Inferring myopia over the lifecourse from uncorrected distance visual acuity in childhood

Comparison of the Performance of ChatGPT, Claude and Bard in Support of Myopia Prevention and Control

Purpose

 Chatbots, which are based on large language models, are increasingly being used in public health. However, the effectiveness of chatbot responses has been debated, and their performance in myopia prevention and control has not been fully explored. This study aimed to evaluate the effectiveness of three well-known chatbots-ChatGPT, Claude, and Bard-in responding to public health questions about myopia.

Methods

 Nineteen public health questions about myopia (including three topics of policy, basics and measures) were responded individually by three chatbots. After shuffling the order, each chatbot response was independently rated by 4 raters for comprehensiveness, accuracy and relevance.

Results

 The study's questions have undergone reliable testing. There was a significant difference among the word count responses of all 3 chatbots. From most to least, the order was ChatGPT, Bard, and Claude. All 3 chatbots had a composite score above 4 out of 5. ChatGPT scored the highest in all aspects of the assessment. However, all chatbots exhibit shortcomings, such as giving fabricated responses.

Conclusion

 Chatbots have shown great potential in public health, with ChatGPT being the best. The future use of chatbots as a public health tool will require rapid development of standards for their use and monitoring, as well as continued research, evaluation and improvement of chatbots.

Relationship between visual impairment and school entrance age in rural China

CLINICAL RELEVANCE

Children with uncorrected visual impairment have lower scores on various motor and cognitive tests. Exploring the association between visual impairment and school entrance age among school children in rural China may assist in enhancing the visual health of early-entry school students.

BACKGROUND

Educational pressures may play a role in the visual health of students. School entrance age is associated with educational pressures. This study explored whether school entrance age can contribute to visual impairment among younger generations.

METHODS

A cross-sectional study was conducted with 17,510 students from 252 primary schools in two prefectures in western China. Information on the sampled students was collected through questionnaires and vision examinations. The relationship between visual impairment and school entrance age was further analysed by multiple regression. The school entrance age was classified as early-entry and late-entry, early-entry was defined as students entering school at the age 6 years.

RESULTS

The results showed that the myopia rate of early-entry students (26.92%) was higher than late-entry students (23.86%). Multiple regression showed that visual impairment increased with the earlier age of school entry (P = 0.044). The prevalence of myopia was also significantly higher in higher grades for children of the same age. The prevalence of myopia in 10-year-old and 11-year-old fourth- and fifth-grade students was 20.6% to 30.5%, 21.7% to 27.4% (P < 0.001). The near work with eyes was significantly different among children of the same age in different grades during this study (P < 0.001).

CONCLUSION

Myopia is related to the school entrance age of children. Children who start school earlier are more likely to suffer from myopia. Educational pressures and digital screens may play a role in the association. Changes in the current education mode by reducing the study burden in the early years of learning may be significant.

Association Between Myopia and Primary Open-Angle Glaucoma by Race and Ethnicity in Older Adults in the California Medicare Population

Importance

Racial and ethnic differences in the association between myopia and primary open-angle glaucoma (POAG) are not well understood.

Objective

To investigate the association between myopia and POAG in the 2019 California Medicare population and to investigate whether there was evidence of effect measure modification of this association by race and ethnicity.

Design, Setting, and Participants

This cross-sectional study used administrative claims data from 2019 California Medicare beneficiaries 65 years or older with California residence and active coverage with Medicare parts A and B. Analysis took place between October 2021 and October 2023.

Exposures

The primary exposure was myopia, which was defined by International Statistical Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) diagnosis codes.

Main Outcomes and Measures

The outcome of interest was POAG, which was defined by ICD-10-CM code.

Results

Of 2 717 346 California Medicare beneficiaries in 2019, 1 440 769 (53.0%) were aged 65 to 74 years, 1 544 479 (56.8%) identified as female, 60 211 (2.2%) had myopia, and 171 988 (6.3%) had POAG. Overall, 346 723 individuals (12.8%) identified as Asian, 117 856 (4.3%) as Black, 430 597 (15.8%) as Hispanic, 1 705 807 (62.8%) as White, and 115 363 (4.2%) as other race and ethnicity. In adjusted logistic regression analyses, beneficiaries with myopia had higher odds of POAG compared with beneficiaries without myopia (odds ratio [OR], 2.41; 95% CI, 2.35-2.47). In multivariable models stratified by race and ethnicity, the association between myopia and POAG was stronger in Asian (OR, 2.74; 95% CI, 2.57-2.92), Black (OR, 2.60; 95% CI, 2.31-2.94), and Hispanic (OR, 3.28; 95% CI, 3.08-3.48) beneficiaries compared with non-Hispanic White beneficiaries (OR, 2.14; 95% CI, 2.08-2.21).

Conclusions and Relevance

In the 2019 California Medicare population, myopia was associated with greater adjusted odds of POAG. This association was stronger among Asian, Black, and Hispanic beneficiaries compared with non-Hispanic White beneficiaries. These findings suggest possible disparities in glaucoma risk by race and ethnicity in individuals with myopia and may indicate greater need for glaucoma screening in individuals with myopia from racial and ethnic minority backgrounds.

