Prevalence and Risk Factors for Myopia in a Rural Korean Population

Dissecting the complex sex-based associations of myopia with height and weight

OBJECTIVES

To assess height and weight as possible sex-specific risk factors for bilateral myopia among young adults.

METHODS

We conducted a cross-sectional study including 101,438 pre-enlisted young adult males and females, aged 17.4 ± 0.6 and 17.3 ± 0.5 years, respectively, and born during 1971-1994. Categories of BMI (body mass index) were defined according to sex-related percentiles for 17-year-olds following U.S. Centers for Disease Control and Prevention growth charts, and subjects were divided into five height and weight categories according to sex-adjusted percentiles. Data included best-corrected visual acuity, diverse socio-demographic variables, anthropometric indices, and refractive errors, namely bilateral myopes and emmetropes.

RESULTS

The prevalence of bilateral myopia in males and females was 19.1% and 26.0%, respectively. Bilateral myopia displayed a J-shaped associated with BMI, achieving statistical significance only among males (p < 0.0001). Weight displayed a U-shaped association with bilateral myopia among both young males (p < 0.0001) and females (p < 0.005). A higher prevalence of bilateral myopia was observed only among males of the lower height category (p < 0.0001), even when controlling for BMI (from normal to obesity). In a multivariable regression model, obesity was associated with higher prevalence of bilateral myopia (OR: 1.21; 95% CI: 1.07-1.38, p = 0.002), only among males. There were no interactions of BMI with height or weight. Bilateral myopia was also associated with prehypertension among males (OR: 1.10, 95% CI: 1.04-1.15, p < 0.001).

CONCLUSIONS

A higher risk for bilateral myopia was associated with either BMI solely or height and weight, as well as pre-hypertension, in males. The possible association with low height requires further research.

Link between parental myopia and early-onset high myopia: Insights from a clinical retrospective analysis

INTRODUCTION

Genetic aetiology is suspected in the development of early-onset high myopia (spherical equivalent refractive error [SER] ≤-6.00 D at ≤6 years of age), considering that the role of environmental factors in inducing high myopia is improbable at an early age. Therefore, we aimed to understand if early-onset high myopia is associated with parental myopia in a clinical setting.

METHODS

A retrospective study was conducted in which information about demographics, age of apparent onset of myopia, refractive error, axial length, number of myopic parents, time spent outdoors and time spent on near-work was obtained from electronic medical records (EMR). It included 195 myopic individuals categorised into (1) Early-onset high myopes (EOHM): SER ≤ -6.00 D with age of presentation ≤6 years, (2) Early-onset low myopes (EOLM): SER > -6.00 D with age of apparent onset ≤6 years, (3) Late-onset high myopes (LOHM): SER ≤ -6.00 D with age of presentation and age of apparent onset >6 years and (4) Late-onset low myopes (LOLM): SER > -6.00 D with age of apparent onset >6 years.

RESULTS

Overall, 63% of individuals were found to have parental myopia. The proportion of individuals with EOHM, EOLM, LOHM and LOLM with parental myopia was 57%, 74%, 53% and 64%, respectively. After adjustment for age, gender and environmental factors, the odds of development of EOHM (Odds ratio: 0.78, 95% confidence interval: 0.25-2.48), EOLM (1.54, 0.65-3.67) or LOHM (0.70, 0.30-1.65) were similar in the presence of myopic parents, when compared with LOLM. The SER and axial length did not differ based on the number of myopic parents in any of these categories.

CONCLUSION

This retrospective analysis reveals that the presence of parental myopia, which was self-reported, did not induce additional risk for early-onset high myopia.

Papillomacular bundle defect (PMBD) in glaucoma patients with high myopia: frequency and risk factors

Little is known about the papillomacular bundle defect (PMBD) in glaucoma. As such, we investigated the frequency of PMBD in glaucoma patients with high myopia, and its risk factors. In this retrospective, cross-sectional study, retinal nerve fiber layer (RNFL) defect was analyzed in 92 glaucomatous eyes with high myopia (axial length of 26.0 mm or more or an average spherical value of - 6.0 diopters or less). After dividing them into two groups with and without PMBD, the clinical characteristics of the groups were compared and analyzed. The mean age of the patients was 52.1 ± 10.5 years, and there were 53 males and 39 females. PMBD were observed in 55 eyes (59.8%). There was no significant intergroup difference in baseline or follow-up intraocular pressure (IOP). Parapapillary atrophy (PPA)-to-disc-area ratio (OR 3.83, CI: 1.58-10.27, p = 0.010), lamina cribrosa defect (LCD; OR 2.92, CI: 1.14-8.13, p = 0.031) and central visual field defect (CVFD; OR 3.56, CI: 1.38-9.58, p = 0.010) were significantly associated with the PMBD..

Myopic Vascular Changes Revealed by Optical Tomography Angiography and Their Association with Myopic Fundus Manifestations

INTRODUCTION

We aimed to quantify and evaluate fundal vascular changes at different severities of myopia using optical tomography angiography (OCTA) and explore their association with fundus changes captured by ultra-widefield (UWF) fundus cameras.

METHODS

Seventy-four participants with myopia were enrolled in the study and underwent basic ophthalmic examination, OCTA, and UWF fundus photography. Multiple parameters were obtained using OCTA (flow area, structure thickness, and vessel density) and UWF fundus cameras (tessellation and parapapillary atrophy [PPA]).

RESULTS

The right eye of 30 participants with low and moderate myopia and 44 participants with high myopia (HM) were included. Patients with HM had a larger flow area of the outer retina (FA-OR) and a smaller thickness of choroid (TC). Axial length was significantly correlated with retinal and choroidal flow area and thickness in the different zones. The PPA area was positively correlated with FA-OR and negatively correlated with TC. Tessellation exhibited different levels of correlation with OCTA parameters regarding the flow area, thickness, and vessel density of the fundal layers, mainly in the inner retina.

CONCLUSION

FA-OR and TC exhibited sensitive changes in patients with HM and axial elongation; therefore, they could serve as predictive OCTA biomarkers. The PPA and tessellation were connected to the vascular and structural changes revealed by OCTA.

Factors associated with myopia in 19-year-old adult men in Korea between 2014 and 2020

Numerous environmental factors that influence myopia have been studied, but only few factors have been definitively identified. We examined factors influencing myopia using data from 2014 to 2020 physical examinations received from the Korean Military Manpower Administration. We used the Cochran-Armitage trend test to investigate the annual prevalence of myopia and high myopia. To determine risk factors for myopia, logistic regression was performed. The data of 2,215,126 19-year-old Korean men were examined. The myopia and high myopia prevalences showed significant annual increases; in 2020, these prevalences were 58.9% and 18.0%, respectively. The myopia prevalence was high when the birth season was spring, education level was high, height was small, weight and body mass index (BMI) were low (< 18.5 kg/m²), and color vision was normal (all, p < 0.05). The high myopia prevalence was high when the birth season was spring, education level was high, height was tall, weight and BMI were low (< 18.5 kg/m²), and color vision was normal (all, p < 0.05). The prevalence of myopia and high myopia in this population is increasing annually. The risk of both conditions increased when the birth season was spring, education level was high, BMI was low, color vision was normal, and diabetes was present.

Myopia Control with Low-Dose Atropine in European Children: Six-Month Results from a Randomized, Double-Masked, Placebo-Controlled, Multicenter Study

The effect and safety of low-dose atropine in myopia control have not been studied in randomized, placebo-controlled trials outside Asia. We investigated the efficacy and safety of 0.1% atropine loading dose and 0.01% atropine compared with a placebo in a European population. Investigator-initiated, randomized, double-masked, placebo-controlled, equal-allocation, multicenter study comparing 0.1% atropine loading dose (six months) followed by 0.01% atropine (18 months), 0.01% atropine (24 months), and placebo (24 months). Participants were monitored for a 12-months washout period. Outcome measures were axial length (AL), cycloplegic spherical equivalent (SE), photopic and mesopic pupil size, accommodation amplitude, visual acuity, intraocular pressure (IOP), and adverse reactions and events. We randomized 97 participants (mean [standard deviation] age, 9.4 [1.7] years; 55 girls (57%) and 42 boys (43%)). After six months, AL was 0.13 mm shorter (95% confidence interval [CI], -0.18 to -0.07 [adjusted p < 0.001]) with 0.1% atropine loading dose and 0.06 mm shorter (95% CI, -0.11 to -0.01 [adjusted p = 0.06]) with 0.01% atropine than in the placebo group. We observed similar dose-dependent changes in SE, pupil size, accommodation amplitude, and adverse reactions. No significant differences in visual acuity or IOP were found between groups, and no serious adverse reactions were reported. We found a dose-dependent effect of low-dose atropine in European children without adverse reactions requiring photochromatic or progressive spectacles. Our results are comparable to those observed in East Asia, indicating that results on myopia control with low-dose atropine are generalizable across populations with different racial backgrounds.

Progression of Myopic Maculopathy: A Systematic Review and Meta-Analysis

PURPOSE

The purpose of this study was to elucidate the risk factors for the progression of myopic maculopathy (MM) based on severity.

METHODS

In this study, we conducted a systematic review and meta-analysis of the literature published before December 2020 on the risk factors for the progression of MM in patients with pathologic myopia (PM) and high myopia (HM). Odds ratios (ORs) for different stages of myopic maculopathy categorized based on the International Meta-Analysis for PM (META-PM) classification were calculated using fixed and random effects models.

