Temporal trend of anisometropia incidence in Chinese school-aged children before and during the COVID-19 pandemic.

Objective: To analyze and compare the temporal trends in the incidence of anisometropia among Chinese school-aged children both before and during the COVID-19 pandemic, and to investigate the impact of the pandemic on the incidence of anisometropia. Methods: We conducted a retrospective study comprising six distinct and independent longitudinal cohorts, each including children aged 6 to 13 years who visited the Joint Shantou International Eye Center between January 2010 and December 2021. Children were grouped into cohorts based on the year of their first eye clinic visit: 2010, 2012, 2014, 2016, 2018, or 2020. Only children without anisometropia at initial visits, followed for 18 ± 6 months, were included. The cumulative incidence and risk factors of anisometropia were analyzed using Kaplan-Meier estimation and Cox proportional hazards regression models. Subgroup analyses were performed based on sex, age groups, initial refractive error status, and initial interocular SE difference. Anisometropic children were further categorized into myopic and non-myopic, with subsequent subgroup analyses conducted. Results: Of 11,235 children were recruited from six cohorts (2010: n = 1,366; 2012: n = 1,708; 2014: n = 1,896; 2016: n = 2,354; 2018: n = 2,514; 2020: n = 1,397), 869 children developed anisometropia during a mean follow-up of 17.5 ± 3.7 months. After adjustment of confounding factors, we found that the risk of anisometropia remained relatively stable before 2020 but significantly increased in the 2020 cohort (adjusted HR 2.93, 95% CI 2.23 to 3.86; p < 0.001). This trend persisted in studies of spherical anisometropia (adjusted HR 2.52, 95% CI 1.60 to 3.97; p < 0.001) and cylindrical anisometropia (adjusted HR 2.91, 95% CI 1.69 to 3.62; p < 0.001). Older age and a greater initial difference in SE between the two eyes were also significantly associated with a higher risk of developing anisometropia (p < 0.001). Subgroup analyses consistently showed increased risk in the 2020 cohort. Conclusion: This study reveals a concerning rise in anisometropia incidence among Chinese school-aged children during the period of the COVID-19 pandemic. These findings highlight the worrisome rise in anisometropia risk during the COVID-19 pandemic and emphasize the importance of early detection and management to safeguard children's visual health.

Combined treatment of human mesenchymal stem cells and green tea extract on retinal ganglion cell regeneration in rats after optic nerve injury.

Retinal ganglion cell (RGC) death and axonal loss cause irreversible vision loss upon optic nerve (ON) injury. We have independently demonstrated that mesenchymal stem cells (MSCs) and green tea extract (GTE) promote RGC survival and axonal regeneration in rats with ON injury. Here we aimed to evaluate the combined treatment effect of human bone marrow-derived MSCs (hBM-MSCs) and GTE on RGC survival and axonal regeneration after ON injury. Combined treatment of hBM-MSCs and GTE promoted RGC survival and neurite outgrowth/axonal regeneration in ex vivo retinal explant culture and in rats after ON injury. GTE increased Stat3 activation in the retina after combined treatment, and enhanced brain-derived neurotrophic factor secretion from hBM-MSCs. Treatment of 10 µg/mL GTE would not induce hBM-MSC apoptosis, but inhibited their proliferation, migration, and adipogenic and osteogenic differentiation in vitro with reducing matrix metalloproteinase secretions. In summary, this study revealed that GTE can enhance RGC protective effect of hBM-MSCs, suggesting that stem cell priming could be a prospective strategy enhancing the properties of stem cells for ON injury treatment.

Persistence of severe global inequalities in the burden of blindness and vision loss from 1990 to 2019: findings from the Global Burden of Disease Study 2019.

