Myopia

Effect of atropine 0.01% on myopia control in children aged 6-13 years during the 2022 lockdown in Shanghai

Purpose

To compare the myopic progression in children treated with 0. 01% atropine and those who discontinued atropine during the 2022-home quarantine in Shanghai.

Methods

In this retrospective study, children aged 6-13 years with follow-up visits before (between January 2022 and February 2022) and after the lockdown (between July 2022 and August 2022) were included. Cycloplegic refraction and axial length (AL) were measured at both visits. The atropine group had continuous medication during the lockdown while the control group discontinued. The 0.01% atropine eyedrops were administered daily before bedtime. The types of spectacle lens were recorded: single vision (SV) spectacles or defocus incorporated multiple segments lenses (DIMS).

Results

In total, 41 children (81 eyes) in the atropine group and 32 children (64 eyes) in the control group were enrolled. No significant difference was found in the demographic characteristics, spherical diopter, spherical equivalent (SE), AL, and follow-up time between the two groups before the lockdown in 2022 (all p > 0.1). After the home confinement, a greater myopia progression was observed in the control group (-0.46 ± 0.42 D) compared to atropine group (-0.26 ± 0.37 D; p = 0.0023). Axial elongation was also longer in the control group than that in children sustained with atropine (0.21 ± 0.17 vs. 0.13 ± 0.15 mm, p = 0.0035). Moreover, there was no significant change of spherical diopter and SE during lockdown in the atropine + DIMS combined subgroup (0.03 ± 0.033 D for spherical diopter, p = 0.7261 and 0.08 ± 0.27 D for SE, p = 0.2042, respectively). However, significant myopic shift was observed in the atropine + SV subgroup during the quarantine time (-0.31 ± 0.39 D for SE and 0.15 ± 0.16 mm for AL, both p < 0.001).

Conclusion

Children treated with 0.01% atropine had slower myopia progression during the lockdown period in Shanghai compared with children discontinued. Moreover, the effect of atropine on myopic prevention can be strengthened with DIMS lenses.

Evaluation of retinal vascular density and related factors using OCTA in children and adolescents with myopia without maculopathy

BACKGROUND

Myopia is the most common ophthalmic condition worldwide with a rapidly increasing prevalence. This study aimed to compare the retinal microvasculature in the superficial capillary plexus (SCP) in children and adolescents with mild and moderate/high myopia using optical coherence tomography angiography, determine the relationship between retinal parameters and axial length (AL), and understand the occurrence and progression of myopia in microcirculation.

METHODS

This prospective observational study included 39 participants with mild myopia and 33 participants with moderate/high myopia. Vessel density (VD) and perfusion density (PD) in the SCP, the foveal avascular zone (FAZ), and AL were compared between the groups and the relationship between these retinal parameters and AL was assessed.

RESULTS

No difference in SCP VD or PD was observed between the two groups. The FAZ did not differ significantly between groups whereas significant differences in age, height, refractive status, and AL were observed. Significantly shorter AL was observed in participants with mild myopia compared with the moderate/high myopia group. Age was positively correlated with height (r = 0.852) and refractive status was negatively correlated with AL (r = -0.588). AL was positively correlated with VD (r = 0.317) and PD (r = 0.308) in the SCP and AL was negatively correlated with the FAZ (r = -0.434).

CONCLUSIONS

This study revealed that superficial foveal microvessel density was unaffected in children and adolescents without pathological myopia. However, myopia progression was associated with a change in AL, and an AL increase altered macular blood flow.

Choroidal Vascular Density Quantification in High Myopia with or without Choroidal Neovascularization Using Optical Coherence Tomography Angiography

Purpose

The aim of this study was to analyze choroidal vascular density alteration in high myopia with or without choroidal neovascularization by using optical coherence tomography angiography (OCTA).

Methods

This was a cross-sectional, observational study that included 60 high-myopia eyes. All the participants had comprehensive ophthalmic assessments with visual acuity, intraocular pressure, slit lamp-assisted biomicroscopy, color fundus photography, axial length, optometry, and OCTA. Age, sex, and comorbidities were collected from their medical charts. Univariate and multiple analyses were made to compare the age, spherical equivalent, choroidal vascular density, gender, and choroidal thickness between normal and patients with choroidal neovascularization.

Results

60 eyes with high myopia were included in our study, including 30 eyes with choroidal neovascularization and 30 eyes without choroidal neovascularization or other fundus pathology. The mean age of high myopic patients was older in the choroidal neovascularization group than in the normal group (48.43 ± 19.06 years vs. 28.83 ± 9.92 years, p < 0.01). The mean choroidal thickness of high myopic patients was thinner in the neovascularization group than in the normal group (68.81 ± 48.81 μm vs. 137.80 ± 66.33 μm, p < 0.01). The mean choroidal vascular density in the normal group was greater than in the choroidal neovascularization group (82.43 ± 8.73 vs. 67.54 ± 12.56, p < 0.01). There was no significant difference in spherical equivalent between the choroidal neovascularization group and the normal group (-10.56 ± 2.97D vs. -11.93 ± 3.38D, p = 0.11). Multivariate analysis showed that after adjusting for covariates, less choroidal vascular density and older age were independent factors associated with choroidal neovascularization in the high myopic eye.

Conclusion

Decreased choroidal vascular density and older age played an important role in the development of choroidal neovascularization in high myopic eyes. OCTA may help us to identify the highly myopic patients that need to intervene.

Trend of myopia through different interventions from 2010 to 2050: Findings from Eastern Chinese student surveillance study

Purpose

First, to investigate the utilization rate and effect of proven myopic interventions. Second, to predict the prevalence of myopia and high myopia, as well as Years Lived with Disability (YLD) caused by an uncorrected refractive error in children and teens in Eastern China from 2010 to 2050 under different interventions.

Methods

(1) The surveillance of common diseases among children and adolescents in Jiangsu Province from 2010 to 2021 provides the database for myopia screening and intervention utilization surveys. (2) The National Bureau of Statistics and the Global Burden of Disease Study 2016 (GBD2016) are the foundation for the estimated myopes and YLD. (3) A systematic review provides the strong or weak impact of intervention in the prediction model. (4) The trend of screening myopia from 2010 to 2050 under various treatments is predicted using a GM (1,1) model.

Results

By the year 2050, myopia is expected to affect 8,568,305 (7-12 years old) and 15,766,863 (13-18 years old) children and adolescents, respectively (95% CI: 8,398,977-8,737,633). The utilization prevalence of myopia-proven interventions for myopic children included outdoor activities, orthokeratology lenses, atropine treatment, contact lenses, frame glasses, and eye exercises, with respective rates of 31.9-33.1, 2.1-2.3, 6.0-7.5, 2.2-2.7, 60.4-62.2, and 64.7-72.5%. All interventions have substantial effects on myopia after parental myopia and behavior pattern adjustment, including physical activity, near work, dietary pattern, and sleep. Under strong intervention, the estimated reduced myopia prevalence by the year 2050 is 1,259,086 (95% CI: 1,089,758-1,428,414) for children aged 7-12, and 584,785 (95% CI: 562,748-606,823) for children aged 13-18, respectively.

Conclusion

Among myopic Chinese children and adolescents, the use rates and effects of proven myopia interventions vary. Under the present intervention strategy, the prevalence of myopia and high myopia will increase from 2010 to 2050. The overall number of myopic people can be greatly decreased by implementing timely, steady, comprehensive interventions.

Associations between anthropometric indicators and refraction in school-age children during the post-COVID-19 era

Purpose

To explore the associations between anthropometric indicators and refraction in school-aged children in the post-COVID-19 era.

Methods

Data were collected from 25,644 children aged 7 to 12 years in 48 elementary schools in Tianjin. The comprehensive examination included height, weight, systolic blood pressure (SBP), diastolic blood pressure (DBP), refraction, and calculation of BMI, with a follow-up visit after 6 months. Myopia was defined as spherical equivalent refraction (SER) ≤-0.50 diopter (D). Bivariate correlation coefficients and multiple linear regression models were used to explore the cross-sectional and longitudinal associations between anthropometric indicators (height, weight, BMI, SBP, and DBP) and refraction.

Results

The mean changes in height, weight, BMI, SBP, DBP, and SER of the participants were 4.03 ± 2.18 cm, 3.10 ± 2.39 kg, 0.45 ± 1.16 kg/m², 2.26 ± 14.74 mmHg, 2.18 ± 11.79 mmHg and -0.17 ± 0.51 D, respectively. Overall, height, weight, BMI, SBP, and DBP were all correlated with SER (r = -0.324, r = -0.234, r = -0.121, r = -0.112, r = -0.066, both p < 0.001), and changes in height and weight were correlated with changes in SER (r = -0.034, -0.031, both p < 0.001). Furthermore, multiple linear regression analysis revealed that the association of BMI, SBP, and DBP with SER was significant in myopic children but not in non-myopic children. The association between changes in weight and changes in SER was only present in non-myopic children but not in myopic children.

Conclusion

Height and weight were negatively correlated with SER in both cross-sectional analysis and longitudinal changes, indicating that children's height, weight and growth rate may be used as a reference indicator for myopia risk prediction and myopia progression monitoring.

