To report the effect of hydroxychloroquine therapy cessation on the multifocal electroretinogram (mfERG) in a case series of patients with rheumatic disease suspected to have retinopathy.
Comprehensive data were retrospectively reviewed on 14 patients from a total of 50 cases who discontinued hydroxychloroquine due to suspected toxicity. Patients were followed for 4 years after the cessation of therapy. mfERG testing had been part of original screening for hydroxychloroquine retinopathy and was continued after therapy cessation at 6-month intervals. Descriptive statistics, independent sample t test, and one-way analysis of variance with repeated measures and post hoc analysis were conducted to determine patients' clinical characteristics and changes in the mfERG after therapy cessation, respectively.
All 14 patients were female; 12 were treated for rheumatoid arthritis and 2 for systemic lupus erythematosus. Three groups were identified: (i) 9 patients in whom the responses of the mfERG recovered to within normative values after cessation of hydroxychloroquine therapy, (ii) 3 who experienced limited recoveries, and (iii) 1 patient whose mfERG response was unchanged. There was no significant difference (p > 0.05) in the clinical characteristics of these patients. However, the proportional reduction of mfERG ring 1, 2, and 3 amplitudes from age normal responses at the time of discontinuation of drug use for the first and second groups of patients was significantly different, with more reduction in group 2 (p < 0.05).
Early detection of hydroxychloroquine retinopathy through screening and subsequent therapy discontinuation could result in recovery of the mfERG ring amplitude response and preservation of visual function.