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Factors Related to the Progression of Myopia in Singaporean Children
Abstract
To examine the possible factors related to the progression of myopia in Singapore children.
One hundred fifty-three Singapore children aged 6 to 12 years were recruited to participate in a concurrent cohort study of the risk factors for the progression of myopia. Socioeconomic status, outdoor activity, and near-work activity were documented in a face-to-face clinic interview. The changes in cycloplegic subjective refraction and autorefraction were ascertained with the use of a Nidek ARK 900 over a 2-year period.
The average rate of progression of myopia as measured by subjective refraction was -0.59 D per year (95% confidence interval -0.52, -0.66). Younger children and children who were more myopic at the beginning (refractive error worse than -2.0 D) of the study had higher myopia progression rates.
Myopia progression was faster for younger children and for children who had more severe myopia at baseline. Socioeconomic status and near-work activity were not related to myopia progression.
... [14][15][16][17] They also suggested that near-work activities are a risk factor for myopic progression, [18,19] but other studies did not support these findings. [20][21][22][23] The prevalence of RE in Saudi Arabia varied widely from 4.5% to 34.9% as many studies reported in deferent children's age groups. [24][25][26] All of these studies have focused only on the prevalence of RE. ...
... These findings are similar to other studies that have investigated the effect of near work activities on RE in children. [20][21][22][23] Most studies have focused only on the relationship between myopia and near work. [14,15,[20][21][22][23]41] Meanwhile, in our study, we did not focus only on one type, we studied the association between all types of RE and near work, and no association was found. ...
... [20][21][22][23] Most studies have focused only on the relationship between myopia and near work. [14,15,[20][21][22][23]41] Meanwhile, in our study, we did not focus only on one type, we studied the association between all types of RE and near work, and no association was found. ...
Purpose:
Refractive error (RE) is one of the most common ocular disorders among children worldwide. This study aimed to investigate the prevalence of RE and possible risk factors among school children in Riyadh.
Methods:
This is a cross-sectional study using data collected at various schools. To achieve the aim of the study, we selected a random sample of 850 school children aged 6-15 years. The examination was based on the RESC protocol and included full visual assessment. Furthermore, a questionnaire was sent to the parents of the participants to ascertain information about lifestyle factors. We constructed a logistic regression model to evaluate the predictors of RE.
Results:
Close to a third of the children had a RE. Of those identified as having the condition, 60% did not wear glasses (newly diagnosed). Nearly all the children (95.4%) in our sample reported using electronic devices, according to parents. No association was found between using electronic devices and having a RE (P = 0.26). Doing outdoor activities was associated with 52% lower odds of a RE (odds ratio = 1.52).
Conclusion:
We found a higher prevalence of uncorrected RE than previously reported in other Saudi studies. About 60% of children who had RE were not wearing glasses, highlighting the need for a standardized school screening program for early detection and management. Outdoor activities were associated with a lower likelihood of having a RE. These findings might support initiatives to encourage outdoor activities among school children.
... Participants completed questionnaires to provide information on various known or suspected risks and protective factors for myopia as follows: age; sex; parental myopia (including the number of parents with myopia and high myopia); near-work activity (including distance and hours per week); screen time (hours per week using electronic devices and watching television); reading and writing habits (including reading posture, the distance between fingertip and nib, and head angle); frequency of visual fatigue per week; outdoor times; and light environment in the classroom. These factors were included as covariates in different multivariable logistic regression models, as these elements have been demonstrated to have possible associations with myopia in previous studies [5,[22][23][24][25]. ...
... Most researchers have now accepted the argument that genetics cannot have a major role, except in the rare cases that are predominantly genetic, because the rate at which gene pools change is inconsistent with the speed at which the epidemic of myopia has emerged [30,31]. Like many other traits, common myopia is complex in its pathogenesis and progression, with contributions from genetic and environmental factors, including lifestyle, reduced outdoor time, and intensive near-work activities [5,[22][23][24][25]. A combination of various factors, rather than a single isolated factor, may determine the refractive state. ...
Background
Nutritional status influences the growth and development of the eyes. However, there are few studies on the association between diet, especially whole grains (WG) consumption, and myopia. The study aimed to evaluate the association between WG intake and myopia prevalence among primary school-age children in China.
Methods
This cross-sectional epidemiological study conducted between November 2019 and December 2019 included 586 children, aged 6–12 years, attending primary school in Binhai district, Tianjin, China. Ophthalmologic examinations and optometric cycloplegic refraction measurements were conducted. Information was collected on known risks and protective factors for myopia and the consumption of WGs, vegetables, and fruits. This association between the probability of myopia and the proportion of WG consumption (WG proportion was calculated as the mean intake from WG sources divided by total grain intake), adjusted for protective and risk factors, was analysed using crude and multivariable logistic regression.
Results
Among the study participants, 226/586 (38.57%) children had myopia in at least one eye. WG intake was inversely correlated with the prevalence of myopia. Furthermore, in the multivariate analysis, WG intake of > 50% was identified as a protective factor against myopia after subsequent adjustment for children’s age, sex, parental myopia, near-work activity, screen time, reading and writing habits, visual fatigue, outdoor time, and classroom light environment (all P < 0.05).
Conclusion
WG intake (> 50%) was an independent protective factor against myopia. Modifying the form of grains consumed (whole versus refined) could be one of the targets of future public health measures.
... However, children from the CLEERE study resided in the United States and might have been exposed to different environments. The findings related to near work and SE progression are mixed, with several studies reporting no association [30][31][32][33] and others reporting a positive association [34]. In our study, near work was measured subjectively using a questionnaire. ...
... Parental myopia was associated with the rate of progression. This is similar to results reported by the COMET study, the Raine Study and a Singapore study including children aged 6 to 12 years, where increasing myopia progression was found in those with a greater number of myopic parents [25,31,36]. Parental myopia is a complex measure and may be a mix of genetic and environmental exposures. ...
Objectives:
To determine spherical equivalent (SE) progression among children in the Shahroud School Children Eye Cohort Study.
Methods:
A prospective cohort study recruited children aged 6 to 12 years in 2015 (baseline) with a follow-up in 2018. Cycloplegic autorefraction and axial length (AL) measurements were included. SE progression over 3 years was analysed in non-myopic (SE ≥ + 0.76 D), pre-myopic (PM; SE between +0.75 D and -0.49 D), low myopic (LM; SE between -0.5 D and -5.99 D), and high myopic (HM; SE ≤ - 6 D) eyes. Age, sex, near work, outdoor time, living place, parental myopia, mother's education, and baseline SE were evaluated as risk factors for SE progression (≤ -0.50 D).
Results:
Data were available for 3989 children (7945 eyes). At baseline, 40.3% (n = 3205), 3.4% (n = 274) and 0.1% (n = 7) eyes had PM, LM and HM, respectively. At the 3-year follow-up, 40.5% (n = 3216), 7.5% (n = 599) and 0.2% (n = 15) eyes had PM, LM, and HM, respectively. SE progression in eyes with LM and HM was -1.08 ± 0.76 D and -1.60 ± 1.19 D, respectively. SE progression was associated with age at baseline (Odds Ratio [OR] = 1.14; 95% confidence interval [CI], 1.08-1.21), female sex (OR = 1.80; 95% CI: 1.48-2.18), near work (OR = 1.08; 95% CI: 1.02-1.14), parental myopia (OR = 1.20; 95% CI: 1.01-1.42) and baseline SE (OR = 2.28; 95% CI: 1.88-2.78).
Conclusion:
A myopic shift was associated with older age, female sex, near work, parental myopia and greater myopic baseline SE. These results help identifying children at risk of progression that may benefit from treatment and lifestyle counselling.
... The initial average astigmatism of right eye of all participants was −0.94 ± 0.75 D, after 1-2 years it dropped by 0.22 ± 0.73 D. In general, astigmatism shows a downward trend with the increasing age, and the 1-year-old group presents the most apparent decline. Different cohort studies (21,25,26) reported that the degree of shift of myopia per year of school-age children was 0.39-0.68 D. In this study, preschool children's shift of myopia is 0.20 D in 1-2 years, which is lower than the research (5) (0.59 D) in Guangzhou. ...
... Our study found that at the first visit, the younger children with greater hyperopic state exhibited more noticeable myopic shift. Our findings are consistent with many reports (25,32,33), but the Guangzhou preschool myopia cohort study found that older preschool children and children with lower negative SE at the first visit showed higher myopia progression. It may be considered that the children they enrolled in the group were already myopic at the beginning, which is more similar to the progression of school-age myopia. ...
PurposeTo investigate the longitudinal changes in refractive error of preschool children and explore the factors related to these changes and the timing of intervention.Methods
The refractive data of preschool children aged 1–6 years were collected from 16 community Health Service Centers in Changsha during April 2016 to July 2019 for the retrospective cohort study. The refractive data of each participant was measured with a hand-held vision screener without cycloplegia. A follow-up for all the included participants was performed. The spherical equivalent change was calculated, subsequently, an analysis of risk factors related to the change was performed.ResultsFour thousand nine hundred twenty-one cases were included in the study with the follow-up for 1–2 years. The refractive status was found smoothly changed in 67.8% of children. The overall initial SE was 0.62 ± 1.13 D, and the average SE change was −0.20 ± 1.23 D per year. However, profound myopic shift was observed in 32.2% of children. The change of SE in 3-year-old group is most overt. The proportions of 1–6 years old who showed moderate and severe myopic shift (SE change ≥–1.00 D) were 21.6, 18.9, 28.2, 25.5, 13.4, and 10%, respectively. At the first visit, the younger children with greater hyperopic state exhibited more noticeable myopic shift, no significant difference was found in gender.Conclusion
The shift from hyperopia to myopia in preschool children is smooth, with −0.20D change on average per year. We suggest that an optometry screening should start at 3-year-old to track children's refractive status. We recommend that preschool children whose SE changes more than −1.00 D per year go to the ophthalmology department for further examination. Our study also found that at the first visit, the younger the child is and the more positive initial SE is, the degree of shift of myopia is greater.
... The law of myopia development after OK lens wear is in consistent with that of natural progression of myopia in children. Myopia development and axial elongation were faster in younger children [24][25][26] and those who had myopic parents [25,27]. However, the children with higher base myopia had faster myopia progression [24], which was in contrast with that after OK lenses wear [19,21]. ...
... Myopia development and axial elongation were faster in younger children [24][25][26] and those who had myopic parents [25,27]. However, the children with higher base myopia had faster myopia progression [24], which was in contrast with that after OK lenses wear [19,21]. The causation may be that to treat higher myopia the central corneal power should be reduced more, thus midperipheral corneal power will increase more and may induce more peripheral retina myopia defocus. ...
Abstract Background To study the baseline factors that related to faster axial elongation after orthokeratology (OK) treatment and the characteristics of cases with axial length decrease in a group of myopia children. Methods This is a retrospective study. The records of 73 children who had wear OK lens for at least one year were reviewed. Only the data of right eyes were included. Baseline data included: age, gender, parental myopia, refractive error, corneal power, central corneal thickness, axial length and anterior chamber depth. Corneal power, central corneal thickness, anterior chamber depth and axial length after one-year of OK lens wear were also collected. The related factors affecting axial length change were analyzed. A comparison was made on the cases of axial length increase and axial length decrease. Results Of the 73 eyes, axial length increased by 0.18 ± 0.17 mm (P
... Furthermore, it is well known in the literature that age is an independent risk factor for the progression of myopia, with a consensus that younger myopic children show a faster AL growth rate than older myopic children. [47][48][49] Thus, younger children might experience greater myopic progression due to the compounded effects of age and COVID-19 lockdowns, which may necessitate more aggressive treatment. *Highest prevalence value in each age group during 2015−2019 screening, † Four rounds of examinations (referred to as rounds 1−4) were conducted at approximately 6-monthly interval. ...