AIMS: To assess the global burden and economic inequalities in the distribution of blindness and vision loss between 1990 and 2019. METHODS: A secondary analysis of the Global Burden of Diseases, Injuries and Risk Factors Study (GBD) 2019. Data for disability-adjusted life-years (DALYs) due to blindness and vision loss were extracted from the GBD 2019. Data for gross domestic product per capita were extracted from the World Bank database. Slope index of inequality (SII) and concentration index were computed to assess absolute and relative cross-national health inequality, respectively. RESULTS: Countries with high, high-middle, middle, low-middle and low Socio-demographic Index (SDI) had decline of age-standardised DALY rate of 4.3%, 5.2%, 16.0%, 21.4% and 11.30% from 1990 to 2019, respectively. The poorest 50% of world citizens bore 59.0% and 66.2% of the burden of blindness and vision loss in 1990 and 2019, respectively. The absolute cross-national inequality (SII) fell from -303.5 (95% CI -370.8 to -236.2) in 1990 to -256.0 (95% CI -288.1 to -223.8) in 2019. The relative inequality (concentration index) for global blindness and vision loss remained essentially constant between 1991 (-0.197, 95% CI -0.234 to -0.160) and 2019 (-0.193, 95% CI -0.216 to -0.169). CONCLUSION: Though countries with middle and low-middle SDI were the most successful in decreasing burden of blindness and vision loss, a high level of cross-national health inequality persisted over the past three decades. More attention must be paid to the elimination of avoidable blindness and vision loss in low-income and middle-income countries.

Artificial Intelligence-based database for prediction of protein structure and their alterations in ocular diseases.

The aim of the study is to establish an online database for predicting protein structures altered in ocular diseases by Alphafold2 and RoseTTAFold algorithms. Totally, 726 genes of multiple ocular diseases were collected for protein structure prediction. Both Alphafold2 and RoseTTAFold algorithms were built locally using the open-source codebases. A dataset with 48 protein structures from Protein Data Bank (PDB) was adopted for algorithm set-up validation. A website was built to match ocular genes with the corresponding predicted tertiary protein structures for each amino acid sequence. The predicted local distance difference test-Cα (pLDDT) and template modeling (TM) scores of the validation protein structure and the selected ocular genes were evaluated. Molecular dynamics and molecular docking simulations were performed to demonstrate the applications of the predicted structures. For the validation dataset, 70.8% of the predicted protein structures showed pLDDT greater than 90. Compared to the PDB structures, 100% of the AlphaFold2-predicted structures and 97.9% of the RoseTTAFold-predicted structure showed TM score greater than 0.5. Totally, 1329 amino acid sequences of 430 ocular disease-related genes have been predicted, of which 75.9% showed pLDDT greater than 70 for the wildtype sequences and 76.1% for the variant sequences. Small molecule docking and molecular dynamics simulations revealed that the predicted protein structures with higher confidence scores showed similar molecular characteristics with the structures from PDB. We have developed an ocular protein structure database (EyeProdb) for ocular disease, which is released for the public and will facilitate the biological investigations and structure-based drug development for ocular diseases. Database URL:  http://eyeprodb.jsiec.org.

Longitudinal in vivo evaluation of retinal ganglion cell complex layer and dendrites in mice with experimental autoimmune encephalomyelitis.

Experimental autoimmune encephalomyelitis (EAE), induced by the immunization of myelin oligodendrocyte glycoprotein (MOG), is related to human MOG antibody-associated disease (MOGAD). Neuroinflammation and demyelination of the optic nerve can lead to retinal ganglion cell (RGC) death and axonal damage in MOGAD. Here, we aimed to evaluate the structural changes in RGCs longitudinally by in vivo imaging in mice with RGCs expressing yellow fluorescent protein along the course of EAE. Successful induction of EAE was confirmed by the neurological function scores and histology analyses. The changes in the thickness of ganglion cell complex (GCC) layer and RGC survival and dendrites were monitored longitudinally along the course of EAE. Before the onset of EAE, there were no significant changes in the number and morphology of RGCs and the thickness of the GCC layer as compared to the mice without EAE induction. After the onset of EAE, the thickness of the GCC layer and the RGC number and dendritic network all gradually decreased along the course of EAE. Notably, dendritic shrinkage could be detected earlier than the thinning of the GCC layer. In summary, this study delineated the longitudinal profile of RGC structural changes in EAE mice, providing an assessment platform for monitoring outcomes of RGC treatments.

Accuracy of new intraocular lens calculation formulas in Chinese eyes with short axial lengths.

