Clinical Efficacy of Ex Vivo Cross-Linking on Neovascularization of the Donor Cornea Carrier Tissue for the Boston Type I Keratoprosthesis

Abstract

Purpose: To evaluate the effect of corneal cross-linking (CXL) on corneal neovascularization (CNV) between eyes that were randomized to receive either CXL or non-CXL donor corneas as the carrier tissue for Boston keratoprosthesis surgery. Design: A retrospective masked analysis of CNV from slit lamp photographs taken at postoperative weeks 16, 24, 36, and 52. Subjects: Sixty-eight donor corneas were prospectively randomized 1:1 to receive either donor corneas that underwent ex vivo CXL or were non-CXL. The images of 47 corneas that were suitable for evaluation were included in the final analysis. Methods: The slit lamp photos were analyzed morphometrically using a standardized protocol on Photoshop CS5 (Adobe Systems Inc) and ImageJ software (National Institutes of Health). Main Outcome Measures: The 2 primary metrics used to quantify CNV were neovascular area (NA), defined as the area of corneal vessels projected onto the plane of a photograph, and invasion area (IA), defined as the fraction of corneal area in which vessels are present. Results: Based on multivariable mixed-effects linear modeling, CXL reduces the percentage of NA in the CXL group by 2.2% (P = 0.113). Similarly, there is an average reduction of 7.8% in the percentage of IA in the CXL group compared with the non-CXL group (P = 0.303). Conclusions: Although not statistically significant, this study observed a trend toward a lower CNV in CXL donor corneas compared with non-CXL donor corneas, suggesting that ex vivo CXL of donor corneas may protect against CNV of the donor cornea. Financial Disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Keywords

• Cross-linking
• Corneal neovascularization
• Keratoprosthesis