Incidence of myopia in Swedish schoolchildren: A longitudinal study.

PURPOSE: The prevalence of myopia in Scandinavia tends to be lower than in other parts of the world. This study aimed to investigate the incidence of myopia and its predictors in Swedish children to characterise this trend. METHODS: A 2-year longitudinal study was conducted following a cohort of schoolchildren aged 8-16 years. Myopia was defined as a spherical equivalent refraction (SER) ≤ -0.50 D. The study enrolled 128 participants, 70 (55%) females with a mean age of 12.0 years (SD = 2.4). RESULTS: The cumulative incidence of myopia during the follow-up period was 5.5%, and the incidence rate of myopia was 3.2 cases per 100 person-years. Participants with myopia at baseline exhibited a faster increase in refractive error during the follow-up period. Likewise, participants with two myopic parents exhibited a more marked change towards myopia, regardless of their initial refractive error. CONCLUSION: In the current study, similar to prevalence, the incidence of myopia was low when compared with other parts of the world. These results lead us to formulate a new hypothesis that the normal emmetropisation process may be protected by low educational pressure practised in Sweden during early childhood. Further research is necessary to test this new hypothesis.

Axial length changes in progressive and non-progressive myopic children in China.

PURPOSE: Due to pubertal development and crystalline lens compensation, axial length (AL) continues to increase among non-progressive myopic children (absolute annual spherical equivalent (SE) progression less than 0.25 diopter), but the amount is unknown. This study was to investigate the cutoff of AL change to accurately differentiate between progressive and non-progressive myopes. METHODS: A total of 8,546 myopic and treatment-naive children aged 6-10 years were enrolled from two cohort studies. AL with optical biometer and cycloplegic SE with auto refraction were evaluated at baseline and annually. Annual AL change was calculated, and the percentiles of annual axial elongation among progressive and non-progressive myopes were estimated by quantile regression with restricted cubic spline. Area under receiver-operating characteristic (ROC) curve (AUROC), positive predictive value (PPV), and negative predictive value (NPV) were applied to evaluate the accuracy of predicting progressive and non-progressive myopes. RESULTS: Among 8,546 myopic children, 603 (7.06%) were non-progressive myopes. Annual AL changes among non-progressive myopes remained stable with the median annual change being 0.25 mm, while the median for progressive myopes decreased with age from 0.58 to 0.42 mm. AUROC for distinguishing between non-progressive and progressive myopes was 0.88 and was > 0.85 for each age group. Annual AL change, the cutoff of 0.20 mm/year, had significantly high PPV and NPV in predicting progressive myopes with high proportion of progressive myopes and non-progressive myopes with low proportions of progressive myopes. CONCLUSION: Myopic children with non-progressive status had markedly less axial elongation than progressive ones. AL changes with cutoff of 0.20 mm/year could differentiate between non-progressive and progressive status and may be an alternative for evaluating progressive status.

Time outdoors positively associates with academic performance: a school-based study with objective monitoring of outdoor time.

BACKGROUND: To explore the relationship between outdoor time and academic performance among school-aged children. METHODS: This study was designed as a cross-sectional study. Data were derived from a school-based prospective children myopia intervention study (STORM). Outdoor time was recorded by self-developed algorithm-validated wristwatches in real-time and calculated as the cumulative average of 10 months. The academic performance was recorded and provided by the participating schools and further standardized. Other information was collected using an online standardized questionnaire. Mixed-effects model and B-Spline method were used to investigate the association between time spent on different types of daily activity, including outdoor activity and academic performance. RESULTS: A total of 3291 children with mean age 9.25 years were included in the final analysis. Overall, outdoor time was associated with academic performance in a non-linear manner; specifically, not exceeding 2.3 h per day, outdoor time was positively associated with academic performance; exceeding 2.3 h per day, this association became non-significant. Likewise, daily sleep duration and out-of-school learning time were associated with academic performance in a non-linear manner, resulting in turning points of 11.3 and 1.4 h per day, respectively. Separate analysis showed that outdoor time and sleep duration but not out-of-school learning time were positively associated with academic performance in Chinese, mathematics and English. CONCLUSION: Outdoor time, sleep duration and out-of-school learning time were associated with academic performance in a non-linear manner. Promotion of outdoor time may not negatively impact on academic performance. TRIAL REGISTRATION: Our study was registered in ClinicalTrials.gov (Identifier: NCT02980445).

