.24 log units (95% CI 1.23 to 1.26) and obeyed a physiological hill of vision. Small differences existed in mean sensitivities between OCCP and SAP which increased with increasing spot eccentricity. Mean deviation (MD) displayed good agreement between the two tests.
Conclusion
Central 10-degree online circular contrast perimetry via a computer-based application has comparable perimetric results to standard automated perimetry in a normal cohort.
... Nearly half of the non-indigenous people and almost three-quarters of the indigenous participants diagnosed with glaucoma were unaware of the diagnosis. 43 ...
... Prevalence of blindness and its causes was not reported by authors. 43,70 ...
Glaucoma is a mixed group of optic neuropathies that lead to irreversible visual field loss and blindness if left untreated. It is estimated that 3.5% of the global population aged 40 to 80 years have any glaucoma, being the primary open-angle and the primary angle-closure glaucoma the most prevalent forms. Although the age-standardized prevalence of blindness caused by glaucoma has decreased substantially over the last decades, population growth and aging impose many challenges in preventing glaucoma-related morbidities on a global level. Also, difficulties in diagnoses and treatment, along with its chronic and irreversible nature, urge the development and implementation of innovative approaches in confronting the disease. This manuscript reviews recent literature related to the epidemiology of primary glaucomas in adults, the risk factors attributed to the development of the disease, and discuss challenges and potential solutions from a public health perspective.
This article is protected by copyright. All rights reserved.
... Glaucoma is the leading cause of irreversible blindness both in Australia and worldwide. [1][2][3][4] Despite its significant impact on public health, over half of glaucoma cases remain undetected globally and in Australia,5,6 highlighting the huge need for effective screening and management strategies. In Australia, optometrists (primary care) and ophthalmologists (tertiary care) are responsible for providing glaucoma care. ...
Purpose
To examine glaucoma practice patterns in Australia, focusing on visual field test uptake and antiglaucoma drug prescribing by optometrists and ophthalmologists.
Design
A serial cross‐sectional study was conducted to describe visual field testing charges and compare them to changes in comprehensive eye examination charges, as well as to analyse Pharmaceutical Benefits Scheme (PBS) items for antiglaucoma prescriptions.
Methods
The study utilised Medicare Benefits Schedule (MBS) reimbursements for visual field testing from January 2003 to December 2022, along with PBS prescriptions for antiglaucoma drugs by optometrists and ophthalmologists from January 2008 to December 2022.
Results
From 2003 to 2022, rates of visual field testing per 100,000 population in Australia showed a consistent increase, except for a decline in 2020 due to COVID‐19 lockdowns, particularly in Victoria. Optometry surpassed ophthalmology in conducting visual field tests in 2009. Prescription rates for antiglaucoma medications rose significantly from 2009 to 2022, following their inclusion in the optometric PBS, with prostaglandin analogues being the most prescribed. During the 2020 lockdowns, visual field testing decreased while antiglaucoma prescriptions remained stable.
Conclusions
The increase in visual field testing and antiglaucoma drug prescriptions underscores the expanding role of optometrists in glaucoma management in Australia. This rise has not impacted ophthalmology prescriptions, suggesting that the growing scope of optometric practice effectively reaches a broader patient population, especially amid the public health crisis of undiagnosed glaucoma.
... Notably, three loci were not present in the Asian population, one of which corresponded to the TMCO1 region where the key SNP (rs4657477) is monomorphic in Asians. Given the higher prevalence of NTG in Asian populations 25 , the absence of a TMCO1related variant could be expected as this gene is likely associated with higher IOP 26 . ...
Primary open-angle glaucoma typically presents as two subtypes. This study aimed to elucidate the shared and distinct genetic architectures of normal-tension (NTG) and high-tension glaucoma (HTG), motivated by the need to develop intraocular pressure (IOP)-independent drug targets for the disease. We conducted a comprehensive multi-ethnic meta-analysis, prioritized variants based on functional annotation, and explored drug-gene interactions. We further assessed the genetic overlap between NTG and HTG using pairwise GWAS analysis. We identified 22 risk loci associated with NTG, 17 of which have not previously been reported for NTG. Two loci, BMP4 and TBKBP1, have not previously been associated with glaucoma at the genome-wide significance level. Our results indicate that while there is a significant overlap in risk loci between tension subtypes, the magnitude of the effect tends to be lower in NTG compared to HTG, particularly for IOP-related loci. Additionally, we identified a potential role for biologic immunomodulatory treatments as neuroprotective agents.
... The sensitivity of the AI system for referable glaucoma in this cohort was 33.3%, significantly lower than the expected sensitivity of 95.6%. To assess the adequacy of the study's power, we calculated the achieved power using a sensitivity of 33.3%, a specificity of 97.4%, a prevalence of referable glaucoma of 15.4% (comprising both glaucoma certain and glaucoma suspect) [14], and a sample size of 900 images graded by 11 optometrists. The predicted power was found to exceed 99.9%, indicating that the study possesses sufficient power to detect the specified outcomes. ...
Background/Objectives: Glaucoma is the leading cause of irreversible blindness, with a significant proportion of cases remaining undiagnosed globally. The interpretation of optic disc and retinal nerve fibre layer images poses challenges for optometrists and ophthalmologists, often leading to misdiagnosis. AI has the potential to improve diagnosis. This study aims to validate an AI system (a convolutional neural network based on the Inception-v3 architecture) for detecting glaucomatous optic neuropathy (GON) using colour fundus photographs from a UK population and to compare its performance against Australian optometrists. Methods: A retrospective external validation study was conducted, comparing AI’s performance with that of 11 AHPRA-registered optometrists in Australia on colour retinal photographs, evaluated against a reference (gold) standard established by a panel of glaucoma specialists. Statistical analyses were performed using sensitivity, specificity, and area under the receiver operating characteristic curve (AUROC). Results: For referable GON, the sensitivity of the AI (33.3% [95%CI: 32.4–34.3) was significantly lower than that of optometrists (65.1% [95%CI: 64.1–66.0]), p < 0.0001, although with significantly higher specificity (AI: 97.4% [95%CI: 97.0–97.7]; optometrists: 85.5% [95%CI: 84.8–86.2], p < 0.0001). The optometrists demonstrated significantly higher AUROC (0.753 [95%CI: 0.744–0.762]) compared to AI (0.654 [95%CI: 0.645–0.662], p < 0.0001). Conclusion: The AI system exhibited lower performance than optometrists in detecting referable glaucoma. Our findings suggest that while AI can serve as a screening tool, both AI and optometrists have suboptimal performance for the nuanced diagnosis of glaucoma using fundus photographs alone. Enhanced training with diverse populations for AI is essential for improving GON detection and addressing the significant challenge of undiagnosed cases.
... Additionally, we will discuss the deployment of AI products in clinical practice, addressing potential risks and the need for validation studies and protocols to ensure the reliability and safety of AI-assisted diagnosis. glaucoma remain undiagnosed globally [1]: 78%−94% for Africa [6], 72%−84% for Asia [7,8], 57%−68% for Europe [9], 62%−78% for North America [10], 75%−88% for Latin America [11] and, 50% −60% for Australia and Oceania [7,[12][13][14]. The estimated numbers of glaucoma cases worldwide in 2020 are 52.7 million detected versus 43.8 million undetected. ...
Glaucoma is the commonest cause of irreversible blindness worldwide, with over 70% of people affected remaining undiagnosed. Early detection is crucial for halting progressive visual impairment in glaucoma patients, as there is no cure available. This narrative review aims to: identify reasons for the significant under-diagnosis of glaucoma globally, particularly in Australia, elucidate the role of primary healthcare in glaucoma diagnosis using Australian healthcare as an example, and discuss how recent advances in artificial intelligence (AI) can be implemented to improve diagnostic outcomes. Glaucoma is a prevalent disease in ageing populations and can have improved visual outcomes through appropriate treatment, making it essential for general medical practice. In countries such as Australia, New Zealand, Canada, USA, and the UK, optometrists serve as the gatekeepers for primary eye care, and glaucoma detection often falls on their shoulders. However, there is significant variation in the capacity for glaucoma diagnosis among eye professionals. Automation with Artificial Intelligence (AI) analysis of optic nerve photos can help optometrists identify high-risk changes and mitigate the challenges of image interpretation rapidly and consistently. Despite its potential, there are significant barriers and challenges to address before AI can be deployed in primary healthcare settings, including external validation, high quality real-world implementation, protection of privacy and cybersecurity, and medico-legal implications. Overall, the incorporation of AI technology in primary healthcare has the potential to reduce the global prevalence of undiagnosed glaucoma cases by improving diagnostic accuracy and efficiency.
... As a leading cause of irreversible vision impairment globally, glaucoma is a considerable public health concern in part due to its insidious, often asymptomatic presentation that makes case detection challenging. 1 Approximately half of the estimated 200 000 Australians with glaucoma are undiagnosed. 2 Provision of appropriate glaucoma care that is in line with evidence is desirable. 3 For example, early diagnosis and appropriate management of glaucoma can slow down or prevent irreversible vision loss 4,5 as well as improve patients' vision-related quality of life and reduce the societal economic burden of disease. ...
Clinical relevance:
Realistic benchmarks can serve as comparators for optometrists wishing to engage in clinical practice audits of their glaucoma care.
Background:
The iCareTrack study established the appropriateness of glaucoma care delivery through clinical record audits of Australian optometry practices. Benchmarks required for monitoring and improving glaucoma care delivery do not exist. This study developed realistic benchmarks for glaucoma care and then benchmarked the performance of practices from the iCareTrack study to establish aspects of care that warrant attention from quality improvement initiatives.
Methods:
Benchmarks were developed from the pre-existing iCareTrack dataset using the Achievable Benchmarks of Care (ABC) method. The iCareTrack study had audited the appropriateness of glaucoma care delivery against 37 clinical indicators for 420 randomly sampled glaucoma patient records from 42 Australian optometry practices. The four-step ABC method calculates benchmarks based on the top 10% of best-performing practices adjusted for low patient encounter numbers. iCareTrack results were compared to the benchmarks to explore the distribution of practices that were at, above or below benchmark.
Results:
Benchmarks were developed for 34 of 37 iCareTrack indicators. For 26 (of 34) indicators, the benchmarks were at or above 90% appropriateness. The benchmarks for 14 (of 34) iCareTrack indicators were met by more than 80% of eligible practices, indicating excellent performance. Some aspects of glaucoma care such as peripheral anterior angle assessment, applanation tonometry, and visual field assessment appeared to be delivered sub-optimally by optometrists when compared to the benchmarks.
Conclusion:
This study established benchmarks for glaucoma care delivery in optometry practices that reflect realistic and top achievable performance. The large number of indicators with benchmarks above 90% confirmed that glaucoma care can and should be delivered by optometrists at very high levels of appropriateness. Benchmarking identified pockets of sub-optimal performance that can now be targeted by quality improvement initiatives.
... The populations of Africa and Asia have a greater prevalence of glaucoma than is found in Europe. The incidence of glaucoma in Europe, in the population over 40 years old, is over 2% (Karvonen et al., 2019;Quigley & Broman, 2006); this prevalence will increase with age to over 4% (Keel et al., 2019;Rudnicka et al., 2006). About risk factors for glaucoma, the participant age was not included as a parameter in this study, as all participants were the same age; also, as all participants were of Caucasian origin, ethnicity was not a relevant parameter. ...
Purpose:
To determine the prevalence of and risk factors for open-angle glaucoma in a population of 70-year-olds in Gothenburg, Sweden and to compare the visual function between the glaucoma population and the non-glaucoma population.
Methods:
Of the entire cohort (n = 1203), 1182 participants responded a questionnaire on self-reported glaucoma and were tested for blood pressure (BP) and diabetes. In all, 560 participants underwent ophthalmic examination including best-corrected visual acuity (BCVA), intraocular pressure (IOP), central corneal thickness (CCT), contrast sensitivity (CS), perimetry and photos of the retina and lens.
Results:
Glaucoma prevalence was 4.8% (95% confidence interval, 3.0%-6.6%), of which 56% was previously undiagnosed. The proportion of participants with diastolic BP >90 mmHg was higher in the non-glaucomatous group (8.3%) than the glaucoma group (0%), p < 0.001. A family history of glaucoma was present in a larger proportion of the glaucoma group (39%) than of the non-glaucomatous group (1.1%), p = 0.001. Mean IOP in individuals without glaucoma was 16 mmHg, versus 21 mmHg in participants with glaucoma detected at the examination. IOP was ≤21 mmHg in 67% among participants with previously unknown glaucoma. BCVA was lower in eyes with previously unknown glaucoma than in eyes without glaucoma (p = 0.017) but BCVA in the best eye did not differ. CCT and CS were similar in all cases.
Conclusions:
The prevalence of glaucoma was comparable to that reported previously. A family history of glaucoma and higher IOP were risk factors associated with glaucoma. BCVA in the best eye did not differ significantly between subjects with and without glaucoma.
... in Japan, Singapore and Australia, respectively. [55][56][57][58][59][60] The prevalence of glaucoma in these regions is generally low compared with what we have in the developing world. Although Japan has a glaucoma prevalence higher than that of some countries in Africa, rates of blindness due to glaucoma in Japan are far below those in Africa. ...
