ASSESSMENT OF EARLY RETINAL ANATOMICAL AND FUNCTIONAL CHANGES IN HYDROXYCHLOROQUINE TREATED PATIENTS BY MULTIFOCAL ELECTRORETINOGRAM AND OPTICAL COHERENCE TOMOGRAPHY

Abstract

Background: Patients having treated with hydroxychloroquine (HCQ) can have retinal function and morphological changes with no evident retinal abnormalities on ophthalmoscopy this can be detected by various imaging Tanique’s. Objective: We aimed to evaluate the early changes of retinal function by multifocal electroretinogram (MF-ERG) and morphology by spectral domain optical coherence tomography (SD-OCT) that may eventually occur in a population of subjects having Rheumatoid Arthritis treated with hydroxychloroquine with no evident retinal abnormalities on ophthalmoscopy. Patients and methods: A prospective study on 30 eyes of patients treated with HCQ (Patient group) and another 30 healthy eyes (control group). SD-OCT and MF-ERG was done in both groups. All patients underwent full medical and ophthalmic history including onset and duration of disease and HCQ therapy, history of ocular surgeries. All patients underwent complete ophthalmic examination including visual acuity: uncorrected VA (UCVA) and best corrected VA (BCVA), anterior segment examination using slit-lamp biomicroscopy, intraocular pressure (IOP) measurement by applanation tonometry, fundus examination, OCT imaging using SD-OCT, and MF-ERG imaging. Results: In patients treated with HCQ, there was a significant reduction in the pri-foveal macular thickness by SD-OCT in comparison to control group. There were also significant MF-ERG changes in the form on decreased P1-wave amplitude and increased P1-wave latency. Conclusion: MF-ERG and SD-OCT were very sensitive tests for the early detection of HCQ-related retinal toxicity. Using either MF-ERG or SD-OCT, or combination of them may be recommended in order to detect retinal changes earlier and also in follow up.