The cornea is a transparent tissue that allows the passage of light into the eye; in addition, it has a cupuliform shape to focus images on the retina. Any circumstance that causes the cornea to lose its transparency (post-traumatic scar, after a bacterial or viral infection) or causes it to become deformed (keratoconus) implies that it must be replaced by a healthy tissue by means of a transplant.
Corneal transplant technique
Nowadays the technique of corneal transplantation has evolved a lot; so much that we can transplant only the diseased part of the cornea. Thus, we have anterior lamellar transplants, where only the anterior part of the cornea is replaced; endothelial transplants, where the inner side of the cornea is transplanted; and full-thickness transplants.
Anterior lamellar transplants (DALK) are indicated in patients with keratoconus or corneal scarring (most frequently caused by herpetic infection). Endothelial transplants (DSAEK or DMEK) are indicated in patients with Fuchs endothelial dystrophy or Guttata cornea.
Preparation of the patient for corneal transplantation
The patient requires a complete ophthalmologic examination and a detailed corneal analysis to determine the depth of the lesion in the case of anterior lamellar transplants. In the case of endothelial transplants, an iridotomy (hole in the iris) is required, which can be performed preoperatively or intraoperatively at the surgeon’s discretion.
Like any other procedure, it requires a preoperative analysis and coagulation study.
Risks of corneal transplantation
As with any operation, corneal transplantation is not without risk. Intraoperative bleeding can occur, which, although extremely rare, is a very serious complication.
In the immediate postoperative period, infections can occur, which are also very infrequent and must be treated aggressively with antibiotics; they may also require a second operation to replace the infected tissue.
On the other hand, and as with any transplant, tissue rejection may occur, although the cornea is an immunologically privileged tissue, since it lacks vessels, which makes rejection a rare occurrence (although patients must be informed and instructed on how to act in this situation, since rejection can be reversed if treated vigorously and in time).
Recovery after a cornea transplant
The patient can lead a normal life 15 – 30 days after the operation. In endothelial transplantation (DSAEK or DMEK) visual recovery is achieved very quickly (on average after 3 months) since it does not require stitches, while anterior lamellar and full thickness transplants have a slower recovery and may require the use of glasses or contact lenses for visual recovery.
Consult your ophthalmologist for more information.