RESULTS

A total of 12,070 affected eyes derived from 5 cohort studies were included in the systematic review. The presence of PM at baseline was found to be significantly associated with an increased risk of MM progression (pooled ORs: 7.17, 95% confidence interval [CI]: 3.29-15.6), and the greater category of MM at baseline was found to be significantly associated with an increased risk of MM progression, that is, eyes with MM category 3 or more compared with eyes with MM category 2 (pooled OR: 10.95, 95% CI: 6.07-19.76) and eyes with MM category 4 compared with eyes with MM category 3 (pooled ORs: 2.45, 95% CI: 0.28-21.37).

CONCLUSIONS

The findings in this systematic review and meta-analysis indicate that the progression of MM is associated with more severe MM at baseline.

Prevalence of Myopia and Influencing Factors among High School Students in Nantong, China: A Cross-Sectional Study

INTRODUCTION

Myopia is an increasingly serious health problem in China. The aim of this study was to investigate the prevalence of myopia and the factors associated with it among students in Nantong, China, to show the current status of myopia prevention.

METHODS

This school-based, cross-sectional study examined students from all high schools in an urban area of Nantong, China. At least two classes were randomly selected from each grade of each school. A self-reported questionnaire was used to collect the required information. Univariate analyses were performed to identify associations between myopia and various parameters. Noncycloplegic autorefraction and visual acuity were assessed for each student. Factors that were statistically significant in univariate analyses were selected for multivariate analyses. Myopia was defined as a spherical equivalent refraction of ≤-0.5 diopters.

RESULTS

The completion percentage of students out of the whole high school was 6.5%. The overall prevalence of myopia was 94%. The response percentage of the number of validated questionnaires was 90.2%, of which 50.2% (n = 1,466) were from male participants, and 49.8% (n = 1,452) were from female participants. The mean (SD) of age was 15.22 ± 1.75 years, ranging from 12 to 18 years. Factors such as female sex, older age, parental myopia, sitting in the back of the classroom, increased homework time, and minimal outdoor activity were significantly associated with a higher risk of myopia (p < 0.05). In the myopic population, most students (67.9%) did not take measures to prevent further progression of myopia.

CONCLUSION

The prevalence of myopia among high school students was 94%. Female sex, older age, parental myopia, sitting in the back of the classroom, increased homework time, and minimal outdoor activity were significantly associated with a higher risk of myopia. Most students with myopia (67.9%) did not take measures to prevent further progression of myopia.

Control of myopia using orthokeratology lenses in Scandinavian children aged 6 to 12 years. Eighteen-month data from the Danish Randomized Study: Clinical study Of Near-sightedness; TReatment with Orthokeratology Lenses (CONTROL study)

Purpose

To investigate the efficacy of myopia control defined by axial elongation and safety of orthokeratology lenses (OKL) in a Scandinavian (Danish) population.

Methods

Sixty Danish children aged 6–12 years with myopia ranging from 0.5 to 4.75 dioptres (D) spherical component and refractive astigmatism ≤2.5 D in both eyes were randomly assigned to either OKL or single‐vision spectacles (SVS). Study duration was 18 months. Outcome measures were axial length (AL) measured with Lenstar LS900 (Haag‐Streit, Koeniz, Switzerland) and adverse events graded with Efron Grading Scale for Contact Lens Complications.

Results

Nineteen participants completed the 18‐month follow‐up in the OKL group and 28 in the SVS group. The average AL elongation in the OKL group was 0.24 mm smaller as compared to the SVS group (95% confidence interval 0.12–0.36, mixed model adjusted for baseline sex, age and AL). There were no fast progressors (>0.75 D/year) in the OKL group during the follow‐up period in contrast to 22% in the SVS group. No treatment‐requiring or vision‐threatening adverse events were observed.

Conclusion

Orthokeratology lenses reduced AL elongation in myopic Scandinavian children by 59%, with no treatment‐requiring or vision‐threatening adverse events. The results align with outcomes of previous clinical trials.

[Occurrence of myopic maculopathy in eyes with staphylomas of various localization]

Complicated myopia develops in young people of working age, of which about 30% subsequently become visually impaired. Formation of ocular staphyloma affects the macula causing myopic maculopathy, which leads to significant and irreversible decrease in visual functions.

PURPOSE

To study the occurrence frequency of various forms of myopic maculopathy in scleral staphylomas of different localization in patients with pathologic myopia.

MATERIAL AND METHODS

The study included 105 patients with high myopia (105 eyes, axial length ≥26 mm). The main group consisted of 50 patients with myopic scleral staphylomas (50 eyes). The comparison group - 55 patients (55 eyes) without scleral staphylomas.

RESULTS

In the main group, myopic maculopathy was detected in 82% of eyes, it was absent in 96% of eyes in the comparison group. In the main group there were: staphyloma of the posterior pole of the eye with involvement of the optic nerve head (ONH) - 44% of eyes; macular staphyloma - 28% of eyes; peripapillary staphyloma - 12% of eyes; staphyloma below the ONH - 16% of eyes. Atrophic, neovascular and traction maculopathy was revealed in 22 eyes with staphylomas of the posterior pole of the eye. Dome-shaped changes in the macula were revealed in 17 patients (19 eyes) of the main group (15 eyes with staphylomas of the posterior pole of the eye, 4 eyes with macular staphylomas). The highest average value of axial length (30.94±0.81 mm) was noted in eyes with macular staphylomas, and the lowest (28.58±1.62 mm) - with staphylomas near the ONH.

CONCLUSION

The presence of myopic maculopathy is associated with the presence of staphylomas with the odds ratio of 120.7 (95%, confidence interval 24.7-589.3). Staphyloma of the posterior pole of the eye and macular staphyloma were associated with the most severe forms of myopic maculopathy and low visual acuity.

Recent trends of refractive surgery rate and detailed analysis of subjects with refractive surgery: The 2008-2015 Korean National Health and Nutrition Examination Survey

The present study was conducted to investigate recent trends of refractive surgery rates and analyze subjects undergoing refractive surgery using large-scale population studies over the past 8 years. We used the dataset of the Korean National Health and Nutrition Examination Surveys, a nationwide population-based cross-sectional study which were performed from 2008 to 2015. Of the 21,415 participants aged 20 to 49 years, 1,621 had refractive surgeries. Seventy three percent of them were females and 81% of them were aged under 40 years old. Over the past 8 years, cumulative prevalence of refractive surgery rate increased more than 10%. Although young (< 40 years, odds ratio (OR) 0.31, P<0.001) women (OR 1.86, P<0.001) living in urban areas (OR 0.51, P<0.001) with high educational attainment (OR 2.67, P<0.001) and income levels (OR 3.16, P<0.001) accounted for a high proportion in refractive surgery group through all survey years, subgroup analyses revealed that gaps between genders (ORs 3.8 in 2008–2009, 2.1 in 2010–2012, and 1.5 in 2013–2015), educational level (ORs 3.0, 2.5, and 2.1, respectively), and highest/lowest quartiles of household income (ORs 5.2, 2.6, and 2.4, respectively) were decreasing over time. Overall, our study suggests that refractive surgery has reached an age where the majority accepts it, and indeed more and diverse people are undergoing refractive surgeries.

Association of Corneal Biomechanics Properties with Myopia in a Child and a Parent Cohort: Hong Kong Children Eye Study

Associations between corneal biomechanics, axial elongation and myopia are important but previous results are conflicting. Our population-based study aimed to investigate factors associated with corneal biomechanics, and their relationships with myopia in children and adults. Data from 3643 children and 1994 parents showed that children had smaller deformation amplitudes (DA) than parents (p < 0.001). A larger DA was significantly associated with elongated axial length (AL; children: ß = 0.011; adults: ß = 0.0013), higher corneal curvature (children: ß = 0.0086; adults: ß = 0.0096), older age (children: ß = 0.010; adults: ß = 0.0013), and lower intraocular pressure (IOP; children: ß = −0.029; adults: ß = −0.031) in both cohorts. The coefficient of age for DA in children was larger than in adults (p < 0.001), indicating that the DA change with age in children is faster than in adults. DA was significantly associated with spherical equivalent (p < 0.001) resulting from its correlation with AL and corneal curvature. In conclusion, the cornea is more deformable in adults than in children, whereas corneal deformation amplitude increases faster with age in children than that in adults, along with AL elongation. Longer AL, steeper corneal curvature, older age and smaller IOP correspond to a more deformable cornea. The association between corneal deformation amplitude and refraction was mediated via AL and corneal curvature.

CORRELATION BETWEEN ATROPHY-TRACTION-NEOVASCULARIZATION GRADE FOR MYOPIC MACULOPATHY AND CLINICAL SEVERITY

PURPOSE

To assess the reliability of the atrophy-traction-neovascularization (ATN) classification in patients with pathologic myopia (PM) and its correlation with best-corrected visual acuity (BCVA).

METHODS

Cross-sectional study. Hundred highly myopic eyes with a spherical equivalent of >-6.0 diopters or axial length of >26 mm and a total ATN score of ≥3 underwent a complete ophthalmological examination, including fundus photography and swept-source optical coherence tomography. Five observers graded each eye using the ATN system. Mean A, T, and N scores were calculated and correlated with age, BCVA (in logarithm of the minimum angle of resolution), and axial length. Patients were considered to present severe PM if either A or T components were ≥3 and/or N was ≥2.