A Study to Analyze Refractive Errors in Relation to Age and Sex

Background and objective Refractive defects should be detected and treated early to avoid irreversible vision loss and other potential problems in the future. In this study, we aimed to analyze the refractive errors (REs) and their relationship with gender and age. Methods This study was conducted at the Northern Border University Health Center, Arar, Saudi Arabia. REs were analyzed using spherical equivalents (SEs), cylinders, and their orientations. SEs of REs were taken as half the cylinder plus the spherical component. Emmetropia was defined as SE between -0.50 and +0.50 diopter sphere (DS), myopia as SE ≤0.50 DS, and hyperopia as SE ≥0.50 DS for adults and SE ≥1.0 for children (up to 10 years). Statistical analysis was performed using the IBM SPSS Statistics software package (IBM, Armonk, NY). Qualitative data were presented as frequency and percentage while quantitative data were presented as mean and standard deviation (SD). Chi-square was used as a significant test and a p-value <0.05 was considered statistically significant. Results A total of 240 patients were included in the study. There were 138 men and 102 females aged 3-60 years (57.5 and 42.5%, respectively). The mean age of males was 24.4 years and that of females was 25.5 years. The p-value was statistically significant in terms of analysis with age. The study found an association between age and RE magnitude and variability. Conclusion Based on our findings, RE is a common problem that affects individuals of all ages. Regular screenings are advised for individuals in order to detect REs early.

The prevalence and county-level socioeconomic correlates of visual impairment and glasses ownership among rural students in Western China

Objectives

Vision health has been a major issue in public health care. The vision problems of children in rural China are of particular concern. Effective policies for children's vision health should consider the heterogeneity of individual health levels and regional differences in healthcare services. This study systematically explored the relationship of student visual impairment and glasses ownership with county-level socioeconomic status (namely, county-level per capita GDP, population density and industrial structure) in rural China.

Methods

The study sample included 99,670 students in grades 4-9 from 445 schools in 13 counties in Shaanxi Province. From 2014 to 2020, students took school-based vision screening tests and completed sociodemographic questionnaires. Multivariate regressions were used for empirical analysis.

Results

The prevalence of visual impairment was 30.4% in the total sample, and the rate of visual impairment in girls (34.3%) was higher than that in boys (27.0%). Among visually impaired students, the rate of glasses ownership was only 39.7%, with girls (40.6%) higher than boys (38.8%). The study also found that the visual impairment was significantly correlated with county-level average income, population density and industrial structure, and the glasses ownership was significantly correlated with population density and industrial structure (all p < 0.001).

Conclusions

The study found that the county-level socioeconomic status was positively and significantly correlated with visual impairment and glasses ownership, respectively. The vision health management services for students should be jointly carried out by the education, medical and public health departments, and additional investment is needed to increase the accessibility and affordability of vision care services, with special focus on poor regions and disadvantaged groups, so as to narrow the gap in vision health services.

Prevalence of refractive error among Chinese preschool children: The Changsha children eye study

Purpose

We aimed to investigate the refractive status and prevalence of refractive error, as well as its characteristics in Chinese preschool children aged 1-6 years old.

Methods

A population-based cross-sectional study-Changsha Children Eye Study (CCES) was conducted. The prevalence of refractive errors among children aged 1-6 years old from 18 community health service centers was surveyed. A handheld child vision screener, Suowei, was used for examination.

Results

A total of 43,105 preschool children were included. The mean spherical equivalent (SE) was 0.42 ± 1.05 D for the right eyes. The mean astigmatism (diopter of cylinder, DC) was -0.83 ± 1.02 D for the right eyes. The magnitude of refractive error was lower in older children, indicating the ongoing of the emmetropization during the 1-6-year-old children. The prevalence of myopia (SE ≤ -1.00 D), hyperopia (SE ≥ +2.00 D) and astigmatism (DC ≥1.50 D) was 2.94, 13.8 and 17.6%, respectively. The prevalence of myopia decreased with the increase of age between the six age groups (P < 0.001). The prevalence of hyperopia was lower in 5-6 years old, whereas, the prevalence of myopia was slightly higher at this period of time. With-the-rule (WTR) astigmatism (+ cylinder axis 90° ± 15°) was the most prevalent type of astigmatism than against-the-rule (ATR) astigmatism (+ cylinder axis 180° ± 15°) and oblique (OBL) astigmatism (X ² = 209.5, P < 0.001). The binary logistic regression model showed that older age and suffering astigmatism were independently associated with the development of myopia. In addition, there was no significant gender difference in the prevalence of myopia, emmetropia, and hyperopia.

Conclusions

Our population-based cross-sectional study investigated the prevalence of myopia, hyperopia, and astigmatism in preschool children aged 1-6 years old. The distribution of the refractive error was disperse in the younger group and gradually turned more centralized in older group. Similar to hyperopia, with age increased, the prevalence of myopia was lower in preschool children younger than 5 years old and then slightly increased at 5-6 years, which may indicate an early sign of myopia in school-age children. Therefore, we emphasize that more attention should be given to the children at this age.

Macular Retinal Microvasculature of Hyperopia, Emmetropia, and Myopia in Children

Purpose

To compare macular retinal microcirculation in myopia, emmetropia, and hyperopia groups and investigate the relationship between macular retinal microcirculation and axial length (AL) in children.

Methods

Forty myopic, 29 emmetropic, and 34 hyperopic eyes were included. All the recruited eyes underwent optical coherence tomography angiography (OCTA) examinations. After adjusting the image size by the Littmann method and Bennett formula, the vessel density (VD) of the deep capillary plexus (DCP) and superficial vascular plexus (SVP) were assessed.

