Prevalence Trend of Myopia after Promoting Eye Care in Preschoolers: A Serial Survey in Taiwan before and during the Coronavirus Disease 2019 Pandemic

Analysis of research hotspots and trends in pediatric ophthalmopathy based on 10 years of WoSCC literature

Background

Ophthalmopathy occurring in childhood can easily lead to irreversible visual impairment, and therefore a great deal of clinical and fundamental researches have been conducted in pediatric ophthalmopathy. However, a few studies have been performed to analyze such large amounts of research using bibliometric methods. This study intended to apply bibliometric methods to analyze the research hotspots and trends in pediatric ophthalmopathy, providing a basis for clinical practice and scientific research to improve children's eye health.

Methods

Publications related to pediatric ophthalmopathy were searched and identified in the Web of Science Core Collection (WoSCC) database. Bibliometric and visualized analysis was performed using the WoSCC analysis system and CiteSpace.6.2.6 software, and high-impact publications were analyzed.

Results

This study included a total of 7,177 publications from 162 countries and regions. Of these, 2,269 from the United States and 1,298 from China. The centrality and H-index were highest in the United States at 0.27 and 66, respectively. The University of London and Harvard University had the highest H-index at 37. Freedman,Sharon F published 55 publications, with the highest H-index at 19. The emerging burst keyword in 2020-2023 was "eye tracking," and the burst keywords in 2021-2023 were "choroidal thickness," "pediatric ophthalmology," "impact" and "childhood glaucoma." Retinopathy of prematurity, myopia, retinoblastoma and uveitis in juvenile idiopathic arthritis were the main topics in the high-impact publications, with clinical studies in the majority, especially in retinopathy of prematurity.

Conclusion

Eye health in children is a research hotspot, with the United States publishing the largest number of papers and having the greatest influence in research on pediatric ophthalmopathy, and China coming in second. The University of London and Stanford University had the greatest influence. Freedman, Sharon F was the most influential author. Furthermore, "choroidal thickness," "pediatric ophthalmology," "impact," "childhood glaucoma" and "eye tracking"are the latest hotspots in the field of pediatric ophthalmopathy. These hotspots represent hot diseases, hot technologies and holistic concepts, which are exactly the research trends in the field of pediatric ophthalmopathy, providing guidance and grounds for clinical practice and scientific research on children's eye health.

The Current and Future Landscape of the Childhood Myopia Epidemic in China-A Review

Over the last two decades, the prevalence of myopia has gradually increased in China. Numerous epidemiological studies suggest that education and inadequate time spent outdoors are the major causes of the current myopia epidemic. China is one of the few countries that has begun to address the myopia epidemic with a national-level strategy, implementing nationwide education reform, cost-reduction measurements, and dissemination of information on myopia prevention and control. These "natural experiments" will provide insights into areas that may face similar or potential myopia problems.

The prevalence of myopia remains stable under tighter COVID-19 social restriction in preschoolers receiving a school-based eyecare program

PURPOSE

This study investigated the impact of different levels of COVID-19 social restrictions (social distancing in 2020, large-scale home confinement in 2021) on myopia prevalence and behaviours in a preschool population with school-based eyecare programme.

METHODS

Repeated cross-sectional surveys were conducted between August and December in 2019, 2020 and 2021. Children aged 5-6 years received ocular examinations, and questionnaires were answered by caregivers before the day of the examination. The main outcome measures were the changes in after-school time spent on homework, screen-based devices and outdoors. Secondary outcome was the change in myopia prevalence (spherical equivalent [SE] ≤ -0.5 D in either eye after cycloplegia).