RESULTS

Hundred eyes (53 left) from 91 patients (78 women) were classified. Mean age, BCVA, and axial length values were, respectively, 65.1 ± 11.7 years (range, 36-97 years), -0.63 ± 0.62 (-3.00 to 0.00), and 29.26 ± 2.7 mm (26.01-37.66 mm). Mean ATN grades for each component were as follows: A = 2.51 ± 0.78 (0.6-4.0), T = 0.88 ± 1.14 (0.0-5.0), and N = 1.31 ± 1.40 (0.0-3.0). Weighted interobserver agreement was 98.1%, 98.7%, and 94.6%, for A, T and N, respectively. In eyes with severe PM, BCVA was significantly lower and axial length was significantly longer.

CONCLUSION

The excellent interobserver rate in this study demonstrates that the updated ATN grading system is an accurate and reliable tool to classify patients with PM. These findings show that BCVA is more compromised in eyes with severe PM, particularly those graded ≥A3 and/or T3.

Design, methodology, and baseline of whole city-million scale children and adolescents myopia survey (CAMS) in Wenzhou, China

Background

Myopia is the most common visual impairment in children and adolescents worldwide. This study described an economical and effective population-based screening pipeline and performed the project of a million scale children and adolescents myopia survey (CAMS), which will shed light on the further study of myopia from the level of epidemiology and precision medicine.

Methods

We developed a novel population-based screening pattern, an intelligent screening process and internet-based information transmission and analysis system to carry out the survey consisting of school children in Wenzhou, China. The examination items include unaided distance visual acuity, presenting distance visual acuity, and non-cycloplegic autorefraction. Myopia and high myopia were defined as spherical equivalent (SE) ≤ − 1.00 diopters (D) and SE ≤ − 6.00 D, respectively. Next, the reports of the vision checking were automatically sent to parents and the related departments. The CAMS project will be done two to four times annually with the support of the government. An online eyesight status information management system (OESIMS) was developed to construct comprehensive and efficient electronic vision health records (EVHRs) for myopia information inquiry, risk pre-warning, and further study.

Results

The CAMS completed the first-round of screening within 30 days for 99.41% of Wenzhou students from districts and counties, in June 2019. A total of 1,060,925 participants were eligible for CAMS and 1,054,251 (99.37% participation rate) were selected through data quality control, which comprised 1305 schools, and 580,609, 251,050 and 170,967 elementary, middle, and high school students. The mean age of participants was 12.21 ± 3.32 years (6–20 years), the female-to-male ratio was 0.82. The prevalence of myopia in elementary, middle, and high school students was 38.16%, 77.52%, and 84.00%, respectively, and the high myopia incidence was 0.95%, 6.90%, and 12.98%.

Conclusions

The CAMS standardized myopia screening model involves automating large-scale information collection, data transmission, data analysis and early warning, thereby supporting myopia prevention and control. The entire survey reduced 90% of staff, cost, and time consumption compared with previous surveys. This will provide new insights for decision support for public health intervention.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40662-021-00255-1.

Influence of the interaction between parental myopia and poor eye habits when reading and writing and poor reading posture on prevalence of myopia in school students in Urumqi, China

Background

To evaluate the prevalence of myopia in school students in Urumqi, China, and explore the influence of the interaction between parental myopia and poor reading and writing habits on myopia to identify the at-risk population and provide evidence to help school students avoid developing myopia.

Methods

A cross-sectional survey was conducted with 6,883 school students aged 7–20 years in Urumqi in December 2019. The Standard Eye Chart and mydriatic optometry were used to determine whether students had myopia. Falconer’s method was used to calculate the heritability of parental myopia. Multivariate unconditional logistic regression models were used to analyze the risk factors for myopia and the additive and multiplicative interaction of parental myopia and poor reading and writing habits.

Results

After standardizing the age of the 6,883 students, the overall prevalence rate of myopia was 47.50 %. The heritability of parental myopia was 66.57 % for boys, 67.82 % for girls, 65.02 % for the Han group, and 52.71 % for other ethnicities. There were additive interactions between parental myopia and poor reading and writing habits; among them, parental myopia and poor eye habits when reading and writing (the distance between the eyes and book is less than 30 cm when reading and writing, fingers block the sight of one eye while holding the pen, and leaning one’s body when reading and writing; habit 1) increased the risk of myopia by 10.99 times (odds ratio [OR] = 10.99, 95 % confidence interval [CI] = 8.33–14.68), parental myopia and poor reading posture (reading while lying down, walking, or in the car; habit 2) increased the risk of myopia by 5.92 times (OR = 5.92, 95 % CI = 4.84–7.27). There was no multiplicative interaction between parental myopia and habit 1 or habit 2 (OR = 0.69, 95 % CI = 0.44–1.08; OR = 0.89, 95 % CI = 0.66–1.21, respectively).

Conclusion

The prevalence of myopia among students in Urumqi, Xinjiang is relatively high. The risk of developing myopia is affected by parental myopia and poor reading and writing habits. In addition, parental myopia amplifies the harm caused by poor reading and writing habits, thereby increasing the risk of myopia. Students with parents who have myopia should be targeted during myopia prevention efforts.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-021-02058-3.

Association study of the serum 25(OH)D concentration and myopia in Chinese children

To analyze the serum 25 hydroxyvitamin D (25[OH]D) concentration in Chinese children with myopia and explore its correlation with myopia.From July to September in 2019, myopic children were collected from the Myopia Influencing Factors Survey Project. The basic information and vision related behaviors of the subjects were collected by questionnaire. The diopter of the children without dilated pupils was measured by the computerized refractometer. Meanwhile, 5 ml fasting venous blood samples were collected for the determination of serum 25(OH)D concentration.A total of 186 children were included in this study, including 90 males and 96 females, with an average age of 8 ± 3.26 years. The detection rate of serum 25(OH)D deficiency in myopic children was 65.59% (122/186). There was statistical significance in the detection rate of serum 25(OH)D deficiency in children with different myopic degrees (χ2 = 6.635, P = .010). The average serum 25(OH)D concentration in myopic children was 14.86 (10.67-18.96) ng/ml, and the difference of serum 25(OH)D concentration in children with different myopia degrees was statistically significant (Z = 20.23, P < .001). Logistic regression analysis showed that after controlling for gender, parental myopia, after-school class, and outdoor activities, the prevalence of developing moderate and high myopia was 2.051 times (95% confidence interval: 1.272-3.724) higher in the serum 25(OH)D deficiency group than in the serum 25(OH)D sufficiency group. There is a positive correlation between serum 25(OH)D concentration and the equivalent spherical degree of myopic children.The study found that serum 25(OH)D concentration is closely related to the prevalence of myopia in Chinese children. The results further support the conclusion that children with a higher level of serum 25(OH)D have a lower prevalence of moderate to high myopia. The results of this study provide a basis for further research into the relationship between vitamin D and visual development in children and its mechanisms.

Socioeconomic mechanisms of myopia boom in China: a nationwide cross-sectional study

OBJECTIVES

To assess the association between socioeconomic development and the myopia boom in China.

DESIGN

Nationwide cross-sectional study.

SETTING

We used data from the China Family Panel Study (CFPS 2010), and the Chinese National Survey on Students' Constitution and Health (CNSSCH 2010).

PARTICIPANTS

Participants included 33 600 individuals and 14 226 families from the CFPS 2010, and 86 199 students aged 7-12 years from the CNSSCH 2010.

MEASURES

The main measure was students' visual impairment (defined as Snellen visual acuity ≤20/25 (0.8) in the worse eye) rate of each province (or municipality or autonomous region); other measures included the Gini coefficient of property, logarithm of average property, Gini coefficient of education, average education duration and return-to-education rate of each province (or municipality or autonomous region). The visual impairment rate was calculated using students' data, aged 7-12 years, from the CNSSCH 2010. The Gini coefficient of property and logarithm of average property were calculated using the families' data from the CFPS 2010; the Gini coefficient of education, average education duration and return-to-education rate were calculated using individuals' data aged 18-44 years from the CFPS 2010.

RESULTS

The urban environment (coefficient: 0.209; p<0.001), Gini coefficient of property (coefficient: 1.979; p=0.005), logarithm of average property (coefficient: 0.114; p<0.001), average education duration (coefficient: 0.041; p<0.001) and return-to-education rate (coefficient: 0.195; p<0.001) were positively associated with the logit function of visual impairment rate.

CONCLUSIONS

Economic development may promote an increased desire to pursue wealth. Regarding high return to education and a fairly competitive education system, individuals are likely to pursue wealth through education, which is associated with a heavier education burden and higher prevalence rates of myopia.

Design and Pilot data of the high myopia registration study: Shanghai Child and Adolescent Large-scale Eye Study (SCALE-HM)

PURPOSE

To describe the methodology and pilot data of the Shanghai Child and Adolescent Large-scale Eye Study (SCALE-HM).

METHODS

This is a population-based, prospective, examiner-masked study with annual follow-up. Patients are 4- to 18-year-olds with high myopia. The participants will fill out questionnaires and then undergo visual acuity, axial length (AL), intraocular pressure, ophthalmologist assessment, microperimetry, cycloplegic refraction, Pentacam, wavefront aberration, fundus, blood and saliva examinations. To describe the pilot data, intergroup differences were assessed with t-tests or analysis of variance and a logistic regression model was used to determine the independent factors associated with peripapillary atrophy (PPA).