Results

The VD of the DCP was significantly lower in the myopia group than in the hyperopia group, whereas no significant differences in the VD of the SVP were observed among the myopia, emmetropia, and hyperopia groups. The VD of the DCP was significantly associated with AL, spherical equivalent (SE), and foveal retinal thickness (FRT), whereas the VD of the SVP was only significantly associated with FRT but not with AL or SE.

Conclusions

The myopic VD of the DCP was significantly lower than the hyperopic one, and the VD of the DCP was significantly associated with AL, indicating that myopia has a lower VD of the DCP, and AL could have a negative effect on the VD of the DCP. Thus, early myopic axial stretching might decrease retinal blood perfusion of the DCP in children.

Longitudinal Changes in Refractive Error Among Preschool Children Aged 1–6 Years: The Changsha Children Eye Study

Purpose

To 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.

Results

Four 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.

Assessment of Choroidal Vascularity and Choriocapillaris Blood Perfusion After Accommodation in Myopia, Emmetropia, and Hyperopia Groups Among Children

Purpose

To investigate choroidal vascularity (CV) and choriocapillaris blood perfusion before and after accommodation in myopia, emmetropia, and hyperopia groups among children.

Methods

This study included 39 myopic eyes from 22 subjects, 17 emmetropic eyes from 11 subjects, and 18 hyperopic eyes from 10 subjects. All subjects were children. Choroidal thickness (CT) and CV, including total choroidal area (TCA), luminal area (LA), and stromal area (SA) were measured using swept-source optical coherence tomography (SS-OCT). Choriocapillaris luminal area (CLA) was measured using SS-OCT-angiography before and after accommodation (near reading with an additional −3 diopter lens).

Results

For baseline results, except horizontal CV (showing no significant differences between myopia and emmetropia groups), both horizontal and vertical CT and CV were significantly smaller in the myopia group than in the emmetropia or hyperopia groups. In terms of CLA, no significant differences were observed among the myopia, emmetropia, and hyperopia groups. In addition, only myopic eyes showed significant decreases in CT and CV, whereas most CT and CV of emmetropic and hyperopic eyes showed non-significant decreases after accommodation. Furthermore, accommodation induced no significant changes in CLA in the myopia, emmetropia, or hyperopia groups.

Conclusion

Myopia had thinner baseline choroid and lower baseline choroidal blood perfusion. Furthermore, myopic eyes were more prone to choroidal thinning and blood perfusion decreases after accommodation.

Video game treatment of amblyopia

Amblyopia is visual impairment characterized by a structurally normal eye showing significantly lower visual acuity than the fellow eye. Traditional treatment of amblyopia includes patching the good eye to force the amblyopic eye to work during normal daily activities; however, this approach is are limited by low compliance. Recently, researchers proposed a new treatment for amblyopia: video game playing. In the current review, we discuss whether video game playing can treat amblyopia, whether video game playing could better treat amblyopia than traditional treatments, and how the video game treats amblyopia and its possible mechanism. Based on results from our literature review and meta-analysis, we suggest there is strong evidence for the effectiveness of video game treatments. Moreover, multiple factors within and outside of video games could influence the treatment effect.

COVID-19 PANDEMİ SÜRECİNDE ONLİNE EĞİTİMİN MİYOPİK ÇOCUKLARDA REFRAKSİYON DEĞERLERİ ÜZERİNE ETKİLERİNİN DEĞERLENDİRİLMESİ

AMAÇ: Bu çalışmanın amacı Covid-19 pandemisi nedeniyle uzaktan eğitim alan çocuklarda refraksiyon değişimlerini değerelendirmektir. GEREÇ VE YÖNTEM: Çalışmaya pandemi döneminde uzaktan eğitim alan ve en az 6 saat ekran maruziyeti olan ve gözlük reçete edilen 18 yaş altı 56 hasta dahil edildi. Snellen Eşeli ile görme keskinliklerine bakıldı. Hastanın tam gördüğü refraksiyon değerleri kaydedilip retrospektif olarak kayıtları tarandı. 2020’deki refraksiyon değerleri 2018 ve 2019’daki refraksiyon değerleri ile karşılaştırıldı. p

Effectiveness of a novel mobile health (Peek) and education intervention on spectacle wear amongst children in India: Results from a randomized superiority trial in India

BACKGROUND

Uncorrected refractive errors can be corrected by spectacles which improve visual functioning, academic performance and quality of life. However, spectacle wear can be low due to teasing/bullying, parental disapproval and no perceived benefit.Hypothesis: higher proportion of children with uncorrected refractive errors in the schools allocated to the intervention will wear their spectacles 3-4 months after they are dispensed.

METHODS

A superiority, cluster-randomised controlled trial was undertaken in 50 government schools in Hyderabad, India using a superiority margin of 20%. Schools were the unit of randomization. Schools were randomized to intervention or a standard school programme. The same clinical procedures were followed in both arms and free spectacles were delivered to schools. Children 11-15 years with a presenting Snellen visual acuity of <6/9.5 in one or both eyes whose binocular acuity improved by ≥2 lines were recruited.In the intervention arm, classroom health education was delivered before vision screening using printed images which mimic the visual blur of uncorrected refractive error (PeekSim). Children requiring spectacles selected one image to give their parents who were also sent automated voice messages in the local language through Peek. The primary outcome was spectacle wear at 3-4 months, assessed by masked field workers at unannounced school visits. www.controlled-trials.com ISRCTN78134921 Registered on 29 June 2016.

