Randomized control trial on the effectiveness of collagen crosslinking on bullous keratopathy

Abstract

Purpose: To investigate the effect of collagen crosslinking (CXL) on patients with bullous keratopathy (BK) in a double-blinded randomized control manner up to 12 months. Methods: Adult patients with bullous keratopathy were recruited. The subjects were randomized either to receive CXL using riboflavin, with (treatment arm) or without (control arm) UVA illumination. The subjects were assessed from baseline to up to 1 year. Results: Thirty-six subjects who had completed 1 year follow up were included (treatment arm: 24, control arm: 12). At baseline, central corneal thickness (CCT) was 720+/- 166um in treatment group and 802+/-189um in control group (p=0.236). CCT decreased in treatment group at 2, 4 and 12 weeks. CCT was significantly thinner at 735+/-146um at 12 weeks (p=0.02), but the effect would not be sustained. Meanwhile, CCT remained similar throughout the follow up in control group. In the treatment group, pain score significantly decreased from 3.79/10 to 1.83 at 2 weeks and 2.05 at 12 weeks. However, pain score also decreased at 2 weeks and 26 weeks in the control group. There were no changes in visual acuity and corneal clarity in both groups. Three subjects (12.5%) in the treatment group developed epithelial defect at 4 weeks. Conclusions: CXL could potential decrease corneal thickness in BK patients. However, the effect subsided after 12 weeks. Although a decrease in pain score existed in the treatment group, similar improvement in the control group would suggest it being a placebo effect. Epithelial debridement during CXL treatment could potentially result in epithelial defect. Financial Disclosure: Yes (The study was funded by Health and Medical Research Fund from the Hong Kong Government)