We systematically reviewed the literature on the effects of the coronavirus disease 2019 (COVID-19) pandemic on the progression, prevalence, and incidence of myopia. A comprehensive literature search was performed on PubMed, Cochrane Central Register of Controlled Trials, and Scopus databases. Studies included in the review assessed myopia progression, prevalence, and/or incidence as the primary outcome. Of 523 articles yielded in the initial search, 23 studies (6 cross-sectional and 17 cohort) were eligible for inclusion. Sixteen of these were conducted in China and one each in Hong Kong, Turkey, Spain, Israel, India, Korea, and Tibet. Quality appraisals were conducted with the Joanna Briggs Institute Critical Appraisal Checklists. Of the included studies, a large majority reported a greater myopic shift and increase in myopia prevalence during the COVID-19 pandemic compared to the pre-COVID-19 years. All three studies on myopia incidence showed increased incidence during the COVID-19 pandemic. Myopia progression accelerated during the COVID-19 pandemic, even in individuals using low-concentration atropine eye drops in two studies but not in those using orthokeratology treatment in one study. Overall, the studies found that the COVID-19 pandemic and its associated home confinement measures generally increased myopia progression, prevalence, and incidence, even in individuals using low-concentration atropine eye drops.
... years) with myopia was − 0.59-0.47D/year. Some studies have revealed that younger children or children with greater initial myopic refractive errors are at a greater risk of myopia progression [41][42][43][44], especially in school-aged children [45,46]. In our study, the myopia progression rate was lower among children referred timely, and children with myopia at study entry. ...
Background
Although school screenings identify children with vision problems and issue referrals for medical treatment at an ophthalmic hospital, the effectiveness of this approach remains unverified.
Objective
To investigate the impact of ophthalmic clinical services on the onset and progression of myopia in preschool children identified with vision impairment.
Methods
Using data from the Shanghai Child and Adolescent Large-scale Eye Study (SCALE), this retrospective cohort study evaluated the visual development of children from three districts—Jing’an, Minhang, and Pudong—which are representative of geographic diversity and economic disparity in Shanghai’s 17 districts. Initially, in 2015, the study encompassed 14,572 children aged 4–6 years, of whom 5,917 needed a referral. Our cohort consisted of 5,511 children who had two or more vision screenings and complete personal information over the follow-up period from January 2015 to December 2020. We divided these children into two groups based on their initial spherical equivalent (SE): a High-risk group (SE > -0.5 D) and a Myopia group (SE ≤ -0.5 D). Within each of these groups, we further categorized children into Never, Tardily, and Timely groups based on their referral compliance to compare the differences in the occurrence and progression of myopia. Cox proportional models were applied to estimate hazard ratios (HRs) for myopia incidence per person-years of follow-up in High-risk group. Generalized additive models(GAM) was used to calculating the progression for annual spherical equivalent changes in all children.
Results
Of the 5,511 preschool children (mean age, 5.25 years; 52.24% male) who received a referral recommendation, 1,327 (24.08%) sought clinical services at an ophthalmic hospital. After six years of follow-up, 65.53% of children developed myopia. The six-year cumulative incidence of myopia in the Never, Tardily, and Timely groups was 64.76%, 69.31%, and 57.14%, respectively. These percentages corresponded to hazard ratios (HRs) of 1.31 (95% CI, 1.10–1.55) for the Tardily group and 0.55 (95% CI, 0.33–0.93) for the Timely group, compared with the Never group. The HRs were adjusted for age, sex, and SE at study entry. Interestingly, the Timely group showed significantly less SE progression than the other groups (P < 0.001), and SE progression was higher in the High-risk group (-0.33 ± 0.37D/year) than in children with myopia (-0.08 ± 0.55D/year).
Conclusion
Timely utilization of ophthalmic clinical services among children aged 4 to 6 years who fail school vision screenings can significantly reduce the incidence of myopia and slow SE progression.
... Baseline myopia has been observed to be a significant predictor of myopia progression in several control studies in various populations [53][54][55] and some cohort studies. 56,57 However, this relationship has not been observed in other control 32,58 and cohort investigations. 59 The observed age-matched rate of progression was substantially lower in the EMR data relative to that found in Western clinical trials. ...
Purpose
This retrospective analysis of electronic medical record (EMR) data investigated the natural history of myopic progression in children from optometric practices in Ireland.
Methods
The analysis was of myopic patients aged 7–17 with multiple visits and not prescribed myopia control treatment. Sex‐ and age‐specific population centiles for annual myopic progression were derived by fitting a weighted cubic spline to empirical quantiles. These were compared to progression rates derived from control group data obtained from 17 randomised clinical trials (RCTs) for myopia. Linear mixed models (LMMs) were used to allow comparison of myopia progression rates against outputs from a predictive online calculator. Survival analysis was performed to determine the intervals at which a significant level of myopic progression was predicted to occur.
Results
Myopia progression was highest in children aged 7 years (median: −0.67 D/year) and progressively slowed with increasing age (median: −0.18 D/year at age 17). Female sex ( p < 0.001), a more myopic SER at baseline ( p < 0.001) and younger age ( p < 0.001) were all found to be predictive of faster myopic progression. Every RCT exhibited a mean progression higher than the median centile observed in the EMR data, while clinic‐based studies more closely matched the median progression rates. The LMM predicted faster myopia progression for patients with higher baseline myopia levels, in keeping with previous studies, which was in contrast to an online calculator that predicted slower myopia progression for patients with higher baseline myopia. Survival analysis indicated that at a recall period of 12 months, myopia will have progressed in between 10% and 70% of children, depending upon age.
Conclusions
This study produced progression centiles of untreated myopic children, helping to define the natural history of untreated myopia. This will enable clinicians to better predict both refractive outcomes without treatment and monitor treatment efficacy, particularly in the absence of axial length data.
... A paired-eye design in this selfcontrolled study necessarily diminishes the varied myopia progression rates among participants, since the myopia in the bilateral eyes normally progresses simultaneously. [27] Moreover, a paired-eye design also takes the advantages to eliminate the influence of many variables that are known related with myopia progression, including age, [28] sex, [29] outdoor activities, [30] near work [31] and myopia onset time. [32]. ...
... A 22-year follow-up [63] in schoolchildren (8-13 years) obtained an association of adulthood high myopia (spherical equivalent ≤ −6.00 D) with more time spent on reading and close work. Contrarily, other authors have reported no correlation between near work and myopia incidence [25,27,64] nor its progression [65,66] in samples of children aged from 6 to 15 years. Meanwhile, Jones-Jordan et al. [67] did not find evidence of the relationship between near work and myopia development in children from 6 to 14 years since the visual activity became different once the myopia was onset. ...
Due to the myopia prevalence increase worldwide, this study aims to establish the most relevant risk factors associated with its development and progression. A review search was carried out using PubMed, Web of Science, and Scopus databases to identify the main myopia risk factors. The inclusion criteria for the articles were those related to the topic, carried out in subjects from 5 to 30 years, published between January 2000 and May 2023, in English, and with the full text available. Myopia etiology has proven to be associated with both genetic and environmental factors as well as with gene–environment interaction. The risk of developing myopia increases in children with myopic parents (one parent ×2 times, two parents ×5 times). Regarding environmental factors, education is the main risk factor correlated with myopia prevalence increase. Further, several studies found that shorter distance (<30 cm) and longer time spent (>30 min) for near work increase the risk of myopia. Meanwhile, increased outdoor activity (>40 min/day) has been shown to be a key factor in reducing myopia incidence. In conclusion, the interventional strategy suggested so far to reduce myopia incidence is an increase in time outdoors and a reduction in the time spent performing near-work tasks.
... p = 0.211). Differences in SEq have been found in some [32][33][34] but not all studies [35,36] and could be associated with the shorter duration of outdoor activity in girls [10,37]. The situation in the current study may also be explained by small sample sizes or selection bias. ...
(1) Purpose: To investigate the efficacy of myopia treatment in children using atropine 0.125% once every two nights (QON) compared with atropine 0.125% once every night (HS). (2) Methods: This retrospective cohort study reviewed the medical records of two groups of children with myopia. Group 1 comprised children treated with atropine 0.125% QON, while group 2 included children treated with atropine 0.125% HS. The first 6 months of data of outcome measurements were subtracted as washout periods in those children undergoing both atropine QON and HS treatment. The independent t-test and Pearson’s chi-square test were used to compare the baseline clinical characteristics between the two groups. A generalized estimating equations (GEE) model was used to determine the factors that influence treatment effects. (3) Results: The average baseline ages of group 1 (38 eyes from 19 patients) and group 2 (130 eyes from 65 patients) were 10.6 and 10.2 years, respectively. There were no significant differences in axial length (AL) or cycloplegic spherical equivalent (SEq) at baseline or changes of them after 16.9 months of follow-up. GEE showed that the frequency of atropine 0.125% use has no association with annual AL (QON vs. HS: 0.16 ± 0.10 vs. 0.18 ± 0.12) and SEq (QON vs. HS: −0.29 ± 0.44 vs. −0.34 ± 0.36) changes in all children with myopia. It also showed that older baseline age (B = −0.020, p < 0.001) was associated with lesser AL elongation. (4) Conclusion: The treatment effects of atropine 0.125% HS and QON were similar in this pilot study. The use of atropine 0.125% QON may be an alternative strategy for children who cannot tolerate the side effects of atropine 0.125% HS. This observation should be confirmed with further large-scale studies.
... Generally, the progression of myopia during teenage years is associated with factors such as age, parental myopia, age at myopia onset, degree of refractive error at baseline, nature and time spent on near work, outdoor activities, outdoor activity, serum vitamin D levels, and level of education. [26][27][28][29][30] Studies investigating adult myopia have suggested age as a main determinant of myopia progression, and hence, younger myopes are more likely to progress with larger myopic shifts compared with older individuals. Other factors including sex, near work, outdoor activity, and parental myopia appear to have a little effect on myopia progression during adulthood. ...
Significance:
Studies on adult myopia progression are limited. This retrospective analysis of a large dataset of young adult myopes characterizes myopia progression during adulthood. Purpose. To determine the mean annual progression of myopia and to estimate the proportion of progressors in adult myopes.
Methods:
Longitudinal, non-cycloplegic subjective refraction data for young adult myopes (spherical equivalent refractive error -0.5D or more), age ranging from 18-30 years, was retrospectively analyzed. The mean annual progression, as well as the proportion of progressors (at least -0.50 D shift between visits and annualized progression of -0.25D or more), were estimated.
Results:
A total of 354 myopes, 230 (64.7%) females, with a mean [SD] age of 22.2 [3.8] years were considered. Mean [SD] annualized progression was -0.10 [0.21] D, -0.08 [0.2] D and -0.04 [0.21] D in 18-21-year, 22-26 year and 27-30-year age groups respectively (P = .003). The difference between 18-21 and 27-30 year age groups was significant (P = .05) while all other pairwise comparisons were not significant. The proportion (95% CI) of progressors in the 18-21, >21-26, and > 26-30 year groups was 18.3% (14.9, 21.7), 10.9% (7.1, 14.7), and 8.8% (4.4, 13.1) respectively. The proportion of progressors working or studying in a higher learning/academic environment was 16.2% with an OR (95%CI) for progression of 2.07 (1.15 - 3.74) compared to those in non-academic environments (P = .02), with no significant effect of gender or ethnicity.
Conclusions:
This study is consistent with other studies on myopia in young adults which show that myopia does not progress by substantial amounts throughout the adult years, particularly after the age of 21 years. While future studies may be challenged by the small rates of change and the small proportion of progressors, further research is needed to understand the implications of adult myopia progression on clinical management.
... It could be speculated that Caucasians have larger NG as compared to Chinese, based on the progression rate much faster in Chinese. Studies investigating myopia progression showed that the average of annual progression of myopic in school age children between − 0.41D ~ -0.71D [26,27], and myopia progression is similar to that reported by Chinese [28][29][30][31]. Secondly, from the literature investigating myopia development, we presume that NG is composed of two components, acquired and innate; the former includes environmental factors such as chromatic aberration of spectacle lens, ambient illumination, visual behaviours, pattern of correction wear; whereas the latter is solely genetic. ...
Purpose︰To assess the potential for delaying or halting myopic excursion during early emmetropization in children and adolescents.
Methods：We followed a population in southern Taiwan, of which we analyzed 69 individuals with refractive errors, a total of 137 eyes, initially between recalled the ages of 7 and 18 years, and recorded for up to 10 years with five refractive corrections at least . We also build a mathematical model to fit/analyze all the data and understand the progression of human eye refractive development as well as the myopic refraction shift during early emmetropization.
Results︰The model predictive errors for the fifth refraction were 0.44 dioptres, and the sharpest myopic progression was observed between the ages of 10.21 and 15.93. The average annual refraction change of the eyes was -0.61 dioptres. The myopic refraction of females tended to progress faster than those of males, however the refraction stabilized earlier in early adulthood for females, while it continued to see myopic progression in the males. The individuals had myopia onset earlier than 9, between 9 and 11, and older than 11, also showed different negative growth factor in the model.