FINDINGS

701 children were prescribed spectacles (intervention arm: 376, control arm: 325). 535/701 (80%) were assessed at 3-4 months: intervention arm: 291/352 (82.7%); standard arm: 244/314 (77.7%). Spectacle wear was 156/291 (53.6%) in the intervention arm and 129/244 (52.9%) in the standard arm, a difference of 0.7% (95% confidence interval (CI), -0.08, 0.09). amongst the 291 (78%) parents contacted, only 13.9% had received the child delivered PeekSim image, 70.3% received the voice messages and 97.2% understood them.

INTERPRETATION

Spectacle wear was similar in both arms of the trial, one explanation being that health education for parents was not fully received. Health education messages to create behaviour change need to be targeted at the recipient and influencers in an appropriate, acceptable and accessible medium.

FUNDING

USAID (Childhood Blindness Programme), Seeing is Believing Innovation Fund and the Vision Impact Institute.

The Effect of Longer-Term and Exclusive Breastfeeding Promotion on Visual Outcome in Adolescence

Purpose

Breastfeeding may influence early visual development. We examined whether an intervention to promote increased duration and exclusivity of breastfeeding improves visual outcomes at 16 years of age.

Methods

Follow-up of a cluster-randomized trial in 31 Belarusian maternity hospitals/polyclinics randomized to receive a breastfeeding promotion intervention, or usual care, where 46% vs. 3% were exclusively breastfed at 3 months respectively. Low vision in either eye was defined as unaided logMAR vision of ≥0.3 or worse (equivalent to Snellen 20/40) and was used as the primary outcome. Open-field autorefraction in a subset (n = 963) suggested that 84% of those with low vision were myopic. Primary analysis was based on modified intention-to-treat, accounting for clustering within hospitals/clinics. Observational analyses also examined the effect of breastfeeding duration and exclusivity, as well as other sociodemographic and environmental determinants of low vision.

Results

A total of 13,392 of 17,046 (79%) participants were followed up at 16 years. Low vision prevalence was 19.6% (95% confidence interval [CI]: 17.5, 22.0%) in the experimental group versus 21.6% (19.5, 23.8%) in the control group. Cluster-adjusted odds ratio (OR) of low vision associated with the intervention was 0.92 (95% CI: 0.73, 1.16); 0.88 (95% CI: 0.74, 1.05) after adjustment for parental and early life factors. In observational analyses, breastfeeding duration and exclusivity had no significant effect on low vision. However, maternal age at birth (OR: 1.13, 95% CI: 1.07, 1.14/5-year increase) and urban versus rural residence were associated with increased risk of low vision. Lower parental education, number of older siblings was associated with a lower risk of low vision; boys had lower risk compared with girls (0.64, 95% CI: 0.59,0.70).

Conclusions

Exclusive breastfeeding promotion had no significant effect on visual outcomes in this study, but other environmental factors showed strong associations. (ClinicalTrials.gov number, NCT01561612.)

Traffic-related air pollution and spectacles use in schoolchildren

Purpose

To investigate the association between exposure to traffic-related air pollution and use of spectacles (as a surrogate measure for myopia) in schoolchildren.

Methods

We analyzed the impact of exposure to NO₂ and PM_2.5 light absorbance at home (predicted by land-use regression models) and exposure to NO₂ and black carbon (BC) at school (measured by monitoring campaigns) on the use of spectacles in a cohort of 2727 schoolchildren (7–10 years old) in Barcelona (2012–2015). We conducted cross-sectional analyses based on lifelong exposure to air pollution and prevalent cases of spectacles at baseline data collection campaign as well as longitudinal analyses based on incident cases of spectacles use and exposure to air pollution during the three-year period between the baseline and last data collection campaigns. Logistic regression models were developed to quantify the association between spectacles use and each of air pollutants adjusted for relevant covariates.

Results

An interquartile range increase in exposure to NO₂ and PM_2.5 absorbance at home was respectively associated with odds ratios (95% confidence intervals (CIs)) for spectacles use of 1.16 (1.03, 1.29) and 1.13 (0.99, 1.28) in cross-sectional analyses and 1.15 (1.00, 1.33) and 1.23 (1.03, 1.46) in longitudinal analyses. Similarly, odds ratio (95% CIs) of spectacles use associated with an interquartile range increase in exposures to NO₂ and black carbon at school was respectively 1.32 (1.09, 1.59) and 1.13 (0.97, 1.32) in cross-sectional analyses and 1.12 (0.84, 1.50) and 1.27 (1.03, 1.56) in longitudinal analyses. These findings were robust to a range of sensitivity analyses that we conducted.

Conclusion

We observed increased risk of spectacles use associated with exposure to traffic-related air pollution. These findings require further confirmation by future studies applying more refined outcome measures such as quantified visual acuity and separating different types of refractive errors.

Morphological and clinical characteristics of myopic posterior staphyloma in Caucasians

PURPOSE

We aimed to study the morphological characteristics of myopic posterior staphyloma in Caucasians and to evaluate the correlation between posterior staphyloma, myopic macular lesions and visual acuity.

METHODS

Ninety eyes of 67 consecutive patients affected by high myopia associated with posterior staphyloma were recruited between January 2012 and December 2013. Posterior staphyloma was classified according to Curtin's criteria. Every patient underwent fundoscopic examination and best corrected visual acuity measurement (BCVA). A and B-scan ultrasound (US), high-resolution, three-dimensional magnetic resonance image (MRI), optical coherence tomography (OCT), fundus autofluorescence (FAF), red free (RF) and color fundus photography studies were performed.