Introduction : This study aimed to determine the awareness and uptake of surgery as a treatment option in patients with glaucoma on medical treatment. Methods : A cross-sectional survey was conducted among consenting patients with primary glaucoma who were on medical treatment. The survey was conducted in two eye care facilities (government-owned and private). After responding to a questionnaire, patients had ocular examinations, including visual acuity, anterior/posterior segment examinations, gonioscopy and central visual field testing. Information was obtained on the patients’ awareness of a surgical option, and reasons for non-uptake among those offered surgery were recorded. Logistic regression analysis was used to identify possible predictors of awareness of glaucoma. Results : Across both facilities, 299 patients with glaucoma with a mean age of 63.9 years participated in this study. There were 167 (55.9%) male and 132 (44.1%) female participants. Two hundred and sixty-seven (89.3%) had a formal education, and of the 169 evaluated for visual fields in the worse eye, 129 (76.3%) had severe (advanced) glaucoma. Only 79 (26.4%) of the participants were aware of surgery as a treatment option for glaucoma. The multivariate analysis found that female patients, patients from the private eye care facility and patients with primary angle closure glaucoma patients were more likely to be aware of glaucoma surgery than male patients, patients from the government-owned eye care facility and patients with primary open-angle glaucoma. Patients with primary angle closure glaucoma were more likely to be aware of glaucoma surgery than those with primary open-angle glaucoma. Cost was identified as the major barrier to the uptake of glaucoma surgery when it was recommended, followed by fear of blindness. Age, level of education and severity of disease had no statistical relationship to awareness of glaucoma surgery. Conclusion : Incorporating routine glaucoma education and counselling into glaucoma care protocols will likely improve awareness of glaucoma surgery as a treatment option.
... We were unable to differentiate between DM type (type 1 diabetes vs. type 2 diabetes) and glaucoma type (primary open-angle vs. angle closure). Despite this, previous reports from a longitudinal Australian populationbased study suggest that around 1 in 20 Australians have diabetes, that the majority (89.7%) have type 2 diabetes (37), and the rate of primary angle-closure glaucoma (PACG) is negligible (0.1%) (38,39). Secondly, we are unable to exclude patients who had undergone glaucoma medical treatment or glaucoma-related surgeries before 2004 as records before that time were unavailable. ...
Background:
Understanding the relationship between diabetes mellitus (DM) and the severity of glaucoma is important for the primary prevention of incident glaucoma. This paper aims to examine the association between DM and incident glaucoma.
Methods:
The 45 and Up Study is a prospective cohort study where Australians aged ≥45 years old were enrolled. The incident of glaucoma at follow-up is the main outcome measured. Glaucoma incidence was identified as those with recorded glaucoma-related medication from the Pharmaceutical Benefits Scheme or surgery recorded in the Medicare Benefits Schedule. Patients with glaucoma were classified into the medical glaucoma group (with glaucoma-related medication but not surgery) and the surgical glaucoma group (with glaucoma-related surgery). A Cox regression model was used to calculate the hazard ratios (HRs) to examine the association between baseline DM and the risk of developing glaucoma during the follow-up period. The reference groups are as follows: (I) non-DM participant; (II) participant with DM, duration between 0 and 5 years; (III) participant uses insulin.
Results:
A total of 255,547 eligible participants, with no glaucoma diagnosis at baseline, were included. During the follow-up period, 7,667 patients (3.0%) were identified as medical glaucoma only and 2,326 patients (0.9%) underwent glaucoma surgery. After controlling for confounders, baseline DM was associated with an increased risk of glaucoma in the medical glaucoma group only [hazard ratio (HR) =1.36, 95% confidence interval (CI) =1.07-1.72, P=0.002]. However, baseline DM (HR =0.97, 95% CI =0.57-1.65, P=0.979) was not associated with an increased risk of surgical glaucoma.
Conclusions:
DM was associated with an increased risk of medical glaucoma only, there was no association identified with surgical glaucoma in the Australian population recruited in the 45 and Up Study.
... As discussed above, there are several advantages to web-based perimetry: access in under-resourced settings, telemedicine if access to clinics is not possible (e.g., during a pandemic), more frequent testing, abilities to further refine the enjoyment of the test, use artificial intelligence and align with computer-based databases. Also, its convenient at-home use may lead to increased penetration of screening--the latter is significant even in developed countries where 50% of glaucoma remains undiagnosed [34]. A barrier for current screening is that people must attend an optometrist's or ophthalmologist's practice. ...
Purpose
To establish a normative database and optimise parameters for personal-computer based perimetry via a web-application using circular contrast targets.
Methods
Online 24-degree 52-loci perimetry was delivered through a web-application using circular flickering contrast targets. Embedding contrast differentials within targets allows calculation of relative decibel (rdB) per 256-bit greyscale level differential. Target light-band maximum brightness colour was fixed, while the dark-band varied to achieve the desired rdB level. A staircase system was used with two reversals ranging from 0 to 36 rdB levels. Blind spot localisation at the start of the test was used to optimise viewing distance and subsequently count fixation losses. Gaze was maintained on a spinning golden star which moves mid-test to maximise sampling area. Patients performed the test to each eye separately using a computer in a darkened room at 40–45 cm.
Results
158 eyes of 101 patients completed the Online Circular Contrast Perimetry (OCCP) test. Mean age was 62.9 ± 14.3 years old. Mean sensitivity reduced with age, at 1.0 relative decibel per decade. Mean sensitivity per locus correlated with standard automated perimetry (SAP) in a physiological hill of vision, with an average difference of 4.02 decibels (95% confidence interval (CI) = 3.77–4.27, p < 0.001) and good agreement between tests.
Conclusions
Online circular contract perimetry provides accurate perimetric testing with comparable results to standard automated perimetry.
... Depending on the study population and definition, the number of suspects-or probable glaucoma-may be on par with or even exceed the number with manifest or diagnosed glaucoma. [15][16][17][18][19][20] Therefore, tackling the issue of a group of individuals at risk of developing glaucoma (i.e., suspects) is relevant and important. ...
Purpose:
To model the healthcare impact (clinical attendance time and financial cost) and clinical outcomes (glaucoma diagnoses) of different risk factor-driven review frequencies for glaucoma suspect patients up until the point of discharge or diagnosis.
Methods:
Medical records of 494 glaucoma suspects were examined to extract the clinical diagnosis. Two criteria for review periods were defined, based on contrasting stringency from established clinical guidelines: American Academy of Ophthalmology (AAO), more stringent/less frequent; and the Australian National Health and Medical Research Council (NHMRC), less stringent/more frequent. We used these data to model patient outcomes and healthcare costs using a Markov model.
Results:
The less stringent/more frequent criterion resulted in more high-risk glaucoma suspects requiring more frequent review compared with the more stringent/less frequent criterion. Across the 15 Markov cycles (7.5 years), the less stringent/more frequent review criterion resulted in 6.6% more diagnoses and fewer overall clinical visits (14.7%) and reduced cost per diagnosis by 12% to 32% (P < 0.0001). The number of glaucoma diagnoses made using each criterion converged at 2.5 to 3 years.
Conclusions:
The stringency of risk assessments for glaucoma suspects impacts review periods and therefore clinical load, healthcare costs, and diagnosis rates. Using current testing methods, more frequent review periods appear advantageous for diagnostic efficiency, with both lower clinic load and lower cost up until the point of discharge or glaucoma diagnosis.
Translational relevance:
A less stringent criterion for assessing the risk of developing glaucoma potentially offers a more cost-effective method for reviewing glaucoma suspects, especially within the first 2.5 years.
... In the present study, we found that the initial diagnosis rate of POAG was 5.21%, which is higher than the prevalence of POAG described in other population-based studies. [15][16][17][18][19][20][21] The major reason was that participants were recruited among outpatients, which would make the rate higher with a smaller screening population. However, this proved to be a cost-effective way to screen POAG. ...
Purpose:
To investigate the agreement of optic nerve head evaluations and initial diagnoses of primary open-angle glaucoma (POAG) by general ophthalmologists and glaucoma specialists in Shanghai, China.
Methods:
This multicenter, cross-sectional study involved the outpatients from the general ophthalmology departments of four top eye hospitals in Shanghai. The participants underwent ocular examinations, including intraocular pressure, fundus photography, corneal thickness, refractometry, visual acuity, visual field and gonioscopy. General ophthalmologists and glaucoma specialists performed the diagnoses and classified them as non-glaucoma, POAG suspects, and POAG. The consistency of initial diagnosis between general ophthalmologists and glaucoma specialists was measured using the weighted kappa coefficient. Logistic regression analysis was used to detect the risk factors for the reliability of POAG diagnosis.
Results:
In 922 participants, the initial diagnosis rates of POAG and non-glaucoma were much higher in the glaucoma specialist group than in the general ophthalmologist group, while the initial diagnosis rates of POAG suspects were higher in the general ophthalmologist group. The weighted kappa coefficient between the two groups was 0.831±0.027 (95% confidence interval, 0.779-0.884). Logistic regression analysis of the risk factors for the reliability of POAG diagnosis showed that the independent risk factors were intraocular pressure (OR 8.363, 95% CI: 4.27-16.37) and vertical cup-to-disc ratio (OR 3.459, 95% CI: 1.54-7.76).
Conclusion:
The diagnosis consistency between the general ophthalmologists and the glaucoma specialists was similar among outpatients in the area of Shanghai. However, general ophthalmologists tended to classify the indefinite subjects as POAG suspects, and their accuracy in diagnosing POAG was low. By paying more attention to the risk factors of POAG diagnosis, general ophthalmologists could improve the diagnosis accuracy.
... [6] In another national study from Australia, the prevalence of confirmed glaucoma cases in non-Indigenous Australians and Indigenous Australians was found to be 1.5% and 0.6%, respectively. [7] In Saudi Arabia, a study from the Central Province suggested that the prevalence of glaucoma is 5.6%, [8] which is similar to rates reported from other Middle East countries. [9][10][11] However, Saudi Arabia is a geographically vast country, and it would be useful to estimate regional glaucoma patterns and currently there is a paucity of information associated with the epidemiological profile of glaucoma in the Eastern Province of Saudi Arabia. ...
Background: Glaucomas remain asymptomatic until severe, indicating that the actual number of affected individuals may be higher than those diagnosed.
Objective: To study the clinical patterns of glaucoma cases in the Eastern Province of Saudi Arabia.
Patients and Methods: This retrospective study was conducted at King Fahd Hospital of the University, Al-Khobar, and Dhahran Eye Specialist Hospital, Dhahran, Saudi Arabia. The medical records of all patients with glaucoma who visited these hospitals from January 2015 to December 2018 were critically reviewed. Data regarding patients' demographic characteristic, clinical data and their medical and surgical management techniques were collected and analyzed.
Results: A total of 999 patients were included, of which 52.9% were males, 94.8% were Saudi, and the mean age was 58.8 years. Bilateral involvement was observed in 82.3% of cases. Primary open-angle glaucoma (POAG) was the most prevalent type of glaucoma (27.7%), followed by secondary glaucomas (26.7%), primary angle-closure glaucoma (PACG) (18.2%), primary congenital glaucoma (2.7%), and juvenile open-angle glaucoma (2.2%), which were the most frequent glaucoma subsets.
Conclusion: The study population was most affected by POAG, secondary glaucomas and PACG. Knowledge regarding prevalence of glaucoma is important to plan services, allocate resources, and prevent blindness.
Glaucoma, a leading cause of irreversible blindness, presents significant challenges for early diagnosis and timely intervention due to its asymptomatic nature and subtle clinical morphology. Early detection and intervention are critical for preventing the disease's progression and vision loss. The increasing global prevalence of glaucoma highlights the need for improved diagnostic and predictive tools to ensure timely and accurate detection of the disease, especially in low-resource settings. Recent advances in artificial intelligence (AI), particularly deep learning (DL) algorithms, have shown promising results in ophthalmic disease diagnosis, including glaucoma. However, there is a paucity of studies developing predictive models based on longitudinal functional data using imaging modalities. This thesis primarily focuses on ophthalmic imaging modalities, such as fundus photographs and optical coherence tomography (OCT) images, to develop and validate diagnostic and predictive AI models for glaucoma care.
The first aim was to critically evaluate the literature to ascertain the overall diagnostic accuracy of AI in detecting glaucoma and to identify the factors that currently limit the implementation of these algorithms in clinical practice. This systematic review and meta-analysis found that, of all the imaging options, fundus and OCT images were the most commonly used modalities with potential for diagnosing glaucoma using DL algorithms. This study highlighted the factors that affected the diagnostic performance, including the reference standard, the instrument used for imaging, dataset selection, image dimensions, and the machine learning classifier. Finally, this study recommends implementing a standard diagnostic protocol for grading, implementing external data validation, and analysis across different ethnicity groups.
Second, this thesis addressed the clinical challenge of predicting glaucoma progression from optic nerve head (ONH) images using AI. The participants were recruited as part of a longitudinal study, and classified as Healthy, Progressed, or Glaucoma based on baseline and follow-up Humphrey visual field (VF) tests. Four potential convolutional neural network (CNN)-based architectures were trained to classify the patients with manifest glaucoma from ONH images. The best-performing model achieved promising results on the testing and external datasets. However, due to a lack of publicly available datasets, the model could not be validated on external data for manifest glaucoma. This study demonstrated the potential of DL techniques in predicting the onset of glaucoma, reducing clinical and financial burdens.
The Humphrey VF test is the gold standard for assessing glaucoma and identifying glaucomatous VF defects (GVFD) patterns, but it is a subjective measurement. Thus, the thesis's third aim was to develop and validate DL-based models to classify patients with and without GVFD and its progression from the OCT scan objectively, without the Humphrey VF test. This aim analysed 1,657 OCT scans from 1,157 patients with follow-up intervals of 4.5 years. Three Densenet201-based models were developed. The potential model exhibited the highest accuracy (80%) in differentiating between eyes with no GVFD and GVFD. This study showed the relationship between the structural and functional impact of glaucoma but had limited accuracy in predicting the severity of progression. However, the model can objectively classify patients with or without GVFD, supporting clinicians in making an accurate diagnosis from both structural and functional parameters without extended follow-up.