Purpose: To compare the measurement accuracy of new/updated intraocular lens (IOL) power calculation methods, namely, Kane, Emmetropia Verifying Optical (EVO), with existing methods (Barrett Universal II, Olsen, Haigis, Hoffer Q, Holladay 1, SRK/T) in Chinese eyes with axial lengths ≤ 22.5 mm. Methods: The study included data from patients who underwent uneventful cataract surgery with the insertion of ZCB00 IOL. Refractive prediction errors were determined by calculating the difference between postoperative refraction and the predicted refraction using each formula. Various parameters were evaluated, including mean prediction error (ME), mean absolute error (MAE), median absolute error (MedAE), and the percentage of eyes with prediction errors (PE) within different ranges. Results: The study enrolled 38 eyes of 38 patients, and the Barrett Universal II formula demonstrated the lowest MAE and MedAE among the tested formulas. Post hoc analysis using Wilcoxon signed-rank pairwise comparisons for non-parametric samples with Bonferroni correction revealed no significant difference in postoperative refractive prediction among all the formulas (P > 0.05). The percentage of eyes with PE within ± 0.5 D was as follows: Barrett Universal II, 81.58%; Haigis, 78.95%; EVO, 76.32%; Olsen, 76.32%; Holladay I, 73.68%; SRK/T, 71.05%; Kane, 68.42%; and Hoffer Q, 65.79%. Conclusion: The Barrett Universal II formula was more accurate than the other formulas for Chinese eyes with AL ≤ 22.5 mm.

Progression and incidence of myopia among schoolchildren in the post-COVID-19 pandemic period: a prospective cohort study in Shantou, China.

OBJECTIVES: To determine the progression and incidence of myopia in Chinese schoolchildren in the post-COVID-19 pandemic period in Shantou, China. DESIGN: Prospective cohort study. SETTING: Shantou Myopia Study, China. PARTICIPANTS: 1-year follow-up data were available for 621 881 schoolchildren (301 999 females). Data on spherical equivalent refraction (SER) were collected. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcomes were myopia progression and incidence. Myopia progression is defined as a change of SER towards the negative direction in the follow-up visit. Incidence is defined as the proportion of schoolchildren who were not myopic but developed myopia in the follow-up study. Age, sex and SER at baseline were evaluated as associated factors for myopia burden, which were defined as the secondary outcomes. RESULTS: Mean progression of SER was -0.35±0.97 D for the population (ranging from -0.06 D at 18 years of age to -0.46 D at 11 years of age), with a rapid myopic progression for students at the age of 10-12 years (-0.50 D in girls and -0.44 D in boys). A myopic shift greater than -0.50 D/year occurred in 256 299 eyes (41.21%). Myopic progression in refraction was associated with the 10-12 years age groups (OR 1.42; 95% CI 1.39 to 1.45, p<0.001), female sex (OR 1.09; 95% CI 1.08 to 1.10, p<0.001) and higher refractive errors at baseline (OR>1.00, p<0.001). The annual incidence of myopia among schoolchildren was 24.85%, with an incidence of 26.69% in girls and 23.02% in boys. CONCLUSIONS: Our study revealed an annual myopia progression of -0.35 D and an incidence of 24.85% among schoolchildren in the post-COVID-19 pandemic period. Myopia progressed rapidly at 10-12 years of age, with -0.50 D in girls and -0.44 D in boys. The incidence was higher for children aged 10-11 years and for girls.

Global, regional, and national burden of multiple sclerosis from 1990 to 2019: Findings of global burden of disease study 2019.