RESULTS

A total of 9997 preschoolers were included in the analysis. Under tighter restrictions, more preschoolers spent ≥1 h/day on screen-based devices (42.8% in 2019, 45.2% in 2020, 48.9% in 2021, p < 0.001), and fewer preschoolers spent ≥30 min/day on after-school outdoor activities (49.5% in 2019, 46.0% in 2020, 41.0% in 2021, p < 0.001) on weekdays. A similar trend was found on weekends. While more preschoolers spent ≥2 h/day on screen-based devices (35.3% in 2019, 38.5% in 2020, 43.0% in 2021, p < 0.001), fewer preschoolers spent ≥2 h/day on outdoor activities (41.7% in 2019, 41.7% in 2020, 34.0% in 2021, p < 0.001). The mean SE and myopia prevalence were stable (9.1% in 2019, 10.3% in 2020, 9.4% in 2021, p = 0.707).

CONCLUSION

Our study showed dose-dependent effect of social restrictions on near-work and outdoor behaviours at home. The prevalence of myopia did not increase significantly with short-term cessation of school-based eyecare programmes.

Prevalence Trend of Myopia during the Post-COVID-19 Epidemic Period among Preschoolers: A Prospective School-based Study

SIGNIFICANCE

Changes in behavior and lifestyle during the post-coronavirus disease 2019 (COVID-19) epidemic may have some impact on myopia rates in preschoolers, and exploring the changes in myopia rates in preschool children may inform the formulation of myopia prevention and control policies.

PURPOSE

This study aimed to investigate the prevalence of myopia in preschool children during the post-COVID-19 epidemic period in Xuzhou, China.

METHODS

A series of cross-sectional school-based studies was conducted. A total of 117,632 preschool children aged 3 to 6 years were subjected to annual vision screening from 2019 to 2021. Spot photo screening was used to record the spherical equivalent refraction for each child and to analyze the prevalence of myopia by age, sex, and region during the post-COVID-19 epidemic period.

RESULTS

A total of 113,979 preschool children were included in the analysis, of whom 60,784 (53.3%) were male and 53,195 (46.7%) were female. For all children, the mean ± standard deviation spherical equivalent refraction in 2019, 2020, and 2021 was +0.32 ± 0.50, +0.34 ± 0.55, and +0.34 ± 0.54 D, respectively (all P < .05), indicative of a very slight hyperopic shift. In all age groups, the change in mean spherical equivalent refraction and its distribution were relatively stable. From 2019 to 2021, the overall prevalence of myopia in preschool children was 3.1, 3.3, and 3.5%, respectively. The rise in myopia rates was minimal. The largest increase in the annual prevalence of myopia was seen among children aged 6 years, at 0.5%, followed by those aged 5 years (0.4%) and aged 3 years (0.4%). The prevalence was higher in boys than girls and in urban versus rural areas.

CONCLUSIONS

During the post-COVID-19 epidemic period, the refractive status of Xuzhou preschool children remained stable.

Effect of the COVID-19 Lockdown on Myopia Progression of School-aged Children: A Retrospective Chart Review

PURPOSE

To study the effect of the coronavirus disease 2019 (COVID-19)-related lockdown on myopia progression of school-aged children, comparing across the years and within different age groups.

METHODS

This was a retrospective chart review of school-aged children with myopia who presented to the pediatric ophthalmology clinic at the American University of Beirut between January 2020 and December 2021 (during COVID-19 lockdown). Annual myopia progression rate (back to January 2016) was computed by dividing the absolute value of the spherical equivalent (SE) difference of two consecutive visits by the duration (in years). Demographic data were retrieved. Patients were then divided into three age groups (3 to 10, 11 to 14, and 15 to 18 years) for analysis.

RESULTS

A total of 443 charts of myopic school-aged children were reviewed. Their average age was 11.81 ± 3.67 years with an average of 3.85 ± 1.67 visits across the years. The mean myopic SE increased over time: SE in 2021 was significantly higher than the mean SE in 2016, 2017, 2018, and 2019. Mean SE in 2020 was significantly higher than that in 2016 and 2017. There was no statistically significant difference in the mean annual progression (in diopters/year). For the 3 to 10 years group, the annual SE progression tended to be highest for 2020-2021 and 2019-2020 compared to previous years.

