Screening for Hydroxychloroquine Retinal Toxicity in Indian Patients.

Abstract

Several studies have reported hydroxychloroquine (HCQ) retinal toxicity in East Asian patients. However, at present, there are limited data from Indian patients. The aim of this study was to investigate the prevalence and pattern of HCQ retinal toxicity in Indian population and to see if screening protocol for retinal toxicity in Indian patients should be any different to others. This was a cross-sectional study involving adult patients with autoimmune rheumatic diseases who had received HCQ for at least 5 years or a cumulative dose of at least 500 g. Retinal toxicity was evaluated using fundus examination, visual fields 10-2 and 30-2 protocol, and spectral domain optical coherence tomography. Of 110 patients screened, retinal toxicity was found in 7 patients (6.36%). A parafoveal pattern was found in 4 patients, whereas a mixed parafoveal and perifoveal pattern was found in 3 patients. None of the patients had isolated perifoveal pattern. Except for the one patient, all the patients with retinal toxicity had more than 10 years (mean, 13 ± 4.89 years; range, 5-20 years) of HCQ usage with a mean cumulative dose of 1573.7 ± 771.5 g. The mean daily dose was 5 ± 1.6 mg/kg per day. Hydroxychloroquine retinal toxicity is more common than previously recognized in patients who have used the drug for more than 5 years. The toxicity manifests as a parafoveal or a mixed parafoveal and perifoveal pattern in Indian patients.