Myopia is Inversely Associated With the Prevalence of Diabetic Retinopathy in the South Korean Population.
PURPOSE
Diabetic retinopathy is a major cause of irreversible vision loss. Recent studies have suggested that myopia may be negatively correlated with the prevalence of diabetic retinopathy. We sought to further investigate the association between refractive error and the likelihood of having diabetic retinopathy in a cross-sectional, population-based study of the South Korean population.


DESIGN
Cross-sectional study.


METHODS
Data were included from right eyes of 13 424 participants who were 40 years and older with gradable fundus photographs of the Fourth and the Fifth Korea National Health and Nutrition Examination Survey. Diabetic retinopathy was graded using standard fundus photographs. Autorefraction data were collected to calculate spherical equivalent of refraction in diopters (D) and further classified into 4 groups: hyperopia (≥1.0 D), emmetropia (-0.99 D to 0.99 D), mild myopia (-1.0 D to -2.99 D), and moderate to high myopia (≤-3.0 D). Demographic, comorbidity, and health-related behavior information was obtained via interview. A multivariate model was used to evaluate the association between the diagnosis of any diabetic retinopathy and the refractive status.


RESULTS
Mild myopia and moderate to high myopia groups were negatively associated with development of any diabetic retinopathy (odds ratio [OR] 0.42; 95% confidence interval [CI] 0.18-0.97 and OR 0.14; 95% CI 0.02-0.88, respectively). In addition, for every 1 D increase in spherical equivalent, there was a 30% increase of having diabetic retinopathy (OR 1.30; 95% CI, 1.08-1.58).


CONCLUSIONS
Our results from a population-based study suggest that myopic status is associated with lower odds of having diabetic retinopathy in the South Korean population.