U.S. Multicenter Trial of CXL for Keratoconus
Ophthalmology, September 2017
Hersh et al. studied data from 2 multicenter trials of corneal collagen cross-linking (CXL) for keratoconus and noted beneficial effects on disease progression.
In the concurrent studies, 205 patients with keratoconus (mean age, 33 years) were assigned randomly to either standard ultraviolet A–riboflavin 0.1% CXL treatment (n = 102 eyes) or sham treatment (riboflavin 0.1% with dextran, no epithelial removal or irradiation; n = 103 eyes). The primary efficacy endpoint was the between-group difference in maximum keratometry change over 1 year. Secondary endpoints were corrected and uncorrected distance visual acuity (CDVA and UDVA, respectively), manifest refraction spherical equivalent (MRSE), endothelial cell count, and adverse events.
Ninety CXL eyes and 76 control eyes were followed for 12 months. The mean decrease in maximum keratometry value in the CXL group was 1.6 ± 4.2 D during the 1-year period; a decrease of ≥ 2.0 D occurred in 28 eyes (31.5%) and an increase of ≥ 2 D occurred in 5 eyes (5.6%). In contrast, the control group had a mean increase of 1.0 ± 5.1 D. The difference in maximum keratometry change between the study groups was 2.6 D. CDVA in the CXL group improved by 5.7 logMAR letters, with 23 of 83 eyes (27.7%) gaining and 5 eyes (6%) losing ≥ 10 letters. UDVA improved by 4.4 logMAR letters in the CXL group. Corneal haze was the most common adverse effect of CXL. The endothelial cell count did not change significantly during the year following treatment, and the between-group differences in MRSE changes were not significant.
The authors concluded that CXL treatment effectively and safely halts the progression of keratoconus, findings supported by several international studies. The benefits include reduced corneal steepness, better visual acuity, and improved subjective functioning.
The original article can be found here.