Myopia Progression in Adults: A Retrospective Analysis.

SIGNIFICANCE: Studies on adult myopia progression are limited. This retrospective analysis of a large data set of young adult myopes characterizes myopia progression during adulthood. PURPOSE: This study aimed to determine the mean annual progression of myopia and to estimate the proportion of progressors in adult myopes. METHODS: Longitudinal, noncycloplegic subjective refraction data for young adult myopes (spherical equivalent refractive error, -0.5 D or more), age ranging from 18 to 30 years, were 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 -0.25 D or more), was estimated. RESULTS: A total of 354 myopes (230 females [64.7%]), with a mean (standard deviation) age of 22.2 (3.8) years, were considered. The mean (standard deviation) annualized progression was -0.10 (0.21), -0.08 (0.2), and -0.04 (0.21) D in the 18- to 21-year, 22- to 26-year, and 27- to 30-year age groups, respectively ( P = .003). The difference between 18- to 21- and 27- to 30-year age groups was significant ( P = .05), whereas all other pairwise comparisons were not significant. The proportion (95% confidence interval) of progressors in the 18- to 21-, >21- to 26-, and >26- to 30-year age groups was 18.3% (14.9 to 21.7%), 10.9% (7.1 to 14.7%), and 8.8% (4.4 to 13.1%), respectively. The proportion of progressors working or studying in a higher learning/academic environment was 16.2% with an odds ratio (95% confidence interval) for progression of 2.07 (1.15 to 3.74) compared with those in nonacademic environments ( P = .02), with no significant effect of sex 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. Although 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.

Association between Global Myopia Prevalence and International Levels of Education.

SIGNIFICANCE: The Global Myopia Prevalence and International Levels of Education study models national trends in educational performance with myopia prevalence in children; it examines the association of near work with myopia in the form of an ecologic analysis and also discusses how this may relate to educational frameworks. PURPOSE: This study aimed to investigate the relationship between myopia prevalence and national educational performance. METHODS: The prevalence of myopia in the 15- to 19-year age group in 35 regions was obtained from a meta-analysis by Holden et al. (Ophthalmology 2016;123:1036-1042) and matched with educational performance quantified by the Organisation for Economic Cooperation and Development Programme for International Student Assessment (PISA) testing from 2000 to 2018. A generalized estimating equation was used to describe the relationship between PISA scores and myopia prevalence. Clustering effects of country and chronological year were accounted for in the analysis. Linear and nonlinear terms of PISA scores using lines of best fit were further explored. RESULTS: There is a significant positive relationship between Organisation for Economic Cooperation and Development PISA educational performance and myopia prevalence in teenagers with higher PISA scores correlating with higher myopia prevalence, even after accounting for chronological year (generalized estimating equation model: P = .001, .008, and .005 for math, science, and reading, respectively). Scatterplots with cubic and logistic fits indicated that PISA math showed the strongest relationship with myopia prevalence ( r2 = 0.64), followed by science ( r2 = 0.41) and reading ( r2 = 0.31). CONCLUSIONS: These results strongly suggest that educational achievement at a national level is associated with higher myopia prevalence. Programme for International Student Assessment scores are a significant driver of many countries' education policies, and countries that have a balance between high PISA scores and lower myopia prevalence may be good models of educational policies to address the myopia public health issue.

Comparing children's, teenagers' and young adults' subjective responses to myopia control contact lenses.

