Cross-Linking del collagene corneale senza disepitelizzazione

Abstract

Aim. The aim of this paper was to evaluate the effectiveness of transepithelial crosslinking (TE CXL) in patients with bilateral progressive keratoconus. Methods. The study population was patients with a history of bilateral progressive keratoconus. The worse eye was treated; the untreated fellow eye served as control. TE CXL was performed stepwise in six steps of irradiation delivered by a laser source (CBM X-linker VEGA ® ) and application of Ricrolin TE ® (0.1% riboflavin, dextrane T500, and enhancers to facilitate passage of the solution through the corneal epithelium) every 5 minutes, 2 hours before imbibtion with Ricrolin TE ® in the worse eye. Results. A gradual improvement in topographic and abberometric values, without postoperative corneal haze or other side effects, was noted in the TE-CXL-treated eyes. Confocal microscopy demonstrated corneal crosslinks starting 5 months after treatment; all indices deteriorated in the control eyes. Conclusion. TE CXL treatment was found to be effective in slowing keratoconus progression, with a statistically significant improvement in parameters. Thanks to transepithelial treatment and absence of side effects, TE CXL permits treatment of keratoconus in cases of corneal thickness <400 micron; "complicated" patients <12 years of age (e.g., trisomy 21 syndrome); patients aged ≥35 years or with a mean K >55. Unlike conventional CXL, TE CXL, because it spares the epithelium, ensures better patient compliance, without postoperative pain or haze or deterioration of vision. TE CXL is an innovative treatment that acts on the anterior third of cornea, without side effects; as it is simple to perform, it can be used in conjunction with conventional CXL, which acts on the posterior third of cornea. Key words: Collagen -Cross-linking reagentsCornea. I l cross-linking del collagene corneale (CXL) è una procedura chirurgica nata allo scopo di rallentare o arrestare la progressione delle patologie corneali da sfiancamento progressivo come il cheratocono, la degenerazione marginale pellucida e le ectasie corneali da chirurgia refrattiva. I primi studi che hanno ampiamente dimostrato che il CXL incrementa la rigidità dello stroma di oltre il 300%, grazie all'incremento del diametro delle fibre collagene del 12,2% e alla formazione di legami cross-link nella struttura del collagene, furono pubblicati a partire dalla fine degli anni '90 1-3 . Il trattamento si basa sull'esposizione dello stroma corneale ai raggi ultravioletti di tipo A dopo imbibizione dello stroma corRicevuto il 5 marzo, 2010. Accettato il 9 marzo, 2010