Background: The global rising prevalence and incidence of multiple sclerosis (MS) has been reported during the past decades. However, details regarding the evolution of MS burden have not been fully studied. This study aimed to investigate the global, regional, and national burden and temporal trends in MS incidence, deaths, and disability-adjusted life years (DALYs) from 1990 to 2019 using the age-period-cohort analysis. Methods: We performed a secondary comprehensive analysis of incidence, deaths, and DALYs of MS by calculating the estimated annual percentage change from 1990 to 2019 obtained from the Global Burden of Disease (GBD) 2019 study. The independent age, period, and birth cohort effects were evaluated by an age-period-cohort model. Results: In 2019, there were 59,345 incident MS cases and 22,439 MS deaths worldwide. The global number of incidences, deaths, and DALYs of MS followed an upward trend, whereas the age-standardized rates (ASR) slightly declined from 1990 to 2019. High socio-demographic index (SDI) regions had the highest ASR of incidences, deaths, and DALYs in 2019, while the rate of deaths and DALYs in medium SDI regions are the lowest. Six regions which include high-income North America, Western Europe, Australasia, Central Europe, and Eastern Europe had higher ASR of incidences, deaths, and DALYs than other regions in 2019. The age effect showed that the relative risks (RRs) of incidence and DALYs reached the peak at ages 30-39 and 50-59, respectively. The period effect showed that the RRs of deaths and DALYs increased with the period. The cohort effect showed that the later cohort has lower RRs of deaths and DALYs than the early cohort. Conclusion: The global cases of incidence, deaths, and DALYs of MS have all increased, whereas ASR has declined, with different trends in different regions. High SDI regions such as European countries have a substantial burden of MS. There are significant age effects for incidence, deaths, and DALYs of MS globally, and period effects and cohort effects for deaths and DALYs.

Prevalence of myopia and uncorrected myopia among 721 032 schoolchildren in a city-wide vision screening in southern China: the Shantou Myopia Study.

AIMS: To explore the prevalence and risk factors for myopia and uncorrected myopia in schoolchildren in southern China. METHODS: The government-led Shantou Myopia Study was conducted from September 2020 to June 2021. Non-cycloplegic refraction was performed. Uncorrected visual acuity (UCVA) was measured along with presenting visual acuity if participants wore spectacles. Spherical equivalent refraction (SER) is defined as the spherical dioptres added to half of the cylindrical dioptres. Myopia is defined as SER <-0.50 dioptre with UCVA of <20/20 in at least one eye. RESULTS: This study enrolled 724 828 schoolchildren (77.8% of all schoolchildren in Shantou) from 901 schools. Data from 721 032 schoolchildren (99.5%) were analysed (mean age 11.53±3.13 years, 6-20 years, 373 230 boys and 347 802 girls). Among them, 373 459 (51.8%) had myopia: 37.1% of 465 696 children in primary schools, 75.4% of 170 164 children in junior high schools and 84.8% of 85 172 children in senior high schools. The prevalence of myopia increases non-linearly with age. Older age, female and urban living environment were independently associated with myopia prevalence and myopic SER. Among the 373 459 children with myopia, 60.0% had no refractive correction: 74.9%, 53.9% and 35.5% in primary, junior high and senior high schools, respectively. CONCLUSION: The overall prevalence of myopia among schoolchildren in Shantou was 51.8%, higher than the national average in China. The proportion of uncorrected myopia is high, especially in primary schools. Our results indicate the need for public education on eye care among schoolchildren even in a municipal city.

Potential productivity loss from uncorrected and under-corrected presbyopia in low- and middle-income countries: A life table modeling study.

Objective: To estimate the burden of potential productivity losses due to uncorrected and under-corrected presbyopia in LMICs among the working-age population in both the cross-sectional and longitudinal manner. Methods: We extracted data for the prevalence of presbyopia from the Global Burden of Diseases (GBD), Injuries, and Risk Factors Study 2019. Data for the gross domestic product (GDP) per capita were extracted from the World Bank database and Central Intelligence Agency's World Factbook. We introduced life table models to construct age cohorts (in 5-year age groups) of the working-age population (aged from 40 to 64 years old) in LMICs, with simulated follow-up until 65 years old in people with and without uncorrected presbyopia. The differences in productivity-adjusted life years (PALYs) lived and productivity between these two cohorts were calculated. The potential productivity loss was estimated based on GDP per capita. The WHO standard 3% annual discount rate was applied to all years of life and PALYs lived. Results: In 2019, there were 238.40 million (95% confidence interval [CI]: 150.92-346.78 million) uncorrected and under-corrected presbyopia cases in LMICs, resulting in 54.13 billion (current US dollars) (95% confidence interval [CI]: 34.34-79.02 billion) potential productivity losses. With simulated follow-up until retirement, those with uncorrected and under-corrected presbyopia were predicted to experience an additional loss of 155 million PALYs (an average loss of 0.7 PALYs per case), which was equivalent to a total loss of US$ 315 billion (an average loss of US$ 1453.72 per person). Conclusions: Our findings highlight the considerable productivity losses due to uncorrected and under-corrected presbyopia in LMICs, especially in a longitudinal manner. There is a great need for the development of enabling eye care policies and programs to create access to eye care services, and more healthcare investment in the correction of presbyopia in the working-age population in LMICs. This study could provide evidences for some potential health-related strategies for socio-economic development.