INTRODUCTION: Myopia control (MC) studies in children link efficacy with subjective performance. There is little MC research in teenagers and young adults. This study compared subjective experience of MC contact lenses in different age groups. METHODS: Data were retrospectively reviewed from two double-masked, bilateral wear, crossover contact lens clinical trials (myopia -0.75D to -3.50D and <1.00 DC; 9-35 years). Participants wore two novel lenses (MC lenses with relative peripheral plus [+1.50D and +2.50D]) and a single-vision (SV) control lens (Clariti® 1 day) for 1 week each. All lenses were made from Somofilcon A material. Data collected included visual acuity (VA), wearing time, subjective ratings of comfort, distance and near vision clarity and overall vision. Generalised estimating equations with subject random intercepts and identity link functions were used in the analysis. RESULTS: A total of 31 participants (10 children, 11 teenagers and 10 adults) were included, with no difference between the age groups for VA with the dispensed lenses (p > 0.05). All groups could discriminate between the SV and MC lenses for vision (distance, near and overall) after 1 week (p < 0.05). There was no difference between groups for comfort or distance and near vision. Children rated the overall vision quality higher than teenagers and adults for both SV and MC lenses (p < 0.05), but there was no difference relative to the SV lens between groups (p > 0.50). Daily wear time was lowest for children for all lens types (all p < 0.02). Wear time was positively associated with ratings of overall vision quality for children and young adults (both p < 0.05). CONCLUSION: All age groups rated SV lenses higher than MC lenses. Subjective ratings of MC lenses appear similar between age groups relative to SV lenses. Wear time was lowest in children and was correlated with overall vision quality ratings in children and young adults.

Normative data for axial elongation in Asian children.

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.

Time Outdoors in Reducing Myopia: A School-Based Cluster Randomized Trial with Objective Monitoring of Outdoor Time and Light Intensity.

PURPOSE: To evaluate the efficacy of time outdoors per school day over 2 years on myopia onset and shift. DESIGN: A prospective, cluster-randomized, examiner-masked, 3-arm trial. PARTICIPANTS: A total of 6295 students aged 6 to 9 years from 24 primary schools in Shanghai, China, stratified and randomized by school in a 1:1:1 ratio to control (n = 2037), test I (n = 2329), or test II (n = 1929) group. METHODS: An additional 40 or 80 minutes of outdoor time was allocated to each school day for test I and II groups. Children in the control group continued their habitual outdoor time. Objective monitoring of outdoor and indoor time and light intensity each day was measured with a wrist-worn wearable during the second-year follow-up. MAIN OUTCOME MEASURES: The 2-year cumulative incidence of myopia (defined as cycloplegic spherical equivalent [SE] of ≤-0.5 diopters [D] in the right eye) among the students without myopia at baseline and changes in SE and axial length (AL) after 2 years. RESULTS: The unadjusted 2-year cumulative incidence of myopia was 24.9%, 20.6%, and 23.8% for control, test I, and II groups, respectively. The adjusted incidence decreased by 16% (incidence risk ratio [IRR], 0.84; 95% confidence interval [CI], 0.72-0.99; P = 0.035) in test I and 11% (IRR = 0.89; 95% CI, 0.79-0.99; P = 0.041) in test II when compared with the control group. The test groups showed less myopic shift and axial elongation compared with the control group (test I: -0.84 D and 0.55 mm, test II: -0.91 D and 0.57 mm, control: -1.04 D and 0.65 mm). There was no significant difference in the adjusted incidence of myopia and myopic shift between the 2 test groups. The test groups had similar outdoor time and light intensity (test I: 127 ± 30 minutes/day and 3557 ± 970 lux/minute; test II: 127 ± 26 minutes/day and 3662 ± 803 lux/minute) but significantly more outdoor time and higher light intensity compared with the control group (106 ± 27 minutes/day and 2984 ± 806 lux/minute). Daily outdoor time of 120 to 150 minutes at 5000 lux/minutes or cumulative outdoor light intensity of 600 000 to 750 000 lux significantly reduced the IRR by 15%～ 24%. CONCLUSIONS: Increasing outdoor time reduced the risk of myopia onset and myopic shifts, especially in nonmyopic children. The protective effect of outdoor time was related to the duration of exposure and light intensity. The dose-response effect between test I and test II was not observed probably because of insufficient outdoor time achieved in the test groups, which suggests that proper monitoring on the compliance on outdoor intervention is critical if one wants to see the protective effect.

Efficacy of contact lenses for myopia control: Insights from a randomised, contralateral study design.