RESULTS

Overall, 134 eyes of 79 participants met the pilot study recruitment criteria. The mean AL and spherical equivalent were 26.91 ± 1.07 mm and -9.40 ± 1.77 D, respectively. Peripapillary atrophy (PPA) (N = 112) and tessellated fundus (N = 67) were the most common fundus changes. The mean AL was significantly longer in PPA (27.08 ± 0.93 mm) than in non-PPA eyes (26.06 ± 1.31 mm; p < 0.001). Axial length (AL) (p = 0.041) was the only independent factor associated with PPA. Axial length (AL) was significantly longer in eyes with diffuse chorioretinal atrophy (N = 11; 28.02 ± 1.31 mm) than without myopic retinal lesions (N = 56; 26.48 ± 0.91 mm, p < 0.001) or with tessellated fundus (N = 67; 27.09 ± 0.97 mm, p = 0.012). The myopic degree was higher in eyes with diffuse chorioretinal atrophy than without myopic retinal lesions (-10.51 ± 2.76 D versus -9.06 ± 1.58 D, p = 0.039).

CONCLUSION

Peripapillary atrophy and tessellated fundus were common in children and adolescents with high myopia. Results from this prospective study will help to understand the mechanisms, development and prognosis of these changes and can guide early myopia screening.

Update and guidance on management of myopia. European Society of Ophthalmology in cooperation with International Myopia Institute

The prevalence of myopia is increasing extensively worldwide. The number of people with myopia in 2020 is predicted to be 2.6 billion globally, which is expected to rise up to 4.9 billion by 2050, unless preventive actions and interventions are taken. The number of individuals with high myopia is also increasing substantially and pathological myopia is predicted to become the most common cause of irreversible vision impairment and blindness worldwide and also in Europe. These prevalence estimates indicate the importance of reducing the burden of myopia by means of myopia control interventions to prevent myopia onset and to slow down myopia progression. Due to the urgency of the situation, the European Society of Ophthalmology decided to publish this update of the current information and guidance on management of myopia. The pathogenesis and genetics of myopia are also summarized and epidemiology, risk factors, preventive and treatment options are discussed in details.

IMI Impact of Myopia

The global burden of myopia is growing. Myopia affected nearly 30% of the world population in 2020 and this number is expected to rise to 50% by 2050. This review aims to analyze the impact of myopia on individuals and society; summarizing the evidence for recent research on the prevalence of myopia and high myopia, lifetime pathological manifestations of myopia, direct health expenditure, and indirect costs such as lost productivity and reduced quality of life (QOL). The principal trends are a rising prevalence of myopia and high myopia, with a disproportionately greater increase in the prevalence of high myopia. This forecasts a future increase in vision loss due to uncorrected myopia as well as high myopia-related complications such as myopic macular degeneration. QOL is affected for those with uncorrected myopia, high myopia, or complications of high myopia. Overall the current global cost estimates related to direct health expenditure and lost productivity are in the billions. Health expenditure is greater in adults, reflecting the added costs due to myopia-related complications. Unless the current trajectory for the rising prevalence of myopia and high myopia change, the costs will continue to grow. The past few decades have seen the emergence of several novel approaches to prevent and slow myopia. Further work is needed to understand the life-long impact of myopia on an individual and the cost-effectiveness of the various novel approaches in reducing the burden.

Posterior chamber collamer phakic intraocular lens implantation: Comparison of efficacy and safety for low and moderate-to-high myopia

PURPOSE

To compare visual, refractive and safety outcomes of central-hole posterior chamber collamer phakic intraocular lens implantation for low and moderate-to-high myopia.

SUBJECTS/METHODS

This retrospective cohort study included 338 eyes submitted to posterior chamber collamer phakic intraocular lens implantation that completed a 12-month postoperative follow-up. Two groups were defined depending on preoperative spherical equivalent: group 1 comprised 106 eyes with manifest spherical equivalent of -6.00 D or less; group 2 comprised 232 eyes with manifest spherical equivalent higher than -6.00 D. Effectiveness, predictability, stability and safety outcomes were compared preoperatively and at 1, 6 and 12 months postoperatively.

RESULTS

At 1-year postoperative, uncorrected and corrected visual acuities were 0.02 ± 0.17 and -0.01 ± 0.12 logMAR (group 1) and 0.04 ± 0.20 and 0.01 ± 0.16 logMAR (group 2), with an efficacy index of 1.05 ± 0.17 and 1.17 ± 0.28. Respectively, 92 (86.8%) and 199 (85.8%) eyes were within ±0.50 D of targeted refraction, and postoperative manifest refraction changes were -0.07 ± 0.25 D and -0.07 ± 0.35 D. Intraocular pressure did not change significantly. The mean rate of endothelial cell loss was 1.12% and 1.10%, respectively. One case of anterior subcapsular cataract (group 2) was observed. ICL exchange occurred in one case (group 1) and three cases (group 2). No vision-threatening complications were reported.

CONCLUSION

The posterior chamber collamer phakic intraocular lens implantation demonstrated high visual and refractive efficacy with an excellent safety profile for the correction of both low and moderate-to-high myopia, revealing equivalent 1-year outcomes regardless of the degree of preoperative myopia.

Recurrent macular hole retinal detachment in a patient with pathologic myopia treated by additional intravitreal silicone oil injection: A case report

RATIONALE

Treatment of macular hole retinal detachment (MHRD) in patients with pathologic myopia may require multiple surgeries due to the risk of surgical failures or recurrences. Intravitreal silicone oil injection before an additional surgery may be another option for recurrent MHRD in aphakic eyes, but this procedure is rarely performed.

PATIENT CONCERNS

A 69-year-old man visited the hospital with a chief complaint of metamorphopsia in his right eye for 5 days. The right eye had undergone a cataract extraction 5 years prior and an Nd:YAG laser capsulotomy 1 year prior. The axial length was 36.18 mm; the fundus examination and optical coherence tomography (OCT) revealed inferior retinal detachment with a macular hole involving the posterior pole. Pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling, endolaser photocoagulation, and silicone oil tamponade were performed. Five months after the surgery, the retina was detached, and a macular hole was observed.

DIAGNOSIS

Recurrent MHRD in a patient with pathologic myopia.

INTERVENTION

PPV with ILM peeling, endolaser photocoagulation, and silicone oil tamponade at the initial visit and additional intravitreal silicone oil injection (0.5 ml) at follow-up visits.

OUTCOMES

The retina was well-attached until 5 months after the additional intravitreal silicone oil injection.

LESSONS

Additional intravitreal silicone oil injection can be a good option for treating MHRD in aphakic eyes if the detachment of the retina is dependent on posturing. The surgeon should consider the volume of silicone oil or postoperative posturing in the treatment of MHRD.

Prevalence, risk factors and impact of posterior staphyloma diagnosed from wide-field optical coherence tomography in Singapore adults with high myopia

PURPOSE

To investigate the prevalence and risk factors of posterior staphyloma using wide-field optical coherence tomography (WF-OCT) in adults with high myopia in Singapore.

DESIGN

Population-based cross-sectional study.

METHODS

Adults with spherical equivalent (SE) ≤ -5D in either eye at the first visit of Singapore Epidemiology of Eye Diseases study and Singapore Prospective Study Program study were recruited. Posterior staphyloma was diagnosed using WF-OCT (PLEX^® Elite9000, Carl Zeiss Meditec). Myopic macular degeneration (MMD), myopic traction maculopathy (MTM) and vision-related quality of life (VRQoL) were assessed using fundus photographs, DRI-Triton OCT (Topcon) and the Impact of Vision Impairment (IVI) questionnaire, respectively. Factors associated with posterior staphyloma were identified with multilevel, multivariable logistic regression. Impact of posterior staphyloma on MMD, MTM and visual function was analysed with multilevel, multivariable logistic regression and linear mixed model, respectively.

RESULTS

Among the 225 eyes [mean SE = -6.5 ± 2.2 D, mean axial length (AL) = 26.2 ± 1.5 mm] of 117 participants (mean age = 60.3 ± 7.1 years), posterior staphyloma was detected in 47 (20.9%) eyes of 38 (32.5%) participants. Older age [odds ratio (OR), 1.18; 95% confidence interval (CI), 1.10-1.26], more myopic SE (0.63; 0.51-0.77) and increased AL (2.51; 1.69-3.73) were associated with higher prevalence of posterior staphyloma (all p < 0.001). Adults with posterior staphyloma had higher odds of MMD (2.67; 1.23-5.82; p = 0.013), MTM (3.79; 1.13-12.68; p = 0.031) and worse IVI Reading (β = -1.44; -2.31 to 0.58; p = 0.001) scores.

CONCLUSIONS

About one in three adults with high myopia had posterior staphyloma, which was associated with increased odds of having myopic maculopathy and a detrimental impact on VRQoL.

Reducing the Global Burden of Myopia by Delaying the Onset of Myopia and Reducing Myopic Progression in Children: The Academy's Task Force on Myopia

In 2019, the American Academy of Ophthalmology (AAO) created the Task Force on Myopia in recognition of the substantial global increases in myopia prevalence and its associated complications. The Task Force, led by Richard L. Abbott, MD, and Donald Tan, MD, comprised recognized experts in myopia prevention and treatment, public health experts from around the world, and organization representatives from the American Academy of Family Physicians, American Academy of Optometry, and American Academy of Pediatrics. The Academy's Board of Trustees believes that myopia is a high-priority cause of visual impairment, warranting a timely evaluation and synthesis of the scientific literature and formulation of an action plan to address the issue from different perspectives. This includes education of physicians and other health care providers, patients and their families, schools, and local and national public health agencies; defining health policies to ameliorate patients' access to appropriate therapy and to promote effective public health interventions; and fostering promising avenues of research.

