Toxic retinopathy associated with long-term hydroxychloroquine therapy

Purpose: To examine the prevalence of hydroxychloroquine (HCQ) retinopathy due to its chronic use in various inflammatory conditions. Methods: It was a cross-sectional, observational study evaluating 80 patients for retinopathy using optical coherence tomography, fundus autofluorescence, and visual field analysis tests. Results: The Chi-squared test was employed, and a P value of <0.05 was considered significant. In our study, a total of 7 patients (8.75%) had definite retinopathy, while eight patients (10%) had possible retinopathy. All seven patients with definite retinopathy and seven out of eight patients with possible retinopathy were female. Most subjects with definite retinopathy were in the 51–60-year age group (57%), and the majority resided in rural areas. The majority of patients with retinopathy had rheumatoid arthritis. Retinopathy was found to be associated with the mean daily dose of HCQ (based on actual body weight) and the duration of HCQ use. All patients with definite retinopathy, as well as seven out of eight patients with possible retinopathy, were using more than 6 mg/kg/day, which exceeds the recommended daily dose of greater than 5 mg/kg. Most of our patients (6 out of 7, or 85.7%) with definite retinopathy had been on HCQ for more than 10 years. Among the subjects with definite retinopathy, 71.4% had a pericentral pattern, 28.5% had a parafoveal pattern, and none had a mixed pattern. Conclusion: HCQ retinopathy is more prevalent at a mean daily dose of >5 mg/kg and with prolonged use of >5 years. Thus, timely screening of patients for retinopathy will help in modifying the dosage or in drug cessation, thus preventing its progression.