CONCLUSIONS

Children had more myopia in 2021 and 2020 (during lockdown) compared to previous years. The myopia annual progression tended to be highest in 2020-2021, especially for the younger age group, but the difference was not statistically significant. [J Pediatr Ophthalmol Strabismus. 2023;60(5):353-358.].

Myopia among children and adolescents: an epidemiological study in Fuzhou City

Objective

To provide a reference for the prevention and control of myopia by analyzing and discussing the findings of an epidemiological survey of the prevalence of myopia among children and adolescents in Fuzhou City from 2019 to 2021.

Methods

Participants for this cross-sectional study were drawn from Gulou District and Minqing County in Fuzhou City using cluster random sampling to account for differences in population density, economic development, and other environmental variables.

Results

Myopia was more prevalent in 2020 than in 2019, but by 2021 it had dropped to about the same level as in 2019. Myopia was more prevalent among girls than boys during the course of the study period, with a three-year prevalence of 44.72% for boys and 52.16% for girls. Mild myopia accounted for 24.14% of all cases, followed by moderate myopia at 19.62%, and severe myopia at 4.58%. Students in urban regions had a prevalence of myopia equivalent to that of students in the suburbs, and this prevalence rose with age.

Conclusion

Myopia was quite prevalent among children and adolescents in Fuzhou City, and was shown to be steadily rising as students progressed through the school system. This suggests that all levels of government, educational institutions, medical facilities, and concerned parents in Fujian Province should focus on the issue of myopia and collaborate to reduce the risk factors for the development of myopia in school-aged participants.

Worsening vision at age 4-5 in England post-COVID: Evidence from a large database of vision screening data

PURPOSE

Myopia prevalence has increased in the UK at age 10-16y, but little is known about younger children. We hypothesise that if the 'myopia epidemic' is affecting young children, then there will be increasing rates of bilateral reduced unaided vision (V) at vision screenings of children 4-5 years of age.

METHODS

Retrospective anonymised data from computerised vision screening at age 4-5 years were analysed from serial cross-sectional data. Refractive error is not assessed in UK vision screening, so vision was investigated. Data were only included from schools that screened every year from 2015/16 to 2021/22. The criterion used was unaided monocular logMAR (automated letter-by-letter scoring) vision >0.20 in both the right and left eyes, so as to maximise the chances of detecting bilateral, moderate myopia rather than amblyopia.

RESULTS

Anonymised raw data were obtained for 359,634 screening episodes from 2075 schools. Once schools were excluded where data were not available for every year and data were cleaned, the final database comprised 110,076 episodes. The proportion (percentage and 95% CI) failing the criterion from 2015/16 to 2021/22 were 7.6 (7.2-8.0), 8.5 (8.1-8.9), 7.5 (7.1-7.9), 7.8 (7.4-8.2), 8.7 (8.1-9.2), 8.5 (7.9-9.0) and 9.3 (8.8-9.7), respectively. The slope of the regression line showed a trend for increasing rates of reduced bilateral unaided vision, consistent with increasing frequency of myopia (p = 0.06). A decreasing linear trendline was noted for children 'Under Professional Care'.

CONCLUSIONS

For children 4-5 years of age, there were signs of reduced vision over the last 7 years in England. Consideration of the most likely causes support the hypothesis of increasing myopia. The increase in screening failures highlights the importance of eye care in this young population.

Myopia Progression during the COVID-19 Era: A Systematic Review and Meta-analysis

BACKGROUND

To evaluate myopia progression during the novel coronavirus disease 2019 (COVID-19) pandemic and its risk factors.

METHODS

We searched PubMed, Scopus, and Web of Science to find literature until August 2022 related to COVID-19 pandemic and myopia progression. Outcomes of myopia progression included axial length (AL) and spherical equivalent (SE). Factors of screen time and outdoor activity time were analyzed.

