A study to determine the effect of hydroxychloroquine (HCQ) on central corneal thickness (CCT) in patients with rheumatoid arthritis (RA)

Corneal thinning is common in rheumatoid arthritis (RA), thereby affecting the central corneal thickness (CCT). Effect of hydroxychloroquine (HCQ) in RA has abounding literature on retinal toxicity, but there is lack of data on its corneal effects. A cross-sectional study was carried out to compare CCT in RA patients before treatment initiation (Group 1) with CCT in those on HCQ for ≥3 months (Group 2). Fifty patients were enrolled in each group. The mean age was 44.36 years with similar age, gender distribution and visual acuity in both groups. The mean CCT of patients in the cohort was 521.80 μm ± 32.57 μm and 523.94 μm ± 33.40 μm in the right eye (RE) and left eye (LE), respectively. Mean CCT in Group 1 was (RE) 522.80 μm/(LE) 524.26 μm and in Group 2 was (RE) 520.80 μm/(LE) 523.62 μm, and there was no significant difference in CCT between both the groups. Median duration of HCQ usage in Group 2 was 24 months, with the median cumulative dosage being 171 g and a majority having a dosage of 200 mg/day. There was no significant correlation between the duration/cumulative dosage of HCQ intake and CCT. No corneal deposits were identified in any patient. CCT of RA patients was similar to those reported in the Indian literature. However, there was no significant change in CCT or corneal deposits identified with an HCQ dosage of 200-400 mg/day. Longer follow-up would provide clarity on the impact of duration and cumulative dosage of HCQ on corneal changes and CCT.