Abstract
Purpose:
To compare collagen lamellae at graft’s interface of corneas after femto-assisted (FLEK) or mechanically precut (DSEAK) endothelial keratoplasty.
Methods:
We collected corneas from patients who underwent penetrating keratoplasty after failed FLEK or DSEAK. Corneas were embedded in glutaraldehyde and graft’s interfaces were observed on semi-thin sections and by transmission electron microscope (TEM). Ten pictures were captured from TEM observation fields within the 3 mm central area for each cornea. Collagen fibers and fibrillae were observed. Damaged collagen layers at the graft’s interface were semi-quantified in the 3 mm central corneal area with a 3 item-based scale (no, mild, severs).
Results:
Ten corneas were harvested and analyzed (5 FLEK, 5 DSEAK). The procedures were indicated after non immune (3 FLEK, 4 DSEAK) or immune (1 FLEK, 1 DSEAK) secondary endothelial failure, and poor visual result (1 FLEK). In the analyzed area on the graft’s side, disrupted collagen fibrillae were systematically observed in FLEK. Recipients and DSEAK displayed normal or irregular arrangement of collagen lamellae, but no disrupted fibrillea was detectable. Endothelial lenticule samples were detached from the recipient cornea in 2/5 (partially) FLEK and 4/5 DSEAK (3 partially, 1 totally).
Conclusions:
Collagen lamellae rearrangement is observed on both sides of FLEK and DSEAK interfaces, mainly caused by edema. Collagen fibrillae disruption is only observed after FLEK on the Femtolaser precut side of the graft, seems to enhance graft’s adhesion to the recipient stroma and contribute to poor visual outcomes reported after FLEK.