RESULTS

Thirty-three studies were included in this meta-analysis. Compared to the same period before the COVID-19 pandemic, myopia prevalence increased (OR = 1.11; 95% CI, 1.05-1.18). The outcomes of SE decreased -0.61 diopter (95% CI, -0.98 to -0.23), and AL increased 0.42 mm (95% CI, 0.13-0.7). Mean screen time was increased 6.25 hours/day (95% CI, 4.84-7.66), and outdoor activity time was decreased -1.52 hours/day (95% CI, -3.20 to -0.15).

CONCLUSION

Establishing care policies is necessary to restrict behavioral changes and their consequences during the pandemic.

[Recommendations for Progressive Myopia in Childhood and Adolescence. Statement of the DOG, BVA and the Bielschowsky Society for Strabismus Research and Neuroophthalmology - Status June 2022]

Since the last and at the same time first statement of the German ophthalmological societies on the possibilities of reducing myopia progression in childhood and adolescence, many new details and aspects have emerged in clinical research. This second statement updates the previous document and specifies the recommendations on visual and reading behavior as well as on pharmacological and optical therapy options, which have been both refined and newly developed in the meantime.

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.

[Recommendations for progressive myopia in childhood and adolescence. Statement of the DOG, BVA and the Bielschowsky Society for Strabismus Research and Neuroophthalmology : Status June 2022]

Since the last and at the same time first statement of the German ophthalmological societies on the possibilities of reducing myopia progression in childhood and adolescence, many new details and aspects have emerged in clinical research. This second statement updates the previous document and specifies the recommendations on visual and reading behavior as well as on pharmacological and optical therapy options, which have been both refined and newly developed in the meantime.

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.

Myopia and axial length in school-aged children before, during, and after the COVID-19 lockdown-A population-based study

Background

Myopic shift had been observed during the COVID-19 lockdown in young school children. It remains unknown whether myopic shift is accompanied with increase in axial length. We aimed to evaluate the impact of the COVID-19 lockdown on myopia and axial length of school children in China by comparing them before, during and after the lockdown.

Methods

In this population-based cross-sectional study, school-based myopia screenings were conducted in the Fall of 2019, 2020, and 2021 (representing before, during and after COVID-19 lockdown respectively) in Chengdu, China. Myopia screenings were performed on 83,132 students aged 6 to 12 years. Non-cycloplegic refractive error was examined using NIDEK auto-refractor (ARK-510A; NIDEK Corp., Tokyo, Japan) and axial length was measured using AL-Scan (NIDEK Corp., Tokyo, Japan). Spherical equivalent (SER, calculated as sphere+ 0.5^*cylinder), prevalence of myopia (SER ≤ -0.50 D), and axial length were compared across 3 years stratified by age.

Results

Myopia prevalence rate was 45.0% (95% CI: 44.6-45.5%) in 2019, 48.7% (95% CI: 48.3-49.1%) in 2020, and 47.5% (95% CI: 47.1-47.9%) in 2021 (p < 0.001). The mean non-cycloplegic SER (SD) was -0.70 (1.39) D, -0.78 (1.44) D, and -0.78 (1.47) D respectively (p < 0.001). The mean (SD) axial length was 23.41 (1.01) mm, 23.45 (1.03) mm, and 23.46 (1.03) mm across 3 years respectively (p < 0.001). From the multivariable models, the risk ratio (RR) of myopia was 1.07 (95% CI: 1.06-1.08) times, the SER was 0.05 D (95% CI: 0.04 D to 0.06 D) more myopic and the mean axial length increased by 0.01 mm (95% CI: 0.01 mm to 0.02 mm) in 2020 compared to 2019. In 2021, the risk ratio (RR) of myopia was 1.05 (95% CI: 1.04-1.06), the mean SER was 0.06 D (95% CI: 0.05 D to 0.07 D) more myopic, and the mean axial length increased by 0.03 mm (95% CI: 0.02 mm to 0.04 mm) compared to 2019.

Conclusions

The COVID-19 lockdown had significant impact on myopia development and axial length, and these impacts remained 1 year after the lockdown. Further longitudinal studies following-up with these students are needed to help understand the long-term effects of COVID-19 lockdown on myopia.

