A prospective, randomized clinical study comparing accelerated corneal collagen crosslinking with 5% NaCl hypertonic saline for bullous keratopathy in Asian eyes

Background:We compared the clinical outcomes of accelerated corneal collagen crosslinking (CXL) and 5% NaCl hypertonic saline (HS) for the treatment of symptomatic bullous keratopathy (BK).Methods:A randomized controlled trial was held at Department of Ophthalmology, Tokyo Dental College Ichikawa General Hospital, Chiba, Japan. Twenty-three eyes of 23 consecutive patients with symptomatic BK were enrolled. The etiology of BK included pseudophakic BK, previous keratoplasty, previous endotheliitis, previous glaucoma surgery, trauma, herpes infection, as well as unknown causes. Eleven eyes received epi-off accelerated CXL (with epithelial abrasion and 18mW/cm² ultraviolet A irradiation for 5minutes) and 12 eyes received HS instillation. In addition to the usual ophthalmic examination, the best-corrected visual acuity (BCVA) and central corneal thickness (CCT) were determined. The CCT was measured using anterior segment optical coherence tomography before and up to 6 months after treatments. Subjective symptoms of pain, blurred vision, photophobia, and irritation were also recorded.Results:The follow-up was completed for all patients in the CXL group. However, 6 patients in the HS group requested CXL treatments after 3 months. The BCVA was not significantly changed during the study periods in both groups. The CCT was significantly thinner in the CXL group compared to the HS group at 1 and 6 months (P=.015 and 0.144, respectively). Among the subjective symptoms recorded, irritation was significantly lower in the CXL group at 1 month (P=.013).Conclusions:Accelerated CXL may produce transient improvement in pain and corneal edema in patients with BK.