The cornea is the window at the front of the eye. In the normal eye the cornea is transparent. Light is able to enter the eye through the clear cornea, pass through the clear lens to focus on the retina at the back of the eye. When the cornea is deformed or damaged from injury or disease, the path of light to the retina is distorted. The picture that the retina passes to the brain is not clear and sight becomes distorted or patchy.
The chief function of the cornea is to help focus and transmit light. When this is interfered with by either irregularity, scarring or waterlogging and cannot be helped any more by any other treatment (eye drops, drugs, spectacles or contact lenses) a corneal graft may be performed to:
- improve your sight,
- alleviate your pain, or
- repair a perforation (if your cornea has ruptured).
What is a corneal graft?
It is an operation in which part of your cornea is removed and replaced with a similar piece of cornea from a donor eye. Moorfields Eye Bank collects and stores donor corneas for transplant.
Mr Sian is able to offer the latest corneal graft surgical techniques such as DMEK or DSAEK for Fuchs corneal dystrophy and bullous keratopathy, anterior lamellar corneal graft (big bubble/ manual technique for keratoconus) and Penetrating keratoplasty.
The type of graft that you are suitable for will depend from the disease affecting your cornea and will be discussed and explained to you at the time of your consultation.
Corneal graft surgery is performed under general or local anaesthetic. For a full thickness graft, a central piece of poor cornea is cut through and removed from your eye. It is replaced by clear cornea removed in the same manner from the donor eye. This is then sewn in place with very fine stitches which are removed 1-2 years later. The operation takes about an hour, and is carried out under either general or local anaesthetic.
Post operative care
After the operation, the operated eye only will be covered with an eye pad and protective plastic eye shield. As the anaesthetic wears off, some discomfort may be felt in and around the operated eye. If you feel any pain, ask for medicine for relief of any pain or sickness. You may resume normal activities when you feel able to do so. You will be shown how to instil eye drops safely and correctly prior to your discharge.
The day after the operation the eye pad is removed. Your sight will probably be blurred; your eye may water and be uncomfortable in bright light. You will be asked to return to the hospital in the next few days to be examined by Mr Sian.
How long will I use eye drops after the operation?
You will continue eye drops for six months or more after the operation. It is essential the eye drop treatment is continued exactly as instructed until the end of the course. This is very important because it helps prevent infection and rejection.
There is a danger of rejection of the transplant as the body’s immune defence system recognises the donor cornea as foreign and attempts to damage the “foreign material”.
Rejections occur most often in the first year after the operation, following a change of treatment, after removal of stitches, or as a result of eye infection or injury. However, rejection can occur at any time after a corneal graft, even years later after your discharge from outpatients. It is therefore important to be aware of the signs.