Myopia

Myopia, also known as short-sightedness or near-sightedness, is a very common condition that typically starts in childhood. Severe forms of myopia (pathologic myopia) are associated with a risk of other associated ophthalmic problems. This disorder affects all populations and is reaching epidemic proportions in East Asia, although there are differences in prevalence between countries. Myopia is caused by both environmental and genetic risk factors. A range of myopia management and control strategies are available that can treat this condition, but it is clear that understanding the factors involved in delaying myopia onset and slowing its progression will be key to reducing the rapid rise in its global prevalence. To achieve this goal, improved data collection using wearable technology, in combination with collection and assessment of data on demographic, genetic and environmental risk factors and with artificial intelligence are needed. Improved public health strategies focusing on early detection or prevention combined with additional effective therapeutic interventions to limit myopia progression are also needed.

Prevalence and risk factors of myopic maculopathy: a cross-sectional study in Han and Uygur adults in Xinjiang, China

OBJECTIVES

To estimate the prevalence, ethnic differences and associated risk factors of myopic maculopathy in Han and Uygur adults in Xinjiang, China.

DESIGN AND SETTING

A cross-sectional study with multistage, stratified cluster sampling method was conducted in Xinjiang, China.

PARTICIPANTS

A total of 4023 Han and Uygur participants aged 40 years and older were eligible for the study.

OUTCOME MEASURES

The association between myopic maculopathy and its risk factors was screened using the generalised estimating equation (GEE) model. We also investigated whether ethnic differences exist between Han and Uygur populations affected by myopic maculopathy. Myopic maculopathy was defined in accordance with International Photographic Classification and Grading System for Myopic Maculopathy.

RESULTS

A total of 3044 subjects (5946 eyes) were included in our study (1736 Han and 1308 Uygur individuals). The participants consisted of 1256 (41.3%) men and 1788 (58.7%) women. The average age was 52.2±9.4 years, and the mean spherical equivalent (SE) was -0.18±2.31 dioptre (D). Myopic maculopathy was detected in 198 eyes of 138 participants. The age-adjusted prevalence of myopic maculopathy reached 5.8% (95% CI 4.8 to 6.8). In the GEE model, myopic maculopathy was significantly associated with old age (per year; OR: 1.16; 95% CI 1.13 to 1.19; p<0.001) and myopic SE (per -1 D; OR: 1.48; 95% CI 1.40 to 1.56; p<0.001). No ethnic differences were detected between Han (98, 5.7%) and Uygur population (40, 3.1%) in terms of the prevalence of myopic maculopathy (OR=0.89; 95% CI 0.53 to 1.48; p=0.64). Neither urbanisation (p=0.38) nor the level of education (p=0.92) was associated with myopic maculopathy.

CONCLUSIONS

A high age-adjusted prevalence of myopic maculopathy was observed in Han and Uygur populations in Xinjiang, China. Old age and high degree of myopic refraction were independent risk factors for myopic maculopathy. No ethnic differences were detected in Han and Uygur populations affected by myopic maculopathy.

Pre-perimetric Open Angle Glaucoma with Young Age of Onset: Natural Clinical Course and Risk Factors for Progression

PURPOSE

To investigate the natural clinical course of more than 5 years and the risk factors of progression in patients with pre-perimetric open angle glaucoma (OAG) of "young age of onset (under age 40)" without treatment.

DESIGN

Retrospective observational case series.

METHODS

Optic disc photography, red-free retinal nerve fiber layer (RNFL) photography, optical coherence tomography, and visual field (VF) examinations were performed every 6 months. Glaucoma progression was defined as structural or functional deterioration. A linear mixed-effects model was used to estimate the rate of structural and functional changes. Kaplan-Meier survival analysis and log-rank testing were used to compare survival experiences, and Cox proportional hazards modeling was performed to identify risk factors for glaucoma progression.

RESULTS

Of the 98 eyes of 98 patients (mean age, 30.6 years old), glaucoma progression was detected in 42 eyes (42.9%). The rate of average RNFL thickness thinning was -0.46 ± 0.50 μm/y, and the mean deviation (MD) change was -0.03 ± 0.13 dB/y. The glaucoma progression probability at 5 years was 39% by structural criteria and 5% by functional criteria. Older age at diagnosis (P = .004), presence of temporal raphe sign (horizontal straight line on macular ganglion cell-inner plexiform layer thickness map) (P = .011), lamina pore visibility (P = .034), and greater pattern standard deviation (P = .005) were significant factors for glaucoma progression.

CONCLUSIONS

In untreated pre-perimetric OAG patients with a "young age of onset" condition, the estimated MD slope for the disease course of more than 5 years was -0.03 dB/y, and the average RNFL thinning rate was -0.46 μm/y. The predictors for progression were structural parameters of temporal raphe sign, lamina pore visibility, and functional parameter of pattern standard deviation.

CHARACTERIZATION OF THE CHOROIDAL VASCULATURE IN MYOPIC MACULOPATHY WITH OPTICAL COHERENCE TOMOGRAPHIC ANGIOGRAPHY

PURPOSE

To characterize the choriocapillaris (CC) in highly myopic eyes with myopic maculopathy, using optical coherence tomographic angiography.

METHODS

Prospective, clinic-based study of 42 eyes of 38 patients with high myopia (≤-6 diopters and axial length ≥26.5 mm). Myopic maculopathy was graded from fundus photographs according to the Meta-Analysis for Pathologic Myopia classification. Macular 3 × 3 mm en face optical coherence tomographic angiographic images were obtained with swept-source optical coherence tomographic angiography and graded for CC flow impairment as follows: 1) intact CC, 2) focal (<1 mm), and 3) extensive (>1 mm).

RESULTS

Of the 42 eyes, 17 (39.5%) had tessellated fundus, 20 (46.5%) had diffuse, and 6 (14.0%) had patchy atrophy. Choriocapillaris flow impairment was observed in all eyes with diffuse and patchy atrophy. Even in eyes with tessellated fundus only, CC signal voids were seen in 3 eyes (17.6%). With increasingly severe myopic maculopathy, the pattern of CC flow impairment changed from predominantly focal to predominantly extensive.

CONCLUSION

Choriocapillaris flow impairment was observed in many highly myopic eyes, even in those with mild fundus changes, and worsened with increasing severity of myopic maculopathy. Longitudinal studies are needed to assess whether CC flow impairment predicts the risk of myopic maculopathy progression.

Visual outcomes and safety after bilateral implantation of a trifocal presbyopia correcting intraocular lens in a Korean population: a prospective single-arm study

Background

To investigate the 3-month postoperative performance and safety after implantation of a trifocal intraocular lens (IOL) in a Korean population.

Methods

This was a clinical, prospective, multicenter, single-arm study. Forty-four subjects (88 eyes) with bilateral cataract with expected postoperative corneal astigmatism of < 1.00 diopter (D) and no ocular disease or eye condition underwent bilateral implantation of the AcrySof IQ® PanOptix IOL (TFNT00). Postoperative examination at 3 months included binocular defocus curve; binocular best corrected distance visual acuity (BCDVA); monocular/binocular uncorrected VA (UCVA) at distance (4 m), intermediate (60 cm), and near (40 cm); contrast sensitivity under photopic conditions with/without glare; and subjective outcomes, including satisfaction and spectacle independence.

Results

Binocular defocus curve at 3 months after bilateral implantation showed VA of 0.1 logMAR or better from + 0.5 D through − 2.5 D. Binocular BCDVA mean ± SD at 4 m was − 0.05 ± 0.07 logMAR. Binocular and monocular UCVA was 0.03 ± 0.1 and 0.08 ± 0.12 logMAR (4 m), − 0.00 ± 0.11 and 0.05 ± 0.13 logMAR (60 cm), and 0.03 ± 0.12 and 0.09 ± 0.13 logMAR (40 cm), respectively. Contrast sensitivity with glare was 1.67 ± 0.13, 1.91 ± 0.17, 1.54 ± 0.21, and 1.14 ± 0.20 log units at 3, 6, 12, and 18 cycles/degree, respectively. At near and intermediate distances, 84 and 77% of subjects reported good/excellent satisfaction, and 84 and 91% of subjects reported spectacle independence, respectively.

Conclusions

In a Korean population, visual performance of the trifocal TFNT00 IOL 3 months postoperatively was < 0.1 logMAR for binocular UCVA at all distances, with high subject satisfaction and spectacle independence.

Trial registration

www.ClinicalTrials.gov (NCT03268746). Registered August 31, 2017.

Association of SNTB1 with High Myopia

PURPOSE

To investigate the associations of Single Nucleotide Polymorphisms (SNPs) in the SNTB1 gene with high myopia in a Han Chinese population.

MATERIALS AND METHODS

Based on previous studies, four SNPs from the SNTB1 gene were chosen for genotyping. This is a case-control genetic association study comprising 193 high myopia participants and 135 normal emmetropic controls from a Han Chinese population. Allelic frequencies of the SNPs and haplotypes were compared to assess the associations of the SNPs with high myopia and axial length (AL).

RESULTS

The SNPs rs7839488 (effect allele: A; OR = 0.685), rs4395927 (effect allele: T; OR = 0.692), and rs6469937 (effect allele: A; OR = 0.683) displayed significant associations with high myopia initially (P = .044, 0.049, and 0.035, respectively), but did not withstand permutation testing (all P_permutation>0.05). rs6469937 displayed associations with high myopia in the dominant model (AG+AA: OR = 0.609) against GG (reference). rs6469937 was also associated with AL in the dominant model (AG+AA: Beta = -0.58) against GG (reference). The haplotype analysis demonstrated ATGA as the protective haplotype against high myopia, which remained statistically significant in permutation testing (P_permutation = 0.045).

CONCLUSIONS

Our findings are suggestive that SNTB1 is associated with high myopia in a Han Chinese population.