Clinicians can construct a more personalised treatment plan and potentially delay or prevent glaucoma progression by predicting early visual function loss. To achieve this, the thesis sought to develop a DL-based regression model to forecast the global VF indices from the OCT scan. This study included a reliable baseline of 3,224 OCT scans and VF reports from 1859 patients with suspected glaucoma or early-stage glaucoma at enrollment. Three predictive models were trained on 80% of total data and validated on 20%, using the baseline OCT scan as input to the models. The best-performing model, Vgg19_bn, achieved notably low predicted errors on the validation set of 255 eyes. For the model's performance across all VF indices, the overall errors were calculated to be a mean absolute error of 1.40 and a root mean square error of 1.74. While these errors suggest the model's overall robust performance, there remains potential for further refinement.
Accurately assessing the cup-to-disc ratio (CDR) is essential for glaucoma screening and monitoring, but manual assessment can be inaccurate and time-consuming. To tackle this challenge, the fifth purpose of the thesis was to develop and validate a DL-based algorithm for automatic CDR quantification for glaucoma screening. A total of 184,580 fundus images were analysed from the UK Biobank, Drishti_GS, and EyePACS. FastAI and PyTorch libraries were used to train a CNN-based model on fundus images from the UK Biobank. Models were constructed to determine image gradability and estimate CDR. The gradability model achieved an accuracy of 97.13% on a validation set of 16,045 images, with 99.26% precision. Using regression analysis, the best-performing model attained an R2 of 0.8561 on a validation set of 12,183 images for determining CDR. This analysis indicated that AI can be effectively employed to automate and enhance the precision of CDR estimation, thereby facilitating more accurate glaucoma diagnosis in clinical practice.
The sixth aim was to develop a robust computer vision model for global glaucoma screening using fundus images. To achieve this aim, the glaucomatous data were collected from 20 publicly accessible databases worldwide and selected the best-performing model from 20 pre-trained models. The top-performing model was further trained to classify healthy and glaucomatous fundus images using Fastai and PyTorch libraries. The best-performing model was validated on 1,364 glaucomatous discs and 2,047 healthy discs with an Area Under the Receiver Operating Characteristic (AUROC) of 0.9920 for glaucoma and 0.9920 for healthy class. The model performed well on an external validation (unseen) set of the Drishti-GS dataset, with an AUROC of 0.8751 and an accuracy of 0.8713. Although the model's accuracy slightly decreased when evaluated on unseen data, this study highlighted the potential of computer vision to assist in glaucoma screening in diverse populations.
Lastly, this thesis addressed the issue of the limited availability of high-quality fundus images for developing AI models for detecting glaucomatous optic neuropathy (GON). The Generative Adversarial Networks (GANs) were explored to train an adversarial model to generate high-quality optic disc images from a diverse and vast dataset. A total of 17,060 fundus images (6,874 glaucomatous and 10,186 healthy) were collected from publicly accessible databases. These images were used to train deep convolutional generative adversarial networks (DCGANs) to synthesise disc images with or without GON. The DCGANs generated high-quality synthetic disc images for healthy and glaucomatous eyes. Two DL-based models were trained to detect GON, one solely on these synthetic images and another on a mixed dataset. When trained on a mixed dataset, the model's AUROC attained 99.85% on internal validation and 86.45% on external validation. This project demonstrated that combining synthetic and real clinical images can improve the DL model’s performance in detecting glaucoma.
In conclusion, this thesis highlighted the potential of integrating AI and computer vision techniques with ophthalmic imaging to revolutionise glaucoma care. Through multiple projects, these highlighted the pathways for improved diagnostic accuracy, early disease prediction, global screening techniques, and generating fundus images. This thesis covers various issues, from diagnostics to prediction and from real to synthetic image utilisation. Future work will refine and validate these models in diverse populations and real-world settings to optimise their potential for global glaucoma care.
Importance
Early detection of glaucoma is essential to timely monitoring and treatment, and primary open-angle glaucoma risk can be assessed by measuring intraocular pressure (IOP) or optic nerve head vertical cup-disc ratio (VCDR). Polygenic risk scores (PRSs) could provide a link between genetic effects estimated from genome-wide association studies (GWASs) and clinical applications to provide estimates of an individual’s genetic risk by combining many identified variants into a score.
Objective
To construct IOP and VCDR PRSs with clinically relevant predictive power.
Design, Setting, and Participants
This genetic association study evaluated the PRSs for 6959 of 51 338 individuals in the Canadian Longitudinal Study on Aging (CLSA; 2010 to 2015 with data from 11 centers in Canada) and 4960 of 5107 individuals the community-based Busselton Healthy Aging Study (BHAS; 2010 to 2015 in Busselton, Western Australia) with an artificial intelligence grading approach used to obtain precise VCDR estimates for the CLSA dataset. Data for approximately 500 000 individuals in UK Biobank from 2006 to 2010 were used to validate the power of the PRS. Data were analyzed from June to November 2023.
Main Outcomes and Measures
IOP and VCDR PRSs and phenotypic variance ( R ² ) explained by each PRS.
Results
Participants in CLSA were aged 45 to 85 years; those in BHAS, 46 to 64 years; and those in UK Biobank, 40 to 69 years. The VCDR PRS explained 22.0% (95% CI, 20.1-23.9) and 19.7% (95% CI, 16.3-23.3) of the phenotypic variance in VCDR in CLSA and BHAS, respectively, while the IOP PRS explained 12.9% (95% CI, 11.3-14.6) and 9.6% (95% CI, 8.1-11.2) of phenotypic variance in CLSA and BHAS IOP measurements. The VCDR PRS variance explained 5.2% (95% CI, 3.6-7.1), 12.1% (95% CI, 7.5-17.5), and 14.3% (95% CI, 9.3-19.9), and the IOP PRS variance explained 2.3% (95% CI, 1.5-3.3), 3.2% (95% CI, 1.3-5.8), and 7.5% (95% CI, 6.2-8.9) ( P < .001) across African, East Asian, and South Asian populations, respectively.
Conclusions and Relevance
VCDR and IOP PRSs derived using a large recently published multitrait GWAS exhibited validity across independent cohorts. The findings suggest that an IOP PRS has the potential to identify individuals who may benefit from more intensive IOP-lowering treatments, which could be crucial in managing glaucoma risk more effectively. Individuals with a high VCDR PRS may be at risk of developing glaucoma even if their IOP measures fall within the normal range, suggesting that these PRSs could help in early detection and intervention, particularly among those who might otherwise be considered at low risk based on IOP alone.
Objective: The aim of this study was to assess the potential impact of antiglaucoma medication preservatives on ocular surface health and the subsequent development of dry eye symptoms.
Methods: A non-randomized controlled trial study was conducted from March 2023 to June 2023.The study enrolled 32 patients, with 16 participants in each group. Patients meeting the inclusion criteria, including confirmed diagnosis of glaucoma and stable ocular health, were allocated to Group A(preserved medication) or Group B(preservative-free medication).Tear Film Break-Up Time(TBUT) and Schirmer's test were employed as objective indicators of tear film stability and tear production respectively. Measurements were recorded at baseline and after a 3-month duration of medication use.
Results: At 1st visit, mean TBUT was 10.87 sec and mean Schirmer's test was 13.75 mm in group A while in group B it was 11.25 sec and 14.56 mm respectively. After 3 months of medication use, mean TBUT and mean Schirmer’s was 9.62 sec and 11.81 mm respectively in group A while in group B it was 10.18 sec and 13.18 mm respectively. The results showed that initial ocular status was similar in both groups however the decrease in values showed ocular surface deterioration. Notably group A demonstrated a more substantial decline in tear production compared to group B.
Conclusion: This study underscores the importance of both preserved and preservative-free anti-glaucoma medications. Although both may potentially exacerbate dry eye symptoms to a greater extent, preservative-free anti-glaucoma may offer benefits in maintaining ocular surface health with long-term use.
Background
To appraise the quality of clinical practice guidelines for glaucoma suspects, and to assess their consistency for how a ‘glaucoma suspect’ is defined and their recommendations for treatment initiation for such individuals.
Methods
This study included all documents that self‐identified as a ‘guideline’ and provided recommendation(s) for the clinical care of glaucoma suspects. The quality of eligible guidelines was assessed using the Appraisal of Guidelines for Research and Evaluation (AGREE) II instrument.
Results
From 1196 records retrieved from comprehensive searches and two records manually included, 20 clinical practice guidelines were deemed eligible. Based on an appraisal using the AGREE II instrument, 16 (80%) guidelines had ≤2 domains with scores >66%. Overall, the lowest scoring domains were for applicability, editorial independence and stakeholder involvement. There was relatively poor agreement across the guidelines for what defines a ‘glaucoma suspect’ or ‘primary open angle glaucoma [POAG] suspect’, as well as the recommendations and criteria for treatment initiation in these populations. There was better agreement for the definition and recommendations for treatment initiation for ‘primary angle closure suspects’.
Conclusions
There is substantial room to improve the methodological quality of most current international clinical guidelines for glaucoma suspects. Clinicians should consider this finding when using such guidelines to inform their care of glaucoma suspects. Substantial variation in the definition of a POAG suspect and recommendations for treatment initiation underscores important gaps in the current evidence for the accurate prediction of glaucoma development and treatment effectiveness in these individuals.
Objective
Timely detection of glaucoma is key to preventing or delaying vision loss. This study aimed to assess whether the routine use of optical coherence tomography (OCT) by optometrists for detection of glaucomatous changes in the optic nerve and retina increased glaucoma referrals to ophthalmologists.
Design
This study was a retrospective review of routinely-collected electronic medical records of patients from a chain of 331 optometry practices in Australia.
Participants
Electronic medical records were reviewed for every patient aged 18-99 years who attended an included practice between January 1 and July 31, 2019.
Methods
Odds of referral for glaucoma assessment were compared between practices performing OCT routinely on all patients (OCT practices, n=175) and without OCT (non-OCT practices, n=20). A subset of referrals were assessed by ophthalmologists to determine the false positive referral rate.
Main Outcome Measures
The primary outcome measure of this study was referral to an ophthalmologist for glaucoma assessment. A secondary outcome was the rate of false positive referrals, analysed in a subset of patients referred for glaucoma assessment.
Results
Records from 994,461 patients (59% female) were included and 10,475 (1.1%) were referred for glaucoma assessment. Most referrals were associated with normal intraocular pressure (non-OCT practices: n=496, 66%; OCT practices: n=6,603, 68%). Referral for glaucoma was higher in OCT practices (n=9,719, 1.1%) compared to non-OCT practices (n=756, 0.8%, age-, gender- and location-adjusted odds ratio 1.39, 95% confidence interval 1.10–1.76). Of 318 referred patients (3%, all from OCT practices) for whom ophthalmologist feedback was available, 68 (21%) were considered not to have glaucoma.
Conclusions
The routine use of OCT in optometric practice may lead to more timely glaucoma detection and prevention of avoidable vision loss.
Background
Primary open-angle glaucoma (POAG) is often divided into two subtypes. High-tension glaucoma (HTG) is characterized by elevated intraocular pressure (IOP), while normal-tension glaucoma (NTG) is characterized by IOP consistently in the normal range. However, this notion is still controversial as some studies argue that different tension subtypes is part of the same pathogenic process while other studies claim that NTG represents a different etiological process where primary neurodegeneration has a higher impact. This study aimed to elucidate the shared and distinct genetic architecture for NTG and HTG.
Method
To identify risk loci specific to NTG, we conducted a large international multi-ethnic multi-trait meta-analysis of 7,942 NTG cases and 384,431 controls without any form of glaucoma, and a structural measurement of the integrity of the optic nerve, vertical cup-to-disc ratio (VCDR, N = 282,100), adjusted for IOP using the mtCOJO method. We also performed an assessment of the genetic overlap between NTG and HTG (N HTG cases = 5144, N controls = 47,997) using the GWAS pairwise method (GWAS-PW).
Findings
This study identified 22 risk loci associated with NTG. Of these, 17 loci are novel for NTG, and two loci, BMP4 and TBKBP1, have not previously been associated at the genome-wide significant level with glaucoma. The contribution of BMP4 in the development of NTG was further supported by integrating single-cell transcriptomic data from neuron-like cells, along with methylomic data from peripheral blood. Examination of each locus across the genome using the GWAS-PW method indicated that risk loci are shared across NTG and HTG. The magnitude of the effect of the genome-wide significant loci tends to be lower in NTG compared to their effects on HTG, particularly for IOP-related loci. Additionally, we identified 42 drug-gene interactions with four genes (ABCA1, CDKN2A, CDKN2B and ITGB3) that were prioritized through our gene-based analysis.
Interpretation
This work expands our understanding of the genetics of NTG and highlights a strong genetic overlap between HTG and NTG. Despite the genetic overlap, we have shown that IOP-related loci tend to have a smaller effect size in NTG when compared with HTG whereas neurodegenerative loci independent of IOP have similar effect sizes on NTG and HTG. These results indicate that while there is a significant overlap in risk loci between NTG and HTG, a precise estimation of their effect sizes on NTG using larger studies could help develop genetic risk prediction models to identify individuals at a higher risk of developing NTG. We have also identified some potential targets for neuroprotective treatment through the interaction of four genes and multiple drugs. By harnessing multi-omics data, we substantiated the involvement of gene expression and DNA methylation of BMP4 in the etiology of NTG.
Purpose:
To examine the optic nerve head (ONH) characteristics of visually normal Aboriginal and Torres Strait Islander children and non-Indigenous Australian children.
Prcis:
This study demonstrated significant differences in optic nerve head characteristics in Aboriginal and Torres Strait Islander compared to non-Indigenous children which has implications for glaucoma risk and diagnosis in Aboriginal and Torres Strait Islander populations.
