What is a cornea?
The cornea is the window at the front of the eye. In a 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.
Reasons for a corneal transplant:
The chief function of the cornea is to help focus and transmit light. When this is interfered with by either irregularity, scarring or water logging and cannot be helped any more by any other treatment (eye drops, drugs, spectacles or contact lenses) a corneal graft may be performed in order to:
What is a corneal transplant?
It is an operation in which part of your cornea is removed and replaced with a similar piece of cornea from a donor eye. The type of transplant that you are suitable for will depend on the disease affecting your cornea and will be discussed and explained to you at the time of your consultation.
Corneal transplant operation
Patients undergoing a corneal graft operation are admitted to a ward the day of their operation and discharged home on the same day. If no donor cornea is available we will attempt to contact you prior to your operation or patients will return home and wait until material becomes available.
Corneal graft surgery is performed under general or local anaesthetic. Checks such as urine tests, blood tests and sometimes an electrocardiogram (ECG) are carried out to make sure you are in good health when general anaesthetic is required.
Your surgeon will carry out the operation with the help of a microscope. 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.
After the operation, only the eye operated on 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. A post operative check up with your specialist consultant will take place at the hospital in the next few days following your surgery.
How long will I use eye drops after the operation?
Your consultant may ask you to put in 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.
Is there anything else I have to do to care for my eye?
You will be given a protective plastic eye shield to wear when sleeping for approximately two weeks after the operation. You should avoid any risk of a direct blow on your operated eye. You may find that you are sensitive to light and a pair of plain dark glasses, which can be supplied to you by us, should help. Ask your ophthalmologist when you may return to work or pursue sports especially swimming.
How long will I be attending hospital after the operation?
Uncomplicated cases can expect to attend about seven times in the first year after surgery and once or twice in the second year. Patients may be discharged from follow-up after the stitches have been removed, usually 1-2 years after the operation. Stitches are removed at outpatient clinic examinations. However, even after discharge you should be aware that rejection episodes may occur which require urgent treatment.
There is a danger of rejection of the transplant because the body’s immune defence system recognises the donor cornea as foreign and tries to damage the “foreign body”. It is very important to look out for signs that your corneal transplant might be undergoing rejection. If you experience one or more of the following, contact us, see a doctor or go to your eye casualty department immediately:
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 transplant, even years later after your discharge from outpatients. It is therefore important to be aware of the danger signs.
What should I do if I think there is a problem with my corneal transplant?
Providing you attend for treatment promptly, rejection reactions can usually be controlled. It is your responsibility to contact us immediately should you be experiencing any problems or your nearest eye department whenever you feel there is a problem with your transplanted eye – even many years later after successful surgery.
Failure to obtain the correct treatment early can result in permanent loss of sight and the need for a repeat transplant which carries a higher risk of failure than the first. If you experience any decrease in sight, pain or redness in the transplanted eye, remember that this may represent a rejection and should be seen within 24 hours by us or in an eye department.
Other complications following a corneal transplant
Serious complications are uncommon following transplant surgery. However, it is a major eye operation and like all operations may be accompanied by complications including haemorrhage (bleeding in the eye) and damage to other parts of the eye. The period after the operation can be complicated by infection, rejection, glaucoma, and cataract formation. Therefore, it is essential that you keep your follow up appointments at The Stoneygate Eye Hospital. If any symptoms suddenly develop you must attend as an emergency patient at an eye casualty department immediately.
Will I see clearly after the operation?
For the first few months after the operation, your vision will fluctuate. This is part of the healing process and you should not expect to have immediate, clear, useful sight.
Your ophthalmologist may prescribe either glasses or a contact lens (a lens fitting on the outside of the cornea), although even these will not be prescribed until some months after the operation. This is because the cornea takes a long time – often at least a year – to heal completely, which is also why the stitches are left in for up to 18 months.
What are donor eyes?
‘Donor eyes’ are eyes which have been removed from a person who has died. Consent for use of the corneas in transplantation will have been obtained from the donor prior to death, or fromthe donor’s family.
How do I know the donated cornea is not infected and that I won’t catch anything?
Corneas are not taken from donors known to have infectious conditions. All donors are screened for carriers of HIV/AIDS or Hepatitis viruses before their corneas are used. The cornea is treated with an antibiotic solution before being used for your operation.
Will the colour of my eye change?
No. The colour of your eye is determined by the iris, surrounding the pupil of the eye, not the cornea. You may, however, notice the stitches as a different colour until they are removed.
Can I continue to drive?
The law requires you to inform the Driver and Vehicle Licensing Agency (DVLA), and your insurance company, of any change in health or sight likely to affect the safety of your driving.You must be able to read a number plate at 20.3 metres (25 yards) in good daylight and with spectacles if worn. You must also have an adequate field of vision. To drive when unable to meet both these requirements is a criminal act and invalidates insurance. Inability to meet standards requires you to notify the DVLA. You should not restart driving until you have had confirmation that your vision meets the standards. A report from your ophthalmologist may be requested. Standards are more stringent for vocational drivers. For further information, please contact the DVLA.