Association between Anemia and Myopia in Korean Adults

Abstract

Objectives: Anemia is a significant public health issue worldwide and has been associated with ocular changes. This study aimed to investigate the relationship between anemia and myopia in an adult population in South Korea.Methods: We analyzed the data of 8,672 participants aged 20 to 54 years in the fifth Korea National Health and Nutrition Examination Survey (KNHANES). Anemia was defined as hemoglobin levels < 13 g/dL for men, < 12 g/dL for women, and < 11 g/dL for pregnant women. Anemia was subdivided into mild anemia (11-12.9 g/dL for men, 11-11.9 g/dL for women, and 10-10.9 g/dL for pregnant women) and moderate to severe anemia ( < 11 g/dL for men and women and < 10 g/dL for pregnant women) categories. Myopia was defined as spherical equivalent value ≤ -0.5 diopters. We performed multivariable logistic regression analysis to examine the relationship between anemia and myopia.Results: The prevalence of myopia was 43.5% in men and 56.5% in women. The prevalence of anemia was 0.9% in men and 14.5% in women. After adjusting for confounders, the risk of myopia was 1.28 times higher in women with anemia than in those without anemia (odds ratio, OR = 1.28, 95% confidence interval, CI = 1.02-1.60, <i>p</i>= 0.036). The risk of myopia was 1.55 times higher in women with moderate to severe anemia than in those without anemia (OR = 1.55, 95% CI = 1.12-2.16, <i>p</i>= 0.026). Anemia was not significantly associated with myopia in men.Conclusions: Women with anemia were at increased risk of myopia compared to those without anemia. The severity of anemia was also associated the risk of myopia.