Patients and methods:
Spectral domain optical coherence tomography (OCT) imaging was performed on the right eye of 95 Aboriginal and Torres Strait Islander children and 149 non-Indigenous Australian children (5-18 years). Horizontal and vertical line scans, centred on the ONH were analysed to determine the dimensions of the ONH (Bruch's membrane opening diameter (BMOD)), optic cup diameter, Bruch's membrane opening minimum rim width (BMO-MRW), and the peripapillary retinal nerve fibre layer (RNFL) thickness).
Results:
The vertical but not horizontal BMOD of Aboriginal and Torres Strait Islander children was significantly larger than non-Indigenous children (mean difference: 0.09 mm, P = 0.001). The horizontal (mean difference: 0.12 mm, P = 0.003) and vertical cup diameter (mean difference: 0.16 mm, P < 0.001) were also significantly larger in Aboriginal and Torres Strait Islander children, as were the horizontal and vertical cup-to-disc ratios (both P < 0.01). Aboriginal and Torres Strait Islander children also had a significantly thinner BMO-MRW in the superior, nasal and temporal meridians (all P < 0.001). Peripapillary RNFL thickness did not differ between groups.
Conclusions:
Differences exist in the ONH structure between Aboriginal and Torres Strait Islander children and non-Indigenous children which may have implications for detection and monitoring of ocular disease in this population and highlights the need to extend this research to the adult population.
This study quantified age-related changes to retinal autophagy using the CAG-RFP-EGFP-LC3 autophagy reporter mice and considered how aging impacts autophagic responses to acute intraocular pressure (IOP) stress. IOP was elevated to 50 mm Hg for 30 minutes in 3-month-old and 12-month-old CAG-RFP-EGFP-LC3 (n = 7 per age group) and Thy1-YFPh transgenic mice (n = 3 per age group). Compared with younger eyes, older eyes showed diminished basal autophagy in the outer retina, while the inner retina was unaffected. Autophagic flux (red:yellow puncta ratio) was elevated in the inner plexiform layer. Three days following IOP elevation, older eyes showed poorer functional recovery, most notably in ganglion cell responses compared to younger eyes (12 months old: -33.4 ± 5.3% vs. 3 months mice: -13.4 ± 4.5%). This paralleled a reduced capacity to upregulate autophagic puncta volume in the inner retina in older eyes, a response that was seen in younger eyes. Age-related decline in basal and stress-induced autophagy in the retina is associated with greater retinal ganglion cells' susceptibility to IOP elevation.
Glaucoma is currently considered one of the leading causes of severe visual impairment and blindness worldwide. Topical medical therapy represents the treatment of choice for many glaucoma patients. Introduction of latanoprost, 25 years ago, with an entirely new mechanism of action from that of the antiglaucoma drugs used up to that time was a very important milestone. Since then, due mainly to their efficacy, limited systemic side effects and once daily dosing, prostaglandin analogues (PGAs) have become as the first-choice treatment for primary open-angle glaucoma. PGAs are in general terms well tolerated, although they are associated with several mild to moderate ocular and periocular adverse events. Among them, conjunctival hyperemia, eyelash changes, eyelid pigmentation, iris pigmentation and hypertrichosis around the eyes are the most prevalent. The objective of this paper is to review the role of PGAs in the treatment of glaucoma over the 25 years since the launch of Latanoprost and their impact on clinical practice outcomes.
Purpose:
To assess whether a glaucoma polygenic risk score (PRS) was associated with treatment commencement or escalation in early primary open angle glaucoma.
Design:
Prospective longitudinal observational cohort study.
Participants:
Participants from the PROGRESSA study (Progression Risk of Glaucoma: RElevant SNPs with Significant Association) were divided into a cohort of glaucoma suspects who were treatment naive at enrolment, and early manifest and suspect glaucoma cases on treatment at enrolment.
Methods:
A per-allele weighted glaucoma PRS was calculated for 1,107 participants. Multivariable mixed effects Cox proportional regression analysis assessed the association between PRS and time to commencement of intraocular pressure (IOP) lowering therapy in 416 glaucoma suspects who were treatment naive at study enrolment. Secondary analysis evaluated the association between PRS and escalation of IOP lowering therapy amongst 691 suspect and early manifest glaucoma cases who were on IOP lowering therapy at enrolment.
Main outcome measures:
Commencement or escalation of IOP lowering therapy.
Results:
A higher glaucoma PRS was associated with a greater risk of commencing IOP-lowering therapy within 5 years (HR: 1.45/Standard Deviation (SD) 95% Confidence Interval (CI) [1.27, 1.62] P<0.001). This finding persisted after adjustment for relevant demographic and clinical parameters (adjusted HR: 1.23/SD 95%CI [1.07, 1.43] P=0.005). Participants in the upper population-based quintile had a 3.3 times greater risk of commencing therapy by 5 years than the lowest quintile (HR: 3.30 95%CI [1.63, 6,70] P<0.001), and a 5.4 greater risk of commencing IOP lowering therapy by 2 years than the lowest quintile (HR: 5.45 95%CI [2.08, 14.25] P<0.001). A higher glaucoma PRS was associated with a greater risk of treatment escalation amongst cases on treatment at enrolment (HR: 1.19/SD 95%CI [1.09, 1.31] P<0.001). In combined analysis of treatment naive suspects and treated cases, participants in the top population-based quintile were at 2.3 times greater risk of requiring initiation or escalation of IOP lowering therapy than the lowest quintile (HR: 2.33 95%CI [1.75, 3.01] P<0.001).
Conclusions:
This study demonstrates novel associations between glaucoma polygenic risk and risk of commencement or escalation of IOP lowering therapy, building upon previous work highlighting the potential clinical utility of genetic risk stratification in glaucoma.
Glaucoma is a chronic degenerative disease that is the second leading cause of irreversible blindness worldwide. For a precise and automatic screening of glaucoma, detecting the optic disc and cup precisely is significant. In this paper, combining the elliptical-like morphological features of the disc and cup, we reformulate the segmentation task from a perspective of ellipse detection to explicitly segment and directly get the glaucoma screening indicator. We detect the minimum bounding boxes of ellipses firstly, and then learn the ellipse parameters of these regions to achieve optic disc and cup segmentation. Considering the spatial geometry prior knowledge that the cup should be within the disc region, Paired-Box RPN is introduced to simultaneously detect the disc and cup coupled. In addition, boundary attention module is introduced to use edges of the disc and cup as an important guide for context aggregation to improve the accuracy. Comprehensive experiments clearly show that our method outperforms the state-of-the-art methods for optic disc and cup segmentation. Simultaneously, the proposed method also obtains the good glaucoma screening performance with calculated vCDR value. Joint optic disc and cup segmentation, which utilizes the elliptical-like morphological features and spatial geometry constraint, could improve the performance of optic disc and cup segmentation.
Purpose: In this paper, we aimed to clinically interpret Temporal-Superior-Nasal-Inferior-Temporal (TSNIT) retinal optical coherence tomography (OCT) images in a convolutional neural network (CNN) model to differentiate between normal and glaucomatous optic neuropathy.
Methods: Three modified pre-trained deep learning (DL) models: SqueezeNet, ResNet18, and VGG16, were fine-tuned for transfer learning to visualize CNN features and detect glaucoma using 780 segmented and 780 raw TSNIT OCT B-scans of 370 glaucomatous and 410 normal images. The performance of the DL models was further investigated with Grad-CAM activation function to visualize which regions of the images are considered for the prediction of the two classes.
Results: For glaucoma detection, VGG16 performed better than SqueezeNet and ResNet18 models, with the highest AUC (0.988) on validation data and accuracy of 93% for test data. Moreover, identical classification results were obtained from raw and segmented images. For feature localization, three models accurately identify the distinct retinal regions of the TSNIT images for glaucoma and normal eyes.
Conclusion: This evidence-based result demonstrates the remarkable effectiveness of using raw TSNIT OCT B-scan for automated glaucoma detection using DL techniques which mitigates the black box problem of artificial intelligence (AI) and increases the transparency and reliability of the DL model for clinical interpretation. Moreover, the results imply that the raw TSNIT OCT scan can be used to detect glaucoma without any prior segmentation or pre-processing, which may be an attractive feature in large-scale screening applications.
Aims and objectives:
The purpose of this study was to assess the safety, feasibility and effectiveness of a nurse-led glaucoma assessment clinic service.
Background:
Glaucoma is a group of serious, irreversible optic neuropathies that progressively damage the optic nerve resulting in blindness. Over 64.3 million people globally are affected by glaucoma with numbers projected to increase to 111.8 million by 2040. Glaucoma is a major public health concern that requires the development of innovative models of care to meet current and future health care demands.
Methods/design:
A mixed method design was used to evaluate the assessment of non-complex glaucoma patients attending a new nurse-led clinic. Under an ophthalmologist's supervision, the glaucoma nurse completed 100 hof clinical training and assessment to ensure they were competent in completing and interpreting the required glaucoma assessment protocols. Interrater reliability between the glaucoma nurse and ophthalmology doctor was undertaken. Glaucoma patient waitlist appointment data were also compared before and after the introduction of the nurse-led clinics. This study adhered to the SQUIRE checklist for the reporting of excellence with quality improvement projects.
Patient contribution:
Patients contributed to the evaluation of this new nurse-led service by providing follow-up feedback on their experience.
Results:
Agreement between clinicians for appropriate follow-up appointment times was high with 93% (n = 315) agreement achieved. Furthermore in 297 (87.5%) cases, both clinicians agreed on the patient being referred to the doctor for follow-up review. Glaucoma consultations were shown to increase from 3,115 appointments in 2019/20 to 3,504 appointments in 2020/21 after the introduction of the nurse-led clinic. The nurse-led clinics accounted for 14.5% (n = 512) of clinic appointments.
Conclusions:
The introduction of the nurse-led glaucoma assessment clinic service allowed patients to be reviewed safely, efficiently and satisfactorily. This new service subsequently allowed for more complex glaucoma patients to be seen by the ophthalmologists.
Relevance to clinical practice:
Findings revealed that suitably trained glaucoma nurses are able to clinically assess and safely monitor stable non-complex glaucoma patients. Highlights the need for appropriate investment in clinical training and supervision to ensure that glaucoma assessment nurses are adequately prepared to undertake this new practice role.
Clinical relevance:
Despite evidence showing that optometry-led collaborative glaucoma care can be delivered at reduced cost compared to ophthalmology-based care without compromising patient outcomes, such models of care are not widely practiced in Australia. Ensuring glaucoma patients have equitable access to effective and cost-effective care is a matter of public health importance.
Background:
This study examined the feasibility and business case assessment for providing glaucoma care from a community optometry perspective.
Methods:
Nine optometrists were interviewed in a semi-structured format, focusing on the economic feasibility, barriers, and benefits of collaborative glaucoma care. The Consolidated Framework for Intervention Research was used for thematic data analysis. Costs and revenues associated with providing glaucoma care were sourced from the literature and interviews. A business case model assessing the profitability of glaucoma care in optometric practice was developed.
Results:
Thematic analysis revealed concerns over financial viability such that current Medicare Benefits Schedule fees are not sufficient to justify the cost of running a community optometry glaucoma clinic. All participants received a supplementary source of revenue. This finding was confirmed by the business case assessment. Inter-professional trust was perceived to be a key barrier to initiation of collaborative care however was able to be overcome quickly upon commencement of a collaborative care relationship. Optometrists perceived that collaborative care was beneficial to all involved, including patients, ophthalmologists, optometrists, and health payers. There was a perception of a growing divide between clinical and retail optometry, which was thought by most participants to be appropriate.
Conclusion:
This study is the first to explore the feasibility and business case for community-based optometrists to provide collaborative glaucoma care in Australia. Our findings show that current public funding is insufficient to justify the business case to private optometry practice, despite being perceived by optometrists as beneficial to all involved.
Optometrists play an integral role in primary eyecare services, including prevention, diagnosis, and management of acute and chronic eye conditions. Therefore, it remains essential that the care they provide be timely and appropriate to ensure the best patient outcomes and optimal utilisation of resources. However, optometrists continuously face many challenges that can affect their ability to provide appropriate care (i.e., the care in line with evidence-based clinical practice guidelines). To address any resulting evidence-to-practice gaps, programs are needed that support and enable optometrists to adopt and utilise the best evidence in clinical practice. Implementation science is a field of research that can be applied to improving the adoption and maintenance of evidence-based practices in routine care, through systematic development and application of strategies or interventions to address barriers to evidence-based practice. This paper demonstrates an approach using implementation science to enhance optometric eyecare delivery. A brief overview of the methods used to identify existing gaps in appropriate eyecare delivery is presented. An outline of the process used to understand the behavioural barriers responsible for such gaps follows, involving theoretical models and frameworks. The resulting development of an online program for optometrists to enhance their capability, motivation, and opportunity to provide evidence-based eyecare is described, using the Behaviour Change Model and co-design methods. The importance of and methods used in evaluating such programs are also discussed. Finally, reflections on the experience and key learnings from the project are shared. While the paper focuses on experiences in improving glaucoma and diabetic eyecare in the Australian optometry context, this approach can be adapted to other conditions and contexts.
Purpose:
The aim was to validate and compare the diagnostic accuracy of a novel 24-degree, 52-loci online circular contrast perimetry (OCCP) application to standard automated perimetry (SAP).
Design:
Prospective cohort study.
Methods:
Two hundred and twenty participants (125 normal controls, 95 open angle glaucoma patients) were included. Agreement, correlation, sensitivity, specificity, and area under receiver operating curves (AUC) were compared for parameters of OCCP, SAP, and optical coherence tomography (OCT) for the retinal nerve fiber layer and macular ganglion cell complex inner plexiform layer.
