DESIGN AND PRELIMINARY-RESULTS OF THE ERLANGEN NON-HIGH-RISK PENETRATING-KERATOPLASTY STUDY

Purpose The purpose of this prospective study is to examine the non-hi gh-risk penetrating keratoplasty clinically, tyndallometrically and im munological-serologically in order to learn more about the pathogenesi s, early symptoms and therapy monitoring of corneal graft rejection. P atients and Methods Since february 1997, patients undergoing non-high- risk-PK have been enrolled in this prospective study. Examinations are done preoperatively and in well-defined postoperative gates (6 weeks, 3 months, 6 months, etc.) and include clinical assessments, corneal t opography, laser-tyndallometry, corneal endothelial cell count and cor neal pachymetry. Preoperatively as well as at each postoperative exami nation, 10 mi serum and perioperatively corneoscleral donor tissue are collected and frozen (- 80 degrees C) to allow immunological and sero logical examinations in case of graft rejection later. A relational da ta base (MS Access) guarantees complete and homogenous standardized cl inical and serological data. We randomised our patients with respect t o duration of topical steroid therapy in standard situations (short-ti me vs, long-time) as well as for systemic steroid therapy (bolus group vs. tapering group) in case of a graft rejection in 2 treatment group s. Results Up to March 1998, 99 patients have been enrolled in this pr ospective study. Our report includes the first consecutive 55 patients (25 female, 30 male, recipient age 56.9 +/- 19.4 years, donor age 57. 0 +/- 19.9 years). Up to now (follow-up 2.5 +/- 2.1,maximum of 7.3 mon ths) we did not observe immunologic graft rejections. In one patient a primary graft failure occurred. Laser tyndallometry showed a reductio n of blood-aqueous barrier breakdown from 6 weeks postoperatively (9.3 +/- 5.7 photon counts/msec) to 3 months post operatively (6.8 +/- 3.5 photon counts/msec). Conclusion This prospective randomized clinical and immunological study after non-high-risk-PK is supposed to give mor e information about pathogenesis, early symptoms and therapy monitorin g of graft rejection after elective PK. The concept and design of this study are described. Preliminary data may give significant results in a few years.