CORNEAL TRANSPLANTATION
What is it?
The cornea is the transparent, smooth, and regular part that is located in the anterior segment of the eyeball, above the iris and the pupil.
Various situations, such as, for example, wounds, causticization (burns produced by chemical substances, such as caustic soda or bleach), or corneal diseases, such as keratoconus, among others, can cause a loss of transparency of the cornea, which reduces vision (blurred vision and / or glare) and can even cause pain.
In those cases where the problem of the cornea cannot be solved with medical treatment or the use of therapeutic contact lenses, the ophthalmologist may recommend a corneal transplant.
Through this procedure the diseased cornea is replaced by a healthy and transparent cornea from a human donor [A person who altruistically decides to donate (give away) their corneas after their death to someone who needs them]. Cornea tissue is removed from the damaged cornea and the donor cornea is put in its place.
Before the cornea is used for transplantation, it is subjected to a series of checks (screening tests for various infectious diseases, such as hepatitis B, AIDS, among others) to guarantee its suitability and safety for transplantation.
What types of corneal transplants are there?
There are different types of corneal transplants:
· Full thickness corneal transplant:
o All layers of the cornea are damaged, so it is necessary to replace the entire cornea. This technique is called penetrating keratoplasty. Using this technique, a circular portion of the center of the diseased cornea and a matching circular area removed from the center of the cornea of a healthy donor are removed, placed and sutured in place.
· Partial thickness corneal transplant:
o Not all the layers of the cornea are damaged, so a selective transplant of the affected areas is performed. This type of transplant is called deep anterior lamellar keratoplasty or partial thickness corneal transplant. It is generally used to treat keratoconus or bulging of the cornea. This technique allows for faster visual recovery and is generally associated with fewer complications.
· Endothelial keratoplasty:
o On certain occasions, the damaged layer is the deepest (endothelium). Endothelial keratoplasty is a surgery that replaces this layer of the cornea with tissue from a healthy donor. Much of the cornea is left intact, thus reducing the risk of new corneal cells being rejected after surgery.
Prognosis
Surgical techniques have improved significantly in recent years, yet complete vision recovery can take up to a year. Most corneal transplant patients achieve good vision.
Although corneal transplantation is a very safe technique, it is not without complications. Approximately one in three patients has a rejection postoperatively. In addition, the transplant can be exhausted (suffer alterations), requiring new transplants.
In some patients it may be necessary to resort to the use of corrective lenses (glasses) or contact lenses to achieve better vision.
