[Show abstract][Hide abstract] ABSTRACT: Purpose:
To evaluate the ability of longitudinal Useful Field of View (UFOV) and simulated driving measurements to predict future occurrence of motor vehicle collision (MVC) in drivers with glaucoma.
Prospective observational cohort study.
117 drivers with glaucoma followed for an average of 2.1 ± 0.5 years.
All subjects had standard automated perimetry (SAP), UFOV, driving simulator, and cognitive assessment obtained at baseline and every 6 months during follow-up. The driving simulator evaluated reaction times to high and low contrast peripheral divided attention stimuli presented while negotiating a winding country road, with central driving task performance assessed as "curve coherence". Drivers with MVC during follow-up were identified from Department of Motor Vehicle records.
Main outcome measures:
Survival models were used to evaluate the ability of driving simulator and UFOV to predict MVC over time, adjusting for potential confounding factors.
Mean age at baseline was 64.5 ± 12.6 years. 11 of 117 (9.4%) drivers had a MVC during follow-up. In the multivariable models, low contrast reaction time was significantly predictive of MVC, with a hazard ratio (HR) of 2.19 per 1 SD slower reaction time (95% CI, 1.30 to 3.69; P = 0.003). UFOV divided attention was also significantly predictive of MVC with a HR of 1.98 per 1 SD worse (95% CI, 1.10 to 3.57; P = 0.022). Global SAP visual field indices in the better or worse eye were not predictive of MVC. The longitudinal model including driving simulator performance was a better predictor of MVC compared to UFOV (R2 = 0.41 vs R2 = 0.18).
Longitudinal divided attention metrics on the UFOV test and during simulated driving were significantly predictive of risk of MVC in glaucoma patients. These findings may help improve the understanding of factors associated with driving impairment related to glaucoma.
PLoS ONE 10/2015; 10(10):e0138288. DOI:10.1371/journal.pone.0138288 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Purpose:
To determine whether progressive retinal nerve fiber layer (RNFL) loss occurs in the contralateral eye of patients with glaucoma showing unilateral progression according to conventional diagnostic methods.
Prospective, longitudinal, observational cohort study.
Three hundred forty-six eyes of 173 patients (118 eyes with glaucoma and 228 eyes with suspect glaucoma at baseline) followed up for an average of 3.5±0.7 years.
All subjects underwent standard automated perimetry (SAP; Humphrey Field Analyzer; Carl Zeiss Meditec, Dublin, CA) and spectral-domain (SD) optical coherence tomography (OCT; Spectralis; Heidelberg Engineering, Inc., Carlsbad, CA) in both eyes at 6-month intervals. Eyes were determined as progressing by conventional methods if there was progression on masked grading of optic disc stereophotographs or SAP Guided Progression Analysis (GPA; Carl Zeiss Meditec; "likely progression"). Rates of change in SD OCT average RNFL thickness were obtained using a linear mixed effects model. Rate of global loss was calculated using a random coefficient model and compared for nonprogressing patients, progressing eyes, and fellow eyes of unilateral progressing patients.
Main outcomes measures:
Rate of change in global RNFL thickness.
Thirty-nine subjects showed evidence of unilateral progression by GPA, disc photographs, or both during follow-up. Mean ± standard error rate of RNFL loss in eyes progressing by conventional methods was -0.89±0.22 μm/year (P < 0.001). The contralateral eyes of these subjects also showed significant loss of RNFL over time (-1.00±0.20 μm/year; P < 0.001). One hundred thirty-four subjects did not show progression by conventional methods in either eye. These eyes also showed a significant decline over time in average RNFL thickness (-0.71±0.09 μm/year; P < 0.001); however, the rate of change in these eyes was slower than that of the contralateral eye of patients showing unilateral progression (P < 0.001).
Loss of RNFL thickness was seen in a substantial number of contralateral eyes of glaucoma patients showing unilateral progression by conventional methods. These findings indicate that assessment of RNFL thickness by SD OCT may show progressive glaucomatous damage that is not detected by visual fields or optic disc stereophotography.
[Show abstract][Hide abstract] ABSTRACT: Early diagnosis and treatment of glaucoma is important to reduce the risk of progressive and irreversible visual loss. The key to diagnosis is recognition of morphological changes to the optic nerve head and retinal nerve fiber layer, but in some patients, functional abnormalities are detected first. This review describes recent innovations with the potential to improve the early detection of glaucoma. Developments in imaging include novel optic nerve head metrics such as Bruch's membrane opening-minimum rim width, enhanced ability to quantify inner layers of the glaucomatous macula, and ability to image deep optic nerve head structures, including the lamina cribrosa. Developments in detection of early glaucomatous functional loss include novel perimetric tests using frequency-doubling technology and flicker-defined form stimuli. Methods to combine results of structural and functional assessments are also presented that may improve early detection of glaucoma
Progress in brain research 07/2015; DOI:10.1016/bs.pbr.2015.03.001 · 2.83 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To study the circadian intraocular pressure-related (IOP) effects of ocular hypotensive medications using a contact lens sensor (CLS).