Artificial intelligence technology for myopia challenges: A review

Myopia is a significant global health concern and affects human visual function, resulting in blurred vision at a distance. There are still many unsolved challenges in this field that require the help of new technologies. Currently, artificial intelligence (AI) technology is dominating medical image and data analysis and has been introduced to address challenges in the clinical practice of many ocular diseases. AI research in myopia is still in its early stages. Understanding the strengths and limitations of each AI method in specific tasks of myopia could be of great value and might help us to choose appropriate approaches for different tasks. This article reviews and elaborates on the technical details of AI methods applied for myopia risk prediction, screening and diagnosis, pathogenesis, and treatment.

Effects of Greenness on Myopia Risk and School-Level Myopia Prevalence Among High School-Aged Adolescents: Cross-sectional Study

BACKGROUND

Myopia is a serious public health issue. High school-aged adolescents in Beijing have an alarming prevalence of myopia. Therefore, determining myopia protective factors is essential. Green space has a certain association with myopia protective factors that can protect against myopia.

OBJECTIVE

This study aims to examine the effects of green space around schools on individual myopia risk in high school-aged adolescents and the school-level myopia prevalence.

METHODS

Green space was measured using the normalized difference vegetation index (NDVI). A total of 13,380 samples of 51 high schools were selected from a 2021 Beijing Municipal Health Commission survey. Adolescent myopia was defined as a spherical equivalent of ≤-1.00 diopters in the worse eye. Generalized linear mixed models with a binomial error structure were used to analyze the effects of the NDVI on personal myopia risk and adjust them by other factors, such as demographics, exposure time, and outdoor exercise. The effects of the NDVI on school-level myopia prevalence with adjusted demographics and the relative position factors of trees were analyzed through quasibinomial regression.

RESULTS

The overall prevalence of myopia was 80.61% (10,785/13,380, 95% CI 79.93%-81.27%). Although with a 0.1 increase in the 500 and 1000 m buffer NDVIs adjusted by demographic and other factors, the high school-aged personal myopia risk significantly dropped by 16% (odds ratio [OR] 0.84, 95% CI 0.73-0.97) and 12% (OR 0.88, 95% CI 0.79-0.99), respectively. However, only the adjusted 500 m buffer NDVI (by demographics and the position of trees) with a 0.1 increase significantly reduced the school-level myopia prevalence by 15% (OR 0.85, 95% CI 0.74-0.98). Subgroup analysis showed that the adjusted effects of the 500 m buffer NDVI are significant in schoolgirls (OR 0.82, 95% CI 0.72-0.93), juniors (OR 0.82, 95% CI 0.72-0.94), the Han nationality (OR 0.84, 95% CI 0.72-0.97), 1-year exposure (OR 0.84, 95% CI 0.71-0.99) and 3-year exposure (OR 0.78, 95% CI 0.65-0.94).

CONCLUSIONS

The greenness of a 500 m buffer around schools is associated with a lower personal myopia risk among adolescents and a lower prevalence of myopia in schools. With regard to prevention and control activities, green space within a 500 m buffer around schools is suggested as an independent protective factor for adolescent myopia.

Rare variant analyses across multiethnic cohorts identify novel genes for refractive error

Refractive error, measured here as mean spherical equivalent (SER), is a complex eye condition caused by both genetic and environmental factors. Individuals with strong positive or negative values of SER require spectacles or other approaches for vision correction. Common genetic risk factors have been identified by genome-wide association studies (GWAS), but a great part of the refractive error heritability is still missing. Some of this heritability may be explained by rare variants (minor allele frequency [MAF] ≤ 0.01.). We performed multiple gene-based association tests of mean Spherical Equivalent with rare variants in exome array data from the Consortium for Refractive Error and Myopia (CREAM). The dataset consisted of over 27,000 total subjects from five cohorts of Indo-European and Eastern Asian ethnicity. We identified 129 unique genes associated with refractive error, many of which were replicated in multiple cohorts. Our best novel candidates included the retina expressed PDCD6IP, the circadian rhythm gene PER3, and P4HTM, which affects eye morphology. Future work will include functional studies and validation. Identification of genes contributing to refractive error and future understanding of their function may lead to better treatment and prevention of refractive errors, which themselves are important risk factors for various blinding conditions.

The impact of parental migration on left-behind children's vision health in rural China

BACKGROUND

Parental migration is an important factor affecting left-behind children's health. However, few studies have addressed the effect of parental migration on children's vision health in China. To fill the gap, this study aimed to assess the impact of parental migration on left-behind children's vision health and to explore the possible mechanisms of the effect.

METHODS

Data were obtained from the baseline survey of the China Education Panel Survey (CEPS), which included over 10,000 junior high school students. This study used myopia, the most common vision problem among junior high school students, and tried to analyze whether myopia was corrected with eyeglasses as indicator variables of vision health. The impact of parental migration on vision health was assessed using an instrumental variables approach.

RESULTS

The results show that parental migration reduced the likelihood of myopia in left-behind children and decreased the possibility of myopic left-behind children being corrected. This result passed a series of robustness tests. The mechanism analysis indicated that compared to non-left-behind children, left-behind children spent more time on outdoor activities and less time on after-school classes, reducing their risk of being myopic. Further, because left-behind children live apart from their parents, their myopia problem is more difficult for parents to notice, and left-behind children are less likely to inform their parents of their myopia than non-left-behind children actively. This helps to explain why left-behind children have a lower correction rate with eyeglasses.

CONCLUSIONS

Our findings suggest that parental migration, while not increasing the prevalence of myopia in left-behind children, has led to inequity in myopic left-behind children's correction. Given the severe consequences of uncorrected myopia, action is required to enhance the correction rate of myopic left-behind children.

The impact of COVID-19 home confinement on axial length in myopic children undergoing orthokeratology

CLINICAL RELEVANCE

Understanding the impact of home confinement on axial length in myopic children undergoing orthokeratology (OK) treatment facilitates the management of myopia control during coronavirus disease 2019 (COVID-19) lockdown.

BACKGROUND

The outbreak of COVID-19 and the corresponding home confinement measures have brought a considerable challenge to myopia control. The study aimed to investigate the influence of home quarantine on axial length in myopic children with OK treatment.

METHODS

Axial length measurements during and before COVID-19 home confinement were retrospectively collected from the myopic children treated with OK, and the children were prospectively followed up after finishing the quarantine. The monthly axial length growth before, during and after confinement was calculated and compared in the full dataset and subgroups stratified by age. Influencing factors for monthly axial length growth during confinement were analysed.

RESULTS

Ninety-two myopic children with OK treatment were enrolled in this study. In the full dataset, covariates adjusted (gender, time interval, baseline axial length and age) monthly axial length growth during confinement was not significantly different from that before (P = 0.213) or after the home confinement (P = 1.000). Multiple linear regression showed that the monthly axial length growth during confinement was negatively correlated with age (P = 0.002). Subgroup analysis based on age demonstrated that the adjusted monthly axial length growth was not significantly different among three periods (P > 0.05) for younger children. For children older than 12-year-old, the adjusted monthly axial length growth during home confinement was significantly slower than before the confinement (P = 0.011), but not the monthly axial length growth after the confinement (P = 1.000).

CONCLUSIONS

COVID-19 home confinement does not increase the myopic axial length elongation in children with OK treatment.

Design and assessment of amblyopia, strabismus, and myopia treatment and vision training using virtual reality

Background

Virtual reality is a relatively new intervention that has the potential to be used in the treatment of eye and vision problems. This article reviews the use of virtual reality-related interventions in amblyopia, strabismus, and myopia research.

Methods

Sources covered in the review included 48 peer-reviewed research published between January 2000 and January 2023 from five electronic databases (ACM Digital Library, IEEE Xplore, PubMed, ScienceDirect and Web of Science). To prevent any missing relevant articles, the keywords, and terms used in the search included "VR", "virtual reality", "amblyopia", "strabismus," and "myopia". Quality assessment and data extraction were performed independently by two authors to form a narrative synthesis to summarize findings from the included research.

Results

Total number of 48 references were reviewed. There were 31 studies published on amblyopia, 18 on strabismus, and 6 on myopia, with 7 studies overlapping amblyopia and strabismus. In terms of technology, smartphone-based virtual reality headset viewers were utilized more often in amblyopia research, but commercial standalone virtual reality headsets were used more frequently in myopia and strabismus-related research. The software and virtual environment were mostly developed based on vision therapy and dichoptic training paradigms.

Conclusion

It has been suggested that virtual reality technology offers a potentially effective tool for amblyopia, strabismus, and myopia studies. Nonetheless, a variety of factors, especially the virtual environment and systems employed in the data presented, must be explored before determining whether virtual reality can be effectively applied in clinical settings. This review is significant as the technology in virtual reality software and application design features have been investigated and considered for future reference.

A meta-analysis of visual outcomes and optical quality after small incision lenticule extraction versus implantable collamer lens for myopia

OBJECTIVE

To evaluate possible differences in visual outcome and optical quality when small incision lenticule extraction (SMILE) versus implantable collamer lens (ICL) is used to correct myopia.

