At Home with Dr Christian Jessen - 139

PROMOTION

EXPERT
EYECARE
GUIDE

A bubble is
used to hold the
replacement layer
in place until it
is ﬁrmly stuck

The cornea is the
clear part at the
front of the eye,
which lets light in

of the cornea and stitch in a replacement from
a donor cornea. This usually improves vision, but
it takes one to two years before the new cornea
has healed enough to remove the stitches.
After this type of corneal transplant, patients
usually need strong glasses to see clearly. Until
all the stitches are removed, the strength of the
glasses required will keep changing, meaning
the patient often has to wait a long time before
getting their ﬁnal glasses.
However, new advances in surgery are now
improving the speed of recovery, and giving
much better vision by replacing only the faulty
layer of the cornea.

A NEW APPROACH

Endothelial cells can stop working properly
due to a disease known as Fuchs' endothelial
dystrophy, or because of damage done
during cataract surgery. If this causes reduced
vision, it's now possible to use a new technique
to replace only the layer with the damaged
endothelial cells on it, and to completely
restore normal vision afterwards.
The Descemet's membrane is an extremely
thin, cellophane-like layer on the back of the
cornea that is lined with endothelial cells.
For the past seven years, Mr Craig has been
carrying out and reﬁning a technique known as
Descemet's membrane endothelial keratoplasty
(DMEK) to restore vision where the cornea
has become waterlogged. DMEK involves the
very delicate task of replacing the Descemet's
membrane, along with its coating of endothelial

cells. Despite the excellent results achieved,
other UK surgeons - unlike those in the USA
and Europe - have been slow to adopt this
latest, technically difﬁcult technique.
First, the fragile replacement membrane
is very carefully removed from the donor
cornea. It's just a fraction of the thickness of a
human hair and carries more than 100,000
very delicate endothelial cells ready to be
transplanted. Because the membrane is elastic,
when it's removed from the donor cornea, it
curls up in a tube-like scroll. This scroll is
sucked up into a glass pipette, then injected
through a small incision into the space in the
eye between the cornea and the iris.

A GENTLE TOUCH

Because endothelial cells are so delicate,
touching them with metal instruments causes
irreversible damage. However, a glass pipette
is so smooth that any damage is minimal. Inside
the eye, the membrane is unrolled and moved
into place using only tiny air bubbles and gentle
currents of ﬂuid. This technique is much more
gentle than using surgical instruments. When the
transplanted membrane is in the middle of the
cornea, a large bubble of air is used to hold
it in place for eight minutes until it sticks to the
patient's cornea. The bubble is then removed.
The patient goes home on the day of surgery.
Their vision will usually begin to clear within a
week, and will typically reach driving standard
within a month or so. Eye drops are required

MEET THE
EXPERT

Ewan Craig
is a consultant
ophthalmic surgeon
at the Shrewsbury
and Telford Hospital NHS Trust,
and Nufﬁeld Health
Shrewsbury Hospital
Mr Craig specialises in corneal
transplantation, microincision cataract
surgery (MICS) and glaucoma. He has
a particular interest in developing and
reﬁning advanced surgical techniques,
and in teaching these techniques to
other surgeons. He has presented
papers and published articles on cornea,
cataract and glaucoma, and has been
an invited speaker on these conditions. He
was the ﬁrst surgeon in the UK providing
the Descemet's membrane endothelial
keratoplasty (DMEK) procedure.
for a year to reduce the risk of the transplant
being rejected - even though DMEK is known
to have a risk of rejection 10 times lower than
other types of corneal transplant. Once the eye
has settled, it can be difﬁcult to see there was
ever a problem - even with a microscope.
Research into regenerating corneal endothelial
cells within the eye is already under way. One
day it may be possible to get any patient's eye
to make new cells without the need for any
corneal transplant. But for now, using a glass
pipette to carry out DMEK seems to offer the
best way of restoring normal vision.

FOR MORE INFORMATION
For further details on DMEK and other
procedures or to book an appointment,
call 07967 717546
or visit www.ewancraig.com
A smooth glass
pipette causes less
damage to cells
http://www.ewancraig.com
At Home with Dr Christian Jessen

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