Conclusions︰The concepts of myopia prevention need to be reformed, that is, instead of regarding hyperopia as reserve at early emmetropization, as paying attention at NG and the time point for an appropriate intervention, so a good model is required.
... However, this relationship has been challenged (19,20). Some research indicated that near-work had a non-significant influence on myopia status (21), myopia incidence (22), or myopia advancement (23). In addition, the direction of causation and the mechanisms involved have been questioned; schooling is a surrogate for near-work activities, but it is difficult to distinguish between reading, writing, and watching electronic screens. ...
Significance
Higher prevalence of myopia is possibly associated with more extended schooling schedules. Therefore, adjustments to high school curricula may aid in reducing the prevalence of myopia among adolescents.
Purpose
To investigate the prevalence of myopia among 15- to 18-year-old adolescents in Tianjin, China, and to evaluate the impact of different educational schedules on the prevalence of myopia among high school students.
Methods
This is a school-based epidemiological study with a cross-sectional design. Ocular biological parameters and noncycloplegic photorefraction were examined using optical biometry devices and photoscreener devices. Each student’s spherical equivalent (SE) and ocular biometry were recorded, and the prevalence of myopia was calculated.
Results
A total of 2,867 participants (1,519 males and 1,348 females) were tested for non-cycloplegic refraction, axial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD) and lens thickness (LT). In this research, the overall prevalence of myopia was 81.6%, with high myopia accounting for 11.8%. Myopia prevalence was substantially higher in general high schools than in vocational high schools, with 86.1 and 70.1%, respectively. There were no significant differences in the prevalence of myopia (p = 0.744) or high myopia (p = 0.851) across the three vocational school years. In the general high school, however, there was an increase of 4.6% (p < 0.05) in myopia prevalence between year 10 and year12.
Conclusion
Comparing vocational and standard high school students, there are considerable disparities in prevalence of myopia, spherical equivalent, and ocular biological parameters. The prevalence of myopia and high myopia increased among standard high school students, but remained relatively consistent among students in vocational schools.
... This may partly be because the children experienced a natural reduction in the rate of axial elongation with age, regardless of treatment. [26][27][28] Nevertheless, children with myopia onset prior to 10 years of age were at risk for high myopia. 29 From another point of view, the use of ortho-k in these younger children helped slow myopia progression earlier, thus reducing the risk of developing high myopia. ...
Purpose:
To investigate the correlation between the baseline axial length (AL) and axial elongation in myopes undergoing orthokeratology (ortho-k).
Methods:
This was a retrospective study. During the 1-year follow-up, 1176 children (aged 8-14 years) were included and divided into an ortho-k group (n = 588) and a single-vision spectacle group (n = 588). The ortho-k group participants (8-11 years of age) who completed the 3-year follow-up (n = 150) were further divided into three subgroups stratified by their baseline AL: subgroup 1 (AL < 24.5 mm), subgroup 2 (24.5 ≤ AL < 26 mm) and subgroup 3 (AL ≥ 26 mm). AL was measured at baseline and during the annual visit.
Results:
The ortho-k group exhibited slower 1-year axial elongation (39% reduction) than the spectacle group. The 1-year axial elongation was negatively correlated with initial age in both groups. A negative association between 1-year axial elongation and baseline AL was observed in the ortho-k group but not in the spectacle group. However, this relationship only existed in ortho-k participants 8-11 years of age. For the younger ortho-k participants who completed the 3-year follow-up, the annual axial elongation was significantly higher in subgroup 1 for the first and second years but not in the third year compared with subgroups 2 and 3.
Conclusion:
Axial elongation was negatively correlated with baseline AL in the ortho-k group. Children aged 8-11 years with longer baseline AL (≥24.5 mm) demonstrated slower annual axial elongation during the first 2 years of ortho-k treatment, which may provide insight into establishing individual guidelines for controlling myopia using ortho-k in children with different baseline characteristics.
... According to Pӓrssinen and Lyyra, a correlation was found between time spent on reading or near work and myopia [27]. Conversely, the studies of Tan et al. reported no statistically significant associations between myopia progression and near activities in children [28,29]. Contrasting evidences could be due to the difference in the age of the participants in the groups analyzed. ...
This topical review aimed to update and clarify the behavioral, pharmacological, surgical, and optical strategies that are currently available to prevent and reduce myopia progression. Myopia is the commonest ocular abnormality; reinstated interest is associated with high and increasing prevalence, especially but not, in the Asian population and progressive nature in children. The growing global prevalence seems to be associated with both genetic and environmental factors such as spending more time indoor and using digital devices, particularly during the coronavirus disease 2019 pandemic. Various options have been assessed to prevent or reduce myopia progression in children. In this review, we assess the effects of several types of measures, including spending more time outdoor, optical interventions such as the bifocal/progressive spectacle lenses, soft bifocal/multifocal/extended depth of focus/orthokeratology contact lenses, refractive surgery, and pharmacological treatments. All these options for controlling myopia progression in children have various degrees of efficacy. Atropine, orthokeratology/peripheral defocus contact and spectacle lenses, bifocal or progressive addition spectacles, and increased outdoor activities have been associated with the highest, moderate, and lower efficacies, respectively.
... For patients who had undergone surgery, our results indicated that participants with older age demonstrated a smaller degree of axial length elongation after adjusting for age and gender. is may help further verify the conclusions of previous studies that younger children were shown to undergo faster rates of axial elongation [20][21][22]. In addition, we found that a better postoperative BCVA was negatively associated with the AL change rate after IOL implantation. ...
Purpose:
To investigate the longitudinal changes and associated factors of axial length (AL) in congenital ectopia lentis (CEL) patients.
Methods:
In this retrospective study, medical records of CEL patients were reviewed from January 2014 to December 2019 at the Zhongshan Ophthalmic (ZOC) in China. Patients were divided into the surgery group and the nonsurgery group. Data of refractive power, best-corrected visual acuity (BCVA), and intraocular pressure (IOP) as well as ocular biometrics including AL, corneal curvature, white-to-white (WTW), and central corneal thickness (CCT) were collected at baseline and each follow-up visit. Multiple linear regression was performed to assess the potential associated factors for axial length growth in congenital ectopia lentis patients.
Results:
Compared with the nonsurgery group, the change rate of AL among children aged 3 to 6 years old was slower in the surgery group (0.443 ± 0.340 mm/year vs. 0.278 ± 0.227 mm/year, P < 0.05). However, no statistically significant difference for the change rate of AL was detected between the surgery group and the nonsurgery group (P > 0.05) among patients aged 7 years or older. For the surgery group, the results of the linear regression model showed that a higher change rate of AL was associated with younger age (older age: β = -0.009, 95% CI: -0.014 to -0.003, and P=0.002) and worse baseline BCVA (logMAR) (β = 0.256, 95% CI: 0.072 to 0.439, and P=0.007). As for the nonsurgery group, younger baseline age (older age: β = -0.027, 95% CI: -0.048 to -0.007, and P=0.01) and longer baseline AL (β = 0.073, 95% CI: 0.023 to 0.122, and P=0.006) were associated with a higher change rate of AL.
Conclusions:
The AL change rate was clearly associated with age both in the surgery group and in the nonsurgery group. Intervention strategies such as surgery should be performed earlier for CEL that meets the surgical criteria. Worse baseline BCVA and longer baseline AL are associated factors that would affect the growth rate of AL in the surgery and nonsurgery group, respectively.
... Hence, the use of near smart-gadgets must be discouraged where ever possible. Many authors have investigated near-work activity as an independent risk factor for myopia, however, studies of the associations between myopia and near-work activities have produced less consistent results 22,[28][29][30] . Increase of near-work activity is interlinked with the concomitant reduction of outdoor activities 31,32 and the direct and independent implication of near-work time with myopia can be difficult. ...
We aimed to evaluate the efficacy and safety of low-dose atropine compared to placebo in the Indian population and also to study the impact of various modifiable and non-modifiable factors on myopia progression (MP) and drug efficacy (DE). It was a single-centre prospective placebo-controlled interventional study. 43 participants aged 6–16 years with progressive myopia received 0.01% atropine in the right eyes (treatment) and placebo in the left eyes (control) for 1-year. The main outcome measures were annual MP and axial length elongation (ALE) in treatment and control eyes and their percentage difference between two eyes (drug efficacy). Secondary outcome measures were the occurrence of any adverse events and the correlation of MP, ALE, and DE with various factors. 40 participants (80 eyes) completed the follow-up. After 1-year, MP was 0.25 D (IQR 0.13–0.44) and 0.69 D (IQR 0.50–1.0) (p < 0.001) in treatment and control respectively (63.89% reduction) with respective ALE of 0.14 mm (IQR 0.05–0.35) and 0.32 mm (IQR 0.19–0.46) (p < 0.001) (44.44% reduction). No adverse events were noted. Reduction in MP and ALE was statistically significant in all children irrespective of age-group, baseline MP, family history, screen-time, near and outdoor-time. The strongest determinants of annual MP were age (Treatment: r = − 0.418, p = 0.007; Control: r = − 0.452, p = 0.003) and baseline MP (Treatment: r = 0.64, p = 0.000; Control: r = 0.79, p = 0.000). Screen-time in control eyes was associated with greater ALE (r = 0.620, p = 0.042). DE was higher when outdoor time exceeded 2 h/day (p = 0.035) while the efficacy was lower with prolonged near activities (p = 0.03), baseline fast-progressors (p < 0.05) and history of parental myopia (p < 0.05). 0.01% atropine is effective and safe in retarding MP and ALE in Indian eyes.
... In the Singapore Cohort Study of the Risk Factors of Myopia (SCORM), Saw et al. 22 found that children with greater axial lengths (ALs) and vitreous chamber depths and thinner lenses had higher incidence rates of myopia. As several studies have reported that myopic children with younger age show significantly faster myopic progression and are more likely to progress to high or pathologic myopia, [23][24][25] it is important to conduct a large-scale study of refractive errors to predict the onset of myopia in school-aged Chinese children. ...
Purpose:
To determine the annual incidences and rates of progression of myopia and high myopia in Chinese schoolchildren from grade 1 to grade 6 and explore the possible cause-specific risk factors for myopia.
Methods:
From 11 randomly selected primary schools in Anyang city, central China, 2835 grade 1 students were examined with annual follow ups for 5 years. Students were invited to undergo a comprehensive examination, including cycloplegic autorefraction, ocular biometry, and standardized questionnaires.
Results:
The mean spherical equivalent refraction decreased substantially from +0.94 ± 1.03 diopter (D) in grade 1 to -1.37 ± 2.08 D in grade 6, with rapid annual myopic shifts, especially for students in grades 3 through 6 (-0.51 to -0.59 D). The prevalence of myopia increased substantially, with the yearly incidence of myopia increasing from 7.8% in grade 1 and 2 to 25.3% in grades 5 and 6, and the incidence of high myopia increased from 0.1% to 1.0%. The 5-year incidence of myopia was lowest among children who has a baseline spherical equivalent refraction of greater than +2.00 D (4.4%), and increased to nearly 92.0% among children whose baseline spherical equivalent refraction was 0.00 to -0.50 D. The incidence of myopia was higher in children who had less hyperopic baseline refraction, two myopic parents, longer axial length, deeper anterior chamber, higher axial length-corneal radius of curvature ratio, and thinner lenses.
Conclusions:
Both the annual incidence and progression rates of myopia and high myopia were high in Chinese schoolchildren, especially after grade 3. Hyperopic refraction of children should be monitored before primary school as hyperopia reserve to prevent the onset of myopia and high myopia.
... This relationship was not found in the SVS Group alone (data not shown). Previously, it was reported that higher myopic patients progressed faster than lower myopic patients [33][34][35]. However, our findings in the OK Group subjects were the opposite of those reported in the previous studies. ...
Purpose:
To evaluate factors related to myopia progression in children wearing either orthokeratology (OK) lenses or single-vision spectacles (SVS) for 2 years.
Study design:
Pooled-analysis retrospective intervention study.
