Pilot-study; Investigation on the application of a new surgical technique (DMET) for treatment of
Fuchs endothelial dystrophy

As described earlier in one of our papers (Recipient endothelium may relate to
corneal clearance in Descemet membrane endothelial transfer. M. Dirisamer et
al. 2012), 12 patients suffering from Fuchs endothelial dystrophy or bullous
keratopathy are treated with a DMEK (Descemet membrane endothelial
keratoplasty) which is a standard operation technique at our clinic. With these
12 patients it was not possible to unroll the transplant and place it on the
recipient stroma, due to complications during the operation. A small part of
the donor tissue did attach to the recipient stroma, the rest was floating in
the anterior chamber as a flat detachment. Thus, the majority of the stroma
remained without new endothelium and Descemet membrane. Since endothelial cells
normaly function as small pumps which pump the excess of fluid out of the
cornea, expectations were that the cornea would be swollen and turbid. This
appeared true for patients suffering from Bullous keratopaty (5 patients).
Remarkably, for patients that suffered from Fuchs endothelial dystrophy (7
patients) a thinner and more transparent cornea was observed. In two cases the
visual acuity increased as well (from 0.4 preoperative to 1.0 six months
postoperative and from 0.15 preoperative to 0.7 six months postoperative). In
the remaining 5 patients the visual acuity did not improve, but this was caused
by the fact that the transplanted tissue was in front of the visual axis.

To simplify the operational technique for the eye surgeon. To minimize the risk
of complications which occur occasionally with the standard technique, such as
glaucoma and cataract. In addition, the surgery is less burdensome to the
patient since the surgery is much shorter than the DMEK surgery and the patient
does not have to look towards the ceiling for 2 to 3 days after the surgery in
order to achieve adherence of the graft.

Patients suffering from Fuchs endothelial dystrophy (but still have enough
cells left in the peripheral part of the cornea) and should be operated on will
be informed on the standard (DMEK) technique as well as on the new experimental
(DMET) technique. When the patient chooses to cooperate in our pilot-study the
operation will proceed according to the protocol of the old DMEK technique,
only after insertion of the graft, the edge of the graft will be fixed in the
incision and positioned in a way that the graft is not interfering with the
visual axis. Postoperative check ups will take place after 1 day, 1 week, 1, 3
and 6 months. If the cornea does not clear within 6 months, the patient will
undergo a reoperation (DMEK).

All patients will undergo 1 DMET operation. If the cornea fails to clear within
6 months, the patient will undergo a reoperation (DMEK).

Postoperative check ups will take place after 1 day, 1 week, 1, 3 and 6 months.
Risks are expected to be low. The operational procedure is less complicated and
less burdensome to the patient since the surgery is much shorter than (all)
other lamellar keratoplasty procedures and also has a lower complication risc.
Recovery of the visual acuity may take somewhat longer than with the DMEK
procedure.