Accelerated Corneal CXL for Ectasia After Excimer Laser: 2-Year Outcomes
The aim of this 2-year follow up study was to evaluate the efficacy and safety of Accelerated Corneal Collagen Crosslinking (ACXL) in patients with iatrogenic ectasia after excimer refractive surgery.
Prospective, non randomized, single-center study. Analysis of 24 patients (40 eyes) treated with ACXL for iatrogenic ectasia after excimer laser at the University of São Paulo, Brazil, between Sep 11 and Jul 12. Inclusion criteria: Progressive ectasia, defined as progressive steepening (>1.0D/year), loss of BCVA and unstable refraction; US CCT ≥ 350 μm. Exclusion criteria: prior corneal surgery, herpetic keratitis, chemical injury or delayed epithelial healing. All patients underwent ACXL (9 mW/cm2 for 10 min), and had measurements of visual acuity, CCT (Orbscan and US), corneal topography and endothelial density before and at 6, 12 and 24 months after procedure.
The study comprised 40 eyes of 24 patients (15 male, 9 female) with mean age of 33,8 ± 7,5 years old (range: 24 – 52 years) that attained at least 2-years of follow-up. The surgical procedure was uneventful in all cases. No statistically significant changes were found in the mean UCVA (P=.649), BCVA (P=.616), average K (P=.837), K steep (P=.956), ultrasonic (P=.135) and Scheimpflug imaging (P=.276) pachymetry and endothelial cell density (P=.523) between preoperative and all postoperative measurements. Beyond that, at least 72,5% of patients presented stable or gains of Snellen lines during follow up.
This study shows that AXL seems to be safe and effective in halting the progression of iatrogenic ectasia after excimer laser, without postoperative complications. However, a longer follow up with larger cohorts is necessary to validate these findings.