Visual impairment in highly myopic eyes: The ZOC-BHVI High Myopia Cohort Study

IMPORTANCE

Understanding visual impairment (VI) under different definitions and potential risk factors in high myopic is important for future myopia control.

BACKGROUND

Limited studies exists investigating the VI among high myopic and with varying VI definitions.

DESIGN

Registry cohort study.

PARTICIPANTS

Eight hundred and eighty-four participants were from ZOC-BHVI study.

METHODS

Subjects aged 7 to 70 years with high myopia were enrolled. Uncorrected visual acuity and best-corrected visual acuity (UCVA and BCVA), cycloplegic refraction, axial length (AL), corneal curvatures, anterior chamber depth and lens thickness were measured. Axial length/corneal radius of curvature ratio (AL/CR ratio) was calculated. Fundus lesions were graded into five categories. VI and blindness were defined based on the better-seeing eye according to the World Health Organization (WHO) criteria and US criteria. Multiple logistic regression analysis was used to assess risk factors for VI.

MAIN OUTCOME MEASURES

Rates of VI and blindness.

RESULTS

A total of 884 participants were included, with mean (SD) age 18.5 (12.4) years and 46.4% male. Rate of UCVI/blindness were 72.6%/27.3% and 17.9%/82.1% based on WHO and US criteria. With respect to BCVA, 4.1%/5.9% of participants had BCVI using two definitions, whereas the rate for blindness was 0.2% and 0.6%. After adjusting confounders, multiple logistic regression showed that more severe fundus lesions, greater AL/CR ratio were at a higher risk of being VI, both in two definitions (P < .005).

CONCLUSIONS AND RELEVANCE

The rate of VI and blindness in highly myopic patients varies significantly using different definition. Severe fundus lesions and greater AL/CR ratios were associated with a higher risk of VI.

Association of VIPR2 and ZMAT4 with high myopia

Background: To investigate the associations of Single Nucleotide Polymorphisms (SNPs) in the VIPR2 and ZMAT4 genes with high myopia in a Han Chinese population.Materials and Methods: In this case-control genetic association study comprising 193 high myopia participants and 135 normal emmetropic controls from a Han Chinese population, 15 SNPs from the VIPR2 and ZMAT4 genes were selected for genotyping based on previous studies. Allelic frequencies of the SNPs and haplotypes were compared for association with high myopia and axial length (AL).Results: RS885863 (G-reference/A-effect) and RS7829127 (A-reference/G-effect) were significantly associated with high myopia (OR = 1.832, P = .045; OR = 0.539, P = .023 respectively). The associations of RS885863 with high myopia were observed under the dominant (GA+AA: OR = 1.972, P < .05) and co-dominant models (Heterozygous GA: OR = 1.874; Homozygous AA: OR = 5.310; P < .05) against GG (reference). The mean AL of GG was 25.94 mm, compared with that in GA and AA of 26.64 mm and 27.48 mm respectively. The associations of RS7829127 with high myopia were observed under the dominant (AG+GG: OR = 0.512, P < .05) and co-dominant models (Heterozygous AG: OR = 0.524; Homozygous GG: OR = 0.307; P < .05) against AA (reference). The mean AL of AA was 26.35 mm, compared with that in AG and GG of 25.62 mm and 25.17 mm respectively. The importance of RS885863 and RS7829127 were also highlighted by their being the constituent SNPs in the haplotypes (ACGA, P = .002; and GA, P = .008 respectively) that were significantly associated with high myopia.Conclusions: Our findings agree that RS885863 from VIPR2 and RS7829127 from ZMAT4 are significantly associated with high myopia in a Han Chinese population.

The Effects of High Lighting on the Development of Form-Deprivation Myopia in Guinea Pigs

Purpose

To investigate the effects of high ambient lighting on refraction and ocular biometry in guinea pig models of form-deprivation myopia (FDM).

Methods

Forty 3-week-old guinea pigs were randomly assigned to groups exposed to either high light (HL, 10,000 lux) or normal light (NL, 500 lux) with normal vision or form deprivation. Throughout the 10-week rearing period, animals were exposed to high light or normal light for 12 hours with a 12-hour light/dark cycle. Refraction, axial length (AL), and radius of corneal curvature (CCR) were measured by cycloplegic retinoscopy, A-scan ultrasonography, and keratometer, respectively.

Results

At the end of treatment, form-deprived eyes under high ambient lighting exhibited more hyperopic refraction and shorter AL than those under normal ambient lighting (2.06 ± 1.68 diopters [D; mean ± SD] vs. -0.59 ± 1.56 D, P < 0.001; 8.36 ± 0.13 mm vs. 8.56 ± 0.16 mm, P < 0.001). Deprived eyes under high ambient lighting were relatively more myopic than their contralateral control eyes at the end of treatment (2.06 ± 1.68 D vs. 5.44 ± 0.66 D, P < 0.001). High lighting induced a significant hyperopic shift in normal eyes after 4 weeks of exposure. There were no significant differences in CCR between eyes exposed to high and normal light, nor between deprived eyes and contralateral eyes.

Conclusions

High ambient lighting could retard, but not fully inhibit, the development of FDM. High light levels contributed to a greater hyperopic shift in normal eyes during the first 4 weeks of treatment. Corneal curvature was unaffected by either high ambient lighting or form deprivation.

Association between serum 25-hydroxyvitamin D levels and myopia in general Korean adults

Purpose

We performed this study to determine the association between serum 25-hydroxyvitamin D [25(OH) D] level and myopia in adults.

Methods

A total of 25,199 subjects aged ≥20 years were included from the National Health and Nutrition Examination Survey 2008-2012. Blood 25(OH)D levels were evaluated from blood samples. Refractive error was measured without cycloplegia. Myopia and high myopia were defined as ≥-0.50 diopters (D) and ≥-6.0 D, respectively. Other covariates such as education, physical activity, and economic status were obtained from interviews.

Results

Linear regression analysis showed that as 25(OH) D level increased by 1 ng/mL, myopic refractive error significantly decreased by 0.01 D (P < 0.001) after adjusting for potential confounders including sex, age, height, education level, economic status, physical activity, and sunlight exposure time. The odds ratios for myopia was 0.75 (95% Confidence interval [CI]; 0.67-0.84, P < 0.001) in the highest 25(OH) D quintile compared to the lowest quintile. The odds ratios for high myopia was 0.63 (95% CI; 0.47-0.85, P < 0.001) in the highest 25(OH)D quintile compared to the lowest quintile.

Conclusion

: Serum 25(OH)D level was inversely associated with myopia in Korean adults.

Reasons for Laser in Situ Keratomileusis in China: A Qualitative Study

SIGNIFICANCE

Myopia is a major health issue in East Asian countries, especially in China. By identifying Chinese patients' motivations for laser in situ keratomileusis (LASIK) surgery, our results are expected to help clinicians counsel patients before LASIK surgery and to maximize patients' post-operative LASIK surgery satisfaction, improving the quality of LASIK surgery services.

PURPOSE

Laser in situ keratomileusis has become a popular type of refractive surgery for the correction of myopia worldwide. This study uses qualitative inquiry approaches to understand the motives and processes of patients' LASIK surgery decision making.

METHODS

A purposive sample of 45 patients who had decided to undergo LASIK was recruited. Our qualitative study used in-depth interviews and used content analysis to interpret the data.

RESULTS

Among 45 participants, 48.9% reported that career requirements were the most important reason for seeking LASIK surgery. The inconvenience of wearing glasses or lenses during activities of daily life was also a primary motive. Improving facial appearance was a main reason for female but not male respondents. Potential complications of spectacles and contact lenses in addition to maturation of LASIK technology were also reported motives to seek surgery. Participants gave multiple, overlapping reasons for LASIK surgery.

CONCLUSIONS

These findings suggest that motives to seek LASIK surgery are not only a desire to correct refractive error but also social factors and confidence in improved surgical technology. The implications for clinicians are to be aware of these multiple motives for LASIK to improve the quality and effectiveness of health services for myopia patients.

Auricular acupressure for myopia in children and adolescents: A systematic review

OBJECTIVES

To identify and assess the evidence showing the efficacy of auricular acupressure alone for myopia in children and adolescents.

METHODS

Randomized controlled trials (RCTs) that were published until March 2019 in Pubmed, Web of Science, OVID, Foreign Medical Literature Retrieval Service, China Knowledge Resource Integrated Database, The Chinese Biological Medicine Database, Wanfang Database, and Chongqing VIP Information were searched. The quality of RCTs was assessed using the Cochrane risk of bias assessment tool.

RESULTS

Ten RCTs were included to be qualitatively summarized, of which 5 studies qualified for the meta-analysis of the efficacy rate in treating myopia. This review demonstrated that auricular acupressure alone was more effective than eye-drops treatment, eye exercise, and was the just as effective as needle acupuncture.

CONCLUSIONS

Auricular acupressure could slow the progression of myopia in children and adolescents. However, there is a need for further studies with higher methodological quality and sufficient follow-up.

Refractive Change and Incidence of Myopia Among A Group of Highly Selected Senior High School Students in China: A Prospective Study in An Aviation Cadet Prerecruitment Class

Purpose

To assess the incidence rate of myopia, refractive change, and the effects of influencing factors on a group of highly selected senior high school students in an Aviation Cadet prerecruitment class in China.

Methods

A total of 800 nonmyopic, male, Grade 9 students aged 14- to 16-years old with cycloplegic refraction of -0.25 or greater diopters (D) to 1.75 D or less in both eyes were enrolled in May 2016. During their senior high school studies, students had one 20-minute physical training period a day, and they were encouraged to participate in outdoor activities during class recess without any time limits. The first follow-up was 8 months after enrollment when they were in Grade 10, and the second follow-up was 1 year after the first follow-up when they were in Grade 11. Comprehensive ocular examinations and a detailed questionnaire, which included questions about outdoor activity time, parental myopia, and near work, were completed at each follow-up.

