Endothelial transplants of smaller size and/or lower cell density

Descemet membrane endothelial keratoplasty (DMEK), i.e. the transplantation of
Descemet membrane in its anatomical position, is currently the most advanced
corneal transplant technique in the treatment of Fuchs endothelial dystrophy
(FED). Recently, we requested and received METC approval for Descemet membrane
endothelial transferral (DMET), in which the donor Descemet membrane is
positioned in the anterior chamber of the eye (i.e. not in its anatomical
position), because clinical observation suggested that the host endothelium
significantly contributes to postoperative corneal clearance. Although tissue
restoration may be 'more physiological', compared to DMEK visual recovery after
DMET is relatively slow. We therefore investigated the possibility of hybrid
techniques in which a transplant of different size and/or with a lower cell
density is implanted, using routine DMEK surgical techniques, but with the aim
to obtain corneal clearance through host endothelial outgrow as in DMET. An
additional advantage of such a hybrid technique may be that the donor tissue
availability may significantly increase, because more than one transplant can
be obtained from a single donor cornea.

To determine whether corneal clearance is obtained with endothelial transplants
of smaller size and/or lower endothelial cell counts.

Cohort study.

50 eyes suffering from Fuchs endothelial dystrophy will be included.

All eyes will undergo endothelial keratoplasty with routine DMEK surgical
techniques, but with a transplants that differ in size and/or endothelial cell
counts, as compared to regular DMEK

Before, and at 1 day, 1 week, 1 month, 6 months, 9 months, 12 months, all eyes
will be evaluated using slitlamp biomicroscopy, Pentacam imaging, specular
microscopy, optical coherence tomography (OCT), and confocal microscopy. Best
corrected visual acuity and complications will be documented at all
examinations.

In the event of primary or secondary transplant failure, routine DMEK will
serve as a surgical back-up procedure.

All patients receive one surgery to implant the adapted transplant. Sometimes a
'rebubbling' might be necessary, as with regular DMEK. If the results are
suboptimal after 6 months, an additional surgery (standard DMEK) will be
performed.

The extend of burden is comparable to a standard DMEK if everything is going
according to plan (i.e., one surgery, and non-invasive check-ups post-surgery).
If the transplant fails, one additional eye surgery will be needed.