The use of hydroxychloroquine is associated with an increased risk of retinopathy in a large cohort study, researchers report, and the risk of retinopathy increases progressively with doses of the drug. “We observed that the long-term risk for hydroxychloroquine retinopathy was greater in patients who received higher doses of hydroxychloroquine in the first 5 years of use,” the authors write. “Dosing higher than 6 mg/kg was associated with a 15-year risk of nearly 22%, whereas this risk was 11% with 5 to 6 mg/kg and less than 3% with 5 mg/kg or lower. The risk for retinopathy with a shorter duration of use was considerably lower. Nevertheless, with regular screening with [spectral domain optical coherence tomography], most cases of retinopathy were detected in the mild, asymptomatic stage.”
The cohort study included all adult patients in a U.S. integrated health network who received hydroxychloroquine for 5 or more years between 2004 and 2020 and had guideline-recommended serial retinopathy screening. Based on hydroxychloroquine doses shown in pharmacy dispensing records, the investigators found: “Among 3,325 patients in the primary study population, 81 developed hydroxychloroquine retinopathy (56 mild, 17 moderate, and 8 severe), with overall cumulative incidences of 2.5% and 8.6% at 10 and 15 years, respectively. The cumulative incidences of retinopathy at 15 years were 21.6% for higher than 6 mg/kg per day, 11.4% for 5 to 6 mg/kg per day, and 2.7% for 5 mg/kg per day or lower. The corresponding risks for moderate to severe retinopathy at 15 years were 5.9%, 2.4%, and 1.1%, respectively.”