Assessment of the influence of keratometry on intraocular lens calculation formulas in long axial length eyes.

PURPOSE: Hyperopic surprises tend to occur in axial myopic eyes and other factors including corneal curvature have rarely been analyzed in cataract surgery, especially in eyes with long axial length (≥ 26.0 mm). Thus, the purpose of our study was to evaluate the influence of keratometry on four different formulas (SRK/T, Barrett Universal II, Haigis and Olsen) in intraocular lens (IOL) power calculation for long eyes. METHODS: Retrospective case series. A total of 180 eyes with axial length (AL) ≥ 26.0 mm were divided into 3 keratometry (K) groups: K ≤ 42.0 D (Flat), K ≥ 46.0 D (Steep), 42.0 < K < 46.0 D (Average), and all the eyes were underwent phacoemulsification cataract surgery with Rayner (Hove, UK) 920H IOL implantation. Prediction errors (PE) were compared between different formulas to assess the accuracy of different formulas. Multiple regression analysis was performed to investigate factors associated with the PE. RESULTS: The mean absolute error was higher for all evaluated formulas in Steep group (ranging from 0.66 D to 1.02 D) than the Flat (0.34 D to 0.67 D) and Average groups (0.40 D to 0.74D). The median absolute errors predicted by Olsen formula were significantly lower than that predicted by Haigis formula (0.42 D versus 0.85 D in Steep and 0.29 D versus 0.69 D in Average) in Steep and Average groups (P = 0.012, P < 0.001, respectively). And the Olsen formula demonstrated equal accuracy to the Barrett II formula in Flat and Average groups. The predictability of the SRK/T formula was affected by the AL and K, while the predictability of Olsen and Haigis formulas was affected by the AL only. CONCLUSIONS: Steep cornea has more influence on the accuracy of IOL power calculation than the other corneal shape in long eyes. Overall, both the Olsen and Barrett Universal II formulas are recommended in long eyes with unusual keratometry.

Comparison of Vault Measurements Using a Swept-Source OCT-Based Optical Biometer and Anterior Segment OCT.

Background: To newly describe the vault measurement by using a widely used swept-source OCT-based optical biometer (IOLMaster700) and accessd the accuracy of vault measurement. Methods: This was a retrospective, cross-sectional study. All patients underwent implantable Collamer lens (ICL) implantation surgery without complications. IOLMaster700 and AS-OCT analyses were conducted for each eye on the same day in the same condition. Measurements of anterior chamber depth (ACD), corneal-ICL (C-ICL), and vault values were made and recorded. The repeatability of the IOL Master700 measurements was quantified based upon intraclass correlation coefficient (ICC) values. Correlations between IOL Master700 and AS-OCT measurements made with these different analytical approaches were assessed. The agreement of instruments was evaluated using Bland-Altman plots. Results: The IOLMaster700 instrument yielded highly reliable measurements of vault, C-ICL, and ACD (ICC = 0.996, 0.995, 0.995, respectively). Vault, C-ICL and ACD values as measured using the IOLMaster700, was slightly smaller than that measured via AS-OCT, but these differences were not significant (p = 0.652, p = 0.121 and p = 0.091, respectively). The vault, C-ICL, and ACD measurements by these two instruments were strongly correlated (r = 0.971, r = 0.944, and r = 0.963, respectively; all p < 0.001). The 95% limits of agreement for vault, C-ICL, and ACD measurements between the two devices were-0.08 to 0.08 mm,-0.14 to 0.11 mm, and-0.13 to 0.10 mm, respectively. Conclusions: The IOLMasrer700 can measure implanted ICL vault with a high degree of accuracy and repeatability. Good correlations and agreement were observed between IOLMaster700 and AS-OCT in measuring vault, C-ICL, and ACD measurements.