METHODS

PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials were searched up to August 2021 to identify relevant studies. The PRISMA guidelines were followed. Primary outcomes were postoperative efficacy, safety, and predictability at the end of follow-up. Secondary outcomes were changes in modulation transfer function cutoff frequency (MTF _cut-off), objective scatter index (OSI) values, total higher-order aberrations (HOAs), spherical aberrations, and coma aberrations.

RESULTS

Seven studies with a total of 1296 eyes (SMILE: 731 eyes; TECXL: 565 eyes) were included. The ICL group had a better MTF _cut-off (P = 0.007) and less change in the proportion of HOAs (P < 0.001), spherical aberrations (P = 0.009), and coma (P = 0.006) than the SMILE group. For the other outcomes, there were no statistically significant differences.

CONCLUSIONS

SMILE and ICL implantation are comparable in efficacy, safety, and predictability for correcting myopia. Larger studies with longer follow-up times are warranted to provide a better understanding of the benefits of SMILE and ICL implantation.

Automated detection of myopic maculopathy using five-category models based on vision outlooker for visual recognition

Purpose

To propose a five-category model for the automatic detection of myopic macular lesions to help grassroots medical institutions conduct preliminary screening of myopic macular lesions from limited number of color fundus images.

Methods

First, 1,750 fundus images of non-myopic retinal lesions and four categories of pathological myopic maculopathy were collected, graded, and labeled. Subsequently, three five-classification models based on Vision Outlooker for Visual Recognition (VOLO), EfficientNetV2, and ResNet50 for detecting myopic maculopathy were trained with data-augmented images, and the diagnostic results of the different trained models were compared and analyzed. The main evaluation metrics were sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), area under the curve (AUC), kappa and accuracy, and receiver operating characteristic curve (ROC).

Results

The diagnostic accuracy of the VOLO-D2 model was 96.60% with a kappa value of 95.60%. All indicators used for the diagnosis of myopia-free macular degeneration were 100%. The sensitivity, NPV, specificity, and PPV for diagnosis of leopard fundus were 96.43, 98.33, 100, and 100%, respectively. The sensitivity, specificity, PPV, and NPV for the diagnosis of diffuse chorioretinal atrophy were 96.88, 98.59, 93.94, and 99.29%, respectively. The sensitivity, specificity, PPV, and NPV for the diagnosis of patchy chorioretinal atrophy were 92.31, 99.26, 97.30, and 97.81%, respectively. The sensitivity, specificity, PPV, and NPV for the diagnosis of macular atrophy were 100, 98.10, 84.21, and 100%, respectively.

Conclusion

The VOLO-D2 model accurately identified myopia-free macular lesions and four pathological myopia-related macular lesions with high sensitivity and specificity. It can be used in screening pathological myopic macular lesions and can help ophthalmologists and primary medical institution providers complete the initial screening diagnosis of patients.

Development and Validation of a Model to Predict Who Will Develop Myopia in the Following Year as a Criterion to Define Premyopia

PURPOSE

To develop and validate models to predict who will develop myopia in the following year based on cycloplegic refraction or ocular biometry and to identify thresholds of premyopia.

METHODS

Prospective longitudinal data of nonmyopic children at baseline from the Guangzhou Twins Eye Study and the Guangzhou Outdoor Activity Longitudinal Study were used as the training set, and the Singapore Cohort Study of the Risk factors for Myopia study formed the external validation set. Age, sex, cycloplegic refraction, ocular biometry, uncorrected visual acuity, and parental myopia were integrated into 3 logistic regression models to predict the onset of myopia in the following year. Premyopia cutoffs and an integer risk score system were derived based on the identified risk.

RESULTS

In total, 2896 subjects with at least 2 visits were included. Cycloplegic refraction at baseline is a better predictor to identify the children with myopia onset [C-statistic=0.91, 95% confidence interval (CI), 0.87-0.94; C-statistic=0.92, 95% CI, 0.92-0.92 for internal and external validation, respectively], comparing to axial length, corneal curvature radius (CR) and anterior chamber depth (C-statistic=0.81, 95% CI, 0.73-0.88; C-statistic=0.80, 95% CI, 0.79-0.80, respectively), and axial length/CR (C-statistic=0.78, 95% CI, 0.71-0.85; C-statistic=0.76, 95% CI, 0.75-0.76). With a risk of >70%, the definitions of premyopia indicating approaching myopia onset were 0.00 D for 6-8 years and -0.25 D for ≥9 years in children with 2 myopic parents.

CONCLUSIONS

Either cycloplegic refraction or ocular biometry can predict 1-year risk of myopia. Premyopia can be successfully defined through risk assessments based on children's age and predict who would require more aggressive myopia prophylaxis.

Longitudinal choroidal thickness changes among Chinese young adults with various refractive errors

Purpose

To determine the characteristics of longitudinal choroidal thickness (CT) and axial length (AL) changes in a group of Chinese young adults with various refractive errors.

Methods

In this 2 year prospective cohort study, a total of 291 (314 enrolled at baseline) Chinese medical freshmen aged 18 to 22 years (mean age, 18.7 ± 0.9 years) underwent eye examinations at baseline and follow-up visits, including cycloplegic refraction, ocular biometry measurements, and swept-source optical coherence tomography. Choroidal thickness measurements were performed at nine locations in the macular area.

Results

At baseline, the CT and AL was significant differences among groups of emmetropia, mild to moderate myopia and high myopia. During a two-year period, there were significant differences found in the changes of the subfoveal CT (p < 0.001) and parafoveal CT of 7 locations between emmetropia and mild to moderate myopia, and the changes of the subfoveal CT (p = 0.002) and parafoveal CT of 6 locations between emmetropia and high myopia. But there were no differences for AL and SE (p > 0.05). The multivariable linear regression analysis showed that baseline subfoveal CT (per 1 μm) was a significant factor affecting the changes of subfoveal CT (p < 0.001), whereas age, gender, and baseline AL were not significantly associated.

Conclusion

The longitudinal change in CT varies with refractive errors in Chinese young adults aged 18 to 22 years over a two-year period. The changes of subfoveal CT were significantly associated with the baseline subfoveal CT, but not associated with baseline AL.

Cataract surgery in myopic eyes

PURPOSE OF REVIEW

We discuss the preoperative, intraoperative, and postoperative considerations for cataract surgery in eyes with high myopia. We also reviewed the recent literature on refractive outcomes and complications of cataract surgery in myopic eyes.

RECENT FINDINGS

Several novel intraocular lens (IOL) power calculation formulas have recently been developed to optimize refractive outcomes. Haigis formula is the most accurate among the third-generation IOL formulas. Novel formulas such as Barrett Universal II, Kane, and modified Wang-Koch adjustment for Holladay I formula provide a better refractive prediction compared with old formulas. Intraoperatively, the chopping technique is preferred to minimize pressure on weak zonules and reduce the incidence of posterior capsule rupture. Anterior capsular polishing is recommended to reduce the risk of postoperative capsular contraction syndrome (CCS). Postoperatively, complications such as refractive surprises, intraocular pressure spikes, and CCS remain higher in myopic eyes. Only 63% of myopic patients with axial length more than 26 mm achieve a visual acuity at least 20/40 after cataract surgery, mainly because of coexisting ocular comorbidities.

SUMMARY

There are multiple preoperative, intraoperative, and postoperative considerations when performing cataract surgery in myopic eyes. Further research is needed to optimize the refractive outcomes in these eyes and determine the best IOL formula. Surgeons should be adept and knowledgeable with different techniques to manage intraoperative complications.

Myopic axial elongation in school children and the COVID-19 lockdown in Russia: The Ural Children Myopia Study

BACKGROUND

To explore an influence of the COVID-19-related lockdown on ocular axial elongation in school children in Russia.

METHODS

The participants of the school-based Ufa Children Myopia Study in Ufa/Russia underwent, at baseline in 2019/2020 before the COVID-19 outbreak and after a COVID-19-related lockdown, a detailed interview and ophthalmological examination including laser interferometric biometry for axial length measurement.

RESULTS

The study included 461 children (age:10.7±2.1 years;range:6.8-16.9 years). The mean follow-up was 1.41±0.33 years. Mean axial length at baseline was 23.96±0.95mm and 23.94±0.95mm in the right and left eyes, respectively. During the study period, annual axial elongation (right/left eyes) was 0.19±0.17mm/0.19±0.22mm. Before the COVID-19 lockdown, the age-dependent coefficient for axial length (ADCAL) for the right/left eyes was 0.21mm (95%CI:0.17,0.25)/0.20mm (95%CI:0.16,0.24). In children younger than 9.6 years (n = 157), annual axial elongation (right eyes) during the study period was larger than the ADCAL before the COVID-19 outbreak (0.29 mm (95%:0.00,0.66) versus 0.21 mm (95%CI:0.02,0.41)). In the groups aged 9.6 to 11.4 years (n = 148) and aged >11.4 years (n = 156), annual axial elongation during the study period was comparable to the ADCAL before the COVID-19 outbreak (0.18mm (95%CI:-0.07,0.46) versus 0.22mm (95%CI:-0.05,0.48), and (0.09mm (95%CI:-0.15,0.34) versus 0.14mm (95%CI:0.00,0.28), respectively). In children aged ≤9 years at study end, axial length at study end was 0.20 mm larger than axial length at baseline in the participants aged ≤9 years at baseline. Larger axial elongation during the study period was associated (multivariable analysis) with younger age (beta:-0.62;P<0.001), female sex (beta:0.21;P<0.001), longer study period (beta:0.22;P<0.001), and longer axial length at baseline (beta:0.28;P<0.001), and marginally, with less time spent outdoors (beta:-0.07;P = 0.06).

