Ocular toxicity due to chloroquine and hydroxychloroquine: electrophysiological and visual function correlates

Chloroquine (CQ) and hydroxycholorquine (HCQ) have been used widely for the treatment of rheumatoid arthritis and other similar inflammatory diseases since the early 50s. They remain the treatment of choice for many patients even today. Significant, either reversible or irreversible central visual loss associated with the drugs is very rare, but an important side effect that can warrant discontinuation of therapy. Early diagnosis of toxicity and evaluation of the visual function are, therefore, important parts of the treatment process. Various electrophysiological and psychophysical tests have been and are used for the detection, follow-up and prognosis of drug-associated central visual loss. A summary and comment on the tests, with emphasis on the use of more recently developed methods, such as the multifocal electroretinography (mfERG), are presented in this review.