The cornea is the transparent surface across the surface of the eye.
A corneal transplant (also called corneal grafting) is a sight-restoring procedure where a surgeon replaces portions of the cornea that has been damaged or diseased with healthy donated corneal tissue. It is the earliest successful transplant on record (1905) and is one of the most common types of organ transplants performed today.
A corneal transplant may be necessary if you suffer from any of the following disorders:
If your surgeon recommends a corneal transplant, it will most likely be after all other treatments have been exhausted. A full examination will need to be performed and you will be taken through the benefits and the risks of a corneal transplant.
There are two types of corneal transplants: partial-thickness and full-thickness. When some of the corneal layers are found to be undamaged or not suffering from disease, a fairly recent advance known as a partial thickness corneal transplant may be advised.
Full-thickness transplants, also called penetrating keratoplasty (PK) is is the most common corneal transplant procedure. If you suffer from keratoconus or corneal scarring and have exhausted all other forms of treatment, this is the procedure that will most likely be recommended./
This procedure requires the surgeon to cut through the entire surface of the abnormal cornea. The surgeon then removes a small disc of the cornea (button-sized) then replaces it with the donor cornea. The disc is gently positioned into the opening and then stitched into place. The surgeon will remove the stitches at a later date.
This involves the removal of only the layer(s) of the cornea that is affected by a disease or disorder, then replacing the layer with healthy donor tissue. Because only a small area of the cornea is disturbed, this procedure usually produces a more stable outcome. If you suffer from a disease such as Fuchs’ Dystrophy, a partial-thickness transplant may be the best course of action. There are several types:
A corneal transplant is a day-surgery procedure and is carried out either in a day surgery or in a hospital (where you will be an outpatient).
A local anaesthetic will be used and you’ll be given a sedative to ensure you are relaxed. The replacement cornea is provided by a donor (someone who has recently died and has previously agreed to donate the tissue). It would only be considered if it has been processed and tested as suitable, ensuring that it is healthy and has not suffered a disease or injury.
Your ophthalmologist will use a microscope when performing the transplant. Sutures are required and are made of a material that is finer than a human hair.
Afterwards, you will be taken to a recovery room to allow the effect of the sedative to wear off. Then, you’ll be given antibiotic eye drops and a protective eye patch. You should be allowed to go home the same day.
Post surgery, a person’s own corneal cells will gradually grow, then fuse to the donor tissue. The recovery of eyesight is gradual and varies depending on the procedure. For penetrating keratoplasty, full recovery can take up to a year, primarily because it takes time for the healing to become stronger and for sutures to be removed.
However, with newer techniques, such as lamellar transplants (which are less invasive), recovery can be faster. You’ll need to have regular post-operative visits, where your ophthalmologist will determine the progress of recovery, or whether there are any complications. Eye drops (and occasionally oral medication) will be required to prevent swelling, infection and pain for at least 6 months.
Generally, the prognosis for the outcome of a corneal transplant is very good. Most people will experience a considerable improvement in vision. However, you will still most likely need glasses or contact lenses.
Adjustment of sutures is often required to try to create a regular and round corneal shape.
Sutures can be removed typically from 6 months to 3 years later. If the shape of the cornea is not ideal after removal of all the sutures, then laser eye surgery (ASLA) may be used to reshape the cornea to a better shape.
A corneal transplant has a high success rate, although, like any surgery, there are always risks. They include:
Rejection occurs in about 20% of corneal transplants and can happen at any time, even years or decades later (although it is often the result of a new injury or illness). A transplant will not last forever and how long it lasts depends on the original condition you had. For example, a transplant for keratoconus usually lasts 15 to 20 years.
Fortunately, in most cases this can be controlled by medication if treated early enough. If you notice redness or blurred vision which persists for longer than 24 hours, you should urgently see your surgeon.
A corneal transplant is one of the most common organ transplant procedures in the world. The majority of corneal transplants give the patient considerable improvement in visual function for many years.