Results

The average spherical equivalent refraction (SER) of the right eyes was 0.39 ± 0.44 D at baseline, 0.16 ± 0.41 D at the first follow-up, and -0.10 ± 0.38 D at the second follow-up. The cumulative refractive change was -0.50 D (95% confidence interval [CI], -0.53 to -0.47). The cumulative incidence rate of myopia was 15.5% (124/800). Incident myopia was significantly associated with outdoor activity for more than 1 versus less than 0.5 hr/d (odds ratio [OR] = 0.272, 95% CI, 0.132-0.560), baseline refraction (OR = 0.079, 95% CI, 0.041-0.153), maternal myopia (OR = 2.251, 95% CI, 1.160-4.368), longer class time (OR =3.215, 95% CI, 1.088-9.499), frequent, continuous, and long time reading/writing (OR = 1.620, 95% CI, 1.022-2.570), and shorter reading/writing distance (OR = 1.828, 95% CI, 1.065-3.140). In multiple linear regression model, having outdoor activity for more than 1 hr/d was protective from cumulative SER decrease. A higher baseline refraction together with longer reading/writing time, frequent, continuous, and longtime reading/writing, and shorter reading/writing distance were risk factors for SER decrease.

Conclusions

In this cohort of highly selected, nonmyopic students, longer outdoor activity time was a protective factor for both incident myopia and refractive change of myopic shift. The risk factors for incident myopia included lower hyperopic baseline refraction, more near work, and maternal myopia. The risk factors for refractive change of myopic shift included more hyperopic baseline refraction and more near work.

Progression of Myopic Maculopathy in Highly Myopic Chinese Eyes

Purpose

To evaluate the 2-year changes in myopic maculopathy and its associations in highly myopic eyes.

Methods

This was a longitudinal, observational cohort study involving 657 Chinese participants with bilateral high myopia (≤ -6.00 diopters spherical power), who were followed for 2 years. The worst eye of each participant was considered for the analysis. Myopic maculopathy was graded based on fundus photographs, using the International Photographic Classification and Grading System for Myopic Maculopathy.

Results

The mean baseline age was 21.6 ± 12.2 years (range, 6.8-69.7 years). Myopic maculopathy progressed in 97 (14.8%) of 657 eyes, of which 24 eyes progressed to a higher category of myopic maculopathy, including from no maculopathy to tessellated fundus in 17 eyes, from tessellated fundus to diffuse atrophy in 6 eyes, and from diffuse to patchy atrophy in 1 eye. Among 122 lesion changes identified, the most common changes were enlargement of diffuse atrophy (n = 50, 41.0%), appearance of lacquer cracks (n = 28, 23.0%), enlargement of patchy atrophy (n = 10, 8.2%) and development of additional lacquer cracks (n = 7, 5.8%). In addition, we identified 1 eye with enlargement of a Fuch's spot, and 1 eye with active choroidal neovascularization. In multiple logistic regression analysis, myopic maculopathy progression was associated with older age, longer axial length, greater change in myopic spherical equivalent and more severe myopic maculopathy at baseline.

Conclusions

Myopic maculopathy progressed in approximately 15% of highly myopic eyes over a 2-year period. Further studies with longer follow up periods are required to confirm identified risk factors for progression.

IMI - Myopia Control Reports Overview and Introduction

With the growing prevalence of myopia, already at epidemic levels in some countries, there is an urgent need for new management approaches. However, with the increasing number of research publications on the topic of myopia control, there is also a clear necessity for agreement and guidance on key issues, including on how myopia should be defined and how interventions, validated by well-conducted clinical trials, should be appropriately and ethically applied. The International Myopia Institute (IMI) reports the critical review and synthesis of the research evidence to date, from animal models, genetics, clinical studies, and randomized controlled trials, by more than 85 multidisciplinary experts in the field, as the basis for the recommendations contained therein. As background to the need for myopia control, the risk factors for myopia onset and progression are reviewed. The seven generated reports are summarized: (1) Defining and Classifying Myopia, (2) Experimental Models of Emmetropization and Myopia, (3) Myopia Genetics, (4) Interventions for Myopia Onset and Progression, (5) Clinical Myopia Control Trials and Instrumentation, (6) Industry Guidelines and Ethical Considerations for Myopia Control, and (7) Clinical Myopia Management Guidelines.

Myopic maculopathy: Current status and proposal for a new classification and grading system (ATN)

Myopia is a highly frequent ocular disorder worldwide and pathologic myopia is the 4th most common cause of irreversible blindness in developed countries. Pathologic myopia is especially common in East Asian countries. Ocular alterations associated with pathologic myopia, especially those involving the macular area-defined as myopic maculopathy-are the leading causes of vision loss in patients with pathologic myopia. High myopia is defined as the presence of a highly negative refractive error (>-6 to -8 diopters) in the context of eye elongation (26-26.5 mm). Although the terms high myopia and pathologic myopia are often used interchangeably, they do not refer to the same eye disease. The two key factors driving the development of pathologic myopia are: 1) elongation of the axial length and 2) posterior staphyloma. The presence of posterior staphyloma, which is the most common finding in patients with pathologic myopia, is the key differentiating factor between high and pathologic myopia. The occurrence of staphyloma will, in most cases, eventually lead to other conditions such as atrophic, traction, or neovascular maculopathy. Posterior staphyloma is for instance, responsible for the differences between a myopic macular hole (MH)-with and without retinal detachment-and idiopathic MH. Posterior staphyloma typically induces retinal layer splitting, leading to foveoschisis in myopic MH, an important differentiating factor between myopic and emmetropic MH. Myopic maculopathy is a highly complex disease and current classification systems do not fully account for the numerous changes that occur in the macula of these patients. Therefore, a more comprehensive classification system is needed, for several important reasons. First, to more precisely define the disease stage to improve follow-up by enabling clinicians to more accurately monitor changes over time, which is essential given the progressive nature of this condition. Second, unification of the currently-available classification systems would establish standardized classification criteria that could be used to compare the findings from international multicentric studies. Finally, a more comprehensive classification system could help to improve our understanding of the genetic origins of this disease, which is clearly relevant given the interchangeable-but erroneous-use of the terms high and pathologic myopia in genetic research.

Prevalence and risk factors of refractive error: a cross-sectional Study in Han and Yi adults in Yunnan, China

Background

Few studies have investigated the prevalence of refractive error (RE) in older adults in China, and most have focused on East China. Our study determined the prevalence and risk factors of RE in Han and Yi adults aged 40–80 years in rural and urban areas in Yunnan Province, Southwest China.

Methods

Our cross-sectional study is part of the China National Health Survey (CNHS). The age-adjusted prevalence rates of RE in Han and Yi adults aged 40–80 years in Yunnan were compared. We used a multivariate logistic regression model to identify risk factors for myopia and hyperopia.

Results

Among 1626 participants, the age-adjusted prevalence rates of myopia, hyperopia, high myopia and astigmatism were 26.35% (95%CI 24.01–28.70%), 19.89% (95%CI 18.16–21.61%), 2.64% (95%CI 1.75–3.53%), and 56.82% (95%CI 54.31–59.34%). Compared to the Yi population, the Han population had higher prevalence of myopia (31.50% vs 16.80%, p < 0.0001), high myopia (3.34% vs 1.31%, p = 0.049) and astigmatism (60.07% vs 50.67%, p = 0.026) but lower prevalence of hyperopia (16.58% vs 27.37%, p < 0.0001). In the multivariate logistic regression, individuals aged 45–49 (p < 0.001), 50–54 (p < 0.001), 55–59 (p = 0.014), and 60–64 years (p = 0.005) had a lower myopia risk than those aged 40–44 years, and individuals aged 50–54 (p = 0.002), 55–59, 60–64 and 65 years and older (all p < 0.001) had a higher hyperopia risk than those aged 40–44 years. Myopia was also associated with height (p = 0.035), time spent in rural areas (p = 0.014), undergraduate/graduate education level (p = 0.001, compared with primary school or lower education level) and diabetes (p = 0.008). The Yi population had a higher risk of hyperopia than the Han population (p = 0.025). Moreover, hyperopia was related to time spent in rural areas (p < 0.001) and pterygium (p = 0.019).

Conclusions

Our study investigated the overall prevalence of RE in older adults in rural and urban areas of Southwest China. Compared to the Yi population, the Han population had a higher prevalence of myopia, high myopia and astigmatism but a lower risk of hyperopia. The prevalence of myopia in the Han population in underdeveloped Southwest China was similar to that of residents in East China or of Chinese Singaporeans under urban or rural settings.

Prevalence and risk factors of myopia in adult Korean population: Korea national health and nutrition examination survey 2013-2014 (KNHANES VI)

PURPOSE

To evaluate the prevalence and risk factors of myopia in adult Korean population.

METHODS

Population-based cross-sectional data of 3,398 subjects aged 19 to 49 years was obtained using the Korea National Health and Nutrition Examination Survey 2013-2014 (KNHANES VI). Data, including refractive errors and potential risk factors were analyzed. The prevalence and risk factors of myopia, low myopia, and high myopia-defined as a spherical equivalent (SEQ) ≤ -0.5 diopters (D), -6.0 D < SEQ <-0.5 D, and SEQ ≤ -6.0 D, respectively-were evaluated.