Results:
Pointwise sensitivity for OCCP was greater than SAP by 1.02 log units (95% CI: 0.95-1.08); 95% limits of agreement 0.860 to 1.17. Correlation and agreement for global indices and regional zones between OCCP and SAP were strong. OCCP mean deviation (MD) AUC was 0.885±0.08, similar to other instruments' parameters with the highest AUC: SAP MD (0.851±0.08), OCT retinal nerve fiber layer inferior thickness (0.908±0.07), OCT ganglion cell complex inner plexiform layer inferior thickness (0.849±0.08), P>0.05. At best cutoff, OCCP MD sensitivity/specificity were comparable to SAP MD (90/74 vs 94/65%).
Conclusions:
OCCP demonstrates similar perimetric sensitivities to SAP and similar AUC to SAP and OCT in distinguishing glaucoma patients from controls. OCCP holds promise as a glaucoma surveillance and screening tool, with the potential to be utilized for in-clinic and at-home perimetry and expand community testing.
Background:
Primary open-angle glaucoma (POAG) is the most common subtype of glaucoma. We evaluate the cost-effectiveness of polygenic risk score (PRS) profiling as a screening tool for POAG.
Methods:
We used a Markov cohort model to evaluate the cost-effectiveness of implementing PRS screening in the UK and Australia, conducted from the healthcare payer's perspective. We used published data to calculate prevalence, transition probabilities, utility, cost and other parameters in the model. Our main outcome measure was the incremental cost-effectiveness ratio (ICER) and secondary outcomes were years of blindness avoided and a 'Blindness ICER'. We did one-way as well as two-way deterministic and probabilistic sensitivity analyses.
Results:
The proposed screening programme for POAG in the UK is predicted to result in ICER of £24,783 (95% CI: £13,373-66,960) and would avoid 1 year of blindness at ICER of £10,095 (95% CI: £5513-27,656). In Australia, it is predicted to result in ICER of AU21,324-95,497) and would avoid 1 year of blindness at ICER of AU8143-37,448). Using the willingness to pay thresholds of $54,808 and £30,000, the proposed screening model is 79.2% likely to be cost-effective in Australia and is 60.2% likely to be cost-effective in the UK, respectively.
Conclusion:
We describe and model the cost-efficacy of incorporating a polygenic risk score for POAG screening in Australia and the UK for the first time and results indicated this is a promising cost-effectiveness strategy.
Objective
To retrospectively analyse the key factors associated with listing decisions by the Pharmaceutical Benefits Advisory Committee (PBAC) for medicines for diabetes and its complications on the Pharmaceutical Benefits Scheme.Methods
The clinical and economic evidence were retrieved from public summary documents (PSD) of all major submissions between July 2005 and March 2020. A multivariate binary logit regression analysis was conducted to assess the relationship between the categorical explanatory variables and PBAC recommendations.ResultsWe identified a total of 211 PSD of which 118 (56%) were recommended for listing. Clinical and economic uncertainty were significantly and inversely associated with the PBAC recommendation. Submissions with high clinical and economic uncertainty were less likely to be recommended.Conclusion
Our findings will enhance the understanding of medical professionals, pharmaceutical companies, and other stakeholders about the rationale of PBAC reimbursement decisions for these medicines and assist prospective applicant sponsor companies in preparing their submissions.
Prcis:
This study demonstrated the prevalence of self-reported glaucoma and its strong association with preexisting systemic chronic diseases in China using the baseline data from China Health and Retirement Longitudinal Study (CHARLS), a nationwide population-based cohort.
Purpose:
The purpose of this study is to estimate the prevalence of self-reported glaucoma and its risk factors using data from the CHARLS.
Materials and methods:
Data on age, sex, area of residence, education, marital status, health-related behaviors, and preexisting comorbidities for this cross-sectional study were retrieved from the CHARLS for 17,713 subjects who completed a questionnaire between June 2011 and March 2012. The prevalence of glaucoma was estimated, and a multivariate weighted analysis was performed to estimate the odds ratios (ORs) of its risk factors.
Results:
Of 16,599 respondents (93.7%) who answered questions regarding glaucoma and their history of systemic chronic diseases, 314 (1.89%) reported having glaucoma before the index date. Qinghai and Beijing had the highest prevalence of glaucoma in China. Glaucoma was significantly associated with hypertension [OR: 1.362; 95% confidence interval (CI), 1.801-2.470], diabetes (OR: 2.597; 95% CI, 1.661-10.207), dyslipidemia (OR: 1.757; 95% CI, 1.157-3.650), lung disease (OR: 2.098; 95% CI, 1.674-6.527), stroke (OR: 5.278; 95% CI, 1.094-25.462), heart disease (OR: 1.893; 95% CI, 1.237-3.363), and health-related behaviors such as smoking and alcohol consumption after adjusting for age, sex, area, education, marital status, and medical insurance.
Conclusions:
Geographic variation in the prevalence of self-reported glaucoma and its strong association with preexisting systemic chronic diseases were observed, suggesting that in addition to ophthalmological examinations, regular physical examinations are necessary for glaucoma patients, especially in areas of high incidence. Appropriate strategies to improve preventive measures for glaucoma are recommended for the Chinese population.
Australia has one of the lowest per capita numbers of ophthalmologists among OECD countries, and they predominantly practise in metropolitan centres of the country. Increasing the size and distribution of the ophthalmology workforce is of critical importance. The objective of this review was to investigate the context of rural ophthalmology training and practise in Australia and how they relate to future ophthalmology workforce development. This scoping review was informed by Arksey and O’Malley’s framework and the methodology described by Coloqhuon et al. The search yielded 428 articles, of which 261 were screened for eligibility. Following the screening, a total of 75 articles were included in the study. Themes identified relating to rural ophthalmology training and practise included: Indigenous eye health; access and utilisation of ophthalmology-related services; service delivery models for ophthalmic care; ophthalmology workforce demographics; and ophthalmology workforce education and training for rural and remote practise. With an anticipated undersupply and maldistribution of ophthalmologists in the coming decade, efforts to improve training must focus on how to build a sizeable, fit-for-purpose workforce to address eye health needs across Australia. More research focusing on ophthalmology workforce distribution is needed to help identify evidence-based solutions for workforce maldistribution. Several strategies to better prepare the future ophthalmology workforce for rural practise were identified, including incorporating telehealth into ophthalmology training settings; collaborating with other health workers, especially optometrists and specialist nurses in eyecare delivery; and exposing trainees to more patients of Indigenous background.
Worldwide, glaucoma affects about 3% of the population over the age of 50 years and is a leading cause of irreversible visual impairment among older people. Because glaucoma is asymptomatic in its early stages and can be challenging to diagnose clinically, it often remains undiagnosed until substantial vision loss has occurred. Efficient methods of glaucoma screening are therefore warranted for early detection of disease. Identification of risk factors for glaucoma – family history of glaucoma, older age, African or Asian ethnicities, raised intraocular pressure, and thin corneas — have helped inform guidelines on the recommended age at commencement and frequency of glaucoma screenings. A genetic predisposition or family history of glaucoma is one of the most important risk factors for the disease. However, an accurate family history cannot always be ascertained. Genetic testing for genes such as myocilin could help to identify high-risk individuals and, with further research, could even provide insight into individual patients' response to treatment. With the ongoing discovery of glaucoma-associated genes and the advent of polygenic risk scores to identify individuals at high risk of glaucoma, gene-based screening for glaucoma is becoming closer to realisation. In the meantime, regularly screening family members of people with existing glaucoma is an efficient way of detecting early glaucoma. Raising public awareness of glaucoma is also necessary to educate the general public on the key role of routine eye examinations and early disease detection. Future studies should be undertaken to explore efficient public health campaign methods for improving glaucoma awareness.
Background:
Frequent intravitreal anti-VEGF injections are impractical for many Aboriginal patients with diabetic macular oedema (DMO). The longer acting intravitreal dexamethasone implant (DEX-implant) is approved for DMO but has not been assessed in an Aboriginal population.
Methods:
This was a prospective, multicentre, randomized, single-masked, non-inferiority clinical trial. Aboriginal adults from Western Australia with DMO were randomized to receive 3-monthly DEX-implant, or monthly intravitreal bevacizumab. The primary outcome was the change in best corrected visual acuity (BCVA) at 12 months.
Results:
The final endpoint was analysed for 24 DEX-implant and 28 bevacizumab injection eyes. Mean BCVA improved by 4.0 letters (-0.08 LogMAR) in the DEX-implant group and worsened by 5.5 letters (0.11 LogMAR) in the bevacizumab group. Before adjusting for cataract surgery, the upper bound of the two-sided 90% CI for the DEX-implant was 3.5 letters (0.07 LogMAR), which met non-inferiority criteria. The BCVA of remote participants who received the DEX-implant improved by 5.5 letters (0.11 LogMAR), compared to an 18.5 letter (0.37 LogMAR) decline for bevacizumab (P=0.04). The incidence of steroid-induced ocular hypertension for the DEX-implant was 33.3%.
Conclusions:
Before adjusting for the effect of cataract surgery, the DEX-implant was non-inferior to bevacizumab for treating DMO in Aboriginal participants. In remote participants, the DEX-implant surpassed non-inferiority to achieve superior outcomes to bevacizumab. The incidence of steroid-induced hypertension was comparable to that reported in non-Aboriginal populations. We provide guidelines for the judicious use of DEX-implant among Aboriginal people, and a framework for performing ophthalmic clinical trials in Aboriginal communities. This article is protected by copyright. All rights reserved.
Clinical relevance
Establishing the level of appropriateness and barriers to glaucoma care delivery by Australian optometrists are important first steps in developing tailored interventions aimed at improving glaucoma care delivery.
Background
To determine the appropriateness of and barriers to glaucoma care by optometrists.
Methods
A mixed method study was conducted. Phase I was a retrospective cross-sectional medical record audit that assessed glaucoma care appropriateness against 37 clinical indicators from a nationally representative sample of 42 optometry practices. In Phase II, focus groups and interviews involving 31 optometrists explored audit findings to identify barriers to appropriate glaucoma care. Barriers were analysed by deductive and inductive qualitative analysis. Saliency analysis was used to identify key domains that influence glaucoma care.
Results
Appropriate glaucoma care was delivered for 63% (95% CI 61%, 64%) of the 420 patient encounters audited. Appropriate care was delivered above 80% for most (57%) indicators, while 14 (38%) indicators were delivered below 60% appropriateness. Good compliance to appropriate care was noted for key indicators of intraocular pressure measurement (90%, 95% CI 87%, 93%) and optic nerve head/retinal nerve fibre layer imaging (78%, 95% CI 74%, 82%). Important barriers identified were beliefs about expected outcomes, lack of perceived relevancy, time constraints, poor organisational culture, knowledge gaps, focusing on some aspects of glaucoma care to the detriment of others, the complexity of glaucoma care, information recall, and social norms.
Conclusion
Glaucoma care was appropriate in most patient encounters, with opportunity to improve some aspects of history taking and physical examinations. Barriers to glaucoma care were diverse, existing at both the practitioner and organisational levels. These findings provide direction for the development of a tailored improvement intervention.
Objective
To estimate global prevalence of blindness and vision loss caused by glaucoma, and to evaluate the impact of socioeconomic factors on it.
Design
A population-based observational study.
Setting
The prevalence of blindness and vision loss due to glaucoma were obtained from the Global Burden of Disease Study 2017 database. The Human Development Index (HDI), inequality-adjusted HDI and other socioeconomic data were acquired from international open databases.
Main outcome measures
The prevalence of blindness and vision loss due to glaucoma by age, gender, subregion and Socio-Demographic Index (SDI) levels. Multiple linear regression analysis was performed to explore the associations between the prevalence and socioeconomic indicators.
Results
The overall age-standardised prevalence of blindness and vision loss due to glaucoma worldwide was 81.5 per 100 000 in 1990 and 75.6 per 100 000 in 2017. In 2017, men had a higher age-standardised prevalence than women (6.07% vs 5.42%), and the worldwide prevalence increased with age, from 0.5 per 100 000 in the 45–49 year age group to 112.9 per 100 000 among those 70+. Eastern Mediterranean and African regions had the highest prevalence during the whole period, while the Americas region had the lowest prevalence. The prevalence was highest in low-SDI and low-income regions while lowest in high-SDI and high-income regions over the past 27 years. Multiple linear regression showed cataract surgery rate (β=−0.01, p=0.009), refractive error prevalence (β=−0.03, p=0.024) and expected years of schooling (β= -8.33, p=0.035) were associated with lower prevalence, while gross national income per capita (β=0.002, p<0.001) was associated with higher prevalence.
Conclusions
Lower socioeconomic levels and worse access to eyecare services are associated with higher prevalence of glaucoma-related blindness and vision loss. These findings provide evidence for policy-makers that investments in these areas may reduce the burden of the leading cause of irreversible blindness.
The purpose of the study: analysis and assessment of the quality of life of glaucoma patients in Kazakhstan on the example of Balkhash. Methods. The study was conducted on the basis of the municipal state institution (KSU) "Polyclinic No. 2" of the city of Balkhash, Karaganda region in the period from 2019 to 2020. The study involved 46 men and 74 women. The average age of the respondents was ≥64 years. To determine the quality of life of glaucoma patients, we conducted a questionnaire compiled by ourselves and the NEI VFQ-25 questionnaire. The respondents were conditionally divided into three groups: group 1-patients who receive only conservative treatment; group 2 – patients who underwent laser correction in parallel with conservative treatment; group 3-patients who, in addition to previous types of treatment, were operated on. Results. Among the comparison groups, the values of indicators of dependence on the help of others (23.7) and role difficulties (23.9) and social activity (81.6) were significantly lower in patients receiving only conservative treatment. In this group, along with the physical and mental components, it was found that the gap in visual indicators is up to 4 times. Conclusions. The results of the study show that in glaucoma patients receiving only conservative treatment, the quality of life is low compared to the control groups according to all indicators of the scales. A significant impact on the decrease in the quality of life of patients receiving conservative treatment is caused by the discomfort associated with regular use of drugs prescribed for glaucoma and their side effects. Keywords: glaucoma, quality of life, NEI VFQ-256 questionnaire, Kazakhstan.
