Corneal Cross-Linking Guards Against Infectious Keratitis: An Experimental Model

to prove if PACK-CXL (Photo-Activated Chromophore for Keratitis – Corneal Cross-Linking) could guard against progression of infectious keratitis (IK) and stop organism penetration only through increasing corneal rigidity and resistance to proteolytic enzymatic digestion of collagen fibers even in the absence of riboflavin microbicidal role.

Animal house at cairo university

Induction of infection with Pseudomonas aeruginosa and Staph aureus bacteria in 20 eyes of 10 rabbits after 6 weeks of crosslinking in half of the eyes while the other acted as control group. Then clinical and histology examination for extent of inflammation, epithelial changes, ulceration, organism penetration, thickness of corneal stromal affection were evaluated.

The control developed the severest inflammation that necessitated sacrifice after 72 hours. Corneal melting occurred in 6 eyes in the control versus none in crosslinked group. The inflammation was confined underneath the corneal epithelium in the superficial part of the stroma with localization in crosslinked eyes.

PACK-CXL provides localization of infection, inflammation and tissues’ damage through increasing the corneal rigidity and resistance to enzymatic digestion mechanically even in the absence of the riboflavin role. The inclusion of early PACK-CXL treatment in the IK treatment algorithm is considered to be appropriate.