PURPOSE: To determine the efficacy of two myopia control contact lenses (CL) compared with a single-vision (SV) CL. METHODS: Ninety-five Chinese children with myopia, aged 7-13 years in a 1-year prospective, randomised, contralateral, cross-over clinical trial with 3 groups; bilateral SVCL (Group I); randomised, contralateral wear of an extended depth of focus (EDOF) CL and SVCL (Group II) and MiSight® CL and SVCL (Group III). In Groups II and III, CL were crossed over at the 6-month point (Stage 1) and worn for a further 6 months (Stage 2). Group I wore SVCL during both stages. At baseline and the end of each stage, cycloplegic spherical equivalent refractive error (SE) and axial length (AL) were measured. Six-monthly ΔSE/ΔAL across groups was analysed using a linear mixed model (CL type, stage, eye and eye* stage included as factors). Intra-group paired differences between eyes were determined. RESULTS: In Group I, mean (SD) ΔSE/ΔAL with SVCL was -0.41 (0.28) D/0.13 (0.09) mm and -0.25 (0.27) D/0.16 (0.09) mm for stages 1 and 2, with a mean paired difference between eyes of 0.01 D/0.01 mm and 0.05 D/-0.01 mm, respectively. ΔSE/ΔAL with SVCL was similar across Groups I to III (Stage 1: p = 0.89/0.44, Stage 2: p = 0.70/ 0.64). In Groups II and III, ΔSE/ΔAL was lower with the EDOF and MiSight® CL than the contralateral SVCL in 68% to 94% of participants, and adjusted 6-month ΔSE/ΔAL with EDOF was similar to MiSight® (p = 0.49/0.56 for ΔSE/ΔAL, respectively). Discontinuations across the three groups were high, but not different between the groups (33.3%, 48.4% and 50% for Groups I to III, respectively [p = 0.19]) and most discontinuations occurred immediately after baseline. CONCLUSIONS: Extended depth of focus and MiSight® CL demonstrated similar efficacy in slowing myopia. When switched from a myopia control CL to SVCL, myopia progression was similar to that observed with age-matched wearers in SVCL and not suggestive of rebound.

Is myopia prevalence related to outdoor green space?

PURPOSE: Rapid urbanisation and lifestyle changes have been associated with a huge increase in myopia across many parts of the world. There is strong evidence that environmental factors including time outdoors and urbanisation can influence the development of myopia, particularly in school-aged children. The aim of this study is to determine whether there is a relationship between the prevalence of myopia and the amount of vegetation/green spaces across different regions of the world, as a risk factor for myopia development. METHODS: The prevalence of myopia in the 15 to 19-year age group in Australia, Brazil, China, Finland, India, Iran, Japan, Oman, Singapore, South Africa and the UK was obtained from a meta-analysis by Holden et al. Normalised Difference Vegetation Index (NDVI) was used to quantify green space exposure based on Landsat 7 Enhanced Thematic Mapper Plus (ETM+) satellite data. Green space was measured in locations specific to 15 studies that reported myopia prevalence. Simple linear regression was used to analyse yearly data, and a mixed effects model was applied to assess the significance of green space when study was a random effect. RESULTS: Myopia prevalence increases significantly when green space was <-0.2, but the effect was less apparent for values >-0.1. When a mixed effects model was used, the effect of green space was found to be significantly associated with myopia prevalence (p = 0.05). CONCLUSIONS: There was evidence of a weak but significant non-linear relationship between myopia and green space, with the effect most apparent at low levels of green space. A larger data sample, along with further investigations into the utilisation of green spaces, are required to understand whether increasing the amount of green space can reduce myopia incidence and progression impact.

The Relationship Between Vision and Comfort in Contact Lens Wear.

OBJECTIVE: Understand relationship between vision and comfort in contact lens (CL) wear. METHODS: Retrospective analysis of five trials using similar protocols with nonpresbyopic (NP) myopes or presbyopic participants (Px) wearing various simultaneous-image designs (SM) and single-vision (SV) CL (NP only). Questionnaires (vision satisfaction, vision clarity: distance/intermediate/near, comfort) on 1 to 10 scale were administered 1 week after fitting. Vision/comfort relationship was analyzed using linear mixed model and presented as regression coefficient with 95% confidence intervals (CIs). RESULTS: Vision ratings correlated with comfort ratings, although this varied depending on type of vision rating and Px category. Vision satisfaction influenced comfort for the NP-SV group (slope: 0.8; 95% CI: 0.58-1.01, P≤0.001), but was significantly lower in the presbyopic group (slope: 0.38; 95% CI: 0.33-0.42; P≤0.001). Controlling for lens material obtained similar results. In the reverse relationship, comfort had a significant impact on vision satisfaction, although again at varying levels for each Px group. NP-SV demonstrated the weakest relationship (slope: 0.47; 95% CI: 0.35-0.59, P≤0.001) in comparison to NP-SM and P-SM groups. CONCLUSION: Vision and comfort in CL wear are inter-related. Consideration of Px characteristics, visual stimulus, and CL comfort needs to be accounted for when assessing overall CL experience.