Methods:
This study involved 105 school-aged children wearing SVS who participated in the multi-center Myovision Study and 89 school-aged children wearing one of 3 OK lens types [Menicon Z Night (M, n = 27), αORTHO®-K (A, n = 32), and Emerald™ (E, n = 30)]. In the OK-lens patients, last examination was performed at ≥ 3-weeks post lens-wear discontinuation. Of the subjects, 102 SVS-Group and 79 OK-Group (M: n = 24, A: n = 28, and E: n = 27) children completed all examinations. A relationship between refractive error (RE) change and 7 factors (correction methods, baseline age, baseline RE, baseline axial length, gender, right or left eye, and follow-up period) was derived by multiple regression modeling. Via those same methods, we investigated the relationship between RE change and 7 factors including 3 OK-lens corrections.
Results:
Related influence factors were correction method (0.85 D myopia reduction in the OK Group, P < 0.001), baseline age (0.16 D myopia reduction in older-age patients, P < 0.001), and baseline RE (0.12 D myopia reduction per 1 D myopia, P = 0.01). No relationship was found between RE change and OK-lens type. No serious adverse events occurred.
Conclusion:
Regardless of OK lens design, myopia progression in school-aged children was suppressed. The effect was examined not only via axial-length elongation but also RE change, and the myopia control effect by OK lenses was found to be 0.85 D over the 2-year period.
... Myopia progression over time could result in high myopia, which is related to some irreversible blinding complications, such as retinal detachment, myopic macular degeneration, and glaucoma [4]. Also, younger children and children with greater initial myopic refractive errors are at a greater risk of myopia progression [5,6]. Therefore, it is essential to identify subjects that are at high risk of developing myopia to facilitate myopia prevention in the early stage, especially during the preschool period. ...
Abstract Backgrounds Myopia has become a global public health problem. Children with early onset of myopia are at particular risk of complications associated with myopia. Younger children and children with greater initial myopic refractive errors are at a greater risk of myopia progression. Therefore, it is essential to identify subjects at high risk of developing myopia to facilitate myopia prevention in the early stage, especially during the preschool period. The purpose of this study was to determine whether premyopia and myopia in preschool children can be predicted by easily obtainable parameters. Methods Data was collected in a population-based cohort. Comprehensive examinations included height, weight, refraction, axial length (AL), and corneal radius of curvature (CR), with a follow-up of 2 years. Parental myopia history was obtained from a questionnaire. Myopia was defined as spherical equivalent (SE) ≤ − 0.50 D. Premyopia was defined as − 0.50 D
... Since the landmark studies by Jones and colleagues 17 and by Rose and associates 18,19 and others, it has become apparent that the amount of time spent outdoors is a significant parameter associated with the development of myopia in school children. [5][6][7][8][9][10][11][12][13][14][15][16][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38] The Sydney Myopia Study showed that exposure to more than two hours of time spent outdoors daily was associated with a reduced odds of myopia, even in children who engaged in high levels of near work. 19 Subsequently, interventional studies revealed that increasing the amount of time spent outdoors decreased the incidence of myopia in children. ...
The prevalence of myopia has markedly increased in East and Southeast Asia, and pathologic consequences of myopia, including myopic maculopathy and high myopia-associated optic neuropathy, are now some of the most common causes of irreversible blindness. Hence, strategies are warranted to reduce the prevalence of myopia and the progression to high myopia because this is the main modifiable risk factor for pathologic myopia. On the basis of published population-based and interventional studies, an important strategy to reduce the development of myopia is encouraging schoolchildren to spend more time outdoors. As compared with other measures, spending more time outdoors is the safest strategy and aligns with other existing health initiatives, such as obesity prevention, by promoting a healthier lifestyle for children and adolescents. Useful clinical measures to reduce or slow the progression of myopia include the daily application of low-dose atropine eye drops, in concentrations ranging between 0.01% and 0.05%, despite the side effects of a slightly reduced amplitude of accommodation, slight mydriasis, and risk of an allergic reaction; multifocal spectacle design; contact lenses that have power profiles that produce peripheral myopic defocus; and orthokeratology using corneal gas-permeable contact lenses that are designed to flatten the central cornea, leading to midperipheral steeping and peripheral myopic defocus, during overnight wear to eliminate daytime myopia. The risk-to-benefit ratio needs to be weighed up for the individual on the basis of their age, health, and lifestyle. The measures listed above are not mutually exclusive and are beginning to be examined in combination.
... The ROMIO study suggested that baseline age may re ect the rate of myopia progression, with younger children shown to undergo faster rates of axial elongation, which has also been proposed by others previously [37,39] . ...
Background: To Investigate the efficacy of overnight orthokeratology (Ortho-k) for myopia control and the relationship between axial length (AL) changes and different baseline factors.
Methods: This is a retrospective study of 675 myopic patients (Affiliated Eye Hospital of Shandong University of TCM) who received Ortho-k correction between August 2015 and July 2017. These subjects were followed up at least for 12 months. Genders, age, parental refractive status, manifest refractions, cycloplegic refractions, uncorrected and best-corrected visual acuities, power vector of astigmatism, corneal curvature, age at initiation of Ortho-k wear (year), intraocular pressuren (IOP), anterior chamber depth (ACD), pupil size (PL), corneal diameter (CD) and AL were obtained for analysis. Correlation and multivariate logistic regression analyses were used to screen for the factors that can improve treatment outcome.
Results: The baseline 675 patients’ AL of was 25.12±1.00 mm, and after 12 months of treatment, the AL was 25.30±0.94 mm, and the axial elongation was 0.18±0.22 mm. Univariate analysis of the right-eye independent variable of 675 patients showed a statistically significant association between age at initiation of Ortho-k wear, spherical equivalent refractive (SER), and changes in AL. Regression analysis results show that age at initiation of Ortho-k wear and SER are independent factors with effects on the treatment outcome.
Conclusion: Ortho-k was effective in slowing myopia progression over a one-year follow-up period. Age at initiation of Ortho-k wear, and SER were found to be associated with increased change of AL during follow-up.
... Previous randomized control trials have suggested that children who develop myopia at a younger age experience a faster progression of the condition. [31,32] In order to avoid irreversible myopic change and complications, timely atropine treatment may be beneficial. Our results showed significantly lesser myopic progression in the atropine-treated group than the untreated group at the end of their 1-year follow-up (P < .01), ...
Topical atropine has become a mainstream treatment of myopia throughout East and Southeast Asia, but it is uncertain whether long-term topical atropine therapy induces intraocular pressure (IOP) elevation and subsequent development of glaucoma. We then prospectively examined the effects of long-term atropine treatment on IOP.
Our case series collected 186 myopic children who were younger than 16 years of age. Complete ocular examination data, IOP and refractive status measurements beginning in 2008 were collected for all participants. Participants were divided into two groups: 121 children who received atropine therapy at various concentrations were classified as the treated group, whereas 65 children who did not receive atropine therapy were classified as the untreated (reference) group. In the treated group, clinicians prescribed different concentrations of atropine eye drops according to their discretion with regard to the severity of myopia on each visit of the patient. We then calculated the cumulative dose of atropine therapy from 2008 to the patients’ last follow-up in 2009. Furthermore, the treated group was then further divided into low- and high-refractive-error groups of nearly equal size for further analysis.
There were no significant differences for the baseline refractive errors and IOPs between the treated and untreated groups. Both the low- and high-cumulative atropine dosage subgroups showed significantly lower myopic progression than the untreated group, but there was no significant difference between the two subgroups in terms of different cumulative dosages. All groups, including the untreated group, showed an increase of mean IOP at the last follow-up, but both low- and high-cumulative atropine dosage subgroups experienced a smaller increase of IOP. The mean IOP of all atropine-treated groups showed no significant increase in either low- or high-refractive-error eyes.
This study revealed that topical atropine eye drops do not induce ocular hypertension and are effective for slowing the progression of myopia. The treatment effects are not correlated with the cumulative atropine dosages.
... The present observational study suggested that AL was not associated with bad eyesight habits. Previous studies have shown that computer/Internet use was not related to incident myopia [34], and time and distance of near-work activity were not related to myopia progression [35], while protective behaviors related to close work (e.g., discontinuing close work every 30 min, longer distance in close work) could decrease myopia prevalence and reduce its progression [30]. But these studies did not measure AL. ...
Purpose
To evaluate the time trend of axial length (AL) and associated factors in 4- and 5-year-old children in Shanghai from 2013 to 2019.
Methods
This was a 7-year observational study of 985 four-year-old and 1059 five-year-old children in Shanghai. AL, horizontal and vertical corneal curvature, spherical equivalent (SE), and body height and weight were measured. Furthermore, a questionnaire was collected, including time outdoors and bad eyesight habits.
Results
In 4-year-old children, no significant difference was found in AL (P = 0.526), but significant differences were observed in SE (P = 0.001), horizontal corneal curvature (P = 0.006), vertical corneal curvature (P = 0.004), height (P < 0.001), and weight (P = 0.022) from 2013 to 2019. In 5-year-old children, no significant differences were found in AL (P = 0.304), SE (P = 0.200), or weight (P = 0.292), but significant differences were observed in horizontal corneal curvature (P = 0.040), vertical corneal curvature (P = 0.015), and height (P < 0.001) from 2013 to 2019. Multivariate analyses revealed that AL was mainly significantly associated with boys and time outdoors in the 4- and 5-year-old children.
Conclusions
The AL of 4- and 5-year-old children remained relatively stable in Shanghai from 2013 to 2019. Longitudinal studies are needed to confirm the relationship between AL elongation and environmental risk factors.
Objective
It is still controversial whether intermittent exotropia (IXT) affects myopic progression during the critical period of visual development. This study retrospectively analyzed the long-term myopic changes and the impact of IXT surgery on myopic progression in school-aged children with moderate IXT.
Methods
The medical records of 65 children from 5 to 13 years old with or without IXT between 2015 and 2021 were retrospectively reviewed. Patients whose spherical equivalent refraction (SER) were less than −3.00 diopter (D) were included and divided into three groups: IXT surgery group (Group A), which comprised 22 IXT patients who received IXT surgery, IXT observation group (Group B), which comprises 19 IXT patients who only received long-term observational follow-up; and normal control group (Group C), which comprised 24 normal controls without IXT. The main outcome measurement was the rate of myopic progression, which was defined as the mean myopic shift in SER per year.
Results
The 3- and 5-years long-term follow-up rates of myopic progression were −0.47 ± 0.28 D per year and −0.48 ± 0.23 D per year respectively in Group B, and those were significantly slower than that in Group C (−0.73 ± 0.32 D per year and −0.76 ± 0.19 D per year respectively). However, there was no significant difference in the rate of myopic progression between Group A and B or between Group A and C.
Conclusion
Moderate IXT may have lower rate of myopic progression in school-aged children. Whether IXT surgery influence the rate of myopic progression still needs further study.
Aim:
To determine the influence of refractive error (RE), age, gender and parental myopia on axial elongation in Chinese children and to develop normative data for this population.
Methods:
This is a retrospective analysis of eight longitudinal studies conducted in China between 2007 and 2017. Data of 4701 participants aged 6-16 years with spherical equivalent from +6 to -6D contributed to one, two or three annualised progression data resulting in a dataset of 11,262 eyes of 26.6%, 14.8% and 58.6% myopes, emmetropes and hyperopes, respectively. Longitudinal data included axial length and cycloplegic spherical equivalent RE. Axial elongation was log-transformed to develop an exponential model with generalised estimating equations including main effects and interactions. Model-based estimates and their confidence intervals (CIs) are reported.
Results:
Annual axial elongation decreased significantly with increasing age, with the rate of decrease specific to the RE group. Axial elongation in myopes was higher than in emmetropes and hyperopes but these differences reduced with age (0.58, 0.45 and 0.27 mm/year at 6 years and 0.13, 0.06 and 0.05 mm/year at 15 years for myopes, emmetropes and hyperopes, respectively). The rate of elongation in incident myopes was similar to that in myopes at baseline (0.33 vs. 0.34 mm/year at 10.5 years; p = 0.32), while it was significantly lower in non-myopes (0.20 mm/year at 10.5 years, p < 0.001). Axial elongation was greater in females than in males and in those with both parents myopic compared with one or no myopic parent, with larger differences in non-myopes than in myopes (p < 0.01).
Conclusions:
Axial elongation varied with age, RE, gender and parental myopia. Estimated normative data with CIs could serve as a virtual control group.
Professor Desmond Fonn starts our series on myopia and therapy with a review of the nature of myopia and its current and projected impact.