RESULTS

The mean age was 64.4 ± 9.48 years (range: 41-82). The mean BCVA was 0.7 ± 0.5 logMAR (range: 0-2). The mean axial length was 29.92 ± 2.39 millimeters (range: 24.25-36.53). The authors found four types of posterior staphyloma according to Curtin's classification: I, II, IV and IX. Significant prevalence of posterior staphyloma in female sex was observed (p = 0.0235). Significant correlation between the depth and the diameters of posterior staphyloma was demonstrated (p < 0.0001). Significant association between posterior staphyloma type and tomographic foveal patterns (p = 0.0230) was highlighted. Posterior staphyloma type I was more frequently associated with peripapillary atrophy and less with macular atrophy compared to type II and IX (p = 0.0169). The prevalence of macular atrophy was more than double in posterior staphyloma type II (33.3 %) in comparison to posterior staphyloma type I (12.5 %).

CONCLUSIONS

This study confirms that the type I and II are the most common types of posterior staphyloma, as already highlighted in the literature. A significant association between the type of posterior staphyloma and the MRI ocular shape pattern, the OCT patterns of macular profile and the location of chorioretinal atrophy was highlighted. The correlation between the depth and the width of posterior staphyloma has demonstrated that the deeper the staphyloma, the wider it was. The deepest area of the posterior staphyloma was characterized by a greater thinning of the sclera and by a higher prevalence of chorioretinal atrophy compared to the other parts of the eye. More studies are necessary to support our findings and to add more information on the natural evolution of posterior staphyloma and on its associated complications.

Global variations and time trends in the prevalence of childhood myopia, a systematic review and quantitative meta-analysis: implications for aetiology and early prevention

The aim of this review was to quantify the global variation in childhood myopia prevalence over time taking account of demographic and study design factors. A systematic review identified population-based surveys with estimates of childhood myopia prevalence published by February 2015. Multilevel binomial logistic regression of log odds of myopia was used to examine the association with age, gender, urban versus rural setting and survey year, among populations of different ethnic origins, adjusting for study design factors. 143 published articles (42 countries, 374 349 subjects aged 1–18 years, 74 847 myopia cases) were included. Increase in myopia prevalence with age varied by ethnicity. East Asians showed the highest prevalence, reaching 69% (95% credible intervals (CrI) 61% to 77%) at 15 years of age (86% among Singaporean-Chinese). Blacks in Africa had the lowest prevalence; 5.5% at 15 years (95% CrI 3% to 9%). Time trends in myopia prevalence over the last decade were small in whites, increased by 23% in East Asians, with a weaker increase among South Asians. Children from urban environments have 2.6 times the odds of myopia compared with those from rural environments. In whites and East Asians sex differences emerge at about 9 years of age; by late adolescence girls are twice as likely as boys to be myopic. Marked ethnic differences in age-specific prevalence of myopia exist. Rapid increases in myopia prevalence over time, particularly in East Asians, combined with a universally higher risk of myopia in urban settings, suggest that environmental factors play an important role in myopia development, which may offer scope for prevention.

Risk factors for myopia in a discordant monozygotic twin study

PURPOSE

Monozygotic (MZ) twin pairs discordant for disease allow careful examination of environmental factors whilst controlling for genetic variation. The purpose of this study was to examine differences in environmental risk factors in MZ twins discordant for myopia.

METHODS

Sixty four MZ twin pairs discordant for refractive error were interviewed. Discordant twins were selected from 1326 MZ twin pairs from the TwinsUK adult twin registry with non-cycloplegic autorefraction. Discordancy was defined as ≥ 2 Dioptres (D) difference in spherical equivalent (SphE) and discordant for class of refractive error. In a 35-item telephone questionnaire twins were separately asked (and scored) about the risk factors urban/rural residence, occupational status and highest educational level. They responded with more (1), less (-1) or the same (0) as their twin on time spent outside, playing outdoor sport, and on close work aged <16 and 16-25 years. The lower SphE twin's score was subtracted from the higher SphE twin's score, and mean values of the difference calculated for each variable.

RESULTS

Sixty four twin pairs were included (mean age 56, range 30-79 years; mean difference in refraction 3.35 D, S.D. 1.55 D, median difference 2.78 D). Within discordant MZ twin pairs, the more myopic twin was associated with having a higher occupational status (mean score between 16 and 25 years -0.11; 95% CI -0.19 to -0.04; mean score aged >25 years -0.23, 95% CI -0.28 to -0.17), being resident in urban area (mean score -0.26; 95% CI -0.33 to -0.18) and performing more close work (mean score <16 years -0.11; 95% CI -0.18 to -0.05; mean score aged 16-25 years -0.17, 95% CI -0.24 to -0.10) than their twin. The twins who spent more time outdoors (mean score <16 years 0.09; 95% CI 0.03-0.15; mean score aged 16-25 years 0.28, 95% CI 0.15-0.41) or performed more outdoors sports (mean score <16 years 0.13; 95% CI 0.04-0.21; mean score aged 16-25 years 0.23, 95% CI 0.10-0.36) were less likely to be myopic than their twin.

CONCLUSIONS

This study has confirmed known environmental risk factors for myopia. These data will allow selection of discordant twins for epigenetic analysis to advance knowledge of mechanisms of refractive error development.

Risk factors for and progression of myopia in young Taiwanese men

Abstract Purpose: To investigate the association between potential risk factors for myopia and its progression in young adult Taiwanese men.