CONCLUSIONS

The COVID-19-related lockdown in the Russian city of Ufa was associated with a relatively minor increase in axial elongation, detected only in children aged <9.6 years.

Five-year change in refractive error and its risk factors: results from the Gutenberg Health Study

BACKGROUND/AIMS

To examine the 5-year change in refractive error in phakic eyes and its risk factors in the general population.

METHODS

The Gutenberg Health Study (GHS) is a population-based cohort study including 15 010 participants from Germany aged 35-74 years at baseline examination (2007-2012). After 5 years, a follow-up examination was carried out (83% participation). 5-year change of spherical equivalent (SE) was computed as difference between follow-up and baseline objective refraction. Linear and logistic regression analysis were conducted analysing potential risk factors. Only phakic eyes at follow-up examination were included.

RESULTS

Right eyes of 10 175 subjects were included. An age-related shift of refractive error was identified, namely -0.12 D for age 35-44 years, 0.25 D for age 45-54 years, 0.25 D for age 55-64 years and 0.12 D for age 65-74 years during the 5-year follow-up. Smokers had a hyperopic shift (OR=1.31; p<0.001), while baseline SE (OR=0.89 per dioptre; p<0.001) and female sex (OR=1.49; p<0.001) were linked with a myopic shift. Education, occupation and other cardiovascular parameters were not associated with change in refractive error.

CONCLUSIONS

The GHS demonstrates a parabolic shift in refractive error with a myopic shift at age 35-44 years, followed by a hyperopic shift at age 45-64 years which decreases at higher age. Smoking is associated with a hyperopic shift whereas female sex and myopic baseline SE is associated with a myopic shift. Educational level and occupation were not linked to a change in refractive error at age 35-74 years.

Ethnic Disparities in Risk Factors for Myopia among Han and Minority Schoolchildren in Shawan, Xinjiang, China

SIGNIFICANCE

The ethnic differences in myopia rates, ocular dimensions, and risk factors between Han and non-Han schoolchildren observed in this study may help fill the knowledge gap about ethnic minorities and are important for China and other countries to address vision-related health inequalities among different ethnic groups.

PURPOSE

This study aimed to investigate the risk factors of juvenile myopia and elucidate the disparities of risk factors among Han and non-Han school students in Xinjiang, China.

METHODS

A population-based cross-sectional study of 876 schoolchildren from grades 1 to 9 was conducted in the Anjihai Middle School in Shawan, Xinjiang Uygur Autonomous Region, China. Visual acuity and ocular biometry were assessed, and personal information, including behavior, birth status, and familial factors, was collected using self-made standardized questionnaires.

RESULTS

The myopia rate among students of Han ethnicity (50.5%) was the highest, followed by Hui (41.3%) and Uygur et al. (32.0%, P < .001). Similar patterns were observed for mean axial length. The mean axial lengths are 23.7, 23.4, and 23.3 mm, respectively ( P = .01). Overall, performing high-quality eye exercises, longer sleep duration, being born in summer, parental smoking, and consuming more food containing anthocyanins were all associated with a lower incidence of myopia. Meanwhile, Han ethnicity, intensive near task, bad eye habits, and myopic mothers were associated with higher odds of myopia. After adjusting for environmental influences pertaining to myopia, the variation in myopia prevalence between Han and Uygur et al. remained significant, whereas it changed to not significant between Han and Hui ethnicities.

CONCLUSIONS

Significant disparities were found in the prevalence of myopia among various ethnic groups in Shawan, Xinjiang. Life habits, birth status, and familial factors may contribute to such variance and play different roles in the occurrence of juvenile myopia among various ethnicities.

Increasing prevalence of myopia and the impact of education in primary-school students in Xi'an, north-western of China

Purpose

The present study was performed to detect the prevalence of myopia among primary-school students in Xi'an, north-western of China.

Methods

The present study was a school-based study with students aged from 6 to 13 years old. All the individuals underwent ophthalmological examination and spherical equivalent (SE) of refractive error were measured with non-cycloplegic refraction. Myopia was defined as a SE of ≤ -0.5 diopters (D), and further divided into three stratified groups based on SE: low myopia (≤ -0.5 to >-3.0 D), moderate myopia (≤ -3.0 to >-6.0 D), and high myopia (≤ -6.0 D). Relative risk factors, including age, sex, grade and ethnicity were investigated using questionnaire.

Results

A total of 4,680 individuals were eligible for this survey and 4,654 (99.4% participation rate) were finally included (51.2% boys). The mean age of participants was 8.756 ± 1.727 years. The whole city-level prevalence of total myopia was 57.1% (95% CI: 55.7-58.6%). Additionally, the prevalence of low, moderate, and high myopia was 45.0% (95% CI: 43.5-46.4%), 11.1% (95% CI: 10.2-12.0%), and 1.0% (95% CI: 0.7-1.3%), respectively. Moreover, grade (education level) instead of age, sex and ethnicity was the most essential risk factor for prevalence of overall myopia (OR = 1.844, 95% CI: 1.605-2.119), and an increase of prevalence by 84.4% per grade was seen. Furthermore, similar associations of grade were significant with low myopia (OR = 1.613, 95% CI: 1.385-1.877) and moderate myopia (OR = 2.186, 95% CI: 1.693-2.823), meanwhile, prevalence of low myopia and moderate myopia demonstrated an increase of prevalence by 61.3 and 118.6% per grade, respectively. None of the factors included in the present study was significant risk factor for high myopia.

Conclusions

The present study investigated a non-negligible high prevalence of myopia among primary-school students in Xi'an, north-western of China, and a gradual increasing in proportion with education level.

Perforating scleral vessels adjacent to myopic choroidal neovascularization achieved a poor outcome after intravitreal anti-VEGF therapy

Background

This study aimed to summarize the features of perforating scleral vessels (PSVs) in patients with myopic choroidal neovascularization (CNV) (mCNV) using optical coherence tomography angiography (OCTA) and to identify the associations with the response after intravitreal anti-vascular endothelial growth factor (anti-VEGF) therapy.

Methods

A consecutive series of naïve patients who had mCNV and received intravitreal anti-VEGF therapy with a follow-up duration of 12 months or more were enrolled. The prevalence, location, and branches of PSVs were analyzed. Projection-resolved OCTA (PR-OCTA) was used to analyze the neovascular signals between CNV and PSVs. Best corrected visual acuity (BCVA) and central macular thickness (CMT) were measured. The proportion of CMT change relative to baseline was used to assess therapeutic response.

Results

A total of 44 eyes from 42 patients with mCNV were enrolled. PSVs were identified in 41 out of 44 eyes. Branches were identified in the PSVs of 24 eyes (57.14%), and 20 eyes did not have PSV branches (47.62%). In eight eyes (18.18%), PSVs were adjacent to mCNV, and in 36 eyes (81.82%), PSVs were not adjacent to mCNV. After anti-VEGF therapy for mCNV, BCVA increased (F = 6.119, p < 0.001) and CMT decreased (F = 7.664, p < 0.001). In the eyes where PSVs were adjacent to mCNV, BCVA improvements (F = 7.649, p = 0.009) were poor, and changes in CMT were small.

Conclusion

The eyes with PSVs adjacent to mCNV showed poor therapeutic responses after intravitreal anti-VEGF therapy.

Inner limiting membrane bridges within Bruch's membrane defects in pathological myopia

The purpose of the study was to examine peculiarities of the inner limiting membrane (ILM) in axially elongated eyes. The histomorphometric study included human globes enucleated due to reasons such as painful secondary angle-closure glaucoma or malignant uveal melanomas. Using light microscopy, we searched for regions with ILM-specific features in association with a marked axial elongation. Out of 279 eyes (279 patients) (mean age: 61.8 ± 13.9 years; axial length: 25.5 ± 3.1 mm (range: 20.0-37.0 mm)), two eyes (axial length: 30 mm and 34 mm, respectively) showed one region and two regions, respectively, characterized by ILM presence and absence of all other retinal layers, retinal pigment epithelium, Bruch´s membrane (BM) and choroid. The length of these regions, called ILM-bridges, was 1.06 mm, 0.73 mm, and 0.62 mm, respectively. All ILM-bridges were spatially associated with a larger, underlying BM defect and with localized scleral thinning without a staphylomatous scleral configuration. The distance between the ILM-bridges and the optic disc ranged between 1.92 mm and 4.21 mm. In univariable analysis, ILM-bridge number increased with longer axial length (beta: 0.19; P = 0.002) and higher BM defect prevalence (beta: 0.21; P = 0.001), while in multivariable analysis, the ILM-bridges number remained to be significantly correlated only with a higher prevalence of BM defect (beta: 0.15; P = 0.048). ILM-bridges occur in eyes with pathologic myopia in spatial association with underlying, larger BM defects. They may be due to an axial elongation-associated local stretching and rupture of all other retinal layers, caused by the BM defect-related enlargement of the retinal undersurface. Future studies may explore whether these histologic observations support the notion of the ILM having a relatively high biomechanical strength against myopic stretching-associated forces.

