The Retina Reference

Hydroxychloroquine Therapy - Normal Multifocal Electroretinography Despite Toxic Dosing

This 57 year woman on hydroxychloroquine for Sjogren's syndrome was 5 feet 1 inch in height, weighed 112 pounds, and was taking 400 mg of hydroxychoroquine per day for 4 years yielding a cumulative dose of 681 mg and an adjusted daily dose of 7.9 mg/kg/d. Despite toxic dosing, both her 10-2 VF and her mf ERG testing were normal in both eyes. This image of her multifocal electroretinogram demonstrates this for both eyes. The R1/R2 ratios are both < 2.6 (the upper limit of normal). For unknown reasons, some persons do not deelop toxicity at doses considered toxic. Nevertheless, based on the toxic dosing, a request was made to her internist to consider reducing the dose of hydroxychloroquine.