University-based prospective, randomized, crossover trial.
Twenty-three patients with primary open-angle glaucoma METHODS: Patients underwent ambulatory recording of IOP-related patterns for 24 hours in one eye during 3 monthly sessions using a CLS. Patients were untreated in session 1 (S1), were randomized to one of 4 classes of glaucoma drops for S2, and had a prostaglandin analog add-on for S3.
Changes in IOP-related patterns were defined using 1) slopes from wake/sitting to sleep/supine, 2) cosinor rhythmometry modeling, and 3) area under receiver operating curve (AUC) of sleep period. Results Mean patient age was 63.8±11.8 years. Positive linear slopes were seen from wake/sitting to sleep/supine at S1 (17.1±14.2 mVeq/h) and S2 (5.5±23.9 mVeq/h) and negative slopes at S3 (-1.9±29.4 mVeq/h) (S1 to S2, p=0.01; S1 to S3, p=0.02). In the prostaglandin group, slopes changed significantly with introduction of drops (S1 to S2, p<0.024) while they did not in a mixed group combining the 3 other classes (S1 to S2, p=0.060). Overall, cosinor amplitudes were 98.4±46.5 mVeq (S1), 113.0±35.6 mVeq (S2), and 109.6±58.3 mVeq (S3) (S1-S2, p=0.23; S1-S3, p=0.66; S2-S3, p=0.93). AUC was 91.8±63.0 mVeq (S1), 76.3±102.7mVeq (S2), and 19.9±135.8 mVeq (S3). Differences between sessions were not statistically significant (S1-S2, p=0.541; S1-3, p=0.083; S2-S3, p=0.092).
Prostaglandin analogs but not other medications seem to flatten the IOP-related increase at transition of the wake/sitting to the sleep/supine period but do not seem to have an effect on acrophase and amplitude.
This article is protected by copyright. All rights reserved.
Clinical and Experimental Ophthalmology 07/2015; DOI:10.1111/ceo.12567 · 2.35 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To evaluate the diagnostic ability of macular ganglion cell and inner plexiform layer measurements in glaucoma, obtained using swept source (SS) and spectral domain (SD) optical coherence tomography (OCT) and to compare to circumpapillary retinal nerve fiber layer (cpRNFL) thickness measurements.
The study included 106 glaucomatous eyes of 80 subjects and 41 eyes of 22 healthy subjects from the Diagnostic Innovations in Glaucoma Study. Macular ganglion cell and inner plexiform layer (mGCIPL), macular ganglion cell complex (mGCC) and cpRNFL thickness were assessed using SS-OCT and SD-OCT, and area under the receiver operating characteristic curves (AUCs) were calculated to determine ability to differentiate glaucomatous and healthy eyes and between early glaucomatous and healthy eyes.
Mean (± standard deviation) mGCIPL and mGCC thickness were thinner in both healthy and glaucomatous eyes using SS-OCT compared to using SD-OCT. Fixed and proportional biases were detected between SS-OCT and SD-OCT measures. Diagnostic accuracy (AUCs) for differentiating between healthy and glaucomatous eyes for average and sectoral mGCIPL was similar in SS-OCT (0.65 to 0.81) and SD-OCT (0.63 to 0.83). AUCs for average cpRNFL acquired using SS-OCT and SD-OCT tended to be higher (0.83 and 0.85, respectively) than for average mGCC (0.82 and 0.78, respectively), and mGCIPL (0.73 and 0.75, respectively) but these differences did not consistently reach statistical significance. Minimum SD-OCT mGCIPL and mGCC thickness (unavailable in SS-OCT) had the highest AUC (0.86) among macular measurements.
Assessment of mGCIPL thickness using SS-OCT or SD-OCT is useful for detecting glaucomatous damage, but measurements are not interchangeable for patient management decisions. Diagnostic accuracies of mGCIPL and mGCC from both SS-OCT and SD-OCT were similar to that of cpRNFL for glaucoma detection.
PLoS ONE 05/2015; 10(5). DOI:10.1371/journal.pone.0125957 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Detection of progression and measurement of rates of change is at the core of glaucoma management, and the use of Spectral Domain Optical Coherence Tomography (SD-OCT) has significantly improved our ability to evaluate change in the disease. In this review, we critically assess the existing literature on the use of SD-OCT for detecting glaucoma progression and estimating rates of change. We discuss aspects related to the reproducibility of measurements, their accuracy to detect longitudinal change over time, and the effect of aging on the ability to detect progression. In addition, we discuss recent studies evaluating the use of combined structure and function approaches to improve detection of glaucoma progression.
