Purpose: To investigate risk factors for high myopia in the general Korean population.
Methods: In this nationwide population study, the dataset of the Korea National Health and Nutrition Examination Survey 2008-2012 was analyzed. The study cohort included 11 703 participants, aged 25-49 years, who underwent neither refractive nor cataract surgery. The association between demographic, socioeconomic, behavioral, and systemic variables and high myopia was investigated.
Results: The mean participant age was 37.9 ± 6.8 years, and the prevalence of high myopia ≤-6.0D was 7.0 ± 0.3% in the study population. The right eyes (-1.76 ± 0.03 D) were more myopic than the left eyes (-1.70 ± 0.03 D; P < 0.001). In multivariate logistic regression analysis, high myopia was associated with age (odds ratio [OR], 0.97 per 1 year-increase) and female sex (OR, 1.24). Other identified risk factors included education level ≥ university graduation (OR, 1.91), the presence of hypertension (OR, 1.69), and serum glucose level (OR, 1.01 per 1 mg/dL). Sunlight exposure of ≥5 h/day (OR, 0.67) and serum 25-hydroxyvitamin D level (OR, 0.97 per 1 ng/mL) showed protective effect against high myopia.
Conclusion: High myopia is associated with younger age, female sex, high education level, longer sunlight exposure, and some other systemic conditions.
Keywords: High myopia; female predilection; glucose; hypertension; risk factor; sunlight exposure; vitamin D.