When an injury or disease damages your cornea, a corneal transplant may be able to restore or dramatically improve your vision. A corneal transplant is an outpatient procedure. Most corneal transplants have a favourable outcome, and success rates are rising as techniques and training methods improve.
The cornea is the clear, dome-shaped surface of the front of the eye. The cornea along with the following helps protect your eyes from dust, germs, and foreign particles:
- eye socket
- white parts of the eye, or sclera
The cornea also permits light to enter your eye.
Cornea transplant is also called ‘keratoplasty‘, is the process of replacing unhealthy cornea with a healthy cornea from a donor through surgery. It aims at helping the visual acuity of a person. There is a high success rate recorded on cornea transplant.
The cornea is a transparent convex layer in front of the eye that is made up of collagens that allows the passage of light rays and helps us focus on the object we are viewing. Injuries, infections and inflammations can make the cornea cloudy, preventing normal vision.
Keratoplasty is mainly of two types;
- Full thickness, also called penetrating corneal transplant, is the process of replacing the entire infected cornea with a healthy cornea. This method is not really in use as it is not always the best.
- Lamellar corneal transplant; Here, the diseased cornea is the only part removed while leaving healthy layers in place. This helps the tectonic integrity of the eye. This technique involves the use of endothelial keratoplasty (EK), which removes diseased tissues from the back of the cornea layers, including endothelium, along with a thin layer of tissue that protects the endothelium called the Descemet membrane. Anterior lamellar keratoplasty is another procedure used in this technique to remove diseased tissue from the front of the cornea layers- stroma and the epithelium- without tampering with the back of the corneal layer.
Criteria for artificial Corneal Transplant
Asides the human donor cornea transplant, medicine has improved to introduce an artificial cornea transplant, ‘kerathoprothesis’. This artificial transplant is recommended when a patient’s immune system has repeatedly rejected a donor’s cornea in several other cornea transplants.
Also, kerathoprothesis is proposed when the patient has certain eye conditions that will dampen the result of a donor’s cornea and render it ineffective. These defects include:
- Severe ocular surface diseases.
- Dry eye.
What is the Procedure of Cornea Transplant?
The cornea donor is usually someone who is dead and had their cornea gotten from their eyes within 6 hours of their demise and taken to the eye bank. Once at the eye bank, the retrieved cornea is examined to see if it is in a good condition for the surgery.
When prepping for the surgery, you will have to perform the following;
- An eye examination test
- Measurement of the eye
- Medical history review
During the Surgery Procedure;
- The patient is placed under general or local anaesthetic. It takes between 1-2 hours to perform.
- At the commencement of the operation, a circular piece of the diseased cornea is removed.
- The diseased cornea is replaced with a similar sized piece of the donor’s cornea.
Doctors may use an artificial cornea (keratoprosthesis) when a patient is not qualified for a cornea.
After the Procedure:
Slight pain is usually felt but settles quickly. The cornea may need time to heal, adjust and takes a while to be stable. Glasses or contact lenses are usually prescribed for at least 6 months after the operation and may usually take a year or more.
After the surgery most people take 6-12 weeks before their sight is completely recovered. But the situation varies for different people. Sometimes, eyesight may get worse before it gets better.
Contact lens and glasses are recommended for astigmatism correction; that is making the transplanted tissue to perfectly fit the patient’s retina.
The eye may be very susceptible to blows on it, bending down, exercise and bricks work for the first few months after operation. It is advisable, in the first few months, to do the following;
- Bend your head backward when washing your hair
- Use recommend glasses or lens
- Regular visit to the hospital
- It is essential not to rub the eyes especially in the early weeks
- Recovery may take up to 6 months to 1 year and longer in some patients
- Only recommended should be used as this aids the healing process
A major risk for a corneal transplant is the organ rejection. The body’s immune system may begin to attack the donated tissue. However, statistics state that this happens in 1 out of every transplants, and anti-rejection medications have been enhanced to stop this from happening
Other risk may include:
- Glaucoma; a higher pressure in the eye.
- Cataracts; clouding of the eye’s lens.
- Swelling of the cornea.
- A detached retina; a situation where the back inside surface of your eye pulls away from its normal position.
When any of these occur, the patient should not fret, but consult his/her surgeon, who will provide an immediate solution to the problem.
Cornea Transplant Survival Rate
According to British Journal of Ophthalmology, the survival rate of corneal transplantation in developing countries is recommendable. some problems such as the development of ectasia and rejection episodes are common in people who had survived more than 20 years.
Success Rate of Corneal Transplant
According to cornea consultants of Albany, 40,000 cornea transplants are performed each year, with a success rate being greatly improved with the advancement of surgical technology. They are mostly done because of the success rate.
Cornea transplant is used in the treatment of the following:
- Endothelial corneal dystrophy
- Corneal degeneration
- Corneal oedemal
- Complications caused by first cornea surgery
- It is used to improve the vision of a person who has damaged cornea.
- It also aids in relieving the pain and clouding symptoms that come with the infections of the cornea.
- It is used for cosmetic reasons especially with patients that has cornea scars that gives a whitish or opaque hue to the cornea.
1. What is an artificial cornea transplant?
Also called 'keratoprosthetics', this is an alternative procedure to patients whose immune system has repeatedly rejected all corneas donated to them in previous corneal transplants, or who are not eligible for human donor cornea transplants due to eye defects like severe ocular surface diseases and dry eye.
2. How long does it take to recover from a cornea transplant?
Cornea transplant recovery rate takes 6 to 12 weeks. Although it can vary according to a patient's immunity level. Eye drops and corrective lens are prescribed to help the eyes heal faster and prevent the body from rejecting the donated tissue.
3. How do you sleep after a cornea transplant?
Sleep by wearing plastic protective eye shield at bedtime, and avoid sleeping on the side of the operated eye or face down.
4. Are you awake during a cornea transplant surgery?
Local anaesthesia is mainly used, so there's a high tendency of you being awake. The anaesthesia will be injected around your eyes, numbing them, preventing them from movement and blocking out pain all through the procedure.
5. How many years does a cornea transplantation last?
Statistics state that most corneal transplants last beyond 10 years. However, this varies per patient. To increase the longevity of the transplant, patients are advised to stick with their prescribed medications and go for bi-annual ophthalmic check-ups