Effect of Hydroxychloroquine Therapy Duration on Retinal Pigment Epithelium in Rheumatological Diseases by Optical Coherence Tomography. A Systematic Review and Meta-Analysis

Abstract Background: Hydroxychloroquine is used increasingly in the management of a variety of autoimmune disorders, However, Hydroxychloroquine has been associated with irreversible visual loss due to retinal toxicity. Cessation of the use of hydroxychloroquine at an early stage of damage might prevent functional loss; however, after maculopathy has developed, cessation of the drug does not show clinical recovery. Because discontinuation of therapy may reverse retinal toxicity, early detection of toxicity changes is important. Aim of Study: To find a relationship between duration of hydroxychloroquine therapy in rheumatological diseases and retinal pigment epithelium changes by optical coherence tomography. Material and Methods: Medical data bases and Cochrane Library were searched for studies from 2011 until 2021. The primary outcome was Retinal Pigment Epithelium thickness ,the secondary outcome was Outer Retinal Thickness and the third outcome was full retinal thickness but unfortunately we didn't find enough papers for the first two outcomes so, our outcome will be the full retinal thicknessat central macula in its four quadrants: Superior, inferior, nasal and temporal difference between hydroxychloroquine drug users of rheu-matological patient in different duration of therapy and healthy controls using optical coherence tomography. Results: Five trials (cross-sectional studies) involved studies and they show in superior quadrant of central macular thickness difference between HCQ users and controls as: Cohran Q = 8.577135 (df = 4) p = 0.0726 and Moment-based estimate of between studies variance = 16.257044, I2 (incon-sistency) = 53.4% (95% CI = 0% to 80.9%), the inferior quadrant of central macular thickness difference as: Cohran Q = 7.759158 (df = 4) p = 0.1008 and Moment-based estimate of between studies variance = 15.932414, I2 (inconsistency) = 48.4% (95% CI = 0% to 79.4%),while nasal quadrant of central macular thickness difference was: Cohran Q = 14.113529 (df = 4) p = 0.0069 and Moment-based estimate of between studies variance = 37.768684, I2 (inconsistency) = 71.7% (95% CI = 0% to 86.8%) and the temporal quadrant of central macular thickness difference between HCQ users and controls was: Cohran Q = 29.001671 (df = 4) p<0.0001, Moment-based estimate of between studies variance = 86.284155, I2 (inconsistency) = 86.2% (95% CI = 65.5% to 92.3%). Conclusion: OCT enables quantitative evaluation of the central macular thickness in rheumatological eyes under treatment of hydroxychloroquine and it has demonstrated the ability of OCT to detect early changes in hydroxychloroquine users group as compared to control group by finding significant thinning between themas found in three studies and decrease inner retinal layers thickness and no changes in outer retinal layers thickness as in one study and no difference in central macular thickness between cases and controls in another study. No relation between retinopathy and neither duration of treatment nore cumulative dose.