Photopic pupil size change in myopic orthokeratology and its influence on axial length elongation

AIM

To explore the photopic pupil size behavior in myopic children undergoing overnight orthokeratology (ortho-k) over 1-year period and its effects on the axial elongation.

METHODS

A total of 202 Chinese myopic children were enrolled in this prospective clinical trial. Ninety-five subjects in ortho-k group and eighty-eight subjects in spectacle group completed the 1-year study. Axial length (AL) was measured before enrollment and every 6mo after the start of ortho-k. The photopic pupil diameter (PPD) was determined using the Pentacam AXL and measured in an examination room with lighting of 300-310 Lx. Stepwise multiple linear regression analysis was used to identify variables contribution to axial elongation.

RESULTS

Compared with spectacle group, the average 1-year axial elongation was significantly slower in the ortho-k group (0.25±0.27 vs 0.44±0.23 mm, P<0.0001). In ortho-k group, PPDs significantly decreased from 4.21±0.62 mm to 3.94±0.53 mm after 1mo of lens wear (P=0.001, Bonferroni correction) and the change lasts for 3-month visit. No significantly change during the other follow-up visits was found (P>0.05, Bonferroni correction). The 4.81 mm PPD may be a possible cutoff point in the ortho-k group. Subjects with PPD below or equal to 4.81 mm tended to have smaller axial elongation compared to subjects with PPD above 4.81 mm after 1-year period (t=-3.09, P=0.003). In ortho-k group, univariate analyses indicated that those with older age, greater degree of myopia, longer AL, smaller baseline PPD (PPD_baseline) experienced a smaller change in AL. In multivariate analyses, older age, greater AL and smaller PPD_baseline were associated with smaller increases in AL. In spectacle group, PPD tended to be stable (P>0.05, Bonferroni correction) and did not affect axial growth.

CONCLUSION

PPDs experience significantly decreases at 1-month and 3-month ortho-k treatment. Children with smaller PPD tend to experience slower axial elongation and may benefit more from ortho-k.

The Association Between Environmental and Social Factors and Myopia: A Review of Evidence From COVID-19 Pandemic

Purpose

To review the association between children's behavioral changes during the restriction due to the pandemic of Coronavirus disease (COVID-19) and the development and progression of myopia.

Design

A literature review.

Method

We looked for relevant studies related to 1) children's behavioral changes from COVID-19 restriction and 2) children's myopia progression during COVID-19 restriction by using the following keywords. They were “Behavior,” “Activity,” “COVID-19,” “Lockdown,” “Restriction,” and “Children” for the former; “Myopia,” “COVID-19,” “Lockdown,” “Restriction” for the latter. Titles, abstracts and full texts from the retrieved studies were screened and all relevant data were summarized, analyzed, and discussed.

Results

Children were less active and more sedentary during COVID-19 restriction. According to five studies from China and six studies, each from Hong Kong, Spain, Israel, South Korea, Turkey and Taiwan included in our review, all countries without myopia preventive intervention supported the association between the lockdown and myopia progression by means of negative SER change ranging from 0.05–0.6 D, more negative SER change (compared post- to pre-lockdown) ranging from 0.71–0.98 D and more negative rate of SER changes (compared post- to pre-lockdown) ranging from 0.05–0.1 D/month. The reported factor that accelerated myopia is an increase in total near work, while increased outdoor activity is a protective factor against myopia progression.

Conclusion

The pandemic of COVID-19 provided an unwanted opportunity to assess the effect of the behavioral changes and myopia in the real world. There is sufficient evidence to support the association between an increase in near work from home confinement or a reduction of outdoor activities and worsening of myopia during the COVID-19 lockdown. The findings from this review of data from the real world may help better understanding of myopia development and progression, which may lead to adjustment of behaviors to prevent myopia and its progression in the future.

