NEW FINDINGS FROM OPHTHALMOLOGY, AJO, AND JAMA OPHTHALMOLOGY Ophthalmology Three-Year Results on Corneal Colla- gen Cross-Linking in Keratoconus

In this prospective, unmasked, randomized controlled trial, WittigSilva et al. found that corneal collagen cross-linking leads to sustained improvements in keratometry values and visual acuity in eyes with progressive keratoconus. The authors enrolled 100 patients with keratoconus and evenly divided them into treatment and control groups. The primary outcome was the maximum simulated keratometry value of the steepest axis on corneal topography. In control eyes, this value increased by a mean of 1.20 ± 0.28 D, 1.70 ± 0.36 D, and 1.75 ± 0.38 D at 12, 24, and 36 months, respectively. By contrast, keratometry value decreased in treated eyes by a mean of –0.72 ± 0.15 D, –0.96 ± 0.16 D, and –1.03 ± 0.19 D at 12, 24, and 36 months, respectively. Six eyes in the treatment group improved by at least –2 D at 36 months, with a maximum improvement of –2.9 D observed in two eyes. Only one eye in the treatment group progressed more than 2 D during the study; this treatment failure occurred in a patient who experienced rosacea keratitis. No control eyes improved by at least 2 D. Moreover, 19 control eyes had documented progression of at least 2 D, with seven progressing by at least 4 D over 36 months. Secondary outcomes included uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA). Treated eyes showed improvements in both at 36 months, while untreated eyes demonstrated deterioration in UCVA and no significant changes in BCVA during the study. Two cases of adverse effects were noted in the treatment group, with one eye experiencing clinically evident postoperative edema associated with a paracentral infiltrate, and a second eye developing subepithelial infiltrates.