Retinal toxicity in long term hydroxychloroquine treatment

Objective-To report clinical experience from patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) who were receiving recommended doses of hydroxychloroquine for more than six years, and were monitored for evidence of hydroxychloroquine related retinopathy every six months. Methods-A prospective (and continuing) evaluation was made of the potential retinal toxicity of hydroxychloroquine in a cohort of 360 Greek patients followed for RA and SLE, 58 of whom have received long term treatment (> six years). Fundoscopy, colour vision tests, dark adaptation tests, visual field testing, automated perimetry, and electroretinogram were performed every six months. Results-Among 58 patients receiving hydroxychloroquine for more than six years, two relatively young women (3.5%), one treated for RA and the other treated for SLE, developed characteristic hydroxychloroquine related toxic retinal lesions after cumulative doses of 700 g (6.5 years) and 730 g (8 years) of hydroxychloroquine, respectively. Bilateral visual acuity was 6/6 and 6/7.5, respectively; both patients had normal colour perception. Despite an early diagnosis and cessation of treatment, permanent visual field paracentral scotomata in both patients, and persisting lesions in fluorescein angiography in the patient with SLE, were observed at 4.5 and 3 years of follow up, respectively. No other specific cases of hydroxychloroquine related retinopathy have to date been identified in the remaining 302 patients. Conclusion-Cases of irreversible, hydroxychloroquine related retinopathy in patients who did not receive overdoses have not been reported previously. The present observations in two relatively young patients should raise our concern regarding the long term usage of an increasingly popular medication in rheumatology practice.