Fuchs

What Is FUCHS'?

Fuchs' Endothelial Dystrophy (Fuchs') is a disease of the cornea named after the German Ophthalmologist who first described it about a century ago.

The cornea is the transparent 'front window' of the eye. It is important because it is the main focusing structure of the eye and so any change in its shape or transparency will reduced vision. The cornea is composed of several layers, the innermost of which is called the 'endothelium'.

Fuchs' is a fairly common disorder. It usually affects both eyes and begins in later life. It sometimes runs in families, although this seems to be unusual.

In Fuchs' the cells of the corneal endothelium are gradually lost, a process which usually takes many years. The cause is completely unknown, although the process may be greatly speeded up if the patient undergoes certain types of eye surgery e.g. cataract surgery. The patient notices gradually worsening vision, usually to both eyes. Vision may be worse in the mornings, improving to a greater or lesser extent as the day progresses. Pain and eye redness only occur at a very late stage in the disease.

A Fuch's cornea photographed using a technique called
'retro-illumination' which shows the corneal endothelium.
The 'stippled' appearance is abnormal and characteristic of this disease.

The treatment for Fuchs’ is cornea transplantation. This is a major operation for the eye but is often highly successful. No other treatments (eyedrops, tablets or life style modification) are effective. Recently there has been a major advance in treatment, with the advent of a new form of cornea transplant. This is a ‘partial’ transplant in which only the diseased endothelium is removed and replaced.

I was one of the first surgeons to perform the new operation in the United Kingdom. The article below describes it in more detail.

New frontiers in cornea transplantation : selective transplantation of the endothelium (innermost layer) via a no-suture, keyhole incision.

The cornea is the clear ‘front window’ of the eye. It may be damaged by disease processes such as Fuchs’ corneal endothelial dystrophy or inadvertently during cataract surgery. Damage causes the cornea to become opaque and the eye blind.

The treatment for severe cornea disease is cornea transplantation – the patient’s cloudy cornea is removed and replaced by a clear cornea obtained from a deceased person, a process similar to kidney and heart transplantation. For decades the technique used has been ‘full thickness’ cornea transplantation. This entails the removal of the entire cornea and its replacement by a transplant. Whilst traditional, full thickness cornea transplantation may successfully restore vision, it may also cause complications. These include severe astigmatism (distortion of the focus of the eye, necessitating the wearing of hard contact lenses after the operation), glaucoma (raised pressure inside the eye) and rejection of the transplant (necessitating another operation to replace it). Full thickness cornea transplantation is also undesirable because it requires virtually the entire front of the patients’ eye to be removed and replaced by the transplant – such large scale surgery may be very traumatic to this delicate organ.

Recently, a remarkable new treatment for cornea disease has become available. This is a revolutionary method of cornea transplantation called ‘selective endothelial transplantation’. The ‘endothelium’ is the layer of the cornea which is on the inside of the eye. Many cornea diseases damage only the endothelial layer, the other regions of the cornea remaining clear. Fuchs’ corneal endothelial dystrophy and damage occurring during cataract surgery are examples. Using the new technique only the diseased endothelium is replaced leaving the remainder of the cornea, which is healthy, in place.

Selective corneal endothelial transplantation is performed through a minute incision on the surface of the eye, only about 4 mm wide. This is approximately the same size as the incision made during cataract surgery. The diseased inner layer is removed through this tiny incision. A transplant composed of healthy corneal endothelium is inserted by gently folding it so that it can enter through the incision. Once inside the eye it is carefully manipulated into position and will miraculously adhere to the patient’s own cornea without sutures!

The new technique is greatly superior to traditional, full thickness cornea transplantation. The tiny incision causes much less trauma to the delicate eye. Disabling post-operative astigmatism is eliminated altogether, no sutures are required and recovery after the operation is much faster.

Case study : A 78 year old lady suffers from Fuchs’ corneal endothelial dystrophy. Her right eye received a full thickness cornea transplant several years previously. Sixteen sutures were required to secure the transplant in place. It was 18 months before healing was complete. She can only see from her right eye whilst wearing a hard contact lens which must be inserted every morning and removed before bed. By contrast her left eye received a selective corneal endothelial transplant a few months ago. Recovery was complete after three months, no sutures were needed and she sees well from her left eye without needing to wear a contact lens.

An opaque cornea prior to selective corneal endothelial transplantation.

A patient with Fuchs’ after selective endothelial transplantation.
The cornea is crystal clear.

N.B. These illustrations of selective replacement of the endothelial (back/innermost/posterior) region of the cornea should be understood as a general guide to the surgery, rather than an exact description.

in health, the cornea is perfectly clear

the endothelial (back/innermost/posterior) region of this cornea is diseased eg: in Fuchs’ dystrophy

the diseased endothelial (back/innermost/posterior) region is removed leaving the normal front (anterior) region in place

a normal cornea will be transplanted into the patient. (a) the healthy endothelial (back/innermost/posterior) region is
removed to match the diseased region that has been removed from the patient’s cornea.
The transplant is (b) folded and (c) inserted into the patient’s eye via a minute incision in the cornea

after insertion, the transplant is unfolded

air is injected to position the transplant against the patient’s cornea.
Once contact is achieved, the transplant will adhere permanently, without requiring sutures

post-operative appearance of cornea transplant (blue region).
Sutures are not required to hold the transplant in place

for more information:
Master Class on Selective Corneal Endothelial Transplantation
and
www.fuchs-dystrophy.org