Effects of Hydroxychloroquine on Progression of Diabetic Retinopathy in Subjects with Rheumatoid Arthritis and Type 2 Diabetes Mellitus

Abstract

Objective: The study was conducted to investigate the effects of hydroxychloroquine, an anti-inflammatory drug, which was recently approved and used as an add on oral antidiabetic drug for uncontrolled Type 2 Diabetes Mellitus (DM) on an adequate dose of sulfonylurea and metformin on the progression of diabetic retinopathy (DR) in subjects with Rheumatoid Arthritis and Type 2 Diabetes Mellitus. The primary objective was to evaluate the effect of hydroxychloroquine on the onset of Diabetic Retinopathy (DR) and progression of the disease. Best-corrected visual acuity (BCVA) charts with 3 or more lines worsening of visual acuity and the development of clinically significant macular edema (CSME) were added as secondary objectives as described in the Early Treatment Diabetic Retinopathy Study (ETDRS). Methods: This retrospective analysis was done from medical records of all Rheumatoid Arthritis (RA) patients who also had T2DM and were treated with hydroxychloroquine (HCQ) 400 mg OD or 200 mg BID (N=65) and received ophthalmologic care at an endocrinology clinic in India up to a mean follow-up of 3.5±0.5 years and matched subjects taking any other disease-modifying antirheumatic drugs (DMARD) and pioglitazone (N=34). Results: Baseline characteristics were similar in both the groups, with matched glycated haemoglobin (9.1 % and 9.2 % respectively, p=0.127). In both groups, over 3.5 years, HbA1c was reduced significantly. No new cases of DR were detected in the HCQ group, whereas 2 patients had developed DR in the pioglitazone group. At the base line visit, mild non-proliferative Diabetic Retinopathy (NPDR) was present in 18 eyes and 14 eyes in the HCQ and pioglitazone groups, respectively. Progression to moderate NPDR over 3.5 years occurred in 2 out of 18 (11 %) eyes in the HCQ group and 8 out of 14 (57 %) eyes in the pioglitazone group, respectively, representing a significant relative risk reduction (p=.001). No patients had progressed from mild NDPR to severe NPDR in the HCQ group, whereas 2 eyes had progressed from mild NPDR to severe NPDR in the pioglitazone group. None of the patients in either arm developed diabetic macular oedema. Conclusion: Progression of DR from mild to moderate NPDR or severe NPDR may be delayed by HCQ. Large scale randomised prospective clinical trial is required to establish the risk-benefit profiles of HCQ in T2DM.