The risk of vision loss in contact lens wear and following LASIK.

PURPOSE: To compare the risk of vision loss following contemporary laser-assisted in situ keratomileusis (LASIK) with different types and modality of use of contact lenses. METHODS: Data from a previously published study were used to derive the incidence of vision loss (≥ 2 line loss of best corrected spectacle acuity) following microbial keratitis for different contact lens types and wearing modality, stratified by duration of lens wear. A literature search on vision loss following LASIK was performed between 2003 and 2019. The prevalence of vision loss at six months post-surgery was captured from clinical trials published after 2003. A proportion meta-analysis was applied to derive the prevalence of vision loss following LASIK. A least-squares fitting of cumulative vision loss (P, /10 000 wearers) over time (t, years) using an exponential model estimated the years of contact lens wear to which the risk of vision loss with LASIK was equivalent. RESULTS: Vision loss following LASIK occurred in 66 (95% confidence interval [CI] 34-108) per 10 000 wearers. As a conservative estimate based on the lower confidence interval of the estimated equivalent years of contact lens wear, daily wear contact lenses and extended overnight silicone wear hydrogel contact lens need to be worn for 103 (95% [CI] 103-391) and 25 (95% [CI] 25-79) years respectively, to equal the rate of vision loss equivalent to a one-off LASIK procedure. CONCLUSIONS: The risk of vision loss to the individual is low with either contact lens wear or refractive surgery. Contact lens wear does not pose a higher risk of vision loss than LASIK surgery for the most common wear modalities.

Potential Lost Productivity Resulting from the Global Burden of Myopia: Systematic Review, Meta-analysis, and Modeling.

PURPOSE: We estimated the potential global economic productivity loss resulting from vision impairment (VI) and blindness as a result of uncorrected myopia and myopic macular degeneration (MMD) in 2015. CLINICAL RELEVANCE: Understanding the economic burden of VI associated with myopia is critical to addressing myopia as an increasingly prevalent public health problem. METHODS: We estimated the number of people with myopia and MMD corresponding to critical visual acuity thresholds. Spectacle correction coverage was analyzed against country-level variables from the year of data collection; variation in spectacle correction was described best by a model based on a human development index, with adjustments for urbanization and age. Spectacle correction and myopia data were combined to estimate the number of people with each level of VI resulting from uncorrected myopia. We then applied disability weights, labor force participation rates, employment rates, and gross domestic product per capita to estimate the potential productivity lost among individuals with each level and type of VI resulting from myopia in 2015 in United States dollars (US$). An estimate of care-associated productivity loss also was included. RESULTS: People with myopia are less likely to have adequate optical correction if they are older and live in a rural area of a less developed country. The global potential productivity loss associated with the burden of VI in 2015 was estimated at US$244 billion (95% confidence interval [CI], US$49 billion-US$697 billion) from uncorrected myopia and US$6 billion (95% CI, US$2 billion-US$17 billion) from MMD. Our estimates suggest that the Southeast Asia, South Asia, and East Asia Global Burden of Disease regions bear the greatest potential burden as a proportion of their economic activity, whereas East Asia bears the greatest potential burden in absolute terms. CONCLUSIONS: Even under conservative assumptions, the potential productivity loss associated with VI and blindness resulting from uncorrected myopia is substantially greater than the cost of correcting myopia.

Prevalence of Refractive Error, Presbyopia, and Spectacle Coverage in Bogotá, Colombia: A Rapid Assessment of Refractive Error.

