Corneal endothelial changes after accelerated corneal collagen cross-linking in keratoconus and postLASIK ectasia

Abstract

Purpose: The purpose of this study was to evaluate the effects of accelerated cross-linking (CXL) on corneal endothelium in keratoconus and postlaser-assisted in situ keratomileusis (LASIK) ectasia.

Design: This study is a prospective nonrandomized controlled study.

Setting: This study was conducted in Mansoura Ophthalmic Center (Mansoura University) and Al-Mostakbal Ophthalmic Center, Mansoura, Egypt.

Methods: In total, 40 eyes with progressive keratoconus and 10 eyes with postLASIK ectasia were subjected to an accelerated CXL (10 mW/cm² for 9 minutes). Qualitative and quantitative analyses of the corneal endothelial cells were conducted before CXL and 3, 6, and 12 months after CXL by using a specular microscope (Tomy EM-3000).

Results: There was a significant reduction in endothelial cell count particularly at 3 and 6 months postCXL. In addition, the coefficient of variance was also statistically significantly higher at 3 and 6 months postoperatively than the preCXL value. There was a slight change in the percentage of hexagonal cells.

Conclusion: The use of accelerated CXL (10 mW/cm² for 9 minutes) has a transient negative impact on endothelial cell density and/or endothelial morphology.

Keywords: accelerated cross-linking; corneal endothelium; keratoconus; postLASIK ectasia.

Figure 1

Qualitative and quantitative analysis of the corneal endothelial cells in keratoconus male patient (24 years old). Notes: Preoperative endothelial cells count was 3,081/mm² (A), decreased to 2,687/mm² at 3 months (B), 2,714/mm² at 6 months (C), and increased to 2,763/mm² at 12 months (D) after accelerated cross-linking. Abbreviations: AVG, average; CD, cell density; CV, coefficient of variance; Max, maximum; Min, minimum; SD, standard deviation.