Myopia is a widespread and complex refractive error in which a person's ability to see distant objects clearly is impaired. Its prevalence rate is increasing worldwide, and as per WHO, it is projected to increase from 22% in 2000 to 52% by 2050. It is more prevalent in developed, industrial areas and affects individuals of all ages. There are a number of treatments available for the control of myopia, such as glasses, contact lenses, laser surgery, and pharmaceuticals agents. However, these treatments are less beneficial and have significant side effects. A novel molecule, 7-methylxanthine (7-MX), has been found to be a highly beneficial alternate in the treatment of myopia and excessive eye elongation. Many preclinical and clinical studies showed that 7-MX is effective for the treatment of myopia and is presently under phase II of clinical investigation. We have also investigated preclinical toxicity studies such as acute, sub-acute, sub-chronic, and chronic on rats. In these studies, 7-MX was found to be non-toxic as compared to other reported anti-myopic agents. Moreover, as an ideal drug, 7-MX is observed to have no or low toxicity, brain permeability, non-allergic, higher oral administration efficacy, and low treatment costs and thus qualifies for the long-term treatment of myopia. This review article on 7-MX as an alternative to myopia treatment will highlight recent findings from well-designed preclinical and clinical trials and propose a potential future therapy.
zet Amaç: Rize Devlet Hastanesi göz polikliniğine başvuran 6-15 yaş grubu çocuklarda kırma kusuru prevalansını araştırmak, kırma kusurlarının biyometrik değerler ve pakimetri arasındaki ilişkisini saptamak. Yöntem ve Gereçler: Göz polikliniğine başvuran 6-15 yaş arası 175 çocuk değerlendirildi. Tüm çocukların tam oftal-molojik muayeneleri yapıldı ve aksiyel uzunlukları ile keratometrik, pakimetrik ve sikloplejik refraksiyon değerleri ölçüldü. Bulgular: Toplam 129 çocukta (%73,7) kırma kusuruna rastlandı. Kırma kusurlarının tiplerine göre dağılımı; %28,6 hipermetropi, %24 hipermetrop astigmat, %8 miyopi, %8 miyop astigmat ve %5,1 miks astigmat şeklindeydi. Kırma kusurlarına ek olarak 71 çocukta (%40,6) ambliyopi, 25 çocukta (%14,3) şaşılık saptandı. Gruplar arasında aksiyel uzunluklarda farklılık saptanırken (p<0.05); pakimetrik değerler ve ortalama keratometrik değerler arasında farklılık saptanmadı (p>0.05). Sonuç: Rize ilinde göz polikliniğine başvuran çocuklarda en sık saptanan kırma kusuru hipermetropidir. Miyopi ve hipermetropiyi belirleyen ana etkenin aksiyel uzunluk olduğu, pakimetrik değerlerin ve ortalama keratometrik değerlerin kırma kusurları ile ilişkisi olmadığı saptanmıştır. Abstract Aim: To evaluate the refractive errors and relationship between refractive errors and biometric values and pachym-etry in children ages between 6-15 in Rize State Hospital ophthalmology clinic. Material and Methods: 175 children between 6-15 ages were enrolled into the study. Complete ophthalmologic examinations were performed for all children. Mean keratometry, axial length, pachymetry and cycloplegic refraction were also measured in all subjects. Results: One hundred and twenty nine children (73,7%) had refractive error. 28,6% of these were hyperopia, 24% were hyperopic astigmatism, 8% were myopia, , 8% were myopic astigmatism, and 5,1% were mix astigmatism. In addition to the refractive errors, 71 children (40.6%) had amblyopia and 25 children (14.3%) had strabismus. There were significant differences in axial length (p<0.05) while no significant differences including mean keratometric values and pachymetric values between groups. Relationship Between Refractive Errors And Biometric Values In 6-15 Year-Old Children Who Admitted to Rize State Hospital Ophthalmology Clinic 25 ORTADOĞU TIP DERGİSİ 5 (1): 25-28 2013
Myopia has reached epidemic levels in recent years. Stopping the development and progression of myopia is critical, as high myopia is a major cause of blindness worldwide. This overview aims at finding the association of time spent outdoors (TSO), near work (NW), and physical activity (PA) with the incidence, prevalence, and progression of myopia in children. Literature search was conducted in PubMed, Scopus, Cumulative Index to Nursing and Allied Health Literature, Cochrane Database of Systematic Reviews, ProQuest, and Web of Science databases. Systematic reviews (SR) and meta-analyses (MA) on the TSO, NW, and PA in relation to myopia were reviewed. Methodological nature of qualified studies were evaluated utilizing the Risk of Bias in Systematic Review tool. We identified four SRs out of which three had MA, which included 62 unique studies, involving >1,00,000 children. This overview found a protective trend toward TSO with a pooled odds ratio (OR) of 0.982 (95% confidence interval (CI) 0.979-0.985, I2 = 93.5%, P < 0.001) per extra hour of TSO every week. A pooled OR 1.14 (95% CI 1.08-1.20) suggested NW to be related to risk of myopia. However, studies associating myopia with NW activities are not necessarily a causality as the effect of myopia might force children to indoor confinement with more NW and less TSO. PA presented no effect on myopia. Though the strength of evidence is less because of high heterogeneity and lack of clinical trials with clear definition, increased TSO and reduced NW are protective against myopia development among nonmyopes.
Clinical relevance
Understanding the impact of home confinement on axial length in myopic children undergoing orthokeratology (OK) treatment facilitates the management of myopia control during coronavirus disease 2019 (COVID-19) lockdown.
Background
The outbreak of COVID-19 and the corresponding home confinement measures have brought a considerable challenge to myopia control. The study aimed to investigate the influence of home quarantine on axial length in myopic children with OK treatment.
Methods
Axial length measurements during and before COVID-19 home confinement were retrospectively collected from the myopic children treated with OK, and the children were prospectively followed up after finishing the quarantine. The monthly axial length growth before, during and after confinement was calculated and compared in the full dataset and subgroups stratified by age. Influencing factors for monthly axial length growth during confinement were analysed.
Results
Ninety-two myopic children with OK treatment were enrolled in this study. In the full dataset, covariates adjusted (gender, time interval, baseline axial length and age) monthly axial length growth during confinement was not significantly different from that before (P = 0.213) or after the home confinement (P = 1.000). Multiple linear regression showed that the monthly axial length growth during confinement was negatively correlated with age (P = 0.002). Subgroup analysis based on age demonstrated that the adjusted monthly axial length growth was not significantly different among three periods (P > 0.05) for younger children. For children older than 12-year-old, the adjusted monthly axial length growth during home confinement was significantly slower than before the confinement (P = 0.011), but not the monthly axial length growth after the confinement (P = 1.000).
Conclusions
COVID-19 home confinement does not increase the myopic axial length elongation in children with OK treatment.
Myopia is far beyond its inconvenience and represents a true, highly prevalent, sight-threatening ocular condition, especially in Asia. Without adequate interventions, the current epidemic of myopia is projected to affect 50% of the world population by 2050, becoming the leading cause of irreversible blindness. Although blurred vision, the predominant symptom of myopia, can be improved by contact lenses, glasses or refractive surgery, corrected myopia, particularly high myopia, still carries the risk of secondary blinding complications such as glaucoma, myopic maculopathy and retinal detachment, prompting the need for prevention. Epidemiological studies have reported an association between outdoor time and myopia prevention in children. The protective effect of time spent outdoors could be due to the unique characteristics (intensity, spectral distribution, temporal pattern, etc.) of sunlight that are lacking in artificial lighting. Concomitantly, studies in animal models have highlighted the efficacy of light and its components in delaying or even stopping the development of myopia and endeavoured to elucidate possible mechanisms involved in this process. In this narrative review, we (1) summarize the current knowledge concerning light modulation of ocular growth and refractive error development based on studies in human and animal models, (2) summarize potential neurobiological mechanisms involved in the effects of light on ocular growth and emmetropization and (3) highlight a potential pathway for the translational development of noninvasive light-therapy strategies for myopia prevention in children.
In 2018, a consortium of government bodies in China led by the Ministry of Education released the Comprehensive Plan to Prevent Nearsightedness among Children and Teenagers (CPPNCT), aiming to reduce the incidence of myopia and control myopic progression in China. Recommendations span from home-based to school-based interventions, including time outdoors, physical activity, light exposure, near-work activity, screen time, Chinese eye exercises, diet and sleep. To date, the levels of evidence for this suite of interventions have not been thoroughly investigated. This review has summarised the evidence of the interventions recommended by the CPPNCT in myopia prevention and control. Thus, the following statements are supposed by the evidence: (1) Increasing time outdoors and reducing near-work time are effective in lowering incident myopia in school-aged children. (2) All interventions have a limited effect on myopia progression. Ongoing research may lead to a better understanding of the underlying mechanisms of myopia development, the interaction of different interventions and recommendations, confounding variables and their true effect on myopia prevention, and the identification of those most likely to respond to specific interventions. This field may also benefit from longer-term studies of the various interventions or strategies covered within this review article, to better understand the persistence of treatment effects over time and explore more novel approaches to myopia control.
Myopia, the most common refractive error, is estimated to affect over two billion people worldwide, especially children from East Asian regions. Children with early onset myopia have an increased risk of developing sight threatening complications in later life. In addition to the contribution of genetic factors, of which expression is controversially suggested to be subject to environmental regulation, various environmental factors, such as near-work, outdoor, and living environment, have also been determined to play significant roles in the development of refractive error, especially juvenile myopia. Cues from daily visual scenes, including lighting, spatial frequency, and optical defocus over the field of visual stimuli, are suggested to influence emmetropisation, thereby affecting myopia development and progression. These risk factors in visual scenes of the everyday life may explain the relationship between urbanicity and myopia prevalence. This review first summarises the previously reported associations between myopia development and everyday-life environments, including schooling, urban settings, and outdoors. Then, there is a discussion of the mechanisms hypothesised in the literature about the cues from different visual scenes of urbanicity in relation to myopia development.
Purpose
To investigate the longitudinal changes in myopia from onset to stabilization in school-aged children with single-vison lenses (SVLs).
Methods
The medical records of patients wearing SVLs with long-term follow-up data between 2006 and 2016 were retrospectively reviewed. The patients who were 6–10 years old at the initial visit and 16 years old at the last assessment were included and analysed. The periods of progression and stabilization of myopia were evaluated by plotting fitted curves of the changes in spherical equivalent (SE).
Results
Seven hundred and seventy-three patients (median initial age 9 years) were accessed over an average of 7 years (IQR, 6–7 years). The initial mean SE was −1.92 ± 1.57 D and increased to −6.05 ± 2.14 D at 16 years old. The average age at myopia stabilization was 14.6 years, and girls slightly stabilized earlier than boys. 73.7% of the 6-year-olds and 85.7% of the 7-year-olds had high myopia at 16 years old, and the risk decreased each year from 7 to 10 years old. Children who had SE greater than −4 D up to 10 years had 89.0% risk of high myopia at 16 years old. Children with SE between −0.5 D and −2 D still had 34% risk of developing high myopia at 16 years old.
Conclusion
This study provides a comprehensive picture of myopia progression from onset to stabilization in school-aged children with SVLs in China. All children who have myopia onset below 10 years of age were at risk for high myopia, and children who have myopia onset below 8 years of age require more attention.
Purpose:
To model juvenile-onset myopia progression as a function of race/ethnicity, age, sex, parental history of myopia, and time spent reading or in outdoor/sports activity.
Methods:
Subjects were 594 children in the Collaborative Longitudinal Evaluation of Ethnicity and Refractive Error (CLEERE) Study with at least three study visits: one visit with a spherical equivalent (SPHEQ) less myopic/more hyperopic than -0.75 diopter (D), the first visit with a SPHEQ of -0.75 D or more myopia (onset visit), and another after myopia onset. Myopia progression from the time of onset was modeled using cubic models as a function of age, race/ethnicity, and other covariates.
Results:
Younger children had faster progression of myopia; for example, the model-estimated 3-year progression in an Asian American child was -1.93 D when onset was at age 7 years compared with -1.43 D when onset was at age 10 years. Annual progression for girls was 0.093 D faster than for boys. Asian American children experienced statistically significantly faster myopia progression compared with Hispanic (estimated 3-year difference of -0.46 D), Black children (-0.88 D), and Native American children (-0.48 D), but with similar progression compared with White children (-0.19 D). Parental history of myopia, time spent reading, and time spent in outdoor/sports activity were not statistically significant factors in multivariate models.
