Evaluation and Follow-up of Myopia Prevalence Among School-Aged Children Subsequent to the COVID-19 Home Confinement in Feicheng, China

Pseudomyopia as an independent risk factor for myopia onset: a prospective cohort study among school-aged children

AIM

To investigate whether pseudomyopia is an independent risk factor for myopia onset based on a population-based cohort study.

METHODS

Non-myopic children were recruited from schools in rural and urban settings of Shangdong province, China. Baseline examinations started in September 2020 and all participants were invited for a 6-month follow-up. Pseudomyopia was defined as spherical equivalent (SE) ≤-0.50 diopters (D) before cycloplegia and >-0.50D after cycloplegia. Myopia was defined as cycloplegic SE ≤-0.50D.

RESULTS

A total of 2328 children (baseline age: 4-17 years) were included in the final analysis. During the 6-month follow-up, 21.1% (355/1680) pseudomyopic eyes developed myopia, and 3.8% (110/2879) non-myopic and non-pseudomyopic eyes developed myopia. After adjusting for multiple myopia risk factors, including baseline cycloplegic SE, near work and outdoor time, pseudomyopia was found to be an independent risk factor for myopia onset (relative risk=2.52, 95% CI 1.86 to 3.42). Additionally, pseudomyopic children with more myopic cycloplegic SE (p<0.001), smaller difference between cycloplegic and non-cycloplegic SE (DIFF, p<0.001), and higher binocular amplitude of accommodation (p<0.001) had higher risk of myopia development.

CONCLUSION

This is an important longitudinal study to prove that pseudomyopia is an independent risk factor for myopia development among school-aged children.

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.

Algorithmic and sensor-based research on Chinese children's and adolescents' screen use behavior and light environment

Background

Myopia poses a global health concern and is influenced by both genetic and environmental factors. The incidence of myopia tends to increase during infectious outbreaks, such as the COVID-19 pandemic. This study examined the screen-time behaviors among Chinese children and adolescents and investigated the efficacy of artificial intelligence (AI)-based alerts in modifying screen-time practices.

Methods

A cross-sectional analysis was performed using data from 6,716 children and adolescents with AI-enhanced tablets that monitored and recorded their behavior and environmental light during screen time.

Results

The median daily screen time of all participants was 58.82 min. Among all age groups, elementary-school students had the longest median daily screen time, which was 87.25 min and exceeded 4 h per week. Children younger than 2 years engaged with tablets for a median of 41.84 min per day. Learning accounted for 54.88% of participants' screen time, and 51.03% (3,390/6,643) of the participants used tablets for 1 h at an average distance <50 cm. The distance and posture alarms were triggered 807,355 and 509,199 times, respectively. In the study, 70.65% of the participants used the tablet under an illuminance of <300 lux during the day and 61.11% under an illuminance of <100 lux at night. The ambient light of 85.19% of the participants exceeded 4,000 K color temperature during night. Most incorrect viewing habits (65.49% in viewing distance; 86.48% in viewing posture) were rectified swiftly following AI notifications (all p < 0.05).

Conclusion

Young children are increasingly using digital screens, with school-age children and adolescents showing longer screen time than preschoolers. The study highlighted inadequate lighting conditions during screen use. AI alerts proved effective in prompting users to correct their screen-related behavior promptly.

Eye exercises for myopia prevention and control: a comprehensive systematic review and meta-analysis of controlled trials

OBJECTIVES

To evaluate the efficacy of eye exercises in preventing and controlling myopia.

METHODS

We searched studies on eye exercises from nine Chinese and English databases from their inception to December 15, 2022. Using random-effect models and sensitivity/subgroup analyses, we estimated the effects of eye exercises compared to control on changes in three measures: visual acuity, refractive error (both quantified using standardized mean differences, SMDs), and protective/mitigating effects (assessed through risk ratios, RRs).

RESULTS

Eleven studies were included in the meta-analysis, with 921 participants. Nine studies had some concerns of bias in at least two domains, and two studies had a high risk of bias in two domains. Seven studies used visual acuity to measure myopia; visual acuity declined after eye-exercise interventions (SMD = -0.67, 95% CI -1.28 to -0.07, Z = 2.17, P = 0.03) and the effect was not better than control (SMD = -0.50, 95% CI -1.16 to 0.16, Z = 1.49, P = 0.14). Two studies used refractive error to measure myopia; the effect of eye-exercise interventions did not differ from control (SMD = -1.74, 95% CI -6.27 to 2.79, Z = 0.75, P = 0.45). Seven studies reported on protective/mitigating effects; eye exercises exhibited a greater protective/mitigating effect than control (RR = 0.40, 95% CI 0.23-0.71, Z = 3.13, P < 0.01).

CONCLUSIONS

Overall, the results suggest that eye exercises have limited to no efficacy in preventing or controlling myopia progression. Until robust evidence supports their efficacy, available evidence suggests retiring the eye-exercise policy.

Effect of wearing peripheral focus-out glasses on emmetropization in Chinese children aged 6-8 years: study protocol for a 2-year randomized controlled intervention trial

BACKGROUND

Myopia is one of the most common eye diseases causing visual impairment and blindness, and the high prevalence in adolescents remains a major public health concern. Based on clinical studies using optical defocus to regulate ocular growth and refractive changes through visual feedback, we hypothesize that early wearing of peripheral myopic defocusing spectacles in children with high risk of myopia may slow the process of emmetropization and even prevent the onset of myopia by inducing more peripheral myopic defocus. The aim of this study is to investigate whether the wearing of peripheral focus-out glasses can be effective in delaying emmetropization in non-myopic children aged 6-8 years.

METHODS

The study is a 2-year randomized controlled trial. A total of 160 subjects will be randomized into the experimental group or the control group. The experimental group will be fitted with direct emmetropia with focus-out glasses (DEFOG) to guide the emmetropization process. The control group will not receive any treatment and will serve as a blank control group. The primary aim is to determine whether non-myopic children wearing DEFOG lenses are superior to those who do not receive any intervention on the progression of cycloplegic objective refraction over 2 years.

DISCUSSION

This is the first randomized controlled trial aiming at myopic prevention by non-invasive intervention in non-myopic children. This study aims to initially investigate whether wearing peripheral focus-out glasses can effectively delay the process of emmetropization in children aged 6-8 years with high risk of myopia, which might give potential clues for further exploration on early prevention of myopia.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05689567. Registered on 10 January 2023.