Characteristics of the optic disc in young people with high myopia

PURPOSE

This study aimed to investigate the characteristics of the optic disc in adolescents and young adults with high myopia by applying optical coherence tomography angiography.

METHODS

A total of 112 patients with high myopia (spherical equivalent refraction (SER) ≤ -6.00 D) aged 12 to 30 years old were enrolled in this cross-sectional study. Parapapillary atrophy (PPA) and ovality index from scanning laser ophthalmoscopy images and the degree of optic disc tilt from the optic nerve head (ONH) OCT B-scans were analysed using ImageJ and MATLAB software. Peripapillary retinal nerve fibre layer thickness (pRNFLT) and radial peripapillary capillary vessel density (RPC VD) around the optic disc were obtained from the images of the optic disc angiography scan.

RESULTS

In young high myopia patients, the PPA area was positively correlated with age, axial length (AL) and pRNFLT (all p < 0.05) and negatively correlated with SER (r = -0.222, p = 0.020). The degree of the optic disc tilt was associated with increasing AL and pRNFLT (all p < 0.05). The disc area was positively correlated with AL, pRNFLT, and RPC VD (all p < 0.05). In the multivariate regression analysis, PPA area was independently associated with the degree of optic disc tilt and disc area. The degree of optic disc tilt was affected by AL and PPA area while the change of disc area was influenced by PPA area and pRNFLT (all p < 0.05).

CONCLUSION

In young patients with high myopia, PPA area, the degree of optic disc tilt and disc area increased with AL and pRNFLT, while decreased with SER. The association between these factors was slightly different in the adolescent and young adult groups. The degree of the optic disc tilt was more associated with AL and SER in the adolescent group while disc area showed more correlated with AL and SER in the young adult group.

Effects of physical activity and use of digital devices on visual acuity in children and adolescents during the COVID-19 pandemic: A cross-sectional study

Purpose

To determine the association between poor visual acuity, the use of digital devices and physical activity (PA) during the COVID-19 pandemic.

Methods

A total of 327,646 Chinese children and adolescents were included in the analysis using a cluster random sampling method; this is a case-control study, of those 144,708 children and adolescents with poor visual acuity were included in the case group, while 182,938 who did not have poor visual acuity were included in the control group. A logistic regression model was used to assess the contribution of PA and the use of digital devices to poor visual acuity.

Results

A total of 144,708 children and adolescents experienced poor visual acuity during the COVID-19 pandemic; 54.8% were male, and 55.2% live in rural areas. Compared to controls, children and adolescents with poor visual acuity exhibited more time for the use of digital devices (4.51 ± 2.44 vs. 3.79 ± 2.34 for cases and controls, respectively; P < 0.001) and PA (3.07 ± 0.92 vs. 2.85 ± 1.00 for cases and controls, respectively; P < 0.001). During the COVID-19 pandemic, risk factors related to poor visual acuity among children and adolescents included the use of digital devices (OR 1.135; 95% CI 1.132-1.139), and PA (OR 1.269; 95%CI 1.259-1.278). The results of interaction analysis show that for children and adolescents aged 12 to 17, the positive association between the use of digital devices and poor visual acuity decreased. The interaction effect between PA and digital devices is 0.987.

Conclusions

Children and adolescents were at risk of poor visual acuity during the COVID-19 pandemic. Extended use of the digital devices increased the risk of poor visual acuity, especially for children aged 6-11 years. But the risk of poor visual acuity among children and adolescents decreases as the time spent on PA increases.

Application of orthokeratology on myopia control and its effect on ocular surface and meibomian gland function in Chinese myopic adolescents

Purpose

This study aimed to investigate the influence of orthokeratology (OK) on myopia control and ocular surface and meibomian gland function in myopic adolescents.

Methods

A prospective study was conducted over a 12-month period. The subjects were classified into two groups, namely, the OK lens group and the frame glasses control group. Axial length, corneal curvature, ocular surface, and meibomian gland parameters were measured at baseline, 1, 3, 6, and 12 months after wearing OK lenses.

Results

The axial length growth rate in the OK group was significantly slower than in the control group (P < 0.01). The naked eye vision and the ocular surface disease index (OSDI) scores recorded 1, 3, 6, and 12 months after wearing OK lenses were significantly higher than the scores recorded before wearing OK lenses. There was no significant difference in other ocular parameters at each follow-up time point compared with pre-wearing (P > 0.05). After using the OK lens for 6 months, the OSDI score and corneal fluorescein staining (CFS) score increased significantly (P < 0.001), but there were no significant differences in other parameters among the groups. No infectious keratitis occurred during the study.

Conclusion

These results provide evidence that the use of OK lenses can control the axial growth and progress rate of myopia compared with frame glasses. During the 12-month follow-up, although wearing OK lenses may have aggravated dry eye symptoms, each patient's ocular surface and meibomian gland function did not change significantly, indicating that the use of OK lenses is a relatively safe modality for the control of myopia in adolescents.

Global trends and frontiers of research on pathologic myopia since the millennium: A bibliometric analysis

Background and purpose

Pathologic myopia (PM) is an international public health issue. This study aimed to analyze PM research trends by reporting on publication trends since 2000 and identifying influential journals, countries, authors, and keywords involved in PM.

Methods

A bibliometric analysis was performed to evaluate global production and development trends in PM since 2000 and the keywords associated with PM.

Results

A total of 1,435 publications were retrieved. PM has become a fascinating topic (with relative research interest ranging from 0.0018% in 2000 to 0.0044% in 2021) and a global public health issue. The top three countries with the highest number of publications were China, the USA, and Japan. The journals, authors, and institutions that published the most relevant literature came from these three countries. China exhibited the most rapid increase in the number of publications (from 0 in 2000 to 69 in 2021). Retina published the most papers on PM. Kyoko Ohno-Matsui and Tokyo Medical and Dental University contributed the most publications among authors and institutions, respectively. Based on keyword analysis, previous research emphasized myopic choroidal neovascularization and treatment, while recent hotspots include PM changes based on multimodal imaging, treatment, and pathogenesis. Keyword analysis also revealed that deep learning was the latest hotspot and has been used for the detection of PM.

Conclusion

Our results can help researchers understand the current status and future trends of PM. China, the USA, and Japan have the greatest influence, based on the number of publications, top journals, authors, and institutions. Current research on PM highlights the pathogenesis and application of novel technologies, including multimodal imaging and artificial intelligence.

Axial Length and Choriocapillaris Flow Deficits in Non-pathological High Myopia

PURPOSE

To examine the relationship between axial length (AL) and choriocapillaris (CC) flow deficits percentage (FD%) in non-pathological highly myopic eyes.

DESIGN

Prospective cross-sectional study.

METHODS

This study included Chinese patients with non-pathological high myopia, which was defined by an AL of > 26 mm and a META-PM classification grade of <2. Swept-source optical coherence tomography angiography was used to obtain 6 × 6 mm images of the macular CC. The CC FD% was measured in the fovea, parafovea, and perifovea subfields.

RESULTS

A total of 1017 individuals (1017 eyes) with a mean age of 35.95 ± 14.11 years were included. After adjusting for age, sex, intraocular pressure, body mass index, systolic blood pressure, and image quality score, the overall CC FD% increased by 0.27% (95% CI 0.02, 0.52; P = .034) for each mm increase in AL. Among subfields, longer AL was associated with a higher CC FD% in the perifovea (β = 0.53, 95% CI 0.30, 0.77; P < .001), and was not associated with a higher CC FD% in the parafovea (β = 0.08, 95% CI -0.26, 0.42; P = .652) and fovea (β = 0.001, 95% CI -0.50, 0.50; P = .999).

CONCLUSIONS

The CC FD% increased with a longer AL in high myopia in the perifovea region but not in the fovea and parafovea fields. These findings may be of interest in elucidating the etiology of myopic axial elongation.

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

Purpose

Due to pubertal development and crystalline lens compensation, axial length (AL) continues to increase among non-progressive myopic children (absolute annual spherical equivalent (SE) progression less than 0.25 diopter), but the amount is unknown. This study was to investigate the cutoff of AL change to accurately differentiate between progressive and non-progressive myopes.

Methods

A total of 8,546 myopic and treatment-naive children aged 6–10 years were enrolled from two cohort studies. AL with optical biometer and cycloplegic SE with auto refraction were evaluated at baseline and annually. Annual AL change was calculated, and the percentiles of annual axial elongation among progressive and non-progressive myopes were estimated by quantile regression with restricted cubic spline. Area under receiver-operating characteristic (ROC) curve (AUROC), positive predictive value (PPV), and negative predictive value (NPV) were applied to evaluate the accuracy of predicting progressive and non-progressive myopes.

Results

Among 8,546 myopic children, 603 (7.06%) were non-progressive myopes. Annual AL changes among non-progressive myopes remained stable with the median annual change being 0.25 mm, while the median for progressive myopes decreased with age from 0.58 to 0.42 mm. AUROC for distinguishing between non-progressive and progressive myopes was 0.88 and was > 0.85 for each age group. Annual AL change, the cutoff of 0.20 mm/year, had significantly high PPV and NPV in predicting progressive myopes with high proportion of progressive myopes and non-progressive myopes with low proportions of progressive myopes.

