New Technique's in Corneal Transplants

Our vision is a precious thing. Many things can rob us of this all important sense. Injury, disease and age are the major contributing factors to the demise of our sight. Thanks to today's high-tech world there are steps we can take to now prevent, improve and lessen the affects of this loss.

There are those who find themselves in need of a corneal transplant. Many go through the conventional Penetrating Keratoplasty (PKP) procedure. The surgeon removes part of the patient's unhealthy, clouded cornea (what should be the clear film that lies over the iris) and replaces it with a cadaver's donated tissue. This is basically done by cutting out a "window" and sewing in the new piece. Those stitches are not removed for at least six months. Even then they may only be taken out over the course of several visits.

"PKP, or total corneal transplant, is considered to be the gold standard for those who have corneas which are scarred or damaged," said Dr. M. Bowes Hamill, an ophthalmologist/corneal specialist who is on the staff of the Baylor College of Medicine's Cullen Eye Institute.

But Hamill says there are some issues to consider, as with all major surgeries, especially those which use donor tissue/organs. In the case of PKP, more often than not the surgery leaves the patient with a serious stigmatism that must be corrected with hard contact lenses. But they can and will see 20/20 with this addition.

The other major drawback, according to Hamill, is that because the tissue never really regains its strength, there is always the chance of a rupture. If the patient is older, has arthritis or other dexterity problems, putting in the contact lenses might prove to be a big problem.

However, there is now a procedure that works better and has less down time: Descemet's Stripping Endothelial Keratoplasty, or DSE.

Hamill feels that this new method should be considered if the patient fits the criteria (transplant is needed due to disease and not injury) and the patient doesn't mind giving up 20/20 vision for about 20/30 to 20/40. The patient will not need to wear contact lenses and the risk of a rupture is no longer a consideration.

While the technology has been around for several years, the procedure itself has been honed with phenomenal results only during the last few years.

Dr. John Hovanesian of Harvard Eye Associates, in Laguna Hills and San Clemente, California answered some questions about this innovative surgery. Hovanesian is a corneal specialist and the first surgeon in Southern California to perform DSEK.

Q. What makes DSEK different from PKP?

A. The main difference is that DSEK uses special instruments to go through the front of the cornea. The back portion (Descemet's membrane) is then painlessly stripped and replaced with a healthy graft from a cadaver donor. Because no stitches are used, the patient recovers much quicker and there is much less of astigmatism, providing the patient with much better vision.

Q. Who are the best candidates for this surgery?

A. Patients who have only one form of eye disease tend to have the best results. While age is truly not a factor, the younger patient does tend to heal faster. But I have personally done the procedure on someone in their 90s and had terrific results.

Q. What kind of "down time" can someone expect to go through?

A. The down time is minimal compared to PKP. The patient does have to lie as flat as possible for the first 24 hours. This is due to the fact that an air bubble is put in to "set" the transplant. The air bubble dissolves after that and the graft is permanently set. The patient may not do any lifting or exercise for one week.

Naturally, it's best to stay away from areas that would have a lot of dust and dirt to avoid the possibility of infection during the first couple of weeks following the procedure. We also don't want the eye (s) to come in contact with chlorinated water.

Q. Is this similar to other transplants where anti-rejection drugs will have to be taken for the rest of their lives?