TRANS-EPITHELIAL CROSS-LINKING

Purpose. To evaluate safety and efficacy of Trans Epithelial Cross linking trough functional and histological corneal induced modifications. Materials and Methods. 8 patients affected from progressive keratoconus and candidated for lamellar corneal transplantation because of corneal thickness under 400 microns, were previously treated by Trans Epithelial Corneal Cross Linking with Ricrolin TE solution (Sooft). Patients were evaluated before and after treatment with a 6 months of maximum follow-up, monitoring the following parameters: UCVA, BSCVA, topographic and in vivo confocal analysis. All crosslinked corneas were explanted during corneal transplantation (DALK, PK) and histologically analysed by optical and electron microscopy. results. After follow-up we recorded an improvement of 1 Snellen line in BSCVA, Sim K max reduction of 0.63 D and SAI reduction of 1.18 D. Histopathological results showed inhomogeneous micromorphological changes immediately below lamina of Bowman and anterior stroma until 80 microns of maximum depth. Conclusion. The variation of corrected visual acuity is likely attributable to the cross linking action concentrated in the most anterior stromal portion as confirmed by histological and confocal study. An increase of corneal surface regularity is described by reduction of Surface Asymmetry Index (SAI), K MAX and Comatic aberration values. Present study confirm safety of TE CXL and If long-term results will confirm also the efficacy of this new method, it will become a new way for the treatment of corneal ectasia (keratoconus, post-LASIK ectasia) with thickness under 400 microns.