Dr. Duffey is fellowship-trained in medical and surgical management of cornea problems. He commonly performs corneal transplantation for conditions such as keratoconus, corneal dystrophies, and corneal scar formation.
Penetrating Keratoplasty (PKP)
Full-thickness penetrating keratoplasty (cornea transplant)
Penetrating Keratoplasty (PKP) is a traditional, full-thickness corneal transplantation in which the donor cornea is transplanted in its entirety to the recipient patient. This is reserved for patients who have full-thickness corneal disease such cornea scars from previous infections or trauma. It requires 16-24 sutures and a prolonged healing time from 1-2 years before complete visual rehabilitation. Often times addition surgery is required to lessen astigmatism to allow a more spherical shaped cornea before the best level of visual acuity can be attained. Most patients will need glasses or a rigid gas permeable contact lens to achieve their best level of vision. Vision usually is significantly improved although rarely is full sight restored to the 20/20 level. This is in contrast to the procedures below (DSEAK and DMEK) where full vision return is often achieved. DMEK replaces only the back surface of the cornea with endothelial cells from the donor cornea.
DSAEK and DMEK
Descemet's Stripping Automated Endothelial Keratoplasty (A Partial Cornea Transplant: DSAEK or DSEK) and Descemet's Membrane Endothelial Keratoplasty (DMEK)
DSAEK is a form of corneal transplant surgery in which approximately the back twenty-percent of the donor cornea (a small amount of stroma, Descemet's membrane and all endothelial cells) are transplanted to the patient. With DMEK, only the diseased portion of the cornea is replaced (Descemet's Membrane and the Endothelial Cells), usually with no stitches, thus decreasing the risk of rejection and other complications from this type of surgery relative to a full-thickness corneal transplant.
What Can You Expect on the Day of Surgery?
You will be brought to the surgery center as an outpatient and undergo either topical or block anesthesia (numbing the eye without putting you to sleep) to receive your cornea transplant. A full-thickness cornea transplant takes anywhere from 30-60 minutes depending if additional procedures need to be performed at the same time (such as cataract extraction and lens implantation, etc.). DSAEK and DMEK are considerably shorter in length, anywhere from 10-30 minutes. Following DSAEK and DMEK you will be asked to lay flat for an hour-and-a-half in the post-operative area before being discharged. This is necessary because an air bubble will be placed in the front half of the eye to allow the partial thickness cornea transplant to remain in place and properly attach without stitches in the first several hours after surgery. You will then be reevaluated by Dr. Duffey in the clinic where some air may be released from the eye before being allowed to return home.
Patients should always have realistic expectations with full-thickness cornea transplantation (PKP), and DSAEK or DMEK. Dr. Duffey along with you will determine which procedure best suits your eye condition and visual needs. Unfortunately, with all types of cornea transplantation rejection can occur, although it is less likely to occur with the lamellar or partial corneal transplants such as DMEK or DSAEK compared to full-thickness penetrating keratoplasty (PKP). Most rejection episodes are treatable if they are caught early. Signs of rejection include decreased vision, eye pain, redness, and increased light sensitivity usually occurring at least three months to many years after cornea transplantation.