Practice Patterns of Screening for Hydroxychloroquine Retinopathy in South Korea

IMPORTANCE: Practice patterns of hydroxychloroquine retinopathy screening have not yet been reported at a national level in South Korea. OBJECTIVE: To investigate the practice patterns of timing and modality for hydroxychloroquine retinopathy screening in South Korea. DESIGN, SETTING, AND PARTICIPANTS: This nationwide population-based cohort study of patients in South Korea used data from the national Health Insurance Review and Assessment database. Patients at risk were identified as those who had initiated hydroxychloroquine therapy between January 1, 2009, and December 31, 2020, and used it for 6 months or more. Patients were excluded if they underwent any of the 4 screening modalities recommended by the American Academy of Ophthalmology (AAO) for other ophthalmic diseases prior to hydroxychloroquine use. The timing and modalities of screening used in baseline and monitoring examinations were assessed between January 1, 2015, and December 31, 2021, among patients at risk and long-term (≥5 years) users. EXPOSURE: Adherence of baseline screening practices to the 2016 AAO recommendations (fundus examination within 1 year of drug use) was evaluated; adherence of monitoring examinations in year 5 was classified as appropriate (≥2 tests recommended by the AAO), unscreened (no test performed), and underscreened (insufficient number of tests). MAIN OUTCOMES AND MEASURES: Timing of screening and modalities used at baseline and monitoring examinations. RESULTS: A total of 65 406 patients at risk (mean [SD] age, 53.0 [15.5] years; 50 622 women [77.4%]) were included; 29 776 patients were long-term users (mean [SD] age, 50.1 [14.7] years; 24 898 women [83.6%]). Baseline screening was performed for 20.8% of the patients within 1 year, with a gradual increase from 16.6% in 2015 to 25.6% in 2021. Monitoring examinations, mostly using optical coherence tomography and/or visual field tests, were performed for only 13.5% of the long-term users in year 5 and for 31.6% of the long-term users after 5 years. Appropriate monitoring was performed for less than 10% of long-term users each year from 2015 to 2021; however, the percentage gradually increased over time. The percentage of patients undergoing any monitoring examination in year 5 was 2.3 times greater for those who had received baseline screening than for those who did not (27.4% vs 11.9%; P < .001). CONCLUSIONS AND RELEVANCE: This study suggests there is an improving trend in retinopathy screening among hydroxychloroquine users in South Korea; however, most long-term users remained unscreened after 5 years of use. Baseline screening may be useful in reducing the number of unscreened long-term users.