Purpose:
This study aims to evaluate the burden and trends of eye diseases, utilisation of eye health care services, and ophthalmic medications among older people living in residential aged care facilities in Australia.
Methods:
A cross-sectional study was conducted using data from the Registry of Senior Australians. Individuals aged ≥65 years who entered permanent residential aged care facilities between 2008 and 2015 were included. The prevalence (95% confidence interval [CI]) of eye diseases by year, eye health care services, and ophthalmic medication use within a year of entry into the service were evaluated. Poisson regression models estimated adjusted rate of change using prevalence ratio (PR) by age, sex, state, and frailty scores.
Results:
Of the 409,186 people studied, 43.6% (N = 178,367) had an eye condition. Of the total cohort, 32.9% (N = 134,566) had chronic eye conditions and 19.7% (N = 80,661) had an acute eye condition. Common chronic eye conditions were glaucoma (13.6%, N = 55,830), cataract (8%, (N = 32,779), blindness (4.5%, N = 18,856), and poor vision (10.3%, N = 42,245). Prevalence of any eye condition (2008: 42.7%, 95% CI = 42.2%-43.2% and 2015: 41.2%, 95% CI = 40.8-41.6%, PR = 0.99, 95% CI = 0.99-0.99, P < 0.001), acute eye conditions (2008: 19.8%, 95% CI = 19.4%-20.2% and 2015: 17.4%, 95% CI = 17.1%-17.6%, PR = 0.97, 95% CI = 0.97-0.98, P < 0.001), and blindness (2008: 5.2%, 95% CI = 5.0%-5.4% and 2015: 3.7%, 95% CI = 3.5%-3.9%, PR = 0.93, 95% CI = 0.93-0.94, p < 0.001). decreased over the study period. The prevalence of glaucoma (2008: 13.5%, 95% CI = 13.2%-13.8% and 2015: 13.8%, 95% CI = 13.5%-13.7%; PR = 1.01, 95% CI = 0.99-1.10, P < 0.001) and cataract (2008: 7.4%, 95% CI = 7.2%-7.7% and 2015: 8.5%, 95% CI = 8.3%-8.7%, PR = 1.00, 95% CI = 1.00-1.01, P < 0.001) remained stable or slightly increased. Overall, 46.4% (N = 82,769) of individuals with eye conditions, accessed at least one eye health service within the first year of entering residential care and 70.5% (N = 125,673) used at least one ophthalmic medication. Optometric services (41.7%, N = 74,358) were the most used eye health care services and anti-infective eye drops (37.2%, N = 66,331) were the most commonly dispensed medications.
Conclusions:
The prevalence of blindness among older Australian using residential aged care services decreased over the study period. However, the burden of eye diseases remained high between 2008 and 2015, whereas the use of eye health care services was disproportionately low. This study provides evidence of a significant need for eye health care services for older people with an eye disease in residential aged care facilities.
Translational relevance:
Four in ten long term aged care residents in Australia had at least one eye condition over the study period, indicating potential for a high eye health care needs in aged care settings.
Topic
Glaucoma is the leading cause of irreversible blindness despite having good prognosis with early treatment. We evaluated the global extent of undetected glaucoma and the factors associated with it in this systematic review and meta-analysis of population-based epidemiological studies.
Clinical relevance
Undetected glaucoma increases the risk of vision impairment, which leads to detrimental effects on the quality-of-life and socio-economic well-being of those affected. Detailed information on the extent and factors associated with undetected glaucoma aid in the development of public health interventions.
Methods
We conducted a systematic review and meta-analysis of population-based studies published between January 1, 1990 to June 1, 2020. Article search was conducted in online databases (PubMED, Web-of-Science), grey literatures (opengrey) and non-government organization (NGOs) reports. Our outcome measure was the proportion of glaucoma cases that were undetected previously. Manifest glaucoma included any form of glaucoma reported in the respective study and may include primary-open-angle-glaucoma (POAG), primary-angle-closure-glaucoma (PACG), and/or secondary glaucoma. Undetected glaucoma was defined as glaucoma cases that were undetected prior to diagnosis in the respective study. Random-effect meta-analysis was used to estimate the pooled proportion and factors associated with undetected glaucoma. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines in our study.
Results
We identified 61 articles from 55 population-based studies (N= 189,359 participants; N= 6,949 manifest glaucoma; N= 5,558 undetected glaucoma). Globally, more than half of all glaucoma cases were previously undetected in each geographical region. Regionally, Africa (OR 12.70, 95% CI 4.91, 32.86) and Asia (OR 3.41, 95% CI 1.63, 7.16) had higher odds of undetected glaucoma as compared to Europe. Countries with low human development index (HDI, <0.55) had higher proportion of undetected manifest glaucoma as compared to countries of medium to very high HDI (≥0.55, all P <0.001). In 2020, 43.78 million POAG cases were undetected, of which 76.7% reside in Africa and Asia.
Conclusion
Undetected glaucoma is highly prevalent across diverse communities worldwide, and more common in Africa and Asia. Strategies to improve detection are needed to prevent excess visual disability and blindness due to glaucoma.
Large degree of variations has been reported in the performance of qualified eyecare practitioners as regard optic nerve head evaluation. This chapter describes in brief recent advances such as artificial intelligence (AI) and advances in imaging and visualisation of ONH. Deep learning model of AI has been developed to discriminate optic nerve photographs from those with and without glaucoma. Adaptive optics are being incorporated to OCT imaging system to improve image resolution and quality.
Clinical relevance: This novel clinical model is the first of its kind in Australia and was designed to help reduce unnecessary referrals into overburdened public systems by utilising pre-existing community-based resources.
Background: The Centre for Eye Health (CFEH) is an intra-professional optometry-led care clinic offering an alternative pathway to traditional ophthalmology-based pathways (public hospital clinics or private practices) for ‘at-risk’ patients requiring ocular imaging, diagnostic and management services. This study evaluates the CFEH integrated eye-care model in the identification of chronic eye diseases within the community.
Methods: A retrospective random clinical audit of over 750 medical records of patients referred to the CFEH between July 2016 and June 2019 was conducted. Demographics of patients, referral type, final diagnosis and recommended management plans were extracted from this subset. Clinic key performance indicators (referral turnaround time, and net cost per patient appointment) were also extracted.
Results: Of the 755 referrals associated with the audited records, 77.4% resulted in the identification of patients with or at-risk of developing eye diseases with 73.5% of this cohort requiring ongoing monitoring at CFEH or referral to ophthalmology. Although the CFEH model is not designed to diagnose or manage acute conditions, 1.5% of patients in this pathway required same day ophthalmological or medical intervention. The cost per patient was equivalent to hospital eye departments costs.
Conclusion: This integrated care pathway has the potential to reduce unnecessary referrals from optometrists to hospital ophthalmological service by offering a safe and effective alternate pathway. The majority of patients seen within this pathway were able to be monitored within optometry-led services. This is a unique clinical model utilising inter-professional referrals within optometry which has the potential to reduce preventable blindness within the community through the early detection of eye diseases.
Importance:
National data on eye healthcare service utilisation will inform Australia's eye health policy.
Background:
To investigate the utilisation of eye healthcare services by Australians.
Design:
Cross-sectional survey PARTICIPANTS: Indigenous Australians aged 40 years and older and non-Indigenous Australians aged 50 years and older.
Methods:
1738 Indigenous Australians and 3098 non-Indigenous Australians were recruited from 30 randomly-selected sites, stratified by remoteness. Sociodemographic, ocular history, and eye healthcare service utilisation data were collected, and an eye examination was conducted.
Main outcome measures:
Recentness of eye examinations, types of providers used, and associated risk factors.
Results:
67.0% of Indigenous Australians and 82.5% of non-Indigenous Australians underwent an eye examination within the previous two years. Indigenous status (p<0.001), male gender (p<0.001), Outer Regional (p<0.001) and Very Remote (p<0.001) residence were associated with less recent examinations. Participants with self-reported eye disease or diabetes were most likely to have been examined within the past year (p<0.001). For Indigenous Australians, older age was associated with recent eye testing (p=0.001). Those with retinal disease and cataract were more likely to see an ophthalmologist (p<0.001), while those with refractive error were more likely to see an optometrist (p<0.001). In Regional Australia, non-Indigenous people were more likely to see optometrists (p<0.001), while Indigenous Australians were more likely to utilise other, non-specialist services (p<0.001).
Conclusions and relevance:
Eye examination frequency has improved in Indigenous and non-Indigenous Australians compared to previous population-based research. Further improvements are required in risk groups including Indigenous Australians, and those living in Regional and Remote areas.
Purpose:
Glaucoma is the leading cause of global irreversible blindness. Present estimates of global glaucoma prevalence are not up-to-date and focused mainly on European ancestry populations. We systematically examined the global prevalence of primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG), and projected the number of affected people in 2020 and 2040.
Design:
Systematic review and meta-analysis.
Participants:
Data from 50 population-based studies (3770 POAG cases among 140,496 examined individuals and 786 PACG cases among 112 398 examined individuals).
Methods:
We searched PubMed, Medline, and Web of Science for population-based studies of glaucoma prevalence published up to March 25, 2013. Hierarchical Bayesian approach was used to estimate the pooled glaucoma prevalence of the population aged 40-80 years along with 95% credible intervals (CrIs). Projections of glaucoma were estimated based on the United Nations World Population Prospects. Bayesian meta-regression models were performed to assess the association between the prevalence of POAG and the relevant factors.
Main outcome measures:
Prevalence and projection numbers of glaucoma cases.
Results:
The global prevalence of glaucoma for population aged 40-80 years is 3.54% (95% CrI, 2.09-5.82). The prevalence of POAG is highest in Africa (4.20%; 95% CrI, 2.08-7.35), and the prevalence of PACG is highest in Asia (1.09%; 95% CrI, 0.43-2.32). In 2013, the number of people (aged 40-80 years) with glaucoma worldwide was estimated to be 64.3 million, increasing to 76.0 million in 2020 and 111.8 million in 2040. In the Bayesian meta-regression model, men were more likely to have POAG than women (odds ratio [OR], 1.36; 95% CrI, 1.23-1.52), and after adjusting for age, gender, habitation type, response rate, and year of study, people of African ancestry were more likely to have POAG than people of European ancestry (OR, 2.80; 95% CrI, 1.83-4.06), and people living in urban areas were more likely to have POAG than those in rural areas (OR, 1.58; 95% CrI, 1.19-2.04).
Conclusions:
The number of people with glaucoma worldwide will increase to 111.8 million in 2040, disproportionally affecting people residing in Asia and Africa. These estimates are important in guiding the designs of glaucoma screening, treatment, and related public health strategies.
To establish the age- and sex-specific prevalence of open-angle glaucoma (OAG) subsuming pseudoexfoliation (PEX) in the city of Reykjavik.
Participants 50 years of age and older who were part of the Reykjavik Eye Study and classified as having glaucoma were divided into three categories:Category 1: two or more of the following based on optic nerve stereophotograph reading: vertical cup to disc ratio (VCDR) 97.5th percentile (>0.7), focal glaucomatous disc change, C/D asymmetry of 97.5th percentile difference between eyes (>0.2) as well as glaucomatous visual field defect (GVFD). Category 2: 99.5th percentile of VCDR (>0.8) and 99.5% percentile difference between eyes (>/=0.3), without a GVFD. Category 3: VA<3/60 and IOP>99.5th percentile or VA <3/60 and evidence of filtering surgery. For a glaucoma suspect, one of the following was present: VCDR>99.5th percentile (>0.8), focal glaucomatous disc change, C/D asymmetry of 99.5th percentile (> or =0.3), GVFD only, IOP> or =23 mmHg (97.5 percentile). PEX was diagnosed by the presence of a central shield and/or a peripheral band on the anterior lens capsule.
Of 42 persons (22 males and 20 females) with OAG, 13 (31.0%) had PEX. The minimum prevalence of OAG was 4.0% (42/1045) (95% CI 2.8-5.2) for those 50 years and older and 10.3% (95% CI 8.5-12.2) for PEX. The prevalence of OAG increases with age (OR=1.10/year, 95% CI 1.07-1.13, P=0.000) and the same applies for the prevalence of PEX, OR=1.10 (95% CI 1.07-1.12, P=0.000).
There is a 10% annual increase for both OAG and PEX in persons 50 years and older.
To describe the age-, gender-, and cause-specific 5-year incidence of bilateral visual impairment in participants in the Melbourne Visual Impairment Project, Victoria, Australia.
Participants aged 40 years and older were recruited from Melbourne, Victoria, Australia, by random cluster sampling. The mean age of the 3271 (83% of the eligible) participants was 59 +/- 12 (SD) years. Of the participants, 54% were female. The initial baseline study (1992-1994) was followed by a 5-year incidence study (1997-1999). At both time points of the study, participants underwent a standardized testing procedure. Distance and near vision was tested using logarithm of the minimum angle of resolution (logMAR) charts, followed by refraction if needed. Visual fields were assessed by the 24-2 Humphrey field test (FastPac, Humphrey Field Analyzer; Carl Zeiss Meditec, Dublin, CA). Also, intraocular pressure, ocular motility, dilated ophthalmoscopy, and photography of the lens and the fundus were conducted. Furthermore, an interview included demographic characteristics, history of eye disease, medical history, and medication use. For classification of visual impairment, both visual acuity (VA) and visual fields (VF) examination results were used. Four levels of bilateral presenting visual impairment were defined: mild (VA, <20/40-20/60, and/or VF, homonymous hemianopia), moderate (VA, <20/60-20/200, and/or VF, constriction <20 degrees to 10 degrees from fixation), severe (VA, <20/200-10/200, and/or VF, constriction <10 degrees to 5 degrees from fixation), and profound (VA, <10/200, and/or VF, constriction <5 degrees from fixation). For all participants found to be visually impaired, the major cause was identified.