Rapid progression of myopia at onset during home confinement

PURPOSE

To determine whether the myopic shift at myopia onset was faster than usual during home confinement associated with the COVID-19 pandemic.

METHODS

Data on refractive error in consecutive children who presented for their first myopic spectacle prescription from September 2020 to May 2021 (new-onset myopia during the pandemic) were collected. Inclusion criteria were age 5-18 years and cycloplegic spherical equivalent in both eyes in the emmetropic range in the pre-pandemic years as recorded 1 year and 2 years before the actual visit. Annualized mean myopic shifts over the two previous periods were calculated.

RESULTS

A total of 39 subjects (59% girls) were enrolled. Mean age at the visit after confinement was 10.79 ± 2.83 years. The mean refractive error for the right eyes in 2018 was +0.29 ± 0.56 D. The year after (2019), these children had a mean spherical equivalent of -0.12 ± 0.70 D. At the enrollment visit after myopia onset in the pandemic period, they had myopia of -1.33 ± 0.73 D. The mean annualized myopic shift for the right eyes was -0.37 ± 0.43 D before the pandemic and -1.12 ± 0.70 D during the pandemic period that included home confinement (P < 0·001 [Wilcoxon text]).

CONCLUSIONS

Previous pre-pandemic prospective studies have reported myopic shift at onset of approximately -0.80 D. The period of strict pandemic home confinement saw higher rates of myopic shift.

Premyopia at Preschool Age: Population-based Evidence of Prevalence and Risk Factors from A Serial Survey in Taiwan

PURPOSE

Premyopia at a young age carries a great risk of developing early-onset myopia, especially in regions with the epidemic of myopia, such as the developed areas in East Asia. This study aims to report the prevalence of premyopia and its risk factors in a Taiwan preschool population and lifestyle changes among premyopic preschoolers before and during the coronavirus disease 2019 (COVID-19) pandemic.

DESIGN

Repeated countywide population-based, cross-sectional study in Yilan County, northeastern Taiwan.

PARTICIPANTS

From 2014 through 2020, a total of 23,930 kindergarteners aged 5-6 years were identified in the Yilan Myopia Prevention and Vision Improvement Program (YMVIP). Of those, 21,761 (11,335 [52.1%] boys; mean age, 5.15 ± 0.37 years) were included for final analysis.

METHODS

Annual kindergarten-based eye examinations and myopia prevention strategies have been conducted since the commencement of the YMVIP in 2014. Refractive error was determined by cycloplegic autorefraction. The data of potential risk factors for myopia were gathered by caregiver-administered questionnaires.

MAIN OUTCOME MEASURES

The prevalence of premyopia (spherical equivalent [SE] > -0.5 diopter [D] and ≤ +0.75 D in the eye with less SE value) RESULTS: The prevalence of myopia (SE ≤ -0.5 D), premyopia, and hyperopia (SE > +0.75) was 10.7% (95% confidence interval [CI], 10.3%-11.1%), 52.0% (95% CI, 51.3%-52.7%), and 37.3% (95% CI, 36.7%-37.9%), respectively. Multinomial logistic regression analysis showed that premyopia prevalence was significantly associated with male gender (odds ratio [OR], 1.25; 95% CI, 1.18-1.32), caregiver myopia (OR, 1.46; 95% CI, 1.37-1.56), screen time ≥ 1 hour per weekdays (OR, 1.10; 95% CI, 1.04-1.17), 2-year exposure to myopia prevention strategy (OR, 0.59; 95% CI, 0.54-0.65), and college or higher education level of caregiver (OR, 0.91; 95% CI, 0.85-0.96). Even without large-scale school closure in Taiwan, there was a slight upward trend of increased time spent on screen-based devices during the COVID-19 pandemic.

CONCLUSIONS

Our findings showed that premyopia was the most common refractive error in a Taiwan preschool population. Premyopia was also associated with both parental and environmental myopiogenic factors. Longitudinal studies are warranted to examine the lifestyle change and myopic shift of premyopic preschoolers in the post-pandemic era.