The Open Ophthalmology Journal 05/2015; 9(1):78-88. DOI:10.2174/1874364101509010078
[Show abstract][Hide abstract] ABSTRACT: Identification of structural damage to the optic nerve and retinal nerve fiber layer (RNFL) is an essential component of diagnosis and management of glaucoma. The introduction of spectral-domain OCT (SD-OCT) has allowed objective quantification of damage to these structures with unprecedented resolution. In addition, recent attention has been directed towards imaging the macular area for quantifying loss of neural tissue caused by the disease. Many studies have evaluated and compared the diagnostic accuracies of a variety of parameters that can be obtained from imaging these areas of the ocular fundus. In this article, we critically review the existing literature evaluating the diagnostic accuracy of SD-OCT in glaucoma and we discuss issues related to how SD-OCT results should be incorporated into clinical practice.
The Open Ophthalmology Journal 05/2015; 9(1):68-77. DOI:10.2174/1874364101509010068
[Show abstract][Hide abstract] ABSTRACT: To examine the relationship between Motor Vehicle Collisions (MVCs) in drivers with glaucoma and standard automated perimetry (SAP), Useful Field of View (UFOV), and driving simulator assessment of divided attention.
A cross-sectional study of 153 drivers from the Diagnostic Innovations in Glaucoma Study. All subjects had SAP and divided attention was assessed using UFOV and driving simulation using low-, medium-, and high-contrast peripheral stimuli presented during curve negotiation and car following tasks. Self-reported history of MVCs and average mileage driven were recorded.
Eighteen of 153 subjects (11.8%) reported a MVC. There was no difference in visual acuity but the MVC group was older, drove fewer miles, and had worse binocular SAP sensitivity, contrast sensitivity, and ability to divide attention (UFOV and driving simulation). Low contrast driving simulator tasks were the best discriminators of MVC (AUC 0.80 for curve negotiation versus 0.69 for binocular SAP and 0.59 for UFOV). Adjusting for confounding factors, longer reaction times to driving simulator divided attention tasks provided additional value compared with SAP and UFOV, with a 1 standard deviation (SD) increase in reaction time (approximately 0.75 s) associated with almost two-fold increased odds of MVC.
Reaction times to low contrast divided attention tasks during driving simulation were significantly associated with history of MVC, performing better than conventional perimetric tests and UFOV.
The association between conventional tests of visual function and MVCs in drivers with glaucoma is weak, however, tests of divided attention, particularly using driving simulation, may improve risk assessment.
[Show abstract][Hide abstract] ABSTRACT: Schizophrenia is a complex mental disorder associated with not only cognitive dysfunctions, such as memory and attention deficits, but also changes in basic sensory processing. Although most studies on schizophrenia have focused on disturbances in higher-order brain functions associated with the prefrontal cortex or frontal cortex, recent investigations have also reported abnormalities in low-level sensory processes, such as the visual system. At very early stages of the disease, schizophrenia patients frequently describe in detail symptoms of a disturbance in various aspects of visual perception that may lead to worse clinical symptoms and decrease in quality of life. Therefore, the aim of this review is to describe the various studies that have explored the visual issues in schizophrenia.
Current Psychiatry Reports 05/2015; 17(5):569. DOI:10.1007/s11920-015-0569-x · 3.24 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The lamina cribrosa is a sieve-like structure where retinal ganglion cell axons and central retinal vessels exit from the eye through the scleral canal. The lamina cribrosa has been known to play an essential role in the physiopathology of glaucoma and has been investigated as a potential location to identify early glaucomatous damage. Many researchers have been studying how the lamina cribrosa responds to intraocular pressure change, leading to axonal insults. Recently, 3D spectral domain optical coherence tomography (SD-OCT) Enhanced depth imaging (EDI), an optical imaging technique, has been proposed to improve OCT imaging of deeper retinal structures such as the choroid and the lamina cribrosa. However, the shadowing from vasculature and other reflective structures make the segmentation of the anterior lamina cribrosa surface difficult. In this paper, we present a new approach for the segmentation of the anterior lamina cribrosa surface. To deal with the complexity of the surface segmentation, we propose the use of a shape-constrained surface evolution method where the surface is refined iteratively using a non-local Markov random field based segmentation. The estimation of the model parameter is addressed using a Metropolis-Hastings algorithm. Our experiments showed a significant correlation between change in the intraocular pressure level and change in the position of the lamina cribrosa over time.
Biomedical Imaging (ISBI), 2015 IEEE 12th International Symposium on, New York; 04/2015
[Show abstract][Hide abstract] ABSTRACT: The lamina cribrosa is the putative site of retinal ganglion cell axonal injury in glaucoma. Although histological studies have provided evidence of structural changes to the lamina cribrosa, even in early stages of glaucoma, until recently, the ability to evaluate the lamina cribrosa in vivo has been limited. Recent advances in optical coherence tomography, including enhanced depth and swept-source imaging, have changed this, providing a means to image the lamina cribrosa. Imaging has identified general and localized configurational changes in the lamina of glaucomatous eyes, including posterior laminar displacement, altered laminar thickness, and focal laminar defects with spatial association with conventional structural and functional losses. In addition, although the temporal relationship between changes to the lamina cribrosa and glaucomatous retinal ganglion cell loss is yet to be elucidated, quantitative measurements of laminar microarchitecture have good reproducibility and offer the potential to serve as biomarkers for glaucoma diagnosis and progression.