Diabetic retinopathy with extensively large area of capillary non-perfusion: characteristics and treatment outcomes.

BACKGROUND: Capillary non-perfusion is an important characteristic for diabetic retinopathy (DR) indicating microvascular damage and ischemia. Data on the description and treatment outcomes of DR with large area of non-perfusion are lacking to date. We aim to describe the characteristics and treatment outcomes in a series of patients with DR who presented extensively large area of capillary non-perfusion (LACNP). METHODS: Fundus fluorescein angiograms from medical charts in patients diagnosed with DR between Jan 2017 and Dec 2019 were retrospectively reviewed. Clinical data in eyes with LACNP including imaging and laboratory findings at the first presentation were analyzed. The LACNP was defined as over 70% area of capillary non-perfusion throughout the whole image retina. The mean follow-up duration was 12.4 ± 16.7 months. Follow-up data including extensive pan-retinal photocoagulation and surgical intervention and treatment outcomes were evaluated. RESULTS: A total of 43 eyes in 24 patients with LACNP were included, accounting for 3.3% of DR populations in the same period. The overall percentage of non-perfusion area was 79.1 ± 8.1%. All patients received proper control of diabetes and hypertension, and extensive pan-retinal laser photocoagulation. During the follow-up periods, 20 eyes (46.5%) developed severe neovascular complications, of which 15 eyes (34.9%) underwent vitrectomy and/or anti-glaucoma surgeries. Conservative therapies including glycemic control and supplemental laser photocoagulation were conducted in 23 eyes (53.5%) without neovascular complications. In the final follow-up, best corrected visual acuity improved or maintained stable in 19 eyes (44.2%) while deteriorated in 24 eyes (55.8%). CONCLUSIONS: The presence of LACNP is the hallmark of advanced DR and often indicates a poor visual outcome, although aggressive treatments may slow DR progression and maintain central vision for some time.

Comparison of accuracy of intraocular lens power calculation for eyes with an axial length greater than 29.0 mm.

PURPOSE: To evaluate and compare the accuracy of six different formulas (Emmetropia Verifying Optical version 2.0, Kane, SRK/T, Barrett Universal II, Haigis and Olsen) in intraocular lens (IOL) power calculation for extremely long eyes. METHODS: Retrospective case-series. Seventy-three eyes with axial length (AL) ≥ 29.0 mm and underwent phacoemulsification cataract surgery with Rayner (Hove, UK) 920H IOL implantation from January 2018 to March 2020 were included. Prediction errors (PE) were calculated and compared between different formulas to evaluate the accuracy of formulas. Multiple regression analysis was performed to investigate factors associated with the PE. RESULTS: The Kane formula had mean prediction error close to zero (- 0.01 ± 0.51 D, P = 0.841), whereas the EVO 2.0, SRK/T, Barrett Universal II, Haigis and Olsen formulas produced hyperopic outcomes (all P < 0.001). The median absolute error [inter-quartile range] produced by the EVO 2.0, Kane, Barrett Universal II and Olsen formulas showed no significant difference (0.33 D [0.48], 0.30 D [0.44], 0.34 D [0.39], 0.29 D [0.37], respectively, pairwise comparison P > 0.05), but was significantly lower than that of the SRK/T and Haigis formulas (0.85 D [0.66], 0.80 D [0.54], respectively, pairwise comparison P < 0.001). The AL and the PE produced by the SRK/T formula were significantly positively correlated in extremely myopic eyes (ß = 0.248, P < 0.001), whereas the trend was not demonstrated in other formulas. CONCLUSIONS: For cataract patients with axial length greater than 29.0 mm, the accuracy of the EVO 2.0, Kane, Barrett Universal II and Olsen formulas is comparable and significantly better than that of the SRK/T and Haigis formulas.

Prevalence of Visual Impairment in Preschool Children in Southern China.

