Corneal Endothelial Cell Changes After Corneal Cross Linking In Keratoconus

Aim: To assess the corneal endothelial cell changes after accelerated corneal cross linking (CXL) in keratoconus patients.
Methods: 60 eyes of 60 patients who undergone accelerated CXL for progressive keratoconus were enrolled. The preoperative and three months postoperative endothelial cell density (ECD) and coefficient of variation (CV)- measured by specular microscopy- together with the central corneal thickness (CCT) -measured by Pentacam -were compared. Intraoperative CCT was also measured intraoperatively using the built-in pachymeter before UV irradiation. We divided the patients into two groups according to intraoperative CCT: below or above 386 μm.
Results: The mean preoperative ECD was 2604.25 ± 222.54 cell/mm2 that decreased to 2584.53 ± 262.55 cell/mm2 postoperatively. The mean CV increased from 39.72 ± 3.84% preoperatively to 40.08 ± 4.17 post operatively. The change in ECD and CV was not statistically significant (p=0.14& 0.16, respectively). There was a statistically significant reduction in the CCT from 492.88 ± 35.08 μm to 482.60 ±37.68 μm postoperatively (p=0.001). According to intraoperative CCT, there was no significant difference between the two groups (below or above 386 μm) regarding the ECD, CV, and percentage of endothelial cell loss (p=0.1&0.9&0.6, respectively).
Conclusions: Accelerated crosslinking is safe in terms of corneal endothelial cell changes. The intraoperative reduction in CCT seems to not affect the endothelial cells significantly even in those with thickness less than 386 μm.