Prevalence and Incidence of Ethambutol-Induced Optic Neuropathy and Its Risk Factors in Korea: A Nationwide Population-Based Study.

Background: A national study was conducted using data from the National Health Insurance database to determine the prevalence, incidence, and risk factors for ethambutol-induced optic neuropathy (EON) in South Korea.

Methods: This retrospective population-based study was conducted from 2011 to 2020. The participants were identified via registered prescription codes between 2011 and 2018. Individuals with records mimicking EON or individuals diagnosed with EON at least once were excluded. A total of 315,888 patients were divided into a case group (EON) and a control group (non-EON).

Results: Among 315,888 participants aged > 20 years, 2,703 cases of EON were identified, including 1,438 females (53.2%) and 1,265 males (46.8%). The estimated prevalence of EON was 8.54 cases per 1,000 persons (95% confidence interval [CI], 8.53-8.55), and the incidence was 159.16 cases per 100,000 person-years (95% CI, 153.27-165.28). The overall male-female ratio was 0.65 for prevalence and 0.69 for incidence. EON patients were more likely to be older (adjusted odds ratio [OR], 1.88; 95% CI, 1.38-2.58), have diabetes (adjusted OR, 1.14; 95% CI, 1.03-1.26), and have renal diseases (without end-stage renal disease [ESRD], adjusted OR = 1.64, 95% CI, 1.3-2.06; with ESRD, adjusted OR, 2.69; 95% CI, 1.92-3.76) than non-EON patients were. Patients with an EMB prescription duration ≥ 6 months had an elevated risk of EON compared with those with a prescription duration < 2 months (OR, 1.44; 95% CI, 1.30-1.60, adjusted for age, sex, hypertension, diabetes, and renal diseases).

Conclusion: The cumulative incidence of EON was 0.9%. The prevalence and incidence rates of EON were higher among women than men. Age, diabetes, renal diseases, and duration of EMB prescription were risk factors for developing EON. These findings could be valuable for the prevention or early management of EON patients.