Conclusions:
Younger age, female sex, and racial/ethnic group were the factors associated with faster myopic progression. This multivariate model can facilitate the planning of clinical trials for myopia control interventions by informing the prediction of myopia progression rates.
Myopia is a major health problem throughout the world due to its increasingly high prevalence in the past few decades. Myopia, in particular high myopia, is associated with a number of ocular complications such as glaucoma and cataract that are potentially blinding. Myopic macular degeneration, a major cause of visual impairment and blindness, affects 1–4% of the general populations in some countries. Increased amount of near-work activities and decreased time spent outdoors are the two most important environmental modifiable risk factors related to myopia onset and progression. Near-work activities including screen time with use of smartphones and devices might be a new major risk factor for myopia. Combining health behavior programs aiming to increase outdoor time and decreasing screen time may prevent the onset of myopia. Interventions to slow the progression of low myopia to high myopia may prevent severe disease and associated pathological myopia complications.
INTRODUCTION: Refractive error may appear through childhood and adolescent. If refractive error left untreated it can result
in amblyopia and strabismus. Visual impairment has significant implication for the affected child and family in terms of education, future employment and personal and social welfare throughout life.
OBJECTIVE: To estimate the prevalence of refractive errors among a sample of children from two primary schools
in Al-Rusafa district in Baghdad. And to detect some factors that may be associated with refractive errors.
METHODS: A cross sectional study was carried at two primary schools in Baghdad from 15 February to 1 April 2009. The two primary schools were selected conveniently. All students were included in this study apart from those with eye infections ,traumatic
eye disease. Snellen’s chart was used to assess visual acuity and retinoscope was used to detect the type of refractive errors for
those with abnormal acuity. .
RESULTS: eight hundred sixty students from two primary schools were participated, and 732 were examined (85%). The prevalence of refractive errors (ametropia) was 7%. The prevalence of myopia was (5.32%), hyperopia was (1.09%), and astigmatism
was (0.68%), while the rest (92.91%) were normal (emmetropia).Twenty-four (3.2%) students wore glasses on the day of examination. These students with glasses had uncorrected visual acuity equal or less than 6/12. Among students who had refractive
errors, 46% of them were wearing corrective lenses, while more than half of them with uncorrected refractive error.
CONCLUSION: The prevalence of refractive errors in primary school children of Baghdad was 7%. Factors that were found to
be associated with refractive errors in Baghdad primary school children were age, reading hours per day, computer usage,
siblings’ history of wearing glasses. .
Key words: Primary schools, refractive errors, myopia, hyperopia, astigmatism
Purpose:
To study the prevalence and risk factors of myopia with data from a questionnaire study conducted in 1983 among Finnish school children.
Methods:
School children (n = 4 961) from the 1st, 5th and 8th grades of school (7-, 11- and 15-year-olds) in Central Finland were screened for vision followed by a questionnaire, which was returned by 4 352 (87.7%) participants. Myopia was categorized based on the questionnaire. Items concerned daily time spent on near work and outdoor activities, excluding time spent at school, watching TV and parental myopia and the associations of myopia with these factors were studied.
Results:
The prevalence of myopia was 3%, 15% and 27% among the 7-, 11- and 15-year-olds, and if daily near work at home was ≤1 hr, myopia prevalence was 0.5%, 3.3% and 17.6%, respectively. The adjusted risk of myopia for each daily near work hour was OR 1.476 (95% confidence interval 1.099-1.984, p = 0.010), OR 1.346 (1.170-1.584, p < 0.001) and OR 1.206 (1.076-1.352, p = 0.001), in the 3 age groups, respectively. The adjusted risk of myopia for each daily hour spent outdoors was OR 0.764 (0.648-0.900, p = 0.001) in the 11-year-olds and OR (0.840, 0.743-0.950, p = 0.005) in the 15-year-olds. Outdoors time prevented myopia at different levels of near work, although less at the highest levels, and near work increased risk of myopia with the level of outdoors time. If the ratio between near work and outdoors time was ≤0. 5 or >1.5, the prevalence of myopia was 1.4% versus 5.6%, 6.3% versus 24.7% and 15.9% versus 36.9%, among the 7-, 11- and 15-year-olds, respectively. The higher prevalence of myopia among the 11- and 15-year-old girls than boys was explained by more near work and less outdoor time among the girls. Having two myopic parents roughly doubled the risk of myopia compared to if one myopic parent in the 11- and 15-year-olds.
Conclusions:
Myopic parents, greater near work time, less outdoors time, a higher near work/outdoors ratio, and being a girl increased the risk of myopia. Myopia was rare in the 7- and 11-year-olds if daily near work at home did not exceed one hour or if the near work/outdoors ratio was not higher than 0.5. Outdoors time was associated with the prevalence of myopia at all levels of near work, although the association was weaker at the highest level.
Purpose
To examine the association between near work, screen time including TV and outdoor time with myopia in children from the Sunflower Myopia Asian Eye Epidemiology Consortium (AEEC).
Methods
We analysed AEEC cross-sectional data (12 241 children) on risk factors (near work, screen time including TV and outdoor time) and myopia of six population-based studies (China, Hong Kong and Singapore). Cycloplegic refraction and axial length (AL) measurements were included. Risk factors were determined using questionnaires. Data were pooled from each study, and multivariable regression analysis was performed to evaluate the associations between risks factors and myopia, spherical equivalent (SE) and AL.
Results
Among the included children, 52.1% were boys, 98.1% were Chinese and 69.7% lived in urban areas. Mean±standard deviation (SD) for age was 8.8 ± 2.9 years, for SE was −0.14 ± 1.8 D and for AL was 23.3 ± 1.1 mm. Myopia prevalence was 30.6%. In multivariate analysis, more reading and writing (OR = 1.17; 95% CI, 1.11–1.24), more total near work (OR = 1.05; 95% CI, 1.02–1.09) and less outdoor time (OR = 0.82, 95% CI, 0.75–0.88) were associated with myopia (p’s < 0.05). These factors were similarly associated with SE and AL (p’s < 0.05), except for total near work and AL (p = 0.15). Screen time including TV was not significantly associated with myopia (p = 0.49), SE (p = 0.49) or AL (p = 0.83).
Conclusion
In this study, increased reading and writing and decreased outdoor time were associated with myopia. Screen time may be a surrogate factor of near work or outdoor time, but further research is needed to assess its role as an independent risk factor for myopia.
Currently there is no consensus regarding the aetiology of the excessive ocular volume that characterizes high myopia. Thus, we aimed to test whether the gene pathways identified by gene set enrichment analysis of RNA-seq transcriptomics refutes the predictions of the Retinal Ion Driven Efflux (RIDE) hypothesis when applied to the induction of form-deprivation myopia (FDM) and subsequent recovery (post-occluder removal). We found that the induction of profound FDM led to significant suppression in the ligand-gated chloride ion channel transport pathway via suppression of glycine, GABAA and GABAC ionotropic receptors. Post-occluder removal for short term recovery from FDM of 6 h and 24 h, induced significant upregulation of the gene families linked to cone receptor phototransduction, mitochondrial energy, and complement pathways. These findings support a model of form deprivation myopia as a Cl⁻ ion driven adaptive fluid response to the modulation of the visual signal cascade by form deprivation that in turn affects the resultant ionic environment of the outer and inner retinal tissues, axial and vitreal elongation as predicted by the RIDE model. Occluder removal and return to normal light conditions led to return to more normal upregulation of phototransduction, slowed growth rate, refractive recovery and apparent return towards physiological homeostasis.
Purpose
To assess the refractive change and incidence of myopia, as well as their risk factors, among Chinese rural children aged 6–17 years.
Methods
Children who completed the baseline vision examination of the Handan Offspring Myopia Study were re-examined, including both cycloplegic and non-cyloplegic autorefraction, with a mean follow-up time of 42.4±1.47 months.
Results
A total of 601 children (68.5%) who completed both baseline and the follow-up examinations were enrolled. The cumulative refractive change and axial length change were −0.53±1.03 diopter and 0.39±0.46 mm (−0.15 diopter/year and 0.11 mm/year), respectively. A hundred and five out of the 469 non-myopic children at baseline become myopic at the follow-up, yielding a cumulative myopia incidence of 22.4% (95% CI: 18.6% to 26.2%), or annual myopia incidence of 6.3%. After adjustment, younger age (β=0.08, p<0.001), more myopic baseline refraction (β=0.31, p<0.001), larger difference between cycloplegic and non-cycloplegic refraction (β=−0.20, p=0.007) and more myopic paternal refraction (β=0.09, p=0.007) were found to be associated with more rapid myopic refractive change. More myopic baseline refraction (relative risk (RR), 95% CI: 0.19, 0.13–0.28, p<0.001) and more myopic paternal refraction (RR, 95% CI: 0.92, 0.84–1.00, p=0.039) were also associated with myopia incidence.
Conclusion
Relatively low myopic refractive change and myopia incidence were found in this study cohort. Children’s refraction and paternal refraction were associated with both myopic refractive change and myopia incidence. Such information will be helpful for further comparisons in other rural versus urban areas of China, and other countries.
Purpose:
Human and animal studies suggest that light-mediated dopamine release may underlie the protective effect of time outdoors on myopia development. Melanopsin-containing retinal ganglion cells may be involved in this process by integrating ambient light exposure and regulating retinal dopamine levels. The study evaluates this potential involvement by examining whether melanopsin-driven pupillary responses are associated with adult refractive error.
Methods:
Subjects were 45 young adults (73% female, 24.1 ± 1.8 years) with refractive errors ranging from -6.33 D to +1.70 D. The RAPDx (Konan Medical) pupillometer measured normalized pupillary responses to three forms of square-wave light pulses alternating with darkness at 0.1 Hz: alternating long wavelength (red, peak at 608 nm) and short wavelength (blue, peak at 448 nm), followed by red only and then blue only.
Results:
Non-myopic subjects displayed greater pupillary constriction in the blue-only condition and slower redilation following blue light offset than subjects with myopia (P = 0.011). Pupillary responses were not significantly different between myopic and non-myopic subjects in the red-only condition (P = 0.15). More hyperopic/less myopic refractive error as a continuous variable was linearly related to larger increases in pupillary constriction in response to blue-only stimuli (r = 0.48, P = 0.001).
Conclusions:
Repeated light exposures to blue test stimuli resulted in an adaptation in the pupillary response (more constriction and slower redilation), presumably due to increased melanopsin-mediated input in more hyperopic/less myopic adults. This adaptive property supports a possible role for these ganglion cells in the protective effects of time outdoors on myopia development.
Purpose
To validate the Clouclip, a continuously measuring objective rangefinder, and examine viewing behaviours during various near tasks in non‐myopic and myopic adults.
Methods
In experiment 1, five Clouclip devices were utilised. An infrared camera was used to visualise and measure infrared beam size and angle. Repeatability for distance tracking was assessed from 5 to 120 cm in 5 cm increments. Accuracy of distance tracking was investigated for paper and iPad targets, spatial integration was calculated, effects of target tilt were determined and light measurements were compared to a lux meter. In experiment 2, viewing behaviour was assessed in 41 subjects (21 non‐myopic, 20 myopic) during four 15‐min near tasks; (1) passive reading of printed material, (2) active writing on printed material, (3) passive viewing on an electronic device and (4) active engagement on an electronic device. Working distance was compared between tasks and refractive error groups.
Results
Clouclip distance tracking showed good repeatability, with a mean difference of 0.34 cm and limits of agreement of ±2.0 cm. Clouclip‐measured and actual distances were highly correlated for paper and electronic targets from 5 to 120 cm, with mean differences and limits of agreement of 3.96 ± 13.78 cm and 4.48 ± 8.92 cm, respectively; variability increased for distances >100 cm. Tracking ability increased with larger target sizes; tracking was accurate when the target occupied 1.5%–20.3% of tracking beam area, depending on distance and with target tilt up to ±60 degrees. Clouclip‐ and lux meter‐measured ambient illumination were highly correlated for a wide range of intensities (r = 0.96, p < 0.001), but with greater variability for intensities >20 000 lux. The Clouclip infrared beam was measured to have a diameter of 25.6 ± 2.2° and a downward angle of 10.3 ± 0.5°. For subject testing, viewing distance was significantly closer for active and passive printed tasks (29.5 ± 6.7 cm and 33.2 ± 8.8 cm, respectively) than for active and passive electronic tasks (35.4 ± 8.0 cm and 40.8 ± 10.4 cm, respectively), with no differences between refractive error groups (p = 0.88).