Of the 3040 people eligible to attend follow-up 2594 (85%) participated. Data were available for 2530 (98%) participants. In 105 participants (4.22%; 95% confidence limit 2.58-5.85) some degree of visual impairment developed. The main causes were undercorrected refractive error (59%), age-related macular degeneration, cataract and neuro-ophthalmic disorders (7% each), glaucoma (3%), and diabetic retinopathy (1%). The main cause of severe and profound visual impairment was age-related macular degeneration (37%).
Undercorrected refractive error was the primary cause of new cases of visual impairment in this population. Further research is needed to understand the origin of this and to develop appropriate prevention measures. Age-related macular degeneration is the primary cause of severe or profound vision loss in Australia. This disease requires further investigation for effective cure and preventive strategies.
To quantify the total economic costs of vision loss in Australia.
Prevalence data of visual impairment, unpublished data on indirect costs, and national healthcare cost databases were used.
Vision disorders cost Australia an estimated A4.8 billion is the loss of wellbeing (years of life lost as a result of disability and premature mortality). Vision disorders rank seventh and account for 2.7% of the national loss of wellbeing. Direct health system costs total A1 billion over the last 10 years and will increase a further A3.2 billion, include carers' costs, low vision aids, lost earnings, and other welfare payments and taxes.
Even a developed economy such as Australia's cannot afford avoidable vision loss. Priority needs to be given to prevent preventable vision loss; to treat treatable eye diseases; and to increase research into vision loss that can be neither prevented nor treated.
To assess the prevalence and types of glaucoma in an Asian Malay population.
The Singapore Malay Eye Study is a population-based, cross-sectional survey that examined 3280 (78.7% response) persons aged 40 to 80 years. Participants underwent a standardized clinical examination including slit-lamp biomicroscopy, Goldmann applanation tonometry, and dilated optic disc assessment. Participants who were suspected to have glaucoma also underwent visual field examination (24-2 SITA standard, Humphrey Visual Field Analyzer II), gonioscopy, and repeat applanation tonometry. Glaucoma was defined according to International Society for Geographical and Epidemiologic Ophthalmology criteria.
Of the 3280 participants, 150 (4.6%) had diagnosed glaucoma, giving an age- and sex-standardized prevalence of 3.4% (95% confidence interval [CI], 3.3%-3.5%). The age- and sex-standardized prevalence of primary open-angle glaucoma was 2.5% (95% CI, 2.4%-2.6%), primary angle-closure glaucoma 0.12% (95% CI, 0.10%-0.14%), and secondary glaucoma 0.61% (95% CI, 0.59%-0.63%). Of the 150 glaucoma cases, only 12 (8%) had a previous known history of glaucoma. Twenty-seven (18%) eyes had low vision (based on best corrected visual acuity logarithm of the minimal angle of resolution [logMAR] >0.30 to <1.00 in the eye with glaucoma for unilateral cases; and based on the better eye for bilateral cases) and 15 (10%) were blind (logMAR, >/=1.00).
The prevalence of glaucoma among Malay persons 40 years of age and older in Singapore is 3.4%, comparable to ethnic Chinese people in Singapore and other racial/ethnic groups in Asia. As in Chinese, Caucasians, and African people, primary open-angle glaucoma was the main form of glaucoma in this population. More than 90% of glaucoma cases were previously undetected.
Purpose:
To present the recruitment and testing methodology of the National Eye Health Survey (NEHS), a population-based study that aimed to determine the prevalence and causes of vision impairment and blindness in Australia.
Methods:
Non-Indigenous Australians aged 50 years and older and Indigenous Australians aged 40 years and older were recruited using a door-to-door approach from 30 randomly selected geographical areas, stratified by remoteness. Participants underwent a vision examination, anterior segment assessment, intraocular pressure testing, perimetry, and fundus photography.
Results:
In total, recruiters approached 23,235 residences, and 11,883 residents were successfully contacted (51.1%). Of these, 6760 (56.9%) were deemed eligible and 5764 agreed to participate (positive response rate = 85.3%). Of those who agreed, 4836 residents attended the examination (4836/6760 = 71.5%). This included 1738 Indigenous Australians (41.1% male) aged 40-92 years (mean ? standard deviation = 55.0 ? 10.0 years) and 3098 non-Indigenous Australians (46.4% male), aged 50-98 years (mean ? standard deviation = 66.6 ? 9.7 years).
Conclusions:
The NEHS achieved an excellent positive response rate, and the data collected from 4836 Australians will provide the first population-based national estimate of the prevalence of vision impairment and blindness. This data will guide future economic analysis, policy formulation, and eye health service delivery in Australia.
Background:
This paper presents the sampling methodology of the National Eye Health Survey that aimed to determine the prevalence of vision impairment and blindness in Australia.
Design:
The National Eye Health Survey is a cross-sectional population-based survey.
Participants:
Indigenous Australians aged 40 years and older and non-Indigenous Australians aged 50 years and older residing in all levels of geographic remoteness in Australia.
Methods:
Using multistage, random-cluster sampling, 30 geographic areas were selected to provide samples of 3000 non-Indigenous Australians and 1400 Indigenous Australians. Sampling involved (i) selecting Statistical Area- Level 2 sites, stratified by remoteness; (ii) selecting Statistical Area- Level 1 sites within Statistical Area- Level 2 sites to provide targeted samples; and (iii) grouping of contiguous Statistical Area- Level 1 sites or replacing Statistical Area- Level 1 sites to provide sufficient samples.
Main outcome measures:
The main outcome measures involved Sites sites selected and participants sampled in the survey.
Results:
Thirty sites were generated, including 12 Major City sites, 6 Inner Regional sites, 6 Outer Regional sites, 4 Remote sites and 2 Very Remote sites. Three thousand ninety-eight non-Indigenous participants and 1738 Indigenous participants were recruited. Selection of Statistical Area- Level 1 site overestimated the number of eligible residents in all sites. About 20% (6/30) of Statistical Area- Level 1 sites were situated in non-residential bushland, and 26.67% (8/30) of Statistical Area- Level 1 populations had low eligibility or accessibility, requiring replacement.
Conclusions:
Representative samples of Indigenous and non-Indigenous Australians were selected, recruited and tested, providing the first national data on the prevalence of vision impairment and blindness in Australia.
Pseudoexfoliation syndrome (XFS) has been found to occur more commonly among indigenous Australians. This paper was designed to determine the prevalence of XFS within the indigenous Australian population living in central Australia.
Clinic-based cross-sectional study.
One thousand eight hundred eighty-four individuals living in one of 30 remote communities within the statistical local area of 'Central Australia' were recruited. This equated to 36% of those aged 20 years or older and 67% of those aged 40 years or older within this district.
Participants aged 20 years or over were recruited as they presented to the eye clinic at each remote community. Slit-lamp examination was performed, and the presence of XFS in each eye was recorded and presented.
Prevalence and associations of XFS.
XFS was present in one or both eyes of 4.7% of the individuals recruited into the study. Prevalence increased with age (5.9% of those ≥40 years and 12.7% ≥ 60 years). There was a significant association between the presence of XFS and climatic keratopathy (χ(2) = 240.13; P < 0.00001). Notably, none of those with XFS had ocular hypertension or glaucoma.
XFS was present in a significantly higher proportion of indigenous Australians compared with previously reported prevalence estimates among non-indigenous Australians. The association found between XFS and climatic keratopathy may represent a common causal link between the two conditions. The lack of association of XFS with ocular hypertension and glaucoma appears to be a unique feature of the indigenous Australian population, and this merits further investigation.
To determine the prevalence of glaucoma within the indigenous Australian population living in central Australia.
1884 individuals aged ≥20 years, living in one of 30 remote communities within the statistical local area of 'Central Australia,' were recruited for this study. This equated to 36% of those aged ≥20 years and 67% of those aged ≥40 years within this district. Slit-lamp examination of the anterior segment and intraocular pressure measurement, followed by stereoscopic slit-lamp funduscopy of the optic nerve, was performed. Selected patients underwent automated visual-field testing. The diagnosis of glaucoma was based on pre-existing definitions. Glaucoma prevalence data are presented.
Seventeen individuals had glaucoma (0.90%). Causes of secondary glaucoma were found in four with neovascular glaucoma, two with uveitic glaucoma and four who had developed glaucoma subsequent to trauma or surgery. The remaining seven had no identifiable cause for their glaucoma and were thus classified as open-angle glaucoma equating to a prevalence of 0.52% (95% CI 0.14% to 0.90%) for those aged ≥40 years. Of these, four had an intraocular pressure ≤21 mm Hg, and three had an intraocular pressure >21 mm Hg.
The prevalence of open-angle glaucoma among indigenous Australians within central Australia was 0.52% for those aged ≥40 years. After adjustment for the age distribution of our sample, this is one-third the prevalence seen among the non-indigenous Australian population and is despite a higher prevalence of ocular parameters considered to be associated with glaucoma.
Define the prevalence of glaucoma within the Indigenous Australian population.
Aboriginal and Torres Strait Islander adults aged ≥ 40 years were recruited from 30 randomly selected sample areas or communities. Participants were regarded to have glaucoma if they had a cup:disc ratio (CDR) of > 0.8, or missed ≥ 2 points on the Frequency Doubling Test and a CDR > 0.7 in at least one eye.
1189 eligible adult participants were examined, representing 72% of the target population. After excluding cases with missing or ungradable information, the authors found a 2.2% (95% CI 1.6% to 3.6%) overall prevalence of glaucoma. In univariate analyses, the odds of glaucoma increased with age (χ² trend=4.38, p < 0.001), male gender (OR 2.43, 95% CI 1.10 to 5.41), less than secondary education (OR 4.74, 95% CI 1.96 to 11.45) and self-reported history of glaucoma (OR 20.8; 95% CI 6.23 to 69.51). After a multivariate analysis, none of these attributes other than history of glaucoma remained significant. No cases of low vision (presenting visual acuity (VA) < 6/12 to ≤ 6/60) or blindness (presenting VA < 6/60) were solely attributable to glaucoma. The mean optic disc diameter was 1.93 mm (SD 0.19) for left and right eyes, while the mean CDR for right eyes was 0.44 (SD 0.15) and for left eyes 0.43 (SD 0.16).
This population-based study examined the prevalence of glaucoma within the Indigenous Australian population, and although an infrequent cause of vision loss, definable rates of disease were seen. The results may suggest a potential introduction of Caucasian glaucoma-associated genes into this community, differently used diagnostic criteria or sampling bias compared with previous surveys.
To assess the prevalence of glaucoma in adult Chinese.
Population-based study.
The Beijing Eye Study in 2001 included 4439 subjects with an age of 40+ years. Glaucoma was determined using the ISGEO (International Society of Geographical and Epidemiological Ophthalmology) classification scheme.
Glaucoma was detected in 158 subjects (3.7%, 95% confidence interval [CI] 3.1%-4.2%), in which open-angle glaucoma (OAG), primary angle-closure glaucoma (PACG), and secondary glaucoma (SG) accounted for 2.6% (95% CI 2.1%-3.0%), 1.0% (95% CI 0.7%-1.3%), and 0.07% (95% CI 0%-0.1%), respectively. The overall glaucoma prevalence for the age groups of 40 to 49 years, 50 to 59 years, 60 to 69 years, and 70+ years was 2.2%, 2.5%, 4.4%, and 9.5%, respectively. Glaucoma prevalence increased significantly with age (P = .001), myopic refractive error (P < .001), and intraocular pressure (P < .001). The age-standardized prevalence of OAG, PACG, and SG was 2.5%, 1.0%, and 0.1%, respectively. Prevalence of glaucoma-related bilateral blindness or unilateral blindness was significantly (P = .02 and P = .03) higher in PACG than in OAG. Frequency of glaucoma-associated blindness and low vision was significantly higher in the rural area than in the urban region (6/62 vs 2/96, P = .04).
In the adult population of Greater Beijing, glaucoma prevalence was 3.6% and increased with age, myopic refractive error, and intraocular pressure. Glaucoma prevalence of 3.6% was comparable with figures from Caucasian populations. The ratio of OAG to PACG of 2.6:1 agrees with recent other studies from East Asia. Glaucoma-related blindness and low vision occurred significantly more often in PACG than in OAG.
The objective of this study is to assess the prevalence of primary open-angle glaucoma (POAG) in a defined population in Rotterdam, The Netherlands.
The Rotterdam Study is a single-center prospective cohort study of a total population of more than 10,000 people, 55 years of age or older. For the current analysis, the first 3062 consecutive, unselected, noninstitutionalized participants were examined according to standard protocols, including perimetry. The diagnosis of POAG was based on the presence of a glaucomatous visual field defect combined with either a vertical cup: disc ratio of 0.5 or more or a cup:disc ratio asymmetry of 0.2 or more, or an intraocular pressure (IOP) more than 21 mmHg, with open and normal anterior chamber angles.
The overall prevalence of POAG in the current study was 1.10% (95% confidence interval [CI]: 1.09, 1.11). Age-specific prevalence figures increased from 0.2% (95% CI: 0.16, 0.24) in the age group of 55 to 59 years to 3.3% (95% CI: 2.57, 4.04) in the age group of 85 to 89 years. Men had a more than three times higher risk of having POAG than women (odds ratio, 3.6). In 52.9% of the patients, POAG had not been diagnosed previously. Of these patients, 38.9% had IOPs of 21 mmHg or lower. In 8.8% of the eyes (2.9% of patients), visual acuity was 20/200 or less due to POAG.
