Refractive Errors Progression in Brazilian Low-Income School Children

Purpose: To assess the progression of refractive error (RE) in low-income school children in Sao Paulo, Brazil. Methods: The study population consisted of a cohort of children (11-14 years of age) from 9 randomly chosen public schools from a study performed in 2004-2005, with refraction in those with visual impairment (uncorrected distance visual acuity ≤ 20/40 in either eye). Eligible participants were those identified in the baseline study as visually impaired. Three years later, follow-up recruitment consisted of invitation for a free ophthalmic exam in the school facilities. Cycloplegic auto-refraction, cycloplegic subjective refraction and fundus examination were performed in those refracted at baseline and follow-up. Risk factors for refractive errors were investigated by administering questionnaires on family demographics, parental glasses usage and near work/outdoor activities. Results: A cohort of 218 children was eligible for a 3-year follow-up, with 136 examined. Myopic progression of -0.50 to -1.49 spherical equivalent (SE) was found in both eyes of 64 (47.1%) children, in 22 (16.2%) firstly right eyes tested only and in 15 (11.0%) second eyes tested only. Both eyes of 14 (10.3%) children had progressed < -1.50 SE, with 11 (8.1%) progressing only in their second eyes tested and 6 (4.4%) in their first eye tested. In multiple regression analysis myopic progression was associated with both parents wearing glasses (p<0.05). Conclusions: Very mild refractive error progression was detected in a low-income urban Brazilian school children population, confirming the previous finding of low prevalence of refractive errors leading to visual impairment in this population.