METHODS

A survey of male military conscripts (aged 18-24 years) was conducted from February 2010 to March 2011 in Taiwan. Participants underwent comprehensive eye examinations, including measurements of axial length and corneal radius by optical biometry and non-cycloplegic autorefraction. Participants also provided self-reported progression of myopia and information regarding potential risk factors, including age, parental myopia, educational level, close work, outdoor activities, and urbanization.

RESULTS

Of 5145 eligible participants, 5048 (98.11%) provided refraction and questionnaire data; 2316 (45.88%) of the 5048 also had biometric measurements. The prevalence of myopia was 86.1% in this group, with a mean refractive error of -3.66 diopters (D). Of the 5048 participants, 1376 (27.3%) had experienced progression of their myopia during the past year. There were trends for a higher prevalence of myopia among older participants (p = 0.014), those with a history of parental myopia (p < 0.001), higher levels of education (p = 0.001), increased time spent reading (p < 0.001), less time outdoors (p = 0.003), and higher levels of urbanization (p = 0.010). However, only parental myopia, close work, and higher urbanization levels were significantly associated with self-reported progression of myopia.

CONCLUSION

Older age, parental myopia, higher educational level, close work, fewer outdoor activities, and higher urbanization level were associated with the prevalence of myopia in Taiwanese men.

An investigation into the validity of self-reported classification of refractive error

PURPOSE

To assess the validity of questionnaire use in the self-identification of refractive status.

METHODS

Two hundred and forty adults (21-60 years of age) presenting for a routine eye examination at various optometric practices in Northern Ireland were asked to complete one of two questionnaires. Both questionnaires used identical questions to ascertain age, gender, current spectacle use, age of first spectacle use and level of education. For the identification of refractive status, Questionnaire 1 used layman's terminology whilst Questionnaire 2 combined optometric terminology with descriptive explanations. Current refractive status was identified by the examining optometrist who did not see the completed questionnaire. The spherical equivalent refractive error of the non-cycloplegic subjective refraction was used to categorise myopia as <0D and hyperopia as ≥+1.00D. Astigmatism was defined according to two different criteria: ≥0.50DC and ≥1.00DC.

RESULTS

Questionnaire 1 had a sensitivity of 0.63 and a specificity of 0.90 for identifying myopia; a sensitivity of 0.58 and a specificity of 0.71 for identifying hyperopia; a sensitivity of 0.12 and a specificity of 0.98 for identifying astigmatism ≥0.50DC and a sensitivity of 0.19 and a specificity of 0.95 for identifying astigmatism ≥1.00DC. Questionnaire 2 had a sensitivity of 0.83 and a specificity of 0.93 for identifying myopia; a sensitivity of 0.45 and a specificity of 0.86 for identifying hyperopia; a sensitivity of 0.32 and a specificity of 0.88 for identifying astigmatism ≥0.50DC and a sensitivity of 0.50 and a specificity of 0.84 for identifying astigmatism ≥1.00DC. For both questionnaires, altering a positive self-identification of myopia to include only those who had worn spectacles prior to age 30 reduced the sensitivity and increased the specificity slightly.

CONCLUSIONS

Questionnaires are a valid tool in self-identification of myopic refractive status. However, they are not an effective way of identifying hyperopia and astigmatism and objective or subjective refraction remains the most appropriate method of identifying such individuals.

Age of myopia onset in a British population-based twin cohort

PURPOSE

School-age myopia is becoming more common in Asia and North America; data from the United Kingdom has suggested a significant amount of myopia develops after the age of 17 years. Age of spectacle wear has been used as a proxy of myopia severity in a recent large genome-wide association study. The purpose of this study was to examine the age of onset of spectacle wear in a large British twin cohort, to examine the reliability and reproducibility of self-reported age of onset as a proxy measure of myopia severity, and to see if there is evidence in the UK of a rising prevalence of myopia.

METHODS

Non-cycloplegic autorefraction was performed on over 6000 subjects from the Twins UK cohort, a large, well-characterized volunteer cohort of British, predominantly Caucasian female twins, between 1998 and 2010. Questionnaires asking age of first spectacle wear were conducted in 2003 and 2008. Myopia was defined as worse than or equal to -1.00 Dioptres, and adult onset myopia as occurring on or after the age of 17 years.

RESULTS

Autorefractive data was available on 6097 participants at a mean age of 53 years. The mean S.E. was -0.36 D (S.D. 2.67, range -25.13 to +9.38). 1705 subjects (28%) were myopic with a mean refractive error of -3.54 (S.D. 2.51, range -25.13 to -1.00) and the median age of first glasses wear was 15 years (mean 18.4 years, S.D. 12.24, range 0-74). Of those who provided an age at which they first wore glasses in both questionnaire sources (n = 628), there was median difference in response of 0 years (S.D. 7.18, mean 0.7, maximum 53). A statistically significant cohort effect for increased myopia prevalence across a range of age groups between 1998-1999 and 2008-2010 was identified, with myopia prevalence increasing from 27% to 34% in those aged 50-54 and from 16% to 32% in those aged 55-59.

CONCLUSIONS

Almost half the myopes in this UK-based population wore glasses after the age of 17; further research into adult-onset myopia is required. Although self-reported age of glasses is reproducible and reflects severity, it only explains approximately 15% of the variance of spherical equivalent, so is a rough proxy of refractive error, but still may be useful in large-scale population studies without access to refraction. We have demonstrated a significant cohort effect for increased myopia prevalence in the UK population over a 10-year period.

