CORNEAL TRANSPLANT SURGERY | EYE CLINIC - EMMETROPIA
Corneal transplantation (keratoplasty) of partial or total thickness is usually performed in cases of keratoconus in advnaced stage
Partial Corneal Transplant
Individuals whose disease is in the anterior portion of the cornea, such as patients who have had complications from LASIK surgery or who have certain corneal dystrophies, are excellent candidates for lamellar corneal transplants.
A lamellar cornea transplant is another name for a partial thickness cornea transplant ie. is only one third of anterior portion the patient's cornea is transplanted. This has many advantages over a normal cornea transplant in that the rate of rejection is almost negligible and if it does reject it can easily be replaced with another lamellar transplant with almost no additional risk to the patient.
An added advantage of the lamellar transplant is that the transplant can be lifted at a later date and the patients' residual refractive error can then be corrected with an excimer laser procedure at very little additional risk to the patient.
Total Corneal Transplant
Corneal transplant procedures may restore vision to otherwise blind eyes in some cases. There are many conditions in which corneal transplantation may be considered. Indications include corneal ulceration, corneal scars, keratoconus, herpes simplex and Varicella zoster, viral infections leading to scarring, Fuch’s endothelial dystrophy, congenital opacities of the cornea, and chemical burns of the eye.
The Corneal Transplantation Procedure:
- A complete preoperative evaluation will be required prior to surgery. The surgeon will make every attempt to confirm retinal and optic nerve function prior to surgery, so as to avoid cases in which visual improvement is unlikely.
- The majority of adult patients may be operated on under local anesthesia. General anesthesia will likely be required for children, anxious, or uncooperative patients. After the anesthetic is given, the surgeon usually sews a ring to the ocular surface to support the eye. The donor cornea is prepared using a punch or corneal trephine to create the corneal “button.” The corneal button will become the transplanted cornea. The diseased, or scarred, cornea is then removed using a corneal trephine, creating a “bed” for the transplant cornea. Finally, the donor cornea is gently sewn into place with ultra-fine sutures (approx. one-third the thickness of human hair, or less).
- Corneal transplantation may be combined with other procedures, particularly cataract surgery with intraocular lens implantation.
- Postoperatively, patients should expect very gradual recovery of vision. In fact, the best vision may not be obtained for six to twelve months or more following surgery, even though vision may be improved from the first day after surgery in some cases. The ophthalmologist will likely begin to remove some sutures from the cornea within a few weeks to a few months after surgery. However, all of the sutures do not need to be removed. In general, sutures are removed to help alleviate astigmatism once the cornea begins to show signs of being securely healed into place.