ARTIFICIAL STIFFENING OF THE CORNEA BY IN DUCTION OF INTRASTROMAL CROSS-LINKS

Purpose: To increase the stability of the cornea by artificial cross-l inking (radiation or chemical agents) and to investigate a future ther apy for keratoconus. Materials and methods: The epithelium of enucleat ed porcine eyes was removed. Ten eyes in each of eight test groups wer e treated with UV light (lambda = 254 nm), 0.5 % riboflavin and UV lig ht (365 nm), blue light (436 nm) and sunlight, and the chemical agents glutaraldehyde (1% and 0.1 %, 10 min) and Karnovsky's solution (0.1 % , 10 min). Strips of 5 mm in width and 9 mm in length were cut from ea ch cornea and the stress-strain behaviour of the strips was measured. For comparison, eight groups of ten untreated corneas each were measur ed by the same method. Results: Compared to untreated corneas riboflav in and UV irradiation as well as glutaraldehyde and Karnovsky's soluti on treatment resulted in significantly increased stiffness of the corn ea (p < 0.05). Conclusions: The biomechanical behaviour of the cornea can be altered by low-concentration glutaraldehyde, Karnovsky's soluti on, and by riboflavin and UV irradiation, which offers potential conse rvative treatment of keratoconus. To optimize this effect further inve stigation is necessary regarding the dose-effect relation and the in-v ivo conditions.