Uncorrected refractive error in older British adults: the EPIC-Norfolk Eye Study

AIM

To investigate the prevalence of, and demographic associations with, uncorrected refractive error (URE) in an older British population.

METHODS

Data from 4428 participants, aged 48-89 years, who attended an eye examination in the third health check of the European Prospective Investigation into Cancer-Norfolk study and had also undergone an ophthalmic examination were assessed. URE was defined as ≥1 line improvement of visual acuity with pinhole-correction in the better eye in participants with LogMar presenting visual acuity (PVA) <0.3 (PVA <6/12). Refractive error was measured using an autorefractor without cycloplegia. Myopia was defined as spherical equivalent ≤-0.5 dioptre, and hypermetropia ≥0.5 dioptre.

RESULTS

Adjusted to the 2010 midyear British population, the prevalence of URE in this Norfolk population was 1.9% (95% CI 0.6% to 3.1%). Lower self-rated distance vision was correlated with higher prevalence of URE (p(trend)<0.001). In a multivariate logistic regression model adjusting for age, gender, retirement status, educational level and social class, independent significant associations with URE were increasing age (p(trend)<0.001) and having hypermetropic or myopic refractive error. Wearing distance spectacles was inversely associated with URE (OR 0.34, 95% CI 0.21 to 0.55, p<0.001). There were 3063 people (69.2%) who wore spectacles/contact lenses for distance vision. Spectacle wear differed according to type of refractive error (p<0.001), and use rose with increasing severity of refractive error (p(trend)<0.001).

CONCLUSION

Although refractive error is common, the prevalence of URE was found to be low in this population reflecting a low prevalence of PVA<0.3.

Validity of noncycloplegic refraction in the assessment of refractive errors: the Tehran Eye Study

PURPOSE

To determine the sensitivity and specificity of noncycloplegic autorefraction for determining refractive status compared to cycloplegic autorefraction.

METHODS

The target population was noninstitutionalized citizens of all ages, residing in Tehran in 2002, selected through stratified cluster sampling. From 6497 eligible residents, 70.3% participated in the study, from August to November 2002. Here, we report data on 3501 people over the age of 5 years who had autorefraction with and without cycloplegia (two drops of cyclopentolate 1.0% 5 min apart, with autorefraction 25 min after the second drop).

RESULTS

Overall, the sensitivity of noncycloplegic autorefraction for myopia was 99%, but the specificity was only 80.4%. In contrast, the sensitivity for hyperopia was only 47.9%, but the specificity was 99.4%. At all ages, noncycloplegic autorefraction overestimated myopia and underestimated hyperopia. Overestimation of myopia was highest in the 21-30 and 31-40 year groups. Underestimation of hyperopia was high up to the age of 50 (20-40%), but decreased with age, to about 8% after the age of 50, down to almost 0% after 70. The difference in mean spherical equivalent with and without cycloplegia fell from 0.71 dioptres (D) in the 5-10 age group to 0.14D in those over 70.

CONCLUSION

Use of noncycloplegic autorefraction in epidemiological studies leads to considerable errors relative to cycloplegic measurements, except in those over 50-60. The difference between cycloplegic and noncycloplegic measurements varies with age and cycloplegic refractive category, and there is considerable individual variation, ruling out adjusting noncycloplegic measurements to obtain accurate cycloplegic refractions.

Myopia

Myopia has emerged as a major health issue in east Asia, because of its increasingly high prevalence in the past few decades (now 80-90% in school-leavers), and because of the sight-threatening pathologies associated with high myopia, which now affects 10-20% of those completing secondary schooling in this part of the world. Similar, but less marked, changes are occurring in other parts of the world. The higher prevalence of myopia in east Asian cities seems to be associated with increasing educational pressures, combined with life-style changes, which have reduced the time children spend outside. There are no reported major genes for school myopia, although there are several genes associated with high myopia. Any genetic contribution to ethnic differences may be small. However, to what extent many genes of small effect and gene-environment interactions contribute to variations in school myopia within populations remains to be established. There are promising optical and pharmacological interventions for preventing the development of myopia or slowing its progression, which require further validation, and promising vision-sparing treatments for pathological myopia.

Ethnic differences in the prevalence of myopia and ocular biometry in 10- and 11-year-old children: the Child Heart and Health Study in England (CHASE)

PURPOSE

Ethnic differences in childhood prevalence of myopia have not been well characterized in the United Kingdom. In this study, ethnic differences in refractive status and ocular biometry were examined in a multiethnic sample of British children.

METHODS

This was a cross-sectional study of 10- and 11-year-old school children of South Asian, black African Caribbean, and white European ethnic origin. Vision, open-field autorefraction (without cycloplegia), and ocular biometry were measured in each eye. Myopia was defined as spherical equivalent refraction of -0.50 D with unaided vision of 20/30 or worse (in one or both eyes). Ethnic differences in the prevalence of myopia were examined by using logistic regression, and multiple linear regression was used for ethnic differences in ocular biometry. All models were adjusted for age, sex, and clustering within school.

RESULTS

Data were available for 1179 children. The prevalence of myopia was 25.2%, 10.0%, and 3.4%, respectively, in the South Asian, black African Caribbean, and white European children. Adjusted odds ratios (ORs) of myopia compared with the white European children were 8.9 (95% confidence interval [CI] 4.0 to 19.4) in the South Asian and 3.2 (95% CI, 1.4 to 7.2) in black African Caribbean children. Ethnic differences in the prevalence of myopia were largely accounted for by ethnic differences in axial length. The South Asian and black African Caribbean children had longer axial lengths (0.44 mm; 95% CI, 0.30 to 0.57 mm and 0.30 mm; 95% CI, 0.16 to 0.44 mm, respectively).

