**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).