PHOTODYNAMIC BIOLOGIC TISSUE GLUE TO ENHANCE CORNEAL WOUND-HEALING AFTER RADIAL KERATOTOMY

Purpose: To evaluate the effect of photodynamic biologic tissue glue ( PBTG) on corneal wound healing after radial keratotomy (RK). Setting: Cornea Research Laboratory, The University of Chicago, Chicago, Illino is, USA. Methods: Bidirectional, eight-incision RK was done in one eye of eight Dutch pigmented rabbits. Then, PBTG was inserted into the RK incisions and activated with an argon blue-green laser in four treatm ent eyes. The rabbits were divided into three groups: early, in which corneal wound healing was assessed at 1 and 3 weeks; late, in which co rneal wound healing was assessed at 8 weeks; enhancement. Results: The PBTG-treated keratotomy wounds had a more prominent epithelial healin g response immediately after RK and a decreased propensity for wound d ehiscence. Collagen fiber arrangement in the PBTG-treated incisions wa s sagittal to the keratotomy wound 1 to 3 weeks after RK and then chan ged to a transverse orientation across the keratotomy wound by 8 weeks . The control keratotomy wounds had a less prominent epithelial healin g response and developed late disorganization of the posterior keratot omy wound at 8 weeks. Keratometry measurements 2 months after RK showe d corneal flattening of 1.0 diopter (D) in the PBTG-treated eye and 6. 5 D in the control eye, which is consistent with histologic studies sh owing more advanced wound healing in the PBTG-treated eyes. After RK e nhancement, the PBTG-treated eye resisted further corneal flattening a nd had 4.5 D of corneal steepening; the control eye had 2.0 D of addit ional corneal flattening. Conclusion: The nontoxic, laser-activated ad hesive PBTG accelerated corneal wound healing after RK and simulated t he placement of sutures into the RK wound. Thus, PBTG may be an altern ative to sutures to correct hyperopia after RK in humans.