RESULTS

The prevalence of myopia and high myopia were 70.6 (standard error (SE), ±1.1)% and 8.0 (SE, ±0.6)%, respectively. In multivariable analysis, younger age, higher education (≥12 years), parental myopia, lower serum 25-hydroxyvitamin D (25(OH)D) concentration (<9 ng/mL), longer time spent on near work (≥3 hours/day), and higher white blood cell (WBC) count (5-8.9 x 103) were associated with increased prevalence of both myopia and high myopia. Serum 25(OH)D concentration of ≥ 9 ng/ml was significantly associated with decreased prevalence of high myopia in participants with near work of ≥3 hours/day, although the effect was not significant in myopia and low myopia.

CONCLUSIONS

The prevalence of myopia and high myopia in Korean adults was substantially high, which increased with decreasing age. In addition to parental myopia, the serum 25(OH)D concentration, near work and inflammation reflected by WBC counts may be associated with myopia.

Molecular genetic aspects of complicated myopia pathogenesis

Complicated myopia (CM) is not only a refractive error but a complex, multifactorial disorder characterized by a mismatch between the optical power of the eye and the axial length that causes the image to be focused off the retina. Genetic factors in progressive myopia play a key role in determining the impact of ecologic factors on refraction development. The majority of genetic variants underlying CM are characterized by modest effect and/or low frequency, which makes them difficult to identify using classic genetic approaches. The genes identified to date account for less than 10% of all myopia cases, suggesting the existence of a large number of yet unidentified low-frequency and/or small-effect variants, which underlie the majority of myopia cases. Genome analysis revealed dozens of loci associated with non-syndromic myopia, and showed that refractive errors are associated with mutations in genes that are involved in the growth and development of the eye by regulating ion transport, neurotransmission, remodeling of extracellular matrix of the retina and other ocular structures. Genetic study of refractive error provides a unique opportunity to detect key molecules that may play important roles in the development of refractive error. Identifying the molecular basis of refractive error helps to understand mechanisms, and subsequently to design rational therapeutic intervention for this condition.

Peripheral retinal changes in highly myopic young Asian eyes

PURPOSE

To determine the type and prevalence of peripheral retinal changes and its relationship with axial length (AL) in a population of young Asian adult males.

METHODS

This was a cross-sectional study of male subjects aged between 19 and 25 years old. High myopes [spherical equivalent refraction, (SER) < -6.00 D] were recruited and underwent further ocular investigations including dilated retinal photography and binocular indirect ophthalmoscopy by two trained ophthalmologists. The frequency of peripheral retinal changes within high myopes was correlated with axial length and also compared with a group of emmetropes (SER between -0.50 D and +1.00 D).

RESULTS

A total of 593 high myopes and 156 emmetropes were recruited. White without pressure (WWOP; n = 458, 46.5%) and lattice degeneration (LD; n = 109, 14.6%) were the commonest findings, and their prevalence was significantly higher among high myopes (LD, 16.9% versus 5.8%; WWOP, 57.2% versus 5.8%; both p < 0.001). Among high myopes, temporal LD was more common (71%) and 35% had more than one area in the same eye. Increasing AL was associated with LD (odds ratio 1.28, p = 0.01) and retinal holes (odd's ratio 1.44, p = 0.02) on multivariate analysis.

CONCLUSION

White without pressure (WWOP) and LD were the commonest peripheral retinal changes. One-third of high myopes with LD had more than one area in the same eye. Increasing AL was associated with LD and retinal holes. Studies in older adults should be conducted to develop clinical guidelines for the management of high myopes.

The increasing prevalence of myopia and high myopia among high school students in Fenghua city, eastern China: a 15-year population-based survey

BACKGROUND

Myopia is the leading cause of preventable blindness in children and young adults. Multiple epidemiological studies have confirmed a high prevalence of myopia in Asian countries. However, fewer longitudinal studies have been performed to evaluate the secular changes in the prevalence of myopia, especially high myopia in China. In the present study, we investigated trends in the prevalence of myopia among high school students in Fenghua city, eastern China, from 2001 to 2015.

METHODS

This was a population-based, retrospective study. Data were collected among 43,858 third-year high school students. Noncycloplegic autorefraction was used to determine refractive error, which was defined as low myopia, moderate myopia, high myopia and very high myopia according to the spherical equivalent from the worse eye of each participant. The prevalence of myopia was calculated and the annual percentage change (APC) was used to quantify the time trends. All analyses were conducted using the SPSS, Stata and Graphpad Prism software.

RESULTS

From 2001 to 2015, the prevalence of overall myopia increased from 79.5% to 87.7% (APC =0.59%), with a significant increase of moderate myopia (38.8% to 45.7%, APC = 0.78%), high myopia (7.9% to 16.6%, APC = 5.48%) and very high myopia (0.08% to 0.92%, APC = 14.59%), while the prevalence of low myopia decreased from 32.7% to 24.4% (APC = - 1.73%). High myopia and very high myopia contributed the major part of the increasing trend of myopia prevalence (contribution rate 27.00% and 69.07%, respectively).

CONCLUSIONS

During the 15-year period, there was a remarkable increase in the prevalence of high and very high myopia among high school students, which might become a serious public health problem in China for the next few decades.

Ocular biometric characteristics of cataract patients in western China

BACKGROUND

We aimed to measure ocular biometric characteristics in older cataract patients from western China.

METHODS

Ocular biometry records were retrospectively analyzed for 6933 patients with cataracts (6933 eyes) at least 50 years old who were treated at West China Hospital of Sichuan University.

RESULTS

Partial coherence laser interferometry gave the following population averages: axial length (AL), 24.32 ± 2.42 mm; anterior chamber depth (ACD), 3.08 ± 0.47 mm; keratometric power (K), 44.23 ± 1.66 diopters; and corneal astigmatism (CA), 1.00 ± 0.92 diopters. The percentage of individuals with AL > 26.5 mm was 13.66%, while the percentage with CA > 1.0 diopters was 35.54%. Mean AL and ACD showed a trend of decrease with increasing age (P < 0.001). AL correlated positively with ACD (Spearman coefficient, 0.542) and CA (0.111), but negatively with K (- 0.411) (all P < 0.01). K also correlated negatively with ACD (- 0.078, P < 0.01).

CONCLUSIONS

These results show, for the first time, that older cataract patients from western China have similar ocular biometric characteristics as other populations. The high prevalence of severe axial myopia warrants further investigation.

Retinal and Choroidal Thickness in Patients with High Myopia without Maculopathy

Objective

To evaluate macular choroidal thickness (CT) and retinal thickness in Turkish patients with high myopia without maculopathy and in normal subjects and to examine the association with age, axial length (AL), best corrected visual acuity (BCVA), cycloplegic refraction, and spherical equivalent (SE).

Methods

This prospective study was performed between January 2015 and June 2016 in the Department of Ophthalmology, Duzce University Medical Faculty. It had 65 individuals (30 patients with high myopia, 35 healthy subjects). Retinal and choroidal images were obtained using spectral-domain optical coherence tomography (OCT). Measurements (one subfoveal, three temporal, three nasal) were taken at 500 μm intervals up to 1,500 μm using the caliper system. Only the right eye was used for subsequent analysis.

Results

The mean age was 29.5 ± 14.5 years and 25.6 ± 7.0 in the high myopia and control groups, respectively. The subfoveal CT was significantly lower in the high myopia group (mean, 218.3 ± 102.25 mm) than the control group (mean, 331.83 ± 99.06 mm; p < 0.001). In both groups, the choroid was thinnest at the nasal 1,500 μm location, being 158.40 ± 90.8 μm and 301 ± 103.59 μm, respectively. Retinal thickness in both groups was thickest at the nasal 1,500 μm location and thinnest in the subfoveal region. In patients with high myopia, CT was negatively correlated with AL (r=-0.490, p=0.006) and age (r=-0.455, p=0.012).

Conclusions

Highly myopic eyes have a thinner choroid, which may be secondary to longer AL but is not an independent factor. Further studies in the field of OCT are important to exploring the pathology of high myopia.

Design and methodology of the Shanghai child and adolescent large-scale eye study (SCALE)

Importance

Nearly half of children suffering vision impairment reside in China with myopia accounting for the vast majority.

Background

To describe the design and methodology of the Shanghai Child and Adolescent Large‐scale Eye Study (SCALE).

Design

The SCALE was a city wide, school‐based, prospective survey.

Participants

Children and adolescents aged 4–14 years from kindergarten (middle and senior), primary schools and junior high schools of all 17 districts and counties of the city of Shanghai, China were examined in 2012–2013.

Methods

Each enrolled child underwent vision assessment (distance visual acuity; uncorrected and with corrective device if worn) and their parent/carer completed a questionnaire designed to elicit risk factors associated with myopia. Additionally, non‐cycloplegic autorefraction and ocular axial length was measured in a subset of the larger sample.

Main Outcome Measures

Prevalence and the associated factors of vision impairment, myopia and high myopia in Shanghai.

Results

In 2012–2013, a total of 910 245 of the eligible 1 196 763 children and adolescents identified from census (76%, mean age 9.0 ± 2.7 years [4–14 years]) were enrolled with visual acuity screened in the city of Shanghai. Of these, 610 952 children (67% of the entire sample) underwent non‐cycloplegic autorefraction and 219 188 (24% of the entire sample) had both non‐cycloplegic autorefraction and axial length measurements.

Conclusions and Relevance

The study results will provide insights on the burden of vision impairment, myopia and high myopia in children and adolescents in a metropolitan area of China, and contribute to the policies and strategies to address and limit the burden.