Possible Adverse Effects of Long-term Use of Hydroxychloroquine on Corneal Endothelium

Abstract

Hydroxychloroquine (HCQ) is a less toxic metabolite of chloroquine which is used to treat rheumatic diseases. It can cause corneal deposits (cornea verticillata), ciliary body dysfunction, posterior subcapsular lens opacity, and retinal toxicity. Symptoms of corneal deposits (cornea verticillata) include haloes and glare. Symptoms of retinopathy include blurred and partial loss of central vision followed by side vision and in the later stage night vision will be affected. In clinical practice, specular microscopy is the most accurate way to examine the corneal endothelium. The aim of this study is detection of possible adverse effects of long term use of hydroxychloroquine on corneal endothelium in patients of rheumatological diseases who used the drug for at least three years. This study included 30 eyes of 15 patients with rheumatological diseases who used hydroxychloroquine for at least 3 years representing the study group and 30 eyes of 15 persons with normal healthy corneas representing the control group. Exclusion criteria included past history of ocular trauma, past history of previous intraocular surgeries, corneal scars or degenerations, cataract and past history of glaucoma. A complete ophthalmological examination was performed for all participants. Specular microscopy was performed for all participants to evaluate changes in the cornea. The results were in the form of central corneal thickness, endothelial cell density, coefficient of variation and percentage of hexagonal cells.