The overall prevalence of POAG in the current study was 1.1%. The prevalence of POAG was higher in men than in women. Of the untreated patients, 38.9% had IOPs of 21 mmHg or lower.
Although glaucoma is a major global cause of blindness, the lack of a uniform definition of the disease in its different forms makes it difficult to assess its public health impact. By considering the common features of glaucoma, we have analysed available data on the three main forms of the disease: congenital/hereditary glaucoma, primary open-angle, and primary angle-closure glaucoma. A simple model was then developed to estimate the extent of glaucoma on a regional basis, taking into account demographic data, e.g., age distribution, gender and ethnic groups. Overall, the results demonstrate that glaucoma is responsible for approximately 5.2 million blind (15% of the total burden of world blindness).
The purpose of this study was to determine the prevalence of open-angle glaucoma and ocular hypertension in an Australian community whose residents are 49 years of age or older.
There were 3654 persons, representing 82.4% of permanent residents from an area west of Sydney, Australia, who were examined. The population was identified by a door-to-door census of all dwellings and by closely matched findings from the national census.
All participants received a detailed eye examination, including applanation tonometry, suprathreshold automated perimetry (Humphrey 76-point test), and Zeiss stereoscopic optic disc photography. Glaucoma suspects were asked to return for full threshold fields (Humphrey 30-2 test), gonioscopy, and repeat tonometry.
A 5-point hemifield difference on the 76-point test was found in 616 persons (19% of people tested). Humphrey 30-2 tests were performed on 336 glaucoma suspects (9.2% of population), of whom 125 had typical glaucomatous field defects. Two hundred three persons had enlarged or asymmetric cup-disc ratios (> or = 0.7 in 1 or both eyes or a cup-disc ratio difference of > or = 0.3). Open-angle glaucoma was diagnosed when glaucomatous defects on the 30-2 test matched the optic disc changes, without regard to the intraocular pressure level. This congruence was found in 87 participants (2.4%), whereas an additional 21 persons (0.6%) had clinical signs of open-angle glaucoma but incomplete examination findings. Open-angle glaucoma was thus found in 108 persons, a prevalence of 3.0% (95% confidence interval [CI], 2.5-3.6), of whom 49% were diagnosed previously. An exponential rise in prevalence was observed with increasing age. Ocular hypertension, defined as an intraocular pressure in either eye greater than 21 mmHg, without matching disc and field changes, was present in 3.7% of this population (95% CI, 3.1-4.3), but there was no significant age-related increase in prevalence. The prevalence of glaucoma was higher in women after adjusting for age (odds ratio, 1.5; CI, 1.0-2.2). There was no sex difference in the age-adjusted prevalence of ocular hypertension.
These data provide detailed age and sex-specific prevalence rates for open-angle glaucoma and ocular hypertension in an older Australian population.
The purpose of the study was to determine the prevalence of glaucoma in Melbourne, Australia.
All subjects were participants in the Melbourne Visual Impairment Project (Melbourne VIP), a population-based prevalence study of eye disease that included residential and nursing home populations. Each participant underwent a standardized eye examination, which included a Humphrey Visual Field test, applanation tonometry, fundus examination including fundal photographs, and a medical history interview. Glaucoma status was determined by a masked assessment and consensus adjudication of visual fields, optic disc photographs, intraocular pressure, and glaucoma history.
A total of 3271 persons (83% response rate) participated in the residential Melbourne VIP. The overall prevalence rate of definite primary open-angle glaucoma in the residential population was 1.7% (95% confidence limits = 1.21, 2.21). Of these, 50% had not been diagnosed previously. Only two persons (0.1%) had primary angle-closure glaucoma and six persons (0.2%) had secondary glaucoma. The prevalence of glaucoma increased steadily with age from 0.1% at ages 40 to 49 years to 9.7% in persons aged 80 to 89 years. There was no relationship with gender. The authors examined 403 (90.2% response rate) nursing home residents. The age standardized rate for this component was 2.36% (95% confidence limits = 0, 4.88).
The rate of glaucoma in Melbourne rises significantly with age. With only half of patients being diagnosed, glaucoma is a major eye health problem and will become increasingly important as the population ages.
To assess the performance of a community-based glaucoma screening algorithm in the general population.
A total of 659 individuals aged 50-90 years were screened for glaucoma. Presenting visual acuity, family history of glaucoma, FDT perimetry, and HRT tests were assessed. Additional samples of participants served as control groups. Participants identified as glaucoma positive received a full ophthalmic examination. Based on this exam a consensus diagnosis was made which served as the gold standard.
The optimal screening strategy combining visual acuity and family history with FDT and HRT had sensitivities, specificities, positive predictive values and negative predictive values of 96.8%, 89.7%, 31.9%, and 99.8% respectively for detecting glaucoma.
By combining assessments of presenting visual acuity and family history of glaucoma with Frequency Doubling Technology perimetry and Heidelberg Retina Tomography, we devised a community glaucoma-screening algorithm that showed a high sensitivity and specificity for detecting glaucoma in the general population.
To establish the reproducibility of a rebound tonometer in humans and the effect of corneal thickness on measurements, comparing it with Goldmann applanation tonometer.
In a first study designed to examine the reliability of the RBT, three experienced ophthalmologists undertook three consecutive intraocular pressure (IOP) measurements in 12 eyes of 12 normal subjects. A cross-sectional study was then performed to compare measurements obtained using the two tonometers in 147 eyes of 85 patients with ocular hypertension or glaucoma.
Intraobserver coefficients of correlation obtained in the reproducibility study were 0.82, 0.73, and 0.87. Interobserver correlation was 0.82. There was a good correlation between IOP readings obtained by the RBT and the GAT (r = 0.865, P < 0.0001). RBT readings were consistently higher than GAT measurements (median difference, 1.8 +/- 2.8 mm Hg). A Bland-Altman plot indicated the 95% limits of agreement between the two methods were -3.7 to 7.3 mm Hg (slope = -0.022, P = 0.618). Using RBT, the point that best discriminated between patients with an IOP < or = 21 mm Hg and those with >21 mm Hg, as determined by the GAT was >23 mm Hg (sensitivity, 70.5%; specificity, 95.1%). In terms of pachymetry, the two tonometers behaved in a similar way, with correlation observed between IOP measurements and central corneal thickness.
Rebound tonometry is a reproducible method of determining IOP in humans. In general, it tends to overestimate IOP compared with Goldmann applanation tonometry. The tonometers used in both methods are similarly affected by pachymetry.
The determination of the cup-to-disc ratio (C/D) is a standard procedure in an eye examination and is pivotal in the diagnosis of glaucoma. Determining the size of the C/D ratios of different races of young people may be helpful in determining the genetically predetermined differences between Aboriginal and non-Aboriginal people. The aim of this study was to determine whether there is a statistically significant difference in the average C/D ratios of young Aboriginal and non-Aboriginal people.
The overall average C/D ratios of 104 subjects aged between five and 23 years were compared for two age-matched groups by stereoscopic indirect ophthalmoscopy. Differences between the overall average C/D ratios of the two groups were assessed for significance using an unpaired Student's t test.
While the range of C/D ratios within each group was the same (zero to 0.7), there was a statistical difference (p < 0.001) between the overall average C/D ratios of the Aboriginal (C/D = 0.295) and non-Aboriginal (C/D = 0.159) groups.
Results indicating a difference between the overall average C/D ratios between Aboriginal and non-Aboriginal young people may have implications for initial assessments of glaucoma in patients of any age.
To evaluate the performance of frequency-doubling technology (FDT) perimetry in a population-based glaucoma prevalence survey.
Population-based cross-sectional study.
Participants older than 40 years randomly selected from the population of Tajimi City.
Each participant underwent screening ophthalmic examinations including a visual field test using FDT with the C-20-1 screening protocol. A diagnosis of glaucoma was determined by glaucoma specialists with another detailed visual field test using Humphrey Field Analyzer (HFA; Humphrey Instruments, San Leandro, CA) with the 30-2 Swedish interactive threshold algorithm standard protocol and stereoscopic disc photographs.
The ratios of reliable FDT results and the sensitivity and specificity for detecting glaucoma in a general population.
Of 5784 eyes of 2892 participants (age range, 40-92 years; refractive error, -23 to 11 diopters) in whom FDT was performed in both eyes, reliable results (< or =33% fixation loss and < or =33% false-positive errors) were obtained in 5707 eyes (98.7%), including 2871 right eyes (99.3%) and 2836 left eyes (98.1%) with a significant bilateral difference (P<0.001, chi-square test). The rate of reliable FDT results did not differ between men and women (P = 0.81) but decreased with age. In 5582 eyes with reliable FDT results, FDT showed 1 or more abnormal points in the visual field in 502 eyes (9.0%), including 388 (7.3%) of 5295 normal eyes, 19 (16.4%) of 116 eyes of glaucoma suspects, and 95 (55.6%) of 171 eyes with definite glaucoma. The sensitivity and specificity values for detecting definite glaucoma were 55.6% and 92.7%, respectively. The positive and negative predictive values were 18.9% and 98.5%, respectively. In further analyses stratified with the mean deviation (MD) of the HFA, the sensitivities were 32.1%, 48.4%, 73.7%, and 96.6% for detecting definite glaucoma with an MD of more than -2 dB, an MD of -2 dB or less and more than -5 dB, an MD of -5 dB or less and more than -8 dB, and an MD of -8 dB or less, respectively.
In a population-based glaucoma screening study, FDT perimetry with the C-20-1 screening protocol was reliably performed in more than 98% of participants. The sensitivity for detecting glaucomatous visual field damages, especially early damage, was not sufficiently high, whereas the specificity was high.
Clinical examination of the optic disc is an essential element in the assessment of its health. Previous work has described normal optic disc appearance among different races. No such description of optic discs exists for indigenous Australians, who are at low risk of developing glaucoma. This study was designed to evaluate optic disc parameters of indigenous Australians.
A sample of 208 indigenous Australians were recruited as they presented to remote clinics in Central Australia. Each subject underwent optic disc photography using a Topcon TRC-NW100 digital fundus camera. Optic discs were measured and analysed with Topcon ImageNet 2000 software.
Among other parameters, mean vertical disc diameter and disc area were 2.13 +/- 0.21 mm (mean +/- SD) and 3.13 +/- 0.57 mm2, respectively, for right eyes and 2.14 +/- 0.21 mm and 3.16 +/- 0.58 mm2 for left eyes. When compared with published studies, these parameters were significantly larger than Caucasians, but similar to African individuals.
Our results suggest that indigenous Australians have optic discs that are larger than those of Caucasians, but similar to those of Africans who are considered to at a greater risk of glaucoma. Factors other than optic disc area are likely to underlie the higher prevalence of primary open angle glaucoma among African individuals.
To document the central corneal thickness (CCT) among a group of Indigenous Australians compared with a group of Australian Caucasian individuals.
Clinic-based case-control study.
A total of 91 Indigenous Australians from remote clinics in Central Australia and 84 Caucasian subjects from a teaching hospital in South Australia were recruited. Each subject underwent ultrasound pachymetry, and results were compared between groups.
Mean +/- SD CCT for Indigenous Australians for right and left eyes, respectively, was 511 +/- 34 microm and 513 +/- 35 microm; and 541 +/- 31 microm and 543 +/- 33 microm in Caucasian subjects (t = 6.96; P < .0001 for right eyes and t = 6.56; P < .0001 for left eyes).
Indigenous Australians exhibit CCT that is significantly lower than that of Caucasian subjects. Given that Indigenous Australians are considered to be at very low risk of developing glaucoma, low CCT values alone may not be sufficient to increase the risk of developing glaucoma in a particular race.
To examine whether glaucoma status or measures of visual function affected by glaucoma are associated with self-reported difficulty with vision-intensive tasks in a population-based study.
Cross-sectional study.
One thousand one hundred sixty individuals who participated in the fourth round of the Salisbury Eye Evaluation study and who did not have visual acuity worse than 20/40 due to a primary cause other than glaucoma.
Glaucoma was assessed using optic nerve head appearance, visual field (VF) testing, gonioscopy, and physician opinion. Vision-related quality of life was assessed using the Activities of Daily Vision Scale (ADVS), whose scores were trichotomized into the following categories: the least difficulty with visual tasks, some difficulty, and the most difficulty. Data on confounders were collected by questionnaire and clinical examination. Multinomial logistic regression was used to adjust for demographic and health factors.
Reported difficulty on the ADVS.
Individuals with bilateral glaucoma were more likely to report the most difficulty on the ADVS than those without glaucoma (odds ratio [OR], 3.25; 95% confidence interval [CI], 1.56-6.76), whereas those with unilateral glaucoma were not more likely to report the most difficulty (OR, 1.05; 95% CI, 0.38-2.91). Worse binocular VF scores were associated with increased odds of the most difficulty on the ADVS after adjusting for acuity and contrast sensitivity (OR, 1.48; 95% CI, 1.29-1.85).
Individuals with bilateral glaucoma reported more difficulty on the ADVS than those without glaucoma. This finding, in conjunction with findings demonstrating decreased mobility in patients with bilateral glaucoma, points to the fact that glaucoma affects the report of difficulty with a variety of visual tasks.
Vision problems among older Australians
- Aihw
AIHW. Vision problems among older Australians. Bulletin no. 27. AIHW cat. No. AUS
60. Canberra: AIHW, 2005.
- J Br
- Ophthalmol
Br J Ophthalmol: first published as 10.1136/bjophthalmol-2017-311786 on 26 April 2018. Downloaded from
National trachoma and eye health program: Royal Australian College of Ophthalmologists
- Raco
RACO. National trachoma and eye health program: Royal Australian College of
Ophthalmologists. 1980.