Keratoplasty can be Penetrating or Lamellar.
Lamellar Keratoplasty can be of two types:
Posterior or Endothelial Lamellar Keratoplasty (DSAEK, DMEK)
This procedure allows, in cases where the corneal disease is limited to the deeper cellular layer of the endothelium, (such as Fuchs Endothelial Dystrophy and Endothelial Decompensation after cataract surgery), to transplant only the diseased layer through a small incision.
The recovery of visual acuity is much faster, weeks instead of months, than the traditional penetrating transplants.
Deep Anterior Lamellar Keratoplasty (DALK)
In reverse situations where the endothelium is healthy, and the cornea is deformed (keratoconus, ectasia), or opacified (maculae, leucoma), there will be every advantage in preserving it by replacing only the altered layers.
This technique can be assisted by Femtosecond Laser.