Abstract
Purpose :
Limited data exist on the real-world outcomes of epithelium off (epi-off), high fluence, Dresden protocol corneal cross-linking (CXL) in the United States for the treatment of progressive keratoconus (KCN). We performed a prospective, noncomparative study to evaluate the outcomes and variables that may affect the results of CXL at a U.S. academic tertiary medical center.
Methods :
We prospectively followed a cohort of 127 eyes in 98 patients with progressive KCN between the ages of 12 to 65 years (median 25, IQR 14.25) that underwent epi-off, Dresden protocol CXL between November 2016 and September 2019 at the Wilmer Eye Institute. Pre- and post-operative best spectacle-corrected visual acuity (BSCVA) measured in logMAR and corneal topographic parameters: K2, Km, Kmax, pachymetry at the apex and thinnest point were measured (Oculus Pentacam, Menlo Park, CA). A linear mixed-effects model compared preoperative variables to postoperative month (POM) 1 and the last documented evaluation (POM 3-24). A subgroup analysis compared patients ≤ 18 years at the first visit to those > 18 years of age.
Results :
POM-1 evaluation occurred in 91 eyes and 106 eyes had a last recorded visit at POM 3-24. Worse BSCVA was noted at POM-1 (0.23 ± 0.02 logMAR preop vs. 0.27 ± 0.02 logMAR POM-1, p = 0.009), with a return to preoperative vision by the last visit (0.22 ± 0.02 logMAR, p = NS). An increase in Kmax was observed at POM-1 (preop Kmax = 60.12 ± 0.83 D vs. POM-1 Kmax = 61.62 ± 0.86 D, p < 0.001), with a return to preoperative values by the last visit (59.48 ± 0.82 D, p = NS). A decrease from preoperative pachymetry at the apex was observed at POM-1 and the last visit (467.63 ± 4.20 µm preop vs. 457.36 ± 4.51 µm POM-1 and 461.34 ± 4.90 µm at the last visit, p < 0.001 and p < 0.05, respectively). No differences were observed between outcomes in pediatric and adult populations (p = NS).
Conclusions :
This study of real-world CXL results in the U.S. demonstrates similar outcomes to those in prior international studies, in terms of flattening of the cornea and preservation of visual acuity. Worsening of BSCVA and pachymetry/keratometry were observed at POM-1, with a subsequent return to preoperative values, similar to other reports. CXL obtained equally effective results in adults and children.
This is a 2020 ARVO Annual Meeting abstract.