Purpose: The goal of this study is to assess the prevalence and distribution of visual impairment in preschool children in southern China. Methods: Preschool children aged 36-83 months were enrolled in a vision screening program in Shantou City. Visual acuity test and non-cycloplegic refraction were conducted. According to the American Academy of Ophthalmology (AAO) guidelines, visual impairment was defined as uncorrected visual acuity (UCVA) in either eye <20/50, 20/40, and 20/32 in children aged 36-47, 48-59, and 60-83 months, respectively, as well as an interocular difference (IOD) of ≥ two lines of UCVA. Results: The UCVA test was successfully performed on 7,880 children (94.6% of the enrolled population). A total of 938 (11.9%; 95% CI 11.2-12.6) children were found to have reduced UCVA in the worse eye, and 393 (5%; 95% CI 4.5-5.5) of the children had an IOD of two or more lines. Combining the reduced UCVA with the IOD criteria identified 1,032 (13.1%; 95% CI 12.4-13.8) children with visual impairment. UCVA in preschool children improves with age naturally and boys have slightly better age-adjusted UCVA than girls. Causes of reduced visual acuity included uncorrected refractive error, amblyopia, congenital cataract, and others. The cylindrical diopter in the right eye of children with reduced vison was higher than that of children with normal vision (1.19 ± 1.05 vs. 0.52 ± 0.49, P < 0.001). A total of 146 (1.9%, 95% CI 1.6-2.2) of the preschool children wore spectacles. The proportion of wearing spectacles increased with age (χ2 = 35.714, P < 0.001), but with IOD increasing by.1 logMAR, the odds of wearing spectacles decreased by 44.8%. Conclusion: This study provided data on the prevalence of visual impairment in preschool children in China by large-scale school-based vision screening. Further studies should be conducted to verify the benefit from vision screening.

Diagnostic Classification of Bruch's Membrane Opening-Minimum Rim Width and Retinal Nerve Fiber Layer Thickness in Myopic Eyes by Optical Coherence Tomography.

Purpose: This study was conducted in order to compare the diagnostic classification of Bruch's membrane opening-minimum rim width (BMO-MRW) and RNFL thickness in normal myopic subjects by using optical coherence tomography (OCT). Methods: This cross-sectional study involved 75 healthy myopic subjects [spherical equivalent (SE) ≤ -0.5D] from April 2019 to January 2020. One eye of each subject was randomly selected for examination. BMO-MRW and peripapillary RNFL thickness were measured by spectral-domain OCT (Spectralis, Heidelberg Engineering GmbH, Heidelberg, Germany). All the subjects were divided into three groups: low myopic group (SE > -3D), moderate myopic group (-6D < SE ≤ -3D), and high myopic group (SE ≤ -6D). A nonparametric test was used to analyze the difference among groups. Linear regression was used to analyze the relationship between BMO-MRW/RNFL thickness and axial length/spherical equivalent. McNemar test was used to compare the diagnostic classification between BMO-MRW and RNFL thickness. Results: The RNFL thickness classified a significantly higher percentage of eyes as outside normal limits/borderline in at least 1 quadrant (BMO-MRW, 4%; RNFL thickness, 34.67%; p < 0.01). There was no significant correlation between BMO-MRW/RNFL thickness and AL/SE. The low myopia (SE > -3D) had a significantly lower percentage of eyes classified as outside normal limits/borderline in at least 1 quadrant than the moderate myopia (-6D < SE ≤ -3D) and high myopia (SE ≤ -6D) (low myopia, 12.5%; moderate/high myopia, 42.42%/50%; p < 0.05). Conclusion: BMO-MRW had a lower percentage of eyes classified as outside normal limits/borderline in at least 1 quadrant than RNFL thickness in normal myopic subjects. When referring to the diagnostic classification of RNFL thickness in myopic subjects, caution should be exercised in interpreting positive results. Further studies are needed to compare the diagnostic accuracy of these two measurements in myopic glaucoma patients.

Determinants of peripapillary retinal nerve fiber layer's grayscale value in normal eyes by spectral domain optical coherence tomography.

