Figure 3. Corneal opacity following keratoplasty. Group R (left): Allogeneic transplantation. Rejection defined as complete graft opacity (opacity grade 4) occurred on average on day 15 after keratoplasty (n=16). All grafts regained clarity in the following weeks to months (follow-up 60 days: n=8, follow-up 1 year: n=8). Group S (middle): syngeneic transplantation of a transplant with surgically removed endothelium. After initially higher opacity compared to the allogeneic group, opacity never reached the maximum grade of 4, thus no rejection occurred (n=11). Control group (right): syngeneic transplantation without prior endothelial alteration. Initial opacity levels are lower compared to the EC-free syngeneic grafts from group S (n=8). (Shown: median±upper/lower quartile).