Importance Hydroxychloroquine sulfate is widely used for the long-term treatment of
autoimmune conditions but can cause irreversible toxic retinopathy. Prior estimations of risk
were low but were based largely on short-term users or severe retinal toxicity (bull's eye
maculopathy). The risk may be much higher because retinopathy can be detected earlier
when using more sensitive screening techniques. Objectives To reassess the prevalence of
and risk factors for hydroxychloroquine retinal toxicity and to determine dosage levels that …