Abstract
Abstract: :
Purpose: Our aim was to evaluate findings of full-field electroretinography (ERG) and multifocal electroretinography (mfERG) in patients taking hydroxychloroquine (HCQ) for different periods of time. We reviewed records for 26 patients using HCQ for 1.5-30 yrs all of whom had an ERG and/or mfERG. Methods: Both ERG and mfERG were done according to the international standards and guidelines. Oscillatory potentials (OPs) were recorded under scotopic and photopic conditions. They were digitally filtered (60-300Hz) and their amplitudes, implicit times and power spectrum were measured. MfERG to 103 hexagons was recorded and the parameters of the first order kernel were measured and analyzed. Results: Out of 26 patients tested only 4 had signs of macular toxicity attributable to the HCQ treatment. However, scotopic OPs showed almost universal decrease in amplitudes. Out of 22 patients who had full-field ERGs, 20% showed lack of scotopic OP4 and 2/3 of those without maculopathy had at least one abnormal full-field ERG parameter. Out of 16 patients who had mfERG, 10 showed either decreased amplitudes or prolonged implicit times, including 3 patients with maculopathy. Conclusion: Retinal function was altered in many patients taking HCQ even without clinical signs of maculopathy. The reason for this remains unknown. This might represent either sub-clinical vasculopathy from the systemic disease process or some retinotoxic effect of HCQ.
Keywords: 395 electroretinography: clinical • 393 electrophysiology: clinical • 460 macula/fovea