Trends in the Prevalence of Blindness and Correlation With Health Status in Korean Adults: A 10-Year Nationwide Population-Based Study

BACKGROUND: Contemporary data on vision impairment form an important basis for public health policies. However, most data on the clinical epidemiology of blindness are limited by small sample sizes and focused not on systemic conditions but ophthalmic diseases only. In this study, we examined the ten-year trends of blindness prevalence and its correlation with systemic health status in Korean adults. METHODS: This study investigated 10,000,000 participants randomly extracted from the entire Korean population (aged ≥ 20 years) who underwent a National Health Insurance Service health checkup between 2009 and 2018. Participants with blindness, defined as visual acuity in the better-seeing eye of ≤ 20/200, were identified. The prevalence of blindness was assessed, and the systemic health status was compared between participants with blindness and without blindness. RESULTS: The mean prevalence of blindness was 0.473% (47,115 blindness cases) and tended to decrease over ten years (0.586% in 2009 and 0.348% in 2018; P < 0.001). The following factors were significantly associated with blindness: female sex, underweight (body mass index < 18.5), high serum creatinine (> 1.5 mg/dL), and bilateral hearing loss. In addition, except for those aged 30–39 and 40–49 years, high fasting glucose (≥ 126 mg/dL) and low hemoglobin (male: < 12 g/dL, female: < 10 g/dL) were significantly correlated with prevalent blindness. CONCLUSION: Our ten-year Korean nationwide population-based study suggested a gradual decrease in the prevalence of blindness and its association with specific systemic health status. These conditions might be the cause or consequence of blindness and can be used as a reference for the prevention and/or rehabilitation of blindness to establish public health policies.