Descemetorhexis only* for treatment of Fuchs endothelial dystrophy

Fuchs endothelial dystrophy (FED) is a disorder that affects primarily the
endothelium and Descemet membrane (DM). Currently, the most advanced technique
to treat FED is Descemet membrane endothelial keratoplasty (DMEK), where just
the affected tissue is replaced with healthy donor tissue in its anatomical
position. Recently, we requested and received METC approval for Descemet
membrane endothelial transferal (DMET) (CCMO: NL42594.098.12), in which the
donor Descemet membrane (DM) is positioned in the anterior chamber of the eye,
because clinical observation suggested that the host endothelium significantly
contributes to postoperative corneal clearance even when not in its anatomical
position. Although tissue restoration may be *more physiological*, visual
recovery after DMET is relatively slow compared to DMEK. Furthermore, it was
recently shown that certain FED corneas can clear with *descemetorhexis only*.
This technique includes removal of the diseased recipient DM and endothelial
cells without replacement by donor tissue. Over time, cells migrate from the
periphery and repopulate the denuded area, forming a new cellular layer. We
therefore want to investigate the possibility of removing only the affected
endothelium and guttae of central FED corneas, with the aim to obtain corneal
clearance through host endothelial outgrow as in DMET. The advantage is that
donor tissue is not needed and associated complications (e.g. allograft
rejection) are avoided. *Descemetorhexis only* can be done by tissue removal
through YAG laser treatment and/or manual surgery.

To determine whether corneal clearance of FED eyes within the first 6 months
after the procedure is obtained by using *descemetorhexis only* after removal
of DM, guttae and/or the affected endothelium.

Cohort study.

20 patients with an ocular disorder owing to Fuchs endothelial dystrophy will
be included.

All eyes will undergo selective removal of guttae and endothelium with surgery
and/or YAG laser treatment.

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

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

The intervention includes removal of the diseased DM, endothelial cells and
guttae from the central part of the cornea by manual surgery and/or low energy
YAG laser. This area will be filled in by endothelial wound healing through
cell migration.

- A lesser burden to the patient compared to standard DMEK because
post-treatment complications associated with donor tissue should be eliminated.
- When YAG treatment may even be less invasive than manual surgery.
- In case cornea does not clear in six months, the patient will receive routine
transplant (DMEK).