Corneal transplant consists of the total or partial replacement of the damaged cornea with a healthy cornea. This procedure is called keratoplasty.
This surgical procedure is indicated in cases of loss of transparency of the cornea, deformations in its format, perforations or in the presence of scars that make vision difficult.
The cornea is a transparent structure, without blood vessels, located in the anterior part of the eyeball and composed of several layers with different functions.
The cornea is considered healthy when its structure does not present opacities, has a normal thickness, and has a normal curvature, allowing images to be sharply focused on the retina. To guarantee a good quality of vision, it is fundamental that the cornea maintains its transparency and integrity. When it presents irreversible lesions, a cornea transplant may be recommended.
According to data from the National Health Service, around 900 corneal transplant operations are carried out every year in Portugal.
In order to perform a corneal transplant, it is necessary to have a cornea donated through a tissue bank and which can be applied to the patient to be operated on.
The surgical technique chosen should take into consideration the reason for the corneal transplant and which corneal layers, being involved in the disease, need to be transplanted. When all corneal layers are transplanted, this is a penetrating keratoplasty. When only some layers of the cornea are transplanted, the procedure is called lamellar keratoplasty. Lamellar keratoplasty can be divided into posterior, when it involves the deeper layers of the cornea, and anterior, when it involves the more superficial layers.