Purpose: To report the prevalence and causes of functional low vision (FLV) in school-age children in Coimbatore District, Tamil Nadu, India and to report our experience using the key informant (KI) method in this setting.
Methods: Children suspected of having low vision were identified by KIs or Aravind Eye Hospital personnel in Coimbatore District. All identified children underwent a cycloplegic refraction and full eye exam. A primary cause of decreased vision was determined for each child. The prevalence of FLV was calculated for children 6-14 years old. Spectacles and low vision devices were provided free of charge.
Results: 345 children aged 6-14 years were referred and 231 had FLV. The positive-predictive value of KI referrals was 64.5%. The prevalence of FLV was 0.071% (7.1 per 10,000; 95% CI 0.062-0.080%) and ranged from 0.026% to 0.141% across the district's blocks. Older children (age 11-14 years; OR 1.41; 95% CI 1.09-1.82) and males (OR 1.52; 95% CI 1.16-1.98) had greater odds of being diagnosed with FLV. The most common causes of FLV were retinal disorders (30.0%) and amblyopia (25.5%). Low vision devices were provided to 169 children who had a mean near and distance visual acuity improvement of 0.31 and 0.63 logMAR, respectively (p < 0.001).
Conclusions: This study reports a moderate prevalence of FLV and demonstrates the ability of KIs to identify school-age children with FLV in South India. The provision of basic low vision services can improve visual outcomes in this population.
Keywords: India; Low vision; epidemiology; key informant; pediatric ophthalmology.