Conclusions
The Clouclip performed well in measuring near and intermediate distances and could distinguish between indoor (<1000 lux) and outdoor (>1000 lux) illumination. A closer working distance was observed for printed tasks compared to those on an iPad, with no difference in viewing distance between non‐myopic and myopic adults.
This study investigated refractive error and optical component changes in a group of 142 Hong Kong schoolchildren from age 6 to 17 years over a 2-year period between 1991 and 1993, Subjects were refracted subjectively and corneal curvatures and ocular dimensions were measured, At the end of the 2-year study, the mean spherical equivalent refraction (SER) was -1.86 D (SD 1.99 D) and 62% of the schoolchildren were myopic, The annual incidence of myopia was 11.8%, Children aged 10 years and under had a greater change in SER toward myopia than older children. The annual rate of myopia progression for the myopic children was -0.46 D (SD 0.40 D) and the rate of progression was greatest between age 6 and 10 years old. Vitreous depth/axial length elongation was the main component contributing to the progression of myopia. Hong Kong schoolchildren develop myopia as early as 6 years old and myopia progresses at a greater rate compared with children of European extraction.
Two hundred and forty mildly myopic schoolchildren aged 9-11 years were randomly allocated to three treatment groups and the progression of myopia was followed-up for three years. The treatment groups were: (1) minus lenses with full correction for continuous use (the reference group), (2) minus lenses with full correction to be used for distant vision only, and (3) bifocal lenses with +1.75 D addition. Three-year refraction values were received from 237 children. The differences in the increases of the spherical equivalents were not statistically significant in the right eye, but in the left eye the change in the distant use group was significantly higher (-1.87 D) than in the continuous use group (-1.46 D) (p = 0.02, Student's t test). There were no differences between the groups in regard to school achievement, accidents, or satisfaction with glasses. In all three groups the more the daily close work done by the children the faster was the rate of myopic progression (right eye: r = 0.253, p = 0.0001, left eye: r = 0.267, p = 0.0001). Myopic progression did not correlate positively with accommodation, but the shorter the average reading distance of the follow-up time the faster was the myopic progression (right eye: r = 0.222, p = 0.0001, left eye: r = 0.255, p = 0.001). It seems that myopic progression is connected with much use of the eyes in reading and close work and with short reading distance but that progression cannot be reduced by diminishing accommodation with bifocals or by reading without spectacles.
In chicks, visual deprivation leads to myopia and enlargement of the vitreous chamber of the eye. When chicks were raised with white translucent occluders over their eyes so that either the nasal half, the temporal half, or all of the retina was visually deprived, the resulting myopia (median = -15 diopters) was limited to the deprived part of the retina, regardless of which half of the retina was visually deprived; the nondeprived part remained nearly emmetropic. Correspondingly, the vitreous chamber was elongated only in the region of the visual deprivation, resulting in eyes with different asymmetric shapes depending on which retinal region was deprived. These results argue for a local regulation of ocular growth that is dependent on vision and suggest a hypothesis to explain the epidemiological association of myopia in humans with large amounts of reading. Because most nonfoveal retinal neurons have large receptive fields, they cannot resolve the individual letters on the printed page; this may lead to their activity being less during reading than during most other forms of visual stimulation. Thus, the impoverished stimulus situation of reading may lead to myopia, as do other types of visual form deprivation.
To determine the epidemiology of refractive errors in an adult Chinese population in Singapore.
A disproportionate, stratified, clustered, random-sampling procedure was used to select names of 2000 Chinese people aged 40 to 79 years from the 1996 Singapore electoral register in the Tanjong Pagar district in Singapore. These people were invited to a centralized clinic for a comprehensive eye examination, including refraction. Refraction was also performed on nonrespondents in their homes. Myopia, high myopia, and hyperopia were defined as a spherical equivalent (SE) in the right eye of less than -0.5 D, less than -5.0 D, and more than +0.5 D, respectively. Astigmatism was defined as less than -0.5 D of cylinder. Anisometropia was defined as a difference in SE of more than 1.0 D between the two eyes. Only phakic eyes were analyzed.
From 1717 eligible people, 1232 (71.8%) were examined. Adjusted to the 1997 Singapore population, the overall prevalence of myopia, hyperopia, astigmatism, and anisometropia was 38.7% (95% confidence interval [CI]: 35.5, 42.1), 28.4% (95% CI: 25.3, 31.3), 37.8% (95% CI: 34.6, 41.1), and 15.9% (95% CI: 13.5, 18.4), respectively. The prevalence of high myopia was 9.1% (95% CI: 7.2, 11.2), with women having significantly higher rates than men. The age pattern of myopia was bimodal, with higher prevalence in the 40 to 49 and 70 to 81 age groups and lower prevalence between those age ranges. Prevalence was reversed in hyperopia, with a higher prevalence in subjects aged 50 to 69. There was a monotonic increase in prevalence with age for both astigmatism and anisometropia. Increasing educational levels, higher individual income, professional or office-related occupations, better housing, and greater severity of nuclear opacity were all significantly associated with higher rates of myopia, after adjustment for age and sex.
The results indicate that whereas myopia is 1.5 to 2.5 times more prevalent in adult Chinese residing in Singapore than in similarly aged European-derived populations in the United States and Australia, the sociodemographic associations are similar.
Many people have reduced unaided vision because of myopia, a spherical error of refraction. The biological theory of myopia views myopia as the result of genetically determined characteristics of eye tissues, whereas the use-abuse theory views myopia as the result of habitual use of the eye at a near focal length, near-work. The use-abuse theory implies that myopia is prevent able whereas the biological theory does not. Myopia varies over age, gender, race, ethnicity, level of education, social class and degree of urbanization. The explanation of the epidemiology of myopia in the use-abuse theory is that some types of people do more near-work than others. Using data from the Health Examination Survey of 12 to 17-year-olds conducted by the US Public Health Service from 1966–1970, this paper finds that the use-abuse theory can explain at least some of the variance of myopia and much of the socially patterned variance. This finding raises the possibility that at least some of the myopia extant in a population is preventable.
Refraction of four hundred sixty-six 26- and 46-year-old Finns revealed that the mean refraction of 26-year-olds was about 1 D more myopic than that of 46-year-olds. Myopic refraction was related to education and occupation. The means of refraction were +0.54 D for those whose education was elementary only and -0.70 D for those with secondary and higher education. Those in managerial positions had a mean refraction of -0.49 D, whereas the unskilled or semiskilled in manufacturing or the service trades had a mean refraction of +0.49 D, and farmers and agricultural workers had +0.33 D. The mean astigmatism of the myopes was +0.74 D and that of the nonmyopes +0.51 D. Both the myopic and hyperopic showed more astigmatism than the emmetropic. The estimated proportion of "late myopia" was 25 to 34% of the myopes at the age of 26 years. Present myopia was higher the earlier the first spectacles were received.
Background. Work and related activities may be connected to myopia development and progression. We investigated the relationship between working activities and the onset as well as worsening of myopia.
Methods. Information on the working status of the mothers of 374 children, the number of hours of close-up work activity, and whether the mother was short-sighted, was obtained by a face-to-face interview. In addition, a subsample of 84 mothers was interviewed over the telephone and asked whether the myopia occurred in adulthood and, if so, the age of cessation of myopia.
Results. The adjusted odds ratio for myopia in working women was 1.9 [95% confidence interval (Cl) 1.2 to 3.2] and the adjusted odds ratio for high myopia (>-6.0 D) was 1.6 (95% Cl 0.8 to 3.0). Women who were working also had higher rates of adult-onset myopia, odds ratio 4.4 (95% Cl 0.9 to 21.2), and a later age of cessation of myopia than nonworking women.
Conclusions. In our study, work was related to myopia in Singapore women. Work may be a surrogate for another risk factor, close-up work activities such as reading, writing, and computer use. (Optom Vis Sci 1999;76:393-396)
(C) 1999 American Academy of Optometry
We performed a 5 year longitudinal study of cycloplegic refraction in a cohort of 350 Japanese schoolchildren from 6 to 11 years of age in a rural area of southwestern Japan. The spherical refraction was measured under cycloplegia with an infrared autorefractometer. The grouped data from 350 right eyes showed leptokurtic frequency distributions, and the median was +0.91 D at age 6 yrs, shifted towards emmetropia with increasing age and reached +0.34 D at age 11 years. The prevalence of myopia of -1.0 D or more was 0.3%, 0.6%, 2.0%, 2.6%, 2.9%, and 4.9% from age 6 to 11 years, and the prevalence of myopia of more than -2.0 D was less than 1% at age 6-9 years and thereafter increased up to 6.0% at age 11 years. Linear regression analysis for the longitudinal refractive data revealed that 247 (70.6%) of the 350 eyes exhibited first-order linear decrease in hyperopia or increase in myopia with an average annual change of -0.15 D/year, 14 (4%) showed second-order curvilinear change, and 89 (25.4%) remained unchanged. In the eyes with linear change, there was a significant relationship between the refraction at age 6 years and the rate of subsequent change such that the less hyperopic or emmetropic at age 6 years, the larger the change. The refraction at birth was estimated by extrapolation of the linear regression analysis results, implying that 88% of newborns have hyperopia of +1.0 D or greater and myopia is rare. These results indicate the current state of refraction in Japanese schoolchildren of a rural area.
This study was undertaken to examine the relations between the rate of childhood myopia progression and variables available in patient records. Data were obtained from four private optometry practices and two university-based longitudinal studies. Subjects were myopes with a minimum number of refractions between the ages of 6 and 15 years. Spectacle prescription types included single-vision lenses with exact distance correction or slight undercorrection, bifocal lenses, and single-vision lenses with overcorrection. Rates of progression were determined by linear regression. Three analyses were conducted: (1) for all patients, analysis of variance of rate as a function of heterophoria through the habitual nearpoint correction, an index of the amount of myopia at the initial examination age, sex, and clinical location; (2) for patients with esophoria through the distance ametropia correction, analysis of variance of rate as a function of correction type (full correction or slight undercorrection vs. bifocals), amount of myopia at the initial examination age, sex, and location; and (3) for patients with orthophoria or exophoria with ametropia correction, analysis of variance of rate as a function of correction type, amount of myopia at the initial examination age, sex, and location. The index of amount of myopia at the initial examination age was a significant variable, as was location. Patients with nearpoint esophoria through their habitual nearpoint correction had greater rates than patients with nearpoint orthophoria or exophoria with the habitual correction. For patients with nearpoint esophoria through the distance refractive correction, rates were less with bifocals than with full correction or slight undercorrection.
The present study has two objectives: 1) to establish the prevalence of myopia among young men appearing before the draft board in eastern Denmark and 2) to examine the relationship between degree of myopia and educational level, intelligence and height.
We conducted a nationwide study of the relationship among refractive error, intelligence scores, and years of schooling in 157,748 males aged 17 to 19 years. We found a strong association of myopia with both intelligence and years of school attendance. The prevalence of myopia was found to be significantly higher in the more intelligent and more educated groups. By fitting models of logistic regressions, we worked out a formula expressing the relationship among the rate of myopia, years of schooling, and intelligence level. We found that years of schooling and intelligence weigh equally in the relationship with myopia.
Refraction of four hundred sixty-six 26- and 46-year-old Finns revealed that the mean refraction of 26-year-olds was about 1 D more myopic than that of 46-year-olds. Myopic refraction was related to education and occupation. The means of refraction were +0.54 D for those whose education was elementary only and -0.70 D for those with secondary and higher education. Those in managerial positions had a mean refraction of -0.49 D, whereas the unskilled or semiskilled in manufacturing or the service trades had a mean refraction of +0.49 D, and farmers and agricultural workers had +0.33 D. The mean astigmatism of the myopes was +0.74 D and that of the nonmyopes +0.51 D. Both the myopic and hyperopic showed more astigmatism than the emmetropic. The estimated proportion of "late myopia" was 25 to 34% of the myopes at the age of 26 years. Present myopia was higher the earlier the first spectacles were received.