Conclusion

Myopic children with non-progressive status had markedly less axial elongation than progressive ones. AL changes with cutoff of 0.20 mm/year could differentiate between non-progressive and progressive status and may be an alternative for evaluating progressive status.

Assessment of neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio in patients with high myopia

BACKGROUND

Previous reports have suggested that inflammation levels play a crucial role in the pathogenesis of high myopia (HM). This study aimed to investigate the relationship between HM and systemic inflammation using the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR).

METHODS

Overall, 100 age- and sex-matched participants were recruited for the study, including 50 participants each in the non-HM (NHM) and HM groups. Ocular examinations and blood tests were performed. The NLR and PLR values were calculated from complete blood counts. Receiver operating characteristic (ROC) curves and optimal cut-off values were used to determine the optimal values of the NLR and PLR to distinguish between the HM and NHM groups.

RESULTS

The values of NLR and PLR were significantly elevated in the HM group compared with those in the NHM group (P < 0.001 and P = 0.010, respectively). Axial length (AL) was significantly correlated with the NLR (r = 0.367, P < 0.001) and PLR (r = 0.262, P = 0.009). In the ROC analysis, the NLR value to distinguish between the HM and NHM groups was 0.728; the best cut-off value was 2.68, with 76% sensitivity and 62% specificity. The PLR value to distinguish between the HM and NHM groups was 0.650; the best cut-off value was 139.69, with 52% sensitivity and 76% specificity.

CONCLUSION

The findings of this study indicate that the development of HM may be associated with systemic inflammation measured using the NLR and PLR.

TRIAL REGISTRATION

The study was registered on December 28, 2021 ( http://www.chictr.org.cn ; ChiCTR2100054834).

Early Detection of Refractive Errors by Photorefraction at School Age

Early detection and treatment of refractive defects during school age are essential to avoid irreversible future vision loss and potential school problems. Previously, vision screening of preschool children used methods based on subjective visual acuity; however, technologies such as photorefraction have promoted the detection of refractive errors quickly and easily. In this study, 1347 children from 10 schools in Madrid aged 4 to 12 years participated in a program of early detection of visual problems, which consisted of visual screening composed of anamnesis and photorefraction with a PlusOptix A12R. The prevalence of refractive errors was analyzed in terms of spherical equivalent, cylinder and its orientation, and potential cases of development of high myopia or amblyopia. Hyperopia predominates in the early years, but the number of myopic subjects is higher than that of hyperopic subjects from the age of ten onwards. At all ages, the predominant orientation of astigmatism was with-the-rule. On average, 80% of the myopic subjects were uncorrected. Potential high myopia increased with age, from 4 to 21% of the measured population. Potential amblyopia cases decreased across age groups, from 19 to 13.7%. There is a need to raise awareness of the importance of vision screening at school age to address vision problems.

Parents' intentions toward preschool children's myopia preventive behaviors: Combining the health belief model and the theory of planned behavior

Objective

This study aimed to develop an integrated model based on the health belief model (HBM) and the theory of planned behavior (TPB) to explore the influencing factors of parents' intentions toward preschool children's myopia preventive behaviors.

Methods

This cross-sectional study was conducted in Minhang District, Shanghai, China in January 2022. One thousand six hundred and twenty-eight parents of preschool children from seven preschools were recruited in the study. A four-part questionnaire was used to collect data on socio-demographic characteristics, HBM variables, TPB variables and parental intentions. This study used exploratory factor analysis to analyze HBM and TPB items. Hierarchical multiple regression analysis was performed to explore the relationship between independent variables and parents' intentions toward preschool children's myopia preventive behaviors.

Results

The final integrative model showed that perceived severity, perceived barriers, attitudes, subjective norms, and perceived behavioral control were associated with parents' intentions toward preschool children's myopia preventive behaviors. In model 1, Child's age was entered as a control variable and explained 0.6% of the variance (F = 7.241, p = 0.007). When the HBM variables were entered in model 2, the proportion of variance increased to 25.4% (F = 73.290, P < 0.001). In model 3, TPB variables were entered and explained 63.2% of the variance (F = 246.076, p < 0.001).

Conclusion

The integrated model of HBM and TPB constructed in this study significantly improved the degree of explanation of parents' intentions toward preschool children's myopia preventive behaviors. Parents' perceived severity, perceived barriers, attitudes, subjective norms, and perceived behavioral control can be prioritized intervention targets for myopia preventive practices in preschool children.

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

Purpose

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

Methods

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

Results

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

Conclusions

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

Association of maternal diabetes during pregnancy with visual acuity development in offspring: a prospective cohort study

AIMS

We aimed to investigate the association between maternal diabetes before or during pregnancy and visual acuity development in offspring at 1 and 4 years old.

METHODS

This prospective cohort study comprised 301 individuals born in 2015-2017. Those who had maternal diabetes during or before pregnancy (type 1 diabetes, type 2 diabetes and gestational diabetes) were investigated. Two visual examinations were routinely performed on children relatively at the age of 1 at physical examination and at the age of 4 at admission to school to assess the possible effects of gestational exposure to diabetes on the visual system of the offspring.

RESULTS

Data were collected on children aged 1 and 4, which consisted of 173 children of mothers exposed to diabetes and 128 children of mothers without diabetes). We found no significant association between maternal diabetes during pregnancy and visual acuity development in 1-year-old offspring. At 4 years old, the incidence of amblyopia and strabismus was similar in both groups. Prenatal exposure to maternal diabetes was associated with a 171% increased risk of high RE: OR 2.71 (95% CI 1.08, 6.81), p < 0.05. Astigmatism (13.3% vs 5.5%) was found to be significantly more prevalent in children born to mothers with GD than in the controls (p = 0.025 in both groups). Moreover, offspring exposed to PGDM had a higher overall risk of high RE than those exposed to GDM during pregnancy (25.0% vs 17.4%). We further found that in the offspring of diabetic mothers, the risk of high RE was significantly increased among children who were female or who spent more time using electronic devices daily.

CONCLUSIONS

Our findings suggest that maternal diabetes during pregnancy is associated with an increased risk of high RE in offspring. Regular ophthalmological screening should be advised to offspring of mothers with diabetes diagnosed before or during pregnancy.

Myopia progression and associated factors of refractive status in children and adolescents in Tibet and Chongqing during the COVID-19 pandemic

Objectives

To investigate myopia progression and associated factors of refractive status among children and adolescents in Tibet and Chongqing in China during the COVID-19 pandemic.

Methods

A population-based cross-sectional study was conducted to compare rates of myopia and high myopia, axial length (AL), spherical equivalent (SE), outdoor activity time, digital device use, and frequency of visual examinations for children and adolescents affected by myopia in Chongqing and Tibet in 2021.

Results

A total of 2,303 students from Chongqing and 1,687 students from Tibet were examined. The overall prevalence of myopia and high myopia in these two groups were 53.80 and 7.04% vs. 43.86 and 1.30%, respectively in each case. The Chongqing students had a longer AL than the group from Tibet (23.95 vs. 23.40 mm, respectively; p < 0.001). The mean SE of the students with myopic parents in Tibet was lower than that of the students in Chongqing with myopic parents (-2.57 ± 2.38 diopters (D) vs. -2.30 ± 2.34 D, respectively) (p < 0.001). Conversely, the mean SE of the students from urban areas in Chongqing was lower than that of the students in Tibet (-2.26 ± 2.25 D vs. -1.75 ± 1.96 D, respectively; p < 0.001). The Chongqing students exhibited lower SE (-2.44 ± 2.22 D) than their Tibetan counterparts (mean SE: -1.78 ± 1.65 D (p = 0.0001) when spending more than 2.5 h outdoors. For example, 61.35% of the students in Tibet spent more than 2.5 h outdoors daily, compared with 43.04% of the students in Chongqing. Correspondingly, the proportion of students using digital devices in Tibet (64.43%) was lower than that in Chongqing (100%). For the latter, 38.62% of the students in Chongqing spent more than 2.5 h online using digital devices compared to 10.49% of the students in Tibet. Greater monitoring of visual status was observed for the Chongqing students (mean SE: -1.90 ± 1.98 D) compared with students in Tibet (mean SE: -2.68 ± 1.85 D) (p = 0.0448), with the frequency of optimal examinations being every 6 months. Outdoor activity time was identified as a common risk factor for myopia in both of the populations examined, with odds ratios (ORs) of 1.84 (95% CI: 1.79-1.90) in Chongqing and 0.84 (95% CI: 0.73-0.96) in Tibet. Digital screen time was associated with myopia and high myopia in Chongqing, with ORs of 1.15 (95% CI: 1.08-1.22) and 1.06 (95% CI: 0.94-1.77), respectively. Digital screen time was also found to be a risk factor for high myopia in Tibet (OR: 1.21, 95% CI: 0.77-1.61). The type of digital devices used was also associated with myopia and high myopia in Tibet (OR: 1.33, 95% CI: 1.06-1.68 and OR: 1.49, 95% CI: 0.84-2.58, respectively). Finally, examination frequency was found to correlate with high myopia in the Tibet group (OR: 1.79, 95% CI: 0.66-2.71).

