Corneal transplantation is a surgical procedure in which a diseased cornea is partially or completely replaced by a healthy cornea from a donor.

Corneal transplantation is a surgical procedure in which a diseased cornea is partially or completely replaced healthy cornea from a donor.

The visual result of a corneal transplantation depends on the transparency of the graft and the regularity of the corneal curvature.

Different types of corneal transplants

Penetrating keratoplasty (classical)

If the stroma and the corneal endothelium are affected, a penetrating keratoplasty is necessary. This type of procedure implies replacing the full thickness of the cornea.

The recipient cornea is cut with a trephine (a circular cutting device) on a diameter of about 7.5 mm and is replaced by a donor graft which is approximately the same diameter (or slightly larger). The graft is fixed with a continuous suture.

Visual outcomes are generally good, but the visual recovery is slow. It takes about three months before getting a transparent cornea and 6-12 months before starting selective removal of the stitches. This step is meant to adjust astigmatism and eventually start with either glasses or, again, contact lenses.

Lamellar graft

There are two types of lamellar grafts:

  1. Endothelial keratoplasty (DSAEK)

This procedure is used to treat cases where the corneal endothelium (the cornea’s back layer) is affected, such as Fuchs Endothelial Dystrophy. It involves the partial replacement of the affected area of the cornea, called the corneal endothelium.

The advantages of this partial transplant are mainly:

  • A decreased risk of rejection
  • Rapid recovery of visual acuity
  • Corneal curvature remains unchanged (without astigmatism)
  1. Deep anterior lamellar keratoplasty (DALK)

DALK is a procedure that consists of replacing the epithelium and the stroma (front layer of the cornea) while preserving the endothelial layer, thereby providing additional structural integrity to the post-grafted cornea. Since graft rejection usually occurs in the endothelium, this technique allows us to reduce it considerably.

Possible complications of corneal transplantation

Graft rejection is the main complication of all types of keratoplasty. The patient must know the rejection signs and consult their eye surgeon urgently. These are mainly:

  • Some pain
  • Some redness in the eye
  • Some discomfort to the light (photophobia)
  • Teary eyes
  • A decreased visual acuity.

Treatment consists of topical steroids in high doses.

Treatment consists of topical steroids in high doses.

  • Cataract formation is induced by surgical stress and prolonged use of cortical eye drops. Fortunately, it can be treated by a simple phaco-emulsification procedure.
  • Non-adherence of the endothelial graft, following DSAEK, may require the injection of an air bubble.