The refractions of 1,118 children, aged 7 to 15 years, were followed for one to eight years; 260 children were hyperopic and 828 were myopic throughout the observation time. Thirty additional hyperopic children became myopic during follow-up. In the cross-sectional study, the mean annual change of refraction in hyperopic children varied from -0.03 to -0.11 diopters in different age groups. In myopic children, the variation was from -0.46 to -0.93 D. In the longitudinal follow-up study (from five to eight years), the mean annual change of refraction in hyperopic children was -0.12 D compared with -0.55 D in myopic children. The mean annual change in the 30 hyperopic children who became myopic was -0.21 D while hyperopic and -0.60 D while myopic. The difference is highly significant. It clearly shows that the changes of refraction in hyperopic schoolchildren occur much more slowly than in myopic children of the same age.
Many people have reduced unaided vision because of myopia, a spherical error of refraction. The biological theory of myopia views myopia as the result of genetically determined characteristics of eye tissues, whereas the use-abuse theory views myopia as the result of habitual use of the eye at a near focal length, near-work. The use-abuse theory implies that myopia is preventable whereas the biological theory does not. Myopia varies over age, gender, race, ethnicity, level of education, social class and degree of urbanization. The explanation of the epidemiology of myopia in the use-abuse theory is that some types of people do more near-work than others. Using data from the Health Examination Survey of 12 to 17-year-olds conducted by the US Public Health Service from 1966--1970, this paper finds that the use-abuse theory can explain at least some of the variance of myopia and much of the socially patterned variance. This finding raises the possibility that at least some of the myopia extant in a population is preventable.
There is little information directly relating ocular refraction and nearwork habits in representative human populations. Ocular refraction (diopters), nearwork (hours per day), and education (years) were therefore measured for 957 persons comprising 80% of the population aged 5 years and above of 3 communities in western Newfoundland. Refraction was moderately, consistently and significantly correlated with nearwork from ages 5 to 60, and remained so after adjustments for the association of refraction and nearwork levels with age, sex and education. Multiple regression coefficients relating refraction to nearwork decreased from -0.43 D/h at ages 5-14 years to -0.22 D/h at ages 60 years and up. The magnitude of this association, and its consistency and persistence over a wide age range, suggest that large amounts of nearwork in childhood may contribute to the prevalence of clinical myopia.
The influence of visual experience on ocular development in higher primates is not well understood. To investigate the possible role of defocus in regulating ocular growth, spectacle lenses were used to optically simulate refractive anomalies in young monkeys (for example, myopia or nearsightedness). Both positive and negative lenses produced compensating ocular growth that reduced the lens-induced refractive errors and, at least for low lens powers, minimized any refractive-error differences between the two eyes. These results indicate that the developing primate visual system can detect the presence of refractive anomalies and alter each eye's growth to eliminate these refractive errors. Moreover, these results support the hypothesis that spectacle lenses can alter eye development in young children.
Previous studies that suggested that lens-wearing may affect eye growth are supported now by primate studies, which raises questions about the use of eyeglasses in children (pages 761–765).
To evaluate whether eye size and shape are different in children based on their parental history of myopia.
A community-based cohort study of schoolchildren (aged 6 to 14 years), the Orinda (Calif) Longitudinal Study of Myopia.
Four campuses of the Orinda Union School District, a predominantly white, high socioeconomic status community.
A cross-sectional volunteer sample of 716 children (662 non-myopic) in the first, third, and sixth grades in 1989, 1990, and 1991. All children in those grades were eligible for inclusion in the study.
None.
Refractive error (measured by autorefraction), corneal curvature (measured by photokeratoscopy), crystalline lens power (measured by video phakometry), and axial ocular dimensions (measured by ultrasonography).
With prevalent cases of myopia excluded and grade in school and "near work" controlled for, children with two myopic parents had longer eyes and less hyperopic refractive error (analysis of covariance, P < or = .01) than children with only one myopic parent or no myopic parents. A model incorporating parental history is only improved by the addition of near work for the prediction of refractive error.
Even before the onset of juvenile myopia, children of myopic parents have longer eyes. These results suggest that the premyopic eye in children with a family history of myopia already resembles the elongated eye present in myopia.
Many ocular measurements are more alike between fellow eyes than between eyes from different individuals. To make appropriate inferences using data from both eyes rather than the best or worst eye, statistical methods that account for the association between fellow eyes must be used.
Marginal and conditional regression models account for the association between fellow eyes in different ways. The authors compare and contrast these methods using data from a series of patients with retinitis pigmentosa in whom the primary object is to identify risk factors, some of which are subject specific and some of which are eye specific, for visual acuity loss (as a binary outcome) among affected subjects.
Odds ratios for age, gender, presence of posterior subcapsular cataract, and genetic type of retinitis pigmentosa obtained from the marginal model were all larger than those from the conditional model. Familial aggregation of visual acuity loss was statistically significant in the marginal, but not in the conditional, model.
The estimates and interpretation of the association between an ocular outcome and risk factors can differ significantly between these two approaches. The choice of model depends on the scientific questions of interest rather than on statistical considerations. Computer programs are available for implementing both models.
The prevalence and degree of myopia were measured in 870 teenagers, males and females. We found a statistically significantly higher prevalence and degree of myopia in a group of 193 Orthodox Jewish male students who differed from the rest in their study habits.
Orthodox schooling is characterized by sustained near vision and frequent changes in accommodation due to the swaying habit during study and the variety of print size. A possible myopic effect of this unique visual demand is postulated.
The aim was to assess the influence of childhood reading on the development of myopia after allowance for familial differences in susceptibility.
The study was a cross sectional survey.
Four fishing harbours in Hong Kong in 1989.
Participants were 408 men and women aged 15-39 years old from 159 families.
Histories of school attendance and reading habits in childhood were obtained at interview. Myopia was assessed by retinoscopy. Associations between myopia (defined as a refractive error of at least -1.0D in one or both eyes) and indices of reading in childhood were explored. Myopia was more common in subjects who had attended school (odds ratio = 1.7, 95% CI 1.0-3.0), with the highest risks in those who had started school at the earliest ages and who had spent the most time reading and writing while at primary school. Allowance for familial tendency to myopia produced no diminution in the risks associated with reading.
These data support the hypothesis that reading in childhood is a cause of short sight.
The purpose of this study was to characterize the clinical course of myopia in a selected pediatric population. The computerized records of a health maintenance organization provided longitudinal data on 501 children aged 5 to 15 years. We examined the influence of age at diagnosis, gender, race, and initial refraction on progression of myopia. Mean follow-up was 34 months, with 75% of children having follow-up longer than 16 months. The mean rate of myopic progression was greater for children whose myopia was diagnosed at a younger age (5-7 years, -0.56 diopters/year versus 11-15 years, -0.28 diopters/year; p < 0.0001). Children with more than one diopter of myopia at first diagnosis progressed faster than children with less than or equal to one diopter of myopia (mean rate -0.48 diopter/year versus -0.41 diopter/year; p = 0.05). Cumulative event rate curves suggest a gender effect in the prepuberty years of 8 to 10, with myopia progressing faster in girls than boys (p = 0.003). Progression of myopia did not differ between white and non-white children. More rapidly progression of myopia is associated with younger age at initial diagnosis and greater severity of initial myopic refraction.
In order to understand and update the prevalence of myopia in Taiwan, a nationwide survey was performed in 1995.
We stratified the cluster sampling by developmental grading of the city, using a size proportional to the population. Two cities were randomly selected from each city grading. The total number of students enrolled was 11,178, including 5,676 boys and 5,502 girls. The refractive status and corneal radius of each student were measured with an autorefractometer under cycloplegia and checked with retinoscopy. Axial length was measured with biometric ultrasound.
The myopic rate was from 12% at the age of 6, it increased to 56% at the age of 12, and then to 76% at the age of 15. A myopic rate of 84% was found for the age range of 16 to 18. The prevalence of high myopia (over -6.0 D) at the age of 18 was 20% in girls and 12% in boys. The mean refractive status became myopic at the age of 9, then increased to -3.92 D in girls and -2.71 D in boys at the age of 18. The increase of axial length is correspondent with the progression of myopia. The anterior chamber depth (ACD) was deeper with age and the severity of myopia, whereas the corneal curvature remained unchanged. The lens thickness became thinner from age 7 to 13, then it became thicker with age and the severity of myopia after age 15. The prevalence and degree of myopia in girls was more severe than in boys.
The prevalence of myopia in Taiwan increased year by year. The increase in severity and prevalence of high myopia may be due to earlier onset.
This study investigated refractive error and optical component changes in a group of 142 Hong Kong schoolchildren from age 6 to 17 years over a 2-year period between 1991 and 1993. Subjects were refracted subjectively and corneal curvatures and ocular dimensions were measured. At the end of the 2-year study, the mean spherical equivalent refraction (SER) was -1.86 D (SD 1.99 D) and 62% of the schoolchildren were myopic. The annual incidence of myopia was 11.8%. Children aged 10 years and under had a greater change in SER toward myopia than older children. The annual rate of myopia progression for the myopic children was -0.46 D (SD 0.40 D) and the rate of progression was greatest between age 6 and 10 years old. Vitreous depth/axial length elongation was the main component contributing to the progression of myopia. Hong Kong schoolchildren develop myopia as early as 6 years old and myopia progresses at a greater rate compared with children of European extraction.
Numerous scientists have noted a relationship between close-up work and myopia.
A questionnaire and four 24-hour diaries were developed to estimate close-up work activity in a cohort study of close-up work and myopia progression in Singapore children. The number of hours per day that children engaged in each type of close-up work activity over a weekday and weekend during the school term, during the examination period, and in the vacation were estimated.
The children spent an average of 6.6 hours per day on total weighted average close-up work, of which 4.3 hours were spent on reading and writing. The intra-class correlation coefficient for the reproducibility of the questionnaire was 0.87 (95% CI 0.85-0.91). The intra-class correlation coefficient for total weighted close-up work was 0.50 (95% CI 0.34-0.66) when the questionnaire was compared with the four 24-hour diaries. The amount of close-up work activity increased with age.
A questionnaire for close-up work was developed and proven to be reproducible and comparable to four 24-hour diaries.
Singapore Census of Population Singapore: Singapore National Printers
- Ke Lau
Lau KE. Singapore Census of Population 1990. Singapore: Singapore
National Printers, 1992.
The age of onset of myopia is a predictor of adult myopia severity
- Sj Chew
- Ritch R Leong
- Yk Chow
- Yc Ng
- Bs Ho
- Cl Thompson
- Hw Beuerman
Chew SJ, Ritch R, Leong YK, Chow YC, Ng BS, Ho CL, Thompson
HW, Beuerman RW. The age of onset of myopia is a predictor of
adult myopia severity. In: Shimizu K, ed. Current Aspects in
Ophthalmology: Proceedings of the XIII Congress of the Asia-Pacific
Academy of Ophthalmology, Kyoto, 12–17 May 1991, vol. 1.
Amsterdam: Excerpta Medica, 1992:680–5.
Non-linear progression of myopia during a school year
- N Tan
- Sm Saw
- D Chee
- Ds Lam
- Hm Cheng
- U Rajan
- Sj Chew
Tan N, Saw SM, Chee D, Lam DS, Cheng HM, Rajan U, Chew SJ.
Non-linear progression of myopia during a school year. Invest Ophthalmol Vis Sci 1998;39:S280.
Non-linear progression of myopia during a school year
- N Tan
- S M Saw
- D Chee
- D S Lam
- H M Cheng
- U Rajan
- S J Chew
Tan N, Saw SM, Chee D, Lam DS, Cheng HM, Rajan U, Chew SJ.
Non-linear progression of myopia during a school year. Invest Ophthalmol Vis Sci 1998;39:S280.
Singapore: Singapore National Printers
- K E Lau
Lau KE. Singapore Census of Population 1990. Singapore: Singapore
National Printers, 1992.
The age of onset of myopia is a predictor of adult myopia severity
- S J Chew
- R Ritch
- Y K Leong
- Y C Chow
- B S Ng
- C L Ho
- H W Thompson
- R W Beuerman
Chew SJ, Ritch R, Leong YK, Chow YC, Ng BS, Ho CL, Thompson
HW, Beuerman RW. The age of onset of myopia is a predictor of
adult myopia severity. In: Shimizu K, ed. Current Aspects in
Ophthalmology: Proceedings of the XIII Congress of the Asia-Pacific
Academy of Ophthalmology, Kyoto, 12-17 May 1991, vol. 1.
Amsterdam: Excerpta Medica, 1992:680-5.