Conclusion

Based on our data, we observed that the prevalence of refractive errors in children and adolescents was significantly lower in Tibet than in Chongqing. These results are potentially due to prolonged outdoor activity time, and the type and time of use for digital devices that characterize the group of children and adolescents from Tibet. It is recommended that parents and children in Chongqing would benefit from increased awareness regarding myopia progression and its prevention.

Screen time and myopia: A serial multiple mediator SEM analysis

Background

COVID-19 has influenced education systems worldwide, and significantly increased screen time for college students, posing a potential risk of myopia. In China, ninety percent of college students suffer from myopia. Excessive screen time changes college students' lifestyles, imposes potential health risks, and affects opportunities for employment. It is important to identify the potential correlation between screen time use and myopia among college students.

Methods

This paper conducted a nationwide experiment using Chinese college students and set a multiple-mediator SEM model to analyze the potential correlation between screen time and myopia. The two mediators were sedentary behavior and physical activity, respectively.

Results

We obtained three valuable conclusions as follows: First, there was no significant direct relationship between screen time and myopia among Chinese college students during the COVID-19 pandemic. Second, sedentary behavior and physical activity significantly predicted the increase/decrease of myopia among Chinese college students, respectively. Third, a serial multiple mediator that encompassed sedentary behavior and physical activity sequentially fully mediated the relationship between screen time and myopia.

Conclusions

Although there was no directly significant relationship between screen time and myopia, screen time can indirectly influence the risk of suffering myopia by influencing sedentary behavior and physical activity. Our study demonstrates the need to prevent the potential influence of overuse of electronic devices on myopia in college students, especially during the COVID-19 pandemic.

Efficacy Comparison of Repeated Low-Level Red Light and Low-Dose Atropine for Myopia Control: A Randomized Controlled Trial

Purpose

To compare the treatment efficacy between repeated low-level red light (RLRL) therapy and 0.01% atropine eye drops for myopia control.

Methods

A single-masked, single-center, randomized controlled trial was conducted on children 7 to 15 years old with cycloplegic spherical equivalent refraction (SER) ≤ −1.00 diopter (D) and astigmatism ≤ 2.50 D. Participants were randomly assigned to the RLRL group or low-dose atropine (LDA, 0.01% atropine eye drops) group and were followed up at 1, 3, 6, and 12 months. RLRL treatment was provided by a desktop light therapy device that emits 650-nm red light. The primary outcome was the change in axial length (AL), and the secondary outcome was the change in SER.

Results

Among 62 eligible children equally randomized to each group (31 in the RLRL group, 31 in the LDA group), 60 children were qualified for analysis. The mean 1-year change in AL was 0.08 mm (95% confidence interval [CI], 0.03–0.14) in the RLRL group and 0.33 mm (95% CI, 0.27–0.38) in the LDA group, with a mean difference (MD) of −0.24 mm (95% CI, −0.32 to −0.17; P < 0.001). The 1-year change in SER was −0.03 D (95% CI, −0.01 to −0.08) in the RLRL group and −0.60 D (95% CI, −0.7 to −0.48) in the LDA group (MD = 0.57 D; 95% CI, 0.40–0.73; P < 0.001). The progression of AL < 0.1 mm was 53.2% and 9.7% (P < 0.001) in the RLRL and LDA groups, respectively. For AL ≥ 0.36 mm, progression was 9.7% and 50.0% (P < 0.001) in the RLRL and LDA groups, respectively.

Conclusions

In this study, RLRL was more effective for controlling AL and myopia progression over 12 months of use compared with 0.01% atropine eye drops.

Translational Relevance

RLRL therapy significantly slows axial elongation and myopia progression compared with 0.01% atropine; thus, it is an effective alternative treatment for myopia control in children.

Enhanced Apoptosis in Choroidal Tissues in Lens-Induced Myopia Guinea Pigs by Activating the RASA1 Signaling Pathway

Purpose

This study aimed to explore the role of the RAS p21 protein activator 1 (RASA1) signaling pathway in apoptosis in choroid tissues from guinea pigs with negative lens-induced myopia (LIM).

Methods

Biometric measurements were performed to examine refractive status, ocular parameters, and choroidal thickness (ChT) after myopia induction. The choroidal morphology was observed by hematoxylin and eosin (H&E) staining and TUNEL assay. The expression of the RASA1 signaling pathway at the mRNA and protein levels in choroidal tissues was measured by real-time quantitative PCR (qPCR) and western blot assays.

Results

Compared with the normal control (NC) group, the ocular length of the guinea pigs in LIM increased remarkably, as did the myopic refraction. ChT decreased after myopia induction. H&E staining showed that the thickness and laxity of the choroidal tissues in LIM were strikingly reduced. The number of apoptotic cells in the LIM eyes was increased. Moreover, qPCR and western blot assays showed that the expression levels of both RASA1 and BCL-2-associated agonist of cell death (BAD) were higher in the LIM group than in the NC group, whereas the expression level of B-cell lymphoma 2 (BCL-2) was decreased after 2 weeks of experimental myopia. However, the trend of RASA1, BAD, and BCL-2 expression was reversed after 4 weeks of experimental myopia compared with levels after 2 weeks of experimental myopia.

Conclusions

Results showed that the RASA1 signaling pathway is activated in choroid tissues in myopic guinea pigs. Activated RASA1 signaling induces high BAD expression and low BCL-2 expression, which in turn promotes apoptosis and ultimately causes ChT thinning in myopic guinea pigs.

Prevalence of myopia and its risk factors in rural school children in North India: the North India myopia rural study (NIM-R Study)

BACKGROUND

To assess the prevalence of myopia and its risk factors in rural school children.

METHODS

Children in classes 4-7 of eight randomly selected schools (five government and three private) in rural Haryana, with unaided vision <6/9.5 were screened, their cycloplegic refraction is done, myopes were identified. A questionnaire-based assessment of risk factors was done for myopes and compared with 10% of randomly selected children with normal vision (controls). The prevalence of myopia and its association with risk factors were assessed.

RESULTS

Children screened were 1486 (89.5% coverage). The mean age of children was 11.2 ± 1.5 years with 861 (57.9%) boys. Prevalence of myopia was 6.4% (95% Confidence intervals [CI]: 5.2%, 7.8%). Prevalence was higher among private schools (10.1%) compared to government schools (1.4%) (p < 0.001), and among girls 7.2% (45/625) compared to boys 5.8% (50/861) (p = 0.2786). The mean spherical equivalent refractive error was -1.61D ± 1.32D. The prevalence of high myopia was 1.1% (1/95). There was a 75% unmet need for spectacles. Studying in private school was positively associated with myopia as per our multivariate analysis (p = 0.016). An inverse association was found for time spent outdoors (p = 0.009). Watching television, indoor time, screen time, age, or gender were not found to be statistically significant as risk factors.

CONCLUSION

The prevalence of myopia is increasing among children of rural areas, especially those in private schools with a strong inverse association with time spent outdoors. Regular screening, lifestyle modification and awareness about modifiable risk factors are essential.

New loci for refractive errors and ocular biometric parameters in young Chinese Han adults

Myopia has become a major public health issue with an increasing prevalence. There are still individuals who experience similar environmental risk factors and, yet, remain non-myopic. Thus, there might be genetic factors protecting people from myopia. Considering the opposite ocular characteristics of primary angle closure glaucoma (PACG) to myopia and possible common pathway between them, we propose that certain risk genes for PACG might act as a protective factor for myopia. In this study, 2,678 young adults were genotyped for 37 targeted single nucleotide polymorphisms. Compared with emmetropia, rs1401999 (allele C: OR=0.795, P=0.03; genotype in dominant model: OR=0.759, P=0.02) and rs1258267 (allele A: OR=0.824, P=0.03; genotype in dominant model: OR=0.603, P=0.01) were associated with low to moderate myopia and high myopia, respectively. Genotype under recessive model of rs11024102 was correlated with myopia (OR=1.456, P=0.01), low to moderate myopia (OR=1.443, P=0.02) and high myopia (OR=1.453, P=0.02). However, these associations did not survive Bonferroni correction. Moreover, rs1401999, rs1258267, and rs11024102 showed associations with certain ocular biometric parameters in different groups. Our study suggests that ABCC5, CHAT and PLEKHA7 might be associated with refractive errors by contributing to the regulation of ocular biometry, in terms of uncorrected results and their biological functions.

Central Corneal Thickness of a Saudi Population in Relation to Age, Gender, Refractive Errors, and Corneal Curvature

Background In this study, we aimed to investigate the relationship between central corneal thickness (CCT) and age, gender, refractive errors, and corneal curvature in a Saudi population. Methodology In this randomized, hospital-based, retrospective study, data were collected from Dr. Sulaiman Al Habib Hospital and Imam Medical Center, Riyadh. A total of 1,005 eyes were included and recruited from patients referred to the refractive surgery clinic for Lasik assessment. The study included patients aged between 17 and 57 years with no history of any ocular pathology, eye surgeries, and systemic disease, as well as all groups with stable refractions. The identifying data were the age and gender of the patients, as well as their CCT, refraction, and corneal curvature. CCT and corneal curvature were measured by ultrasound pachymeter Pentacam. Results The distribution of CCT was 543.81 ± 34.47 μm. A significant difference in the mean CCT was observed across different refractive errors (p = 0.004). Patients with astigmatism had the lowest CCT, followed by myopic and hyperopic patients. An association between the spherical equivalent of patients with myopia and CCT (p = 0.001) was noted. Conclusions In the Saudi population, we found no significant association between mean corneal curvature and CCT in all three groups. Spherical equivalent in myopic patients was significantly associated with CCT. A significant difference in the mean CCT was observed across different refractive errors. There was a significant negative and weak correlation between age in myopic and astigmatism patients and CCT. Gender was significantly associated with CCT in patients with astigmatism.

