Evaluation of Corneal Parameters and Meibomian Gland Alterations After Corneal Cross-Linking in Patients With Progressive Keratoconus

Objectives:The aim of the study was to evaluate the changes in corneal parameters and meibomian gland alterations after corneal cross-linking (CXL) for progressive keratoconus.Methods:Thirty nine eyes of 39 keratoconus patients were treated with CXL. Corneal topography, specular microscopy, the Ocular Surface Disease Index (c) (OSDI), noninvasive tear break-up time (NITBUT), and meibography indices were evaluated preoperatively and at the first, third, and sixth months after CXL.Results:The flattest keratometry (K1) (P=0.003), steepest keratometry (K2) (P<0.001), apex, central, and thinnest corneal thicknesses (P<0.001) showed significant differences after cross-linking, whereas the changes in the maximum keratometry (Kmax) were not significant (P=0.140). The endothelial cell density, coefficient of variation, and hexagonality were unchanged. The NITBUT values decreased after cross-linking; however, there was no significant change in OSDI index (P=0.313), meiboscore (P=0.392), and meibomian gland loss degrees (P=0.300). No change was detected in the morphology of the meibomian glands after CXL.Conclusion:In eyes with keratoconus, a flattening in keratometry readings and thinning in corneal thickness were observed after CXL. The corneal endothelium is protected by dextran-free riboflavin. Cross-linking procedure causes dry eye by changing the corneal structure without affecting the morphology of the meibomian glands.