To determine and evaluate the distribution, variation, and determinants of peripapillary retinal nerve fiber layer (pRNFL) grayscale value with spectral-domain optical coherence tomography (SD-OCT) in normal eyes. In this cross-sectional study, three hundred ninety-seven normal eyes from 397 healthy Chinese adults aged 18-80 were consecutively recruited from a tertiary eye care center. An SD-OCT instrument took pRNFL imaging. We used a customized software to measure pRNFL parameters, including thickness and grayscale value. Univariable and multiple linear regression analyses were performed to examine the relationship between pRNFL grayscale value with ocular (e.g., axial length [A.L.], spherical equivalent [S.E.], intraocular pressure [IOP]), and systemic (e.g., age, sex) factors. A total of 397 eyes from 397 healthy subjects were included in the final analysis with mean (± SD) age 44.63 ± 16.43 years (range 18-80 years) and 196 (49.4%) males. The mean average of pRNFL grayscale value and thickness 164.82 ± 5.69 and 106.68 ± 8.89 µm, respectively. pRNFL grayscale value in nasal sectors (163.26 ± 9.31) was significantly lower comparing those in all other five sectors (all with p < 0.001)]. In multivariable analysis, average pRNFL grayscale value was independently correlated to older age (ß = - 0.053, p = 0.002), longer axial length (ß = - 0.664, p = 0.003), lower RPE grayscale value (ß = 0.372, p < 0.001) and lower ImageQ (ß = 0.658, p < 0.001). In this study, we provided normative SD-OCT data on the pRNFL grayscale value profile in nonglaucomatous eyes. Lower average pRNFL grayscale value was independently correlated to older age, longer axial length, lower RPE grayscale value, and lower ImageQ. These determinants should be considered when interpreting pRNFL grayscale value in glaucoma assessment.

Corneal curvature-associated MTOR variant differentiates mild myopia from high myopia in Han Chinese population.

BACKGROUND: Myopia is the most prevalent ocular disorder in the world, and corneal parameters have been regarded as key ocular biometric parameters determining the refractive status. Here, we aimed to determine the association of genome-wide association study-identified corneal curvature (CC)-related gene variants with different severity of myopia and ocular biometric parameters in Chinese population. METHODS: Total 2,101 unrelated Han Chinese subjects were recruited, including 1,649 myopia and 452 control subjects. Five previously reported CC-associated gene variants (PDGFRA, MTOR, WNT7B, CMPK1 and RBP3) were genotyped by TaqMan assay, and their association with different myopia severity and ocular biometric parameters were evaluated. RESULTS: Joint additive effect analysis showed that MTOR rs74225573 paired with PDGFRA rs2114039 (P = .009, odds ratio (OR) = 4.91) or CMPK1 rs17103186 (P = .002, OR = 13.03) were significantly associated with higher risk in mild myopia. Critically, mild myopia subjects had significantly higher frequency in MTOR rs74225573 C allele than high myopia subjects (P = .003), especially in male subjects (P = .001, OR = 0.49). High myopia subjects carrying MTOR rs74225573 C allele have significant flatter CC (P = .035) and longer corneal radius (P = .044) than those carrying TT genotype. CONCLUSION: This study revealed that male high myopia subjects are more prone to carry CC-related MTOR rs74225573 T allele, whereas mild myopia subjects are prone to carry the C allele. MTOR rs7422573 variant could be a genetic marker to differentiate mild from high myopia in risk assessment. ABBREVIATIONS: ACD: anterior chamber depth; AL: axial length; AL/CR: axial length/corneal radius ratio; ANOVA: analysis of variance; CC: corneal curvature; CCT: central corneal thickness; C.I.: confidence interval; CMPK1: cytidine/uridine monophosphate kinase 1; CR: corneal radius; D: diopter; GWAS: genome-wide association studies; HWE: Hardy-Weinberg equilibrium; LT: lens thickness; MIPEP: mitochondrial intermediate peptidase; MTOR: mechanistic target of rapamycin kinase; OR: odds ratio; PDGFRA: platelet-derived growth factor receptor-α; RBP3: retinol-binding protein 3; SD: standard deviation; SE: spherical equivalence; SNTB1: syntrophin beta 1; VCD: vitreous chamber depth; VIPR2: vasoactive intestinal peptide receptor 2; WNT7B: wingless/integrated family member 7B.