Effects of air pollution on myopia: an update on clinical evidence and biological mechanisms

Myopia is one of the most common forms of refractive eye disease and considered as a worldwide pandemic experienced by half of the global population by 2050. During the past several decades, myopia has become a leading cause of visual impairment, whereas several factors are believed to be associated with its occurrence and development. In terms of environmental factors, air pollution has gained more attention in recent years, as exposure to ambient air pollution seems to increase peripheral hyperopia defocus, affect the dopamine pathways, and cause retinal ischemia. In this review, we highlight epidemiological evidence and potential biological mechanisms that may link exposure to air pollutants to myopia. A thorough understanding of these mechanisms is a key for establishing and implementing targeting strategies. Regulatory efforts to control air pollution through effective policies and limit individual exposure to preventable risks are required in reducing this global public health burden.

Development and validation of a novel nomogram for predicting the occurrence of myopia in schoolchildren: A prospective cohort study

PURPOSE

Myopia is a major public health issue and occurs at young ages. Apart from its high prevalence, myopia results in high costs and irreversible blinding diseases. Accurate prediction of the risk of myopia onset is crucial for its precise prevention. We aimed to develop and validate an effective nomogram for predicting myopia onset in schoolchildren.

DESIGN

School-based prospective cohort study.

METHODS

A total of 1073 schoolchildren were enrolled from November 2014 to May 2019 in China, and were divided into the training and validation cohorts. Myopia was defined as a spherical equivalent refraction (SER) ≤-0.5 diopters. Predictors of myopia were determined through the least absolute shrinkage and selection operator regression and multivariable Cox proportional hazard model based on the training cohort. The predictive performance of the nomogram was validated internally through time-dependent receiver operating characteristic (ROC) curves, calibration plot, decision curve analysis, and Kaplan-Meier curves.

RESULTS

Independent predictors at baseline including gender, SER, axial length, corneal refractive power, and positive relative accommodation were included in the nomogram prediction model. This nomogram demonstrated excellent calibration, clinical net benefit, and discrimination, with all the area under the ROC curves (AUCs) between 0.74 and 0.86 in the training and validation cohorts. The Kaplan-Meier curves showed that 3 distinct risk groups stratified through X-tile analysis were well discriminated and robust among subgroups. The Harrell's C-index and net reclassification improvement demonstrated that the nomogram substantially improved compared with previous models. An online myopia risk calculator was generated for better individual prediction.

CONCLUTIONS

The nomogram provides accurate and individual prediction of myopia onset in schoolchildren. External validation is needed to verify the generalizability of this nomogram.

Intraocular Amphiregulin antibody and axial elongation in nonhuman primates

Purpose

To examine the effect of intraocularly applied amphiregulin antibody on physiological axial elongation in young nonhuman primates.

Methods

The experimental study included six male 12-months-old macaque nonhuman primates (body weight:2.46 ± 0.25kg;range:2.20-2.90kg). In the experimental group (n=3 animals), three intravitreal injections of amphiregulin antibody (100μg/50μl) were applied to the left eyes at intervals of 4-6 weeks, and injections of phosphate buffered solution (50μl) were applied to the right eyes. Three other animals were assigned to a blank control group.

Results

During the study period of 23.6 weeks, axial length in the experimental group did not change in the left eyes (18.91 ± 0.37mm to 18.94 ± 0.67mm;P=0.90), while it linearly increased in the right eyes (18.87 ± 0.38mm to 19.24 ± 0.53mm;P=0.056) and in the control group (left eyes:19.15 ± 0.22mm to 19.48 ± 0.22mm;P=0.009; right eyes:19.17 ± 0.15 mm to 19.46 ± 0.23 mm;P=0.024). The interocular difference in axial elongation increased in the experimental group from -0.11 ± 0.12mm at 4 weeks after baseline to -0.34 ± 0.15mm at the study end, while in the control group, the interocular side difference did not change significantly (from 0.01 ± 0.10 mm to 0.03 ± 0.08 mm;P=0.38). The difference in the interocular difference in axial elongation between the two groups was significant at 8 weeks (P=0.01), 15 weeks (P=0.007), and at study end (P=0.02). The interocular difference in axial length correlated with the interocular difference in vitreous cavity length (standardized regression coefficient beta:0.85;P<0.001). The interocular axial length difference was inversely associated with the interocular refractive error difference (beta:-0.49;P<0.001).

Conclusions

Intraocularly applied amphiregulin antibody (100μg) reduced the physiological ocular axial elongation in juvenile nonhuman primates.

Differences in close-work activities and optical axis length between only children and non-only children: a cross-sectional study

Background

This study aimed to investigate the differences in optical axial length and close-work activities between only children and children with siblings in Wenzhou.

Methods

This was a cross-sectional population-based study. In total, 2913 school-aged children and their parents in Wenzhou were included as study subjects from April to May 2021. Data regarding the optical axial length, spherical equivalent refraction, number of children in a family, parental myopia, and close-work activities were collected through eye examinations and questionnaires. A multivariable logistic regression was used to analyze the association between the number of children in a family and optical axial length.

Results

The children were aged 9.80 ± 3.41 years. The overall percentage of children with an axial length > 24 mm was 38.9%, 44.5% in only children and 35.6% in multiples. The multivariable logistic regression analysis showed that the odds of having an AL > 24 mm were 1.24 times higher in only children than in multiples (OR: 1.24, 95% CI: 1.025–1.480, P = 0.028). Only children were 1.331 times more likely to perform homework > 1 h on weekends than multiples (OR: 1.331, 95% CI: 1.049–1.688, P = 0.019). Only children in upper grades were 1.543 times more likely to perform homework > 1 h on weekends than multiples (OR: 1.543, 95% CI: 1.065–2.235, P = 0.025). Boys who were only children were more likely to attend three or more extracurricular classes for academic subjects than multiples (OR: 1.224, 95% CI: 1.011–1.562, P = 0.004).

Conclusions

Being an only child may be associated with a higher risk of myopia and higher odds of close-work behaviors. Only children, especially those in upper grades, are more likely to spend more time on homework than their peers who are multiples. Only children, especially boys, are more likely to attend extracurricular classes in academic subjects.

Trial registration

This trial is registered as ChiCTR1900020584 at www.Chictr.org.cn.

Compartmental analysis of three-dimensional choroidal vascularity and thickness of myopic eyes in young adults using SS-OCTA

Purpose: We aimed to investigate the change of three-dimensional (3D) choroidal thickness (ChT), choroidal vessel volume (CVV), and choroidal vessel index (CVI) in young myopic adults using swept-source optical coherence tomography angiography (SS-OCTA) and compare the difference of these indicators in different quadrants of the macula and optic disc.

Methods: A total of 248 eye samples from 135 participants were used in this cross-sectional study. Each participant underwent detailed history taking and ocular examinations. Based on axial length (AL), patients were divided into the emmetropia (EM) group, mild-myopia (MIM) group, moderate-myopia (MOM) group, and high-myopia (HM) group. 6 mm × 6 mm (1,024 × 1024 B-scans) SS-OCTA scans were performed centered on the fovea and optic disc. 3D ChT, CVV, and CVI were measured based on a built-in deep learning algorithm. Differences in ChT, CVV, and CVI were analyzed in different regions and different myopic groups.

Results: Significant reduction in the global CVV were found in the HM group (1.930 ± 0.865) in comparison with the EM (3.486 ± 0.992), MIM (3.238 ± 1.033), and MOM (2.589 ± 1.083) groups (p < 0.001). The global CVI was also lower in the HM group (0.258 ± 0.061) than in the EM (0.320 ± 0.055), MIM (0.320 ± 0.051), and MOM (0.286 ± 0.066) groups (p < 0.001). The ChT was thinner in eyes with HM (242.753 ± 65.641) than in eyes with EM (377.532 ± 80.593), MIM (348.367 ± 78.191), or MOM (300.197 ± 87.175) (p < 0.001). Compartmental analysis revealed that ChT, CVV, and CVI in the nasal quadrant of the macula and temporal and inferior quadrants of the optic disc were much lower than those in other quadrants (p < 0.05). Correlation analyses found that ChT, CVV, and CVI were negatively correlated with AL and spherical equivalence.

Conclusion: 3D ChT, CVV, and CVI gradually decreased as the degree of myopia increased. The changes were more dramatic on the nasal side of the macula and the temporal and inferior sides of the optic disc. These findings demonstrated the 3D choroidal change and highlighted the papillo-macular bundle as a sensitive region in myopic development.