It is the first lens in the eyeball and its transplant is possible thanks to donor corneas, which are in the so-called ‘eye banks’.
The cornea has three layers: the epithelium, the stroma and the endothelium, which may have diseases or be affected by different complaints.
Previously what was done was to completely eliminate the cornea, transplanting all its layers and replacing it with another complete cornea.
Nowadays, advances enable all this structure to be replaced in layers, since there are patients who have the disease in a more superficial layer and others in a deeper layer. This layered surgery is what we call a lamellar transplant.
When all layers of the patient’s cornea are damaged, we perform a penetrating transplant. In cases where the disease is more localised, we can do selective transplants, i.e. if it damages the most superficial layer, a SALK (Superficial Anterior Lamellar Keratoplasty) is performed. However, if it is more extensive and deep through the stroma, a DALK (Deep Anterior Lamellar Keratoplasty) is performed. Finally, if the problem is only in the deepest part, in the endothelium, DMEK (Descemet Membrane Endothelial Keratoplasty) is performed.
In the same way, donor eyes are evaluated to select which layers are healthy and which meet the requirements for donor tissue. Therefore, assuming that a donor had a scar on his or her stroma, the endothelium could still be used for another person to see.