SIGNIFICANCE: Uncorrected refractive error is the leading cause of visual impairment; therefore, reducing its prevalence is important worldwide. For two decades, there has not been a comprehensive assessment of refractive error in Latin America. PURPOSE: The purpose of this study was to determine the current prevalence of refractive error, presbyopia, spectacle coverage, barriers to uptake refractive services, and spectacle correction in people 15 years and older in Bogotá, Colombia. METHODS: A cross-sectional community-based survey was conducted using 50 randomly selected clusters from 10 districts of Bogotá reflecting the socioeconomic status of the city. Respondents 15 years and older were interviewed and underwent standardized clinical eye examinations. Prevalence of uncorrected refractive error, spectacle coverage, and visual impairment were standardized to 2015 age-sex population distribution of Bogotá and further analyzed. RESULTS: A total of 2886 subjects (90% of 3206 eligible subjects) participated in the study; 39.1% were male and 60.9% were female in the age range of 15 to 96 years, with a median age of 46 years (interquartile range, 45 to 54 years). Age- and sex-standardized prevalence of visual impairment was 19.3% (95% confidence interval [CI], 17.8 to 20.8%). Prevalence of uncorrected refractive error was 12.5% (95% CI, 11.3 to 13.7%). Prevalence of presbyopia among participants 35 years and older was 55.2% (95% CI, 52.9 to 57.4%). Spectacle coverage was 50.9% for distance vision, and it was 33.9% for presbyopia. Main barrier to spectacle uptake was a limitation in affording spectacles because of economic factors (29.5%). CONCLUSIONS: This study provides a current estimate of refractive error using the Rapid Assessment of Refractive Error for Colombia and the Latin American region. The prevalence of uncorrected refractive error and presbyopia was high, and the barriers to spectacle uptake were higher in the lowest socioeconomic strata. The results obtained in the present study will help in making evidence-based decisions related to eye care service delivery in Colombia.

Myopia control with novel central and peripheral plus contact lenses and extended depth of focus contact lenses: 2 year results from a randomised clinical trial.

PURPOSE: We aimed to determine myopia control efficacy with novel contact lenses (CL) that (1) reduced both central and peripheral defocus, and (2) provided extended depth of focus with better global retinal image quality for points on, and anterior to, the retina and degraded for points posterior to the retina. METHODS: Children (n = 508, 8-13 years) with cycloplegic spherical equivalent (SE) -0.75 to -3.50D were enrolled in a prospective, double blind trial and randomised to one of five groups: (1) single vision, silicone hydrogel (SH) CL; (2) two groups wearing SH CL that imposed myopic defocus across peripheral and central retina (test CL I and II; +1.00D centrally and +2.50 and +1.50 for CL I and II at 3 mm semi-chord respectively); and (3) two groups wearing extended depth of focus (EDOF) hydrogel CL incorporating higher order aberrations to modulate retinal image quality (test CL III and IV; extended depth of focus of up to +1.75D and +2.50D respectively). Cycloplegic autorefraction and axial length (AL) measurements were conducted at six monthly intervals. Compliance to lens wear was assessed with a diary and collected at each visit. Additionally, subjective responses to various aspects of lens wear were assessed. The trial commenced in February 2014 and was terminated in January 2017 due to site closure. Myopia progression over time between groups was compared using linear mixed models and where needed post hoc analysis with Bonferroni corrections conducted. RESULTS: Myopia progressed with control CL -1.12 ± 0.51D/0.58 ± 0.27 mm for SE/AL at 24 months. In comparison, all test CL had reduced progression with SE/AL ranging from -0.78D to -0.87D/0.41-0.46 mm at 24 months (AL: p < 0.05 for all test CL; SE p < 0.05 for test CL III and IV) and represented a reduction in axial length elongation of about 22% to 32% and reduction in spherical equivalent of 24% to 32%. With test CL, a greater slowing ranging from 26% to 43% was observed in compliant wearers (≥6 days per week; Control CL: -0.64D/0.30 mm and -1.14D/0.58 mm vs test CL: -0.42D to -0.47D/0.12-0.18 mm and -0.70 to -0.81D/0.19-0.25 mm at 12 and 24 months respectively). CONCLUSIONS: Contact lenses that either imposed myopic defocus at the retina or modulated retinal image quality resulted in a slower progression of myopia with greater efficacy seen in compliant wearers. Importantly, there was no difference in the myopia control provided by either of these strategies.

Shanghai Time Outside to Reduce Myopia trial: design and baseline data.

