Corneal transplantation is a surgical procedure which includes resection of the cornea of the eye and its replacement with a cornea of the donor (a cadaver). Corneal transplantation may be total (penetrating keratoplasty) or partial (lamellar keratoplasty).
The cornea that is going to be used is taken form a recently deceased individual who used to be healthy and whose cornea has not been affected by any disease.
The surgery is always performed by a well experience ophthalmologist and is basically done on an outpatient basis.
Corneal Transplantation Indications
There are certain eye conditions which cause damage to the cornea. Severe damage to the organ eventually requires transplantation. Some of these conditions are keratoconus, pseudophakic bullous keratopathy, corneal degeneration, keratoglobus and dystrophy.
Furthermore, certain injuries to the cornea can be successfully treated only with corneal transplantation. This particularly refers to corneal perforation.
The cornea that has been severely damaged due to unresponsive treatment by antibiotics or antiviral drugs is also supposed to be replaced.
Finally, the surgery may be of cosmetic purpose, improving the appearance of the cornea in people suffering from corneal scars.
Corneal Transplantation - the Very Surgery
Patients are operated under general anesthesia or are administered local anesthesia and sedatives.
During penetrating keratoplasty a circular disc of the cornea is cut and removed. What follows is cutting a circular graft from the donor cornea and its insertion onto the desirable place. Finally, the transplanted part of the cornea is stitched to the rest of the eye.
Lamellar keratoplasty is a procedure which includes transplantation of approximately 95% of cornea. This is a very successful surgery with practically no rejection of the donor cornea because surgeons leave certain parts of the patient's cornea (the Descemet membrane and endothelium).
Corneal Transplantation Risks
Since the cornea has no blood vessels (is avascular) there is practically no blood loss. Blood eventually appears and is associated with suturing the metal ring to the sclera. Each individual loses no more than 2 ml of blood during corneal transplantation.
However, there is risk of postoperative infection. The absence of blood vessels prolongs the healing time. As it is the case with any other wound, even this can be contaminated with different microorganisms. In order to reduce the risk of infection, patients are prophylactically prescribed antibiotics.
Graft failure may occur, but it is rather rare. Sometimes the transplanted cornea may be rejected even years/decades after surgery. Rejection is mostly associated with a new illness or some kind of injury.
The success of corneal transplantation does not depend on the very surgery. Improvement of visual acuity also depends upon whether the rest of the eye is healthy.