MR E MARK TALBOT

INFORMATION SHEET

CORNEAL GRAFT SURGERY

The cornea is the most important focusing element of the eye. Infections of the cornea or injuries to the cornea can cause scarring which impair the focus and tends to scatter the light.

The cornea is kept clear and healthy and free of excess fluid by cells lining the back surface of the cornea (endothelial cells). These cells pump fluid out of the cornea.

The total number of cells gradually reduces with age. When this number of cells falls below a critical level the cornea becomes water logged and this causes reduced clarity of the cornea and vision. Endothelial cell loss also occurs following inflammation inside the eye and following eye injury or eye surgery.

With further cell loss and water collection in the cornea blisters on the surface of the cornea develop, this is called bullous keratopathy. If these blisters pop nerve endings are exposed causing pain until the surface heals. Corneal graft surgery can be performed to exchange the old window, which is waterlogged, for a new healthy cornea which has a full complement of endothelial cells on the back surface.

The cornea is provided by donation, that is, it is a human cornea taken after the time of death from the donating person. The donor is screened for hepatitis and AIDS before using the material. The donor cornea is examined to check that there are adequate cells and that there is no infection in the cornea.

Corneal graft surgery is simply trephining out the full thickness of the window of the eye and inserting the new window into this space and it is kept in position with fine stitches inserted with the help of magnification as seen through the operating microscope.

Surgery is normally performed under general anaesthetic but can be performed under local anaesthetic.

Other surgery, such as a glaucoma operation may be carried out before a corneal graft is done.

Sometimes cataract surgery is done during a corneal graft operation.

After surgery drops are instilled into the eye, mainly to prevent infection (antibiotics) or rejection (steroid drops).

Following corneal graft surgery it is likely that you will attend approximately monthly for a year when the eye will be examined looking for signs of rejection or pressure problems or suture problem.

It is likely that you will require removal of sutures at different times (perhaps two or three episodes).

It is not until approximately a year after surgery that the best vision is achieved.

The main risks to the success of a corneal graft are lid problems, dry eye, glaucoma and rejection.

It is important to keep all clinic appointments made because sometimes early signs of rejection can be detected before it is noticeable to the patient. The earlier the rejection is treated the more chance there is of turning the rejection round and gaining a recovery.

The success rate for a straightforward corneal graft without any risk factors is approximately 90%. The more risk factors there are the less the success rate. Corneal graft rejection can occur at any time in the future after surgery but occurs most frequently in the first three months. Most have occurred within the first year and then a few occur after this time.

Corneal graft surgery can improve the vision tremendously if the vision is reduced only due to the corneal problem. However, quite often there is also another associated problem such as ageing of the retina or glaucomatous damage to the optic nerve, or water logging of the retina from past inflammation in the eye. All these three factors can reduce significantly the final visual outcome if they are present.

Following corneal graft surgery you will have open access to urgent eye care, that is if you have any concern that there has been a detrimental change following surgery, then we would prefer to check this to exclude any serious complication.

Corneal graft surgery can be looked upon as changing the window of the eye. Unfortunately it is not necessarily a long- term cure, as the previous eye condition can recur and have an adverse effect on the graft.

The symptoms of graft rejection:

1. Hazy vision.

2. Redness of the eye.

3. Pain going from dark illumination into bright light.

Sometimes there is only one symptom.