Prevalence and Risk Factors of Refractive Errors Among School-Going Children

Abstract

Objectives: To study the prevalence of refractive errors and evaluate the demographic, familial, behavioral, and environmental risk factors associated with refractive errors in school-going children.

Study Design: A Cross-sectional study.

Place and Duration of the Study: Department of Ophthalmology, MMC/BKMC, Mardan, from Jan 2020 to Dec 2021

Material and Methods: A cross-sectional study was carried out on 100 school-going children aged 6-16 years. Schools were selected consecutively to recruit participants. The demographic data, family history, screen time, near-work duration, outdoor activities, and previous spectacle use were collected using a structured questionnaire. Visual acuity was tested with a Snellen chart, and objective & subjective refraction was performed for children with lower visual acuity. Refractive errors were classified as myopia (-0.5 D or less), hypermetropia (+0.5 D or more), or astigmatism (any refractive error other than myopia and hypermetropia). SPSS version 27.0 was used for data analysis. The frequencies, percentages, mean ± standard deviation, and chi-square tests were used. Logistic regression was performed to determine the significant risk factors (p<0.05).

Results: Among 100 children, the mean age was 11.2 ± 2.8 years. Refractive errors were identified in 32 (32.0%) children, while 68 (68.0%) had normal refractive status. Myopia was the most frequent refractive error, observed in 19 (19.0%) children, followed by astigmatism in 9 (9.0%) and hypermetropia in 4 (4.0%). Refractive errors were more common among children aged ≥12 years than younger children (40.0% vs. 24.0%, p=0.048). A significant association was observed with family history of refractive error, with 45.5% of children having an affected parent developing refractive errors compared with 25.6% without such history (p=0.032). Children reporting ≥4 hours of daily screen exposure had a higher prevalence than those with <4 hours (41.9% vs. 22.0%, p=0.036). Near work exceeding 3 hours/day was also associated with refractive errors (40.0% vs. 22.5%, p=0.047). Children spending ≥2 hours/day outdoors had fewer refractive errors than those with less outdoor activity (22.2% vs. 40.7%, p=0.041). Sex was not significantly associated with refractive errors (p=0.614).

Conclusion: In the studied school-going children, refractive errors were observed in about 33%, with myopia as the most common error. Positive family history, prolonged screen exposure, and increased near work were significantly associated with refractive errors, and increased outdoor activity appeared to have a protective association. Childhood vision impairment can be minimized by regular vision screening, early refractive correction, spectacle correction, and encouragement of outdoor activities at school.

Keywords: Refractive errors; Myopia; Schoolchildren; Vision screening