IMPORTANCE: Myopia is a major public health concern worldwide, while outdoor time is indicated to be protective against the onset of myopia. BACKGROUND: To describe the methodology and baseline data of the Shanghai Time Outside to Reduce Myopia (STORM) trial. DESIGN: A 2-year, school-based, prospective, cluster randomized trial. PARTICIPANTS: Children from grade I and II classes of 24 schools from eight districts in Shanghai, China, were randomized to either a control group, a test group I (40-min outdoor time/day) or test group II (80-min outdoor time/day). METHODS: At baseline and annual intervals, cycloplegic autorefraction and axial length measurement will be performed. Time outdoors and light exposure will be monitored via parent/carer questionnaires and a wearable device. MAIN OUTCOME MEASURES: Spherical equivalent, prevalence of myopia and time outdoors in each group. RESULTS: A total of 6295 eligible children (age 7.2 ± 0.7 y [6-9 y]) were randomized to control (n = 2037), test group I (n = 2329) and test group II (n = 1929). At baseline, spherical equivalent was +0.98 ± 1.02D, +1.02 ± 1.02D and +1.00 ± 0.99D (P = 0.708), myopia prevalence was 8.9, 7.7 and 7.8% (P = 0.270) and time outdoors was 58.5 ± 35.8, 59.8 ± 34.7 and 58.5 ± 35.3 min/d (P = 0.886) for control, test groups I and II, respectively. CONCLUSIONS AND RELEVANCE: Myopia prevalence was high at nearly 8 to 9% in school children aged 7 years in Shanghai, China. The current trial will help evaluate if increased time outdoors has a role to play in reducing the incidence of myopia and/or slow the progression of myopia.

Effect of school eye health promotion on children's eye health literacy in Vietnam.

Health promotion intervention in schools is a useful strategy to improve students' health awareness. The purpose of this study was to assess the effect of eye health promotion interventions on eye health literacy in school children in Vietnam. A piloted questionnaire was administered to 300 children from five secondary schools in Ba Ria-Vung Tau, Vietnam at baseline and re-administered after the eye health promotion interventions. McNemar chi-square and logistic regression were used for statistical analysis. A total of 300 children aged 12-15 years (mean, 13.3 ± 1.3 years; 60% female) participated in the baseline survey. The participation rate in the post-health promotion survey was 94.7%. After the health promotion interventions, number of children who had correct eye health knowledge increased by 10-20% (60-75% to 70-95%), more children reported having had an eye examination (63.3% to 84.7%; p < 0.001) and more reported wearing spectacles (36.1% to 43.4%; p = 0.04). Children in urban schools were twice as likely to have improved knowledge of vision loss compared with children in rural schools (odds ratio, 2.1-4.1; p = 0.01 to p < 0.001). Children from rural schools had significantly higher odds of visiting doctor after the eye problems worsened (odds ratio, 4.5; p < 0.001). These results imply that eye health promotion interventions significantly improve eye health knowledge, attitudes and practices of school children. Additionally, participation of parents and teachers as change agents may further improve children's health literacy.

Global Prevalence of Presbyopia and Vision Impairment from Uncorrected Presbyopia: Systematic Review, Meta-analysis, and Modelling.

TOPIC: Presbyopia prevalence and spectacle-correction coverage were estimated by systematic review and meta-analysis of epidemiologic evidence, then modeled to expand to country, region, and global estimates. CLINICAL RELEVANCE: Understanding presbyopia epidemiologic factors and correction coverage is critical to overcoming the burden of vision impairment (VI) from uncorrected presbyopia. METHODS: We performed systematic reviews of presbyopia prevalence and spectacle-correction coverage. Accepted presbyopia prevalence data were gathered into 5-year age groups from 0 to 90 years or older and meta-analyzed within World Health Organization global burden of disease regions. We developed a model based on amplitude of accommodation adjusted for myopia rates to match the regionally meta-analyzed presbyopia prevalence. Presbyopia spectacle-correction coverage was analyzed against country-level variables from the year of data collection; variation in correction coverage was described best by a model based on the Human Development Index, Gini coefficient, and health expenditure, with adjustments for age and urbanization. We used the models to estimate presbyopia prevalence and spectacle-correction coverage in each age group in urban and rural areas of every country in the world, and combined with population data to estimate the number of people with near VI. RESULTS: We estimate there were 1.8 billion people (prevalence, 25%; 95% confidence interval [CI], 1.7-2.0 billion [23%-27%]) globally with presbyopia in 2015, 826 million (95% CI, 686-960 million) of whom had near VI because they had no, or inadequate, vision correction. Global unmet need for presbyopia correction in 2015 is estimated to be 45% (95% CI, 41%-49%). People with presbyopia are more likely to have adequate optical correction if they live in an urban area of a more developed country with higher health expenditure and lower inequality. CONCLUSIONS: There is a significant burden of VI from uncorrected presbyopia, with the greatest burden in rural areas of low-resource countries.

