Evaluation of Retinal Toxicity by SD-OCT Due to Long-Term Exposure to Hydroxycholorquine among Rheumatoid Arthritis Patients

Abstract

ydroxychloroquine is used increasingly in the management of a variety of autoimmune disorders, with well-established roles in dermatology and rheumatology with an emerging roles in oncology. Hydroxychloroquine has demonstrated a survival benefit in patients with rheumatoid arthritis and systemic lupus erythematosis; some clinicians advocate its use in all such patients. However, Hydroxychloroquine and chloroquine (CQ) have been associated with irreversible visual loss due to retinal toxicity The prevalence of retinopathy in the studies using less advanced methods as fundoscopy, visual acuity, Amsler grid, and/or color vision assessments, had an estimated risk of hydroxychloroquine retinopathy ranging from 0.4% to 1.9%. In the studies that used modern standard screening modalities such as SD-OCT, multifocal ERG (mf-ERG) and visual field perimetry, the prevalence of hydroxychloroquine retinopathy ranged from 1.6% to 8.0% and was 5.2–7.5% in patients who were treated with hydroxychloroquine for >5 years. The prevalence of hydroxychloroquine retinopathy was 5.7-fold higher among patients whose average hydroxychloroquine daily dose was >5.0 mg/kg actual body weight (ABW) than in patients whose average daily dose was ≤5.0 mg/kg ABW. Thereby, the latest 2016 AAO dosing guidelines and 2018 RCO guidelines recommend <5.0 mg/kg of ABW, a more conservative cut- off than any prior ABW- based dosing recommendation.