CONCLUSIONS

Among British children exposed to the same schooling environment, the South Asians had the highest prevalence of myopia, followed by the black African Caribbeans compared with the white Europeans. A quarter of British South Asian children were myopic, which is strongly related to increased axial length.

Correctable and non-correctable visual impairment among young males: a 12-year prevalence study of the Military Service in Poland

PURPOSE

To evaluate the prevalence of correctable and non-correctable visual impairment in a representative sample of young males commissioned for Military Service in Poland.

MATERIAL AND METHODS

Data concerning vision status was retrospectively reviewed in 969 subjects of European Caucasian origin, most of whom live and have lived in Poland. They were selected from the original database comprising 105017 subjects examined in the period 1993-2004. Based on the age of subjects they were divided into two groups; group I aged 18-24 and group II aged 25-34 years. Visual impairment was defined as distance visual acuity of <20/40 in one or both eyes. Non-correctable impairment was defined as that which was not eliminated by refractive correction.

RESULTS

A total of 1938 eyes of 969 white males were examined. There was statistically significant association between rates of visual impairment and increasing age (p < 0.001). Visual impairment was found in 128 (13.2%) subjects in at least one eye. Non-correctable visual impairment was found in 12 (1.2%) subjects. Amblyopia was the main cause, accounting for eight cases (66.67%). Correctable visual impairment was found in the remaining 116 (12.0%) patients. Among them myopia was the most common refractive error and accounted for 75.8%. Differences between age-specific rates of refractive errors were statistically significant (p = 0.003).

CONCLUSIONS

Appropriate refractive correction improves visual acuity in most subjects presenting with visual impairment. There was a relatively low prevalence of non-correctable visual impairment in a population of young adults in Poland, and this was mainly due to amblyopia.

Two-year multicenter, randomized, double-masked, placebo-controlled, parallel safety and efficacy study of 2% pirenzepine ophthalmic gel in children with myopia

PURPOSE

To evaluate if the safety and efficacy of the relatively selective M1-antagonist, pirenzepine, in slowing the progression of myopia in children is sustained over a 2-year period.

METHODS

This was a multicenter, parallel-group, placebo-controlled, double-masked, randomized clinical trial. Enrolled were children aged 8 to 12 years, with entry spherical equivalent refractive error of -0.75 to -4.00 D and astigmatism </=1.00 D. Patients were randomized in a 2:1 ratio to receive 2% pirenzepine ophthalmic gel or a placebo control (vehicle), twice daily to each eye. The main outcome measure was spherical equivalent refractive error via cycloplegic autorefraction.

RESULTS

At study entry, spherical equivalent was -2.10 +/- 0.90 D (mean +/- SD) for the pirenzepine group (n = 117) and -1.93 +/- 0.83 D for the placebo group (n = 57; p = 0.22). At 1 year, there was a mean increase in myopia of 0.26 D in the pirenzepine group versus 0.53 D in the placebo group (p < 0.001). Eighty-four patients elected to continue for a second year (pirenzepine = 53, placebo = 31). At 2 years, the mean increase in myopia was 0.58 D for the pirenzepine group and 0.99 D for the placebo group (p = 0.008). Thirteen (11%) pirenzepine patients dropped out due to adverse effects in the first year, and 1 did so in the second year.

CONCLUSIONS

Pirenzepine ophthalmic gel 2% was effective compared with placebo in slowing the progression of myopia over a 2-year treatment period and demonstrated a clinically acceptable safety profile.

Effect of breastfeeding and sociodemographic factors on visual outcome in childhood and adolescence

BACKGROUND

It has been suggested that early life factors, including breastfeeding and birth weight, program childhood myopia.

OBJECTIVE

We examined the relation of reduced unaided vision (indicative of myopia) in childhood and adolescence with infant feeding, parental education, maternal age at birth, birth weight, sex, birth order, and socioeconomic status.

DESIGN

Three British cohorts recruited infants born in 1946 (n = 5362), 1958 (n = 18,558), and 1970 (n = 16,567). Adjusted odds ratios (ORs) for unaided vision of 6/12 or worse at ages 10-11 and 15-16 y from each cohort were pooled by using fixed-effects meta-analyses.

RESULTS

The prevalence of reduced vision ranged from 4.4% to 6.5% at 10-11 y and from 9.4% to 11.4% at 16 y, with marginally higher levels in later cohorts. Breastfeeding declined across successive cohorts (65%, 43%, and 22% in those breastfed for >1 mo, respectively). Pooled ORs showed no associations between infant feeding and vision after adjustment at either age. Parental education (OR: 1.48, high versus low education; 95% CI: 1.23, 1.79), maternal age (OR: 1.10, per 5-y increase; 95% CI: 1.04, 1.17), birth weight (OR: 0.85, per 1-kg rise; 95% CI: 0.76, 0.95), number of older siblings (OR: 0.89, per older sibling; 95% CI: 0.83, 0.94), and sex (OR: 1.10, girls versus boys; 95% CI: 0.98, 1.23) were related to adverse visual outcome in childhood. Stronger associations were observed in adolescence, except that the association with birth weight was null.

CONCLUSIONS

Infant feeding does not appear to influence visual development. Consistent associations of reduced vision with parental education, sex, maternal age, and birth order suggest that other environmental factors are important for visual development and myopia in early life.