INDUCTION OF CROSS-LINKS IN CORNEAL TISSUE

The aim of this study was to investigate the possibility of induction of cross-links in corneal tissue in order to increase the stiffness as a basis for a future conservative treatment of keratectasia. Collagen ous biomaterials can be stabilized by chemical and physical agents. Th e epithelium of enucleated porcine eyes was removed. Eight test groups , 10 eyes each, were treated with UV-light (lambda = 254 nm), 0.5% rib oflavin, 0.5% riboflavin and W-light (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 each cornea and the stress-strain behavio ur of the strips was measured to assess the cross-linking process. For comparison, ten untreated corneas were measured by the same method. C ompared to untreated corneas treatment with riboflavin and UV-irradiat ion as well as weak glutaraldehyde or Karnovsky's solutions resulted i n an increased stiffness of the cornea. The biomechanical behaviour of the cornea can be altered by glutaraldehyde, Karnovsky's solution, an d with riboflavin and UV-irradiation which offers the potential of a c onservative treatment of keratoconus. To optimize this effect further investigation is necessary regarding the dose-response and in-vivo app lication. (C) 1998 Academic Press Limited.