Subjective Ratings and Satisfaction in Contact Lens Wear.

SIGNIFICANCE: This study shows satisfaction in contact lens (CL) wear is influenced by both comfort and vision. Eighty-six percent of participants were willing to continue with trial CL wear if satisfied with both comfort and vision, dropping to 50% if either variable was unsatisfactory and 0% if both were unsatisfactory. PURPOSE: The aim of this study was to understand the relationship between subjective ratings and satisfaction with CL wear. METHODS: This was a retrospective analysis of two daily-disposable CL trials (delefilcon A, somofilcon A) on participants 40 years or younger followed over 3 months. Subjective ratings (numerical rating scale 1 to 10, 1-point step) collected at visits following baseline (2 weeks, 1 and 3 months) included comfort (insertion, during day, end of day), vision clarity, and binary response for satisfaction with comfort and vision (yes/no). Willingness to continue with trial CL was obtained at completion. RESULTS: There was no significant association of comfort on insertion with comfort satisfaction (odds ratio [OR], 1.2; P = .30); however, comfort during day (OR, 2.1; P < .001) and end of day (OR, 3.4; P < .001) was associated with comfort satisfaction. For comfort during day ratings of at least 8/10 and end of day of at least 6/10, 90% of participants were considered satisfied. There was a 14% increase in participants satisfied with comfort for each unit increase on the numerical rating scale from ratings of 3 to 8 for comfort during day and a 20% increase from ratings of 3 to 7 for comfort end of day. The percentage of satisfied participants reached its maximum at a lower end of day rating (8/10) compared with during day (10/10). The percentage of participants satisfied with vision reached its maximum (100%) at a vision rating of 9/10. CONCLUSIONS: Satisfaction in CL wear is influenced by both comfort and vision. A higher rating for comfort during the day compared with end of day is necessary for participants to attain satisfaction.

The Relationship between Progression in Axial Length/Corneal Radius of Curvature Ratio and Spherical Equivalent Refractive Error in Myopia.

SIGNIFICANCE: This study demonstrates that mean axial length/corneal radius of curvature ratio (AL/CR) can be used to detect low and high myopia but cannot clinically monitor myopia progression because the relationship between AL/CR and progression in myopia is different between low and high myopia. PURPOSE: The purpose of this study was to investigate the relationship of AL/CR with magnitude and progression of myopia. METHODS: Retrospective analysis was conducted comparing the right eyes of those with high myopia (n = 308; age, 7 to 16 years; myopia sphere, -6.00 diopters or worse) with those with low myopia (n = 732; age, 7 to 16 years; myopia sphere, between -0.50 and -3.50 diopters; cylinder, ≤1.00 diopters). Baseline axial length, corneal radii of curvature, and cycloplegic objective refraction were analyzed. Myopia progression in the low-myopia group at 6- and 12-month follow-up was measured, and the differences in slopes of AL/CR were compared for slow (<0.75 diopters) and fast progressing (≥0.75 diopters). RESULTS: Mean AL/CR values were significantly different (P < .001) between high myopia (3.46 ± 0.10) and low myopia (3.16 ± 0.07). In high and low myopia, slopes of axial length versus corneal curvature radius were not significantly different (P > .05), and slopes of AL/CR versus spherical equivalent were significantly different after adjusting for spherical equivalent and age (P < .05). Slopes of AL/CR progression and spherical equivalent progression were significantly different in low myopia between fast and slow progressing (P < .001), but the relationship between progression in AL/CR and progression in spherical equivalent was not strong. CONCLUSIONS: The AL/CR can be used to classify different grades of myopia, but it is not useful in determining the magnitude of myopia or monitoring progression because AL/CR is not linearly related to spherical equivalent and because progression in AL/CR is not strongly related to spherical equivalent progression.