Incidence of Myopia in Southern India in the Longitudinal Andhra Pradesh Eye Disease Study

Abstract

Purpose : The Andhra Pradesh Eye Disease Study 3 (APEDS3) was a 15 year follow up of participants in APEDS1 who were examined in phases between 1996 and 2000. Surviving participants of all ages (n=5398; 83.6%) in three rural areas were traced and examined between 2012 and 2016 in the same order. The aim of this study was to estimate the incidence of myopia and to investigate socio-demographic risk factors.

Methods : Visual acuity (VA) was measured using a standard logarithm of minimum angle of resolution (logMAR) chart at 3 meters. Unaided, presenting, pinhole and best-corrected VA were measured. Incident myopia, defined as a spherical equivalent of <-0.75 D in participants without refractive error at baseline, was estimated for participants below 30 years and those 30 years and above at baseline. Data on right eyes was used in the analysis: t tests were used for continuous variable and chi square tests for categorical variables. For univariable and multivariable analysis, logistic regression was used.

Results : At follow-up 2,229 (<30 years) and 2480 (≥30years) participants did not have myopia at APEDS1, with no differences by sex. In the surviving cohort, the cumulative incidence of myopia in individuals <30 years at APEDS1 was 8.7% (95% CI: 7.5-9.9) and mean myopia was -1.5 D (SD: 1.4D; range: -0.75 to -13D). In multiple regression analysis, the odds of incident myopia were higher in females (OR: 1.7, 95% CI: 1.2-2.3) and in one of the three rural locations (OR: 2.1, 95% CI: 1.3-3.2). In those ≥30 years, the cumulative incidence was 33.6% (95% CI: 31.5-35.8) with a mean myopia of -2.7 D (SD: 1.8D; range: -0.75 to -13D). In multiple regression the odds of incident myopia increased with increasing age (reference: 30-39 years) {40-49 years (OR: 2.0 95% CI: 1.6-2.4), 50-59 years (OR: 2.2 95% CI: 1.7-2.9), 60-69 years (OR: 1.9 95% CI: 1.2-2.9) and was higher in one rural area (OR: 1.6, 95% CI: 1.6-2.0), but was lower in females (OR: 0.6, 95% CI: 0.5-0.8).

Conclusions : The overall incidence of myopia was high in this Southern Indian population indicating a need for strategies to address uncorrected refractive myopia. A limitation of the study is that the data on near work, time spend outdoors and family history of myopia were not collected, which needs to be kept in mind when interpreting the results.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.