Urban-Rural and School-Type Disparities in the Prevalence of Myopia and High Myopia in South India

Given the rising and varying prevalence of myopia across different Indian states, the prevalence of myopia among school children from rural and urban regions of the south Indian state of Telangana is reported.

A cross-sectional study was conducted among children aged 8-17 years. The logMAR visual acuity chart was used to determine the unaided visual acuity (UAVA) at 4 m. An open-field autorefractor was used to determine the non-cycloplegic spherical equivalent refraction (SER) at 3 m. Myopia was defined as SER ≤ -0.75 D and UAVA ≥ 0.20 logMAR. Myopes were further sub-categorised into low myopia (SER ≤ -0.75 to > -6.00 D) and high myopia (SER ≤ -6.00 D). Urban and rural regions were defined and classified based on the Government of India's census data (2021).

A total of 4261 participants were included (mean age: 13.6 ± 1.9 years). The overall myopia prevalence was 16.9% (95% CI: 15.8-18.0%), with higher prevalence in urban (22.8%; 95% CI: 21.2-24.4%) than in rural (6.9%; 95% CI: 5.7-8.2%) regions (p < 0.001). Children in private schools had a higher myopia prevalence than those in public schools in both rural (10.4 vs. 6.0%, p = 0.005) and urban regions (25.2 vs. 11.2%, p < 0.001). Multivariable logistic regression analyses revealed higher odds of myopia in participants going to private schools in both rural (OR: 2.34, 95% CI: 1.45-3.76%, p < 0.001) and urban regions (OR: 2.45, 95% CI: 1.80-3.34%, p < 0.001), independent of age and sex. The overall prevalence of high myopia was 0.8% (95% CI: 0.5-1.1%) with a higher prevalence in urban (1.2%) than in rural (0.2%, p < 0.001) regions.

The differences in myopia prevalence (3.5-fold higher) and high myopia (6-fold higher) between urban and rural regions, along with the consistent gradient between private and public schools, suggest that underlying environmental, behavioural and socioeconomic factors (not directly measured in this study) may contribute to the observed disparities.