Partial Thickness Corneal Transplants (DSAEK and DMEK)
The front of the eye is covered by a clear portion called the cornea which functions as the “windshield” of the eye. The cornea needs to stay clear in order for the light to travel through it and allow us to see. The inner layer of the cornea is composed of endothelial cells which function as “water pumps” to remove excess fluid and keep the cornea clear and transparent. We lose some of those cells over time, but most people have enough cells left over throughout their lifetime to not cause a problem.
People with endothelial dysfunction (ex. Fuchs dystrophy or bullous keratopathy) lose those cells faster than an average person. This leads to blurry vision as the cornea gets progressively more swollen over time.
Fortunately, with new technology over the past 10-15 years, a full thickness corneal transplant is no longer required. Before the invention of partial transplants (DSAEK and DMEK), the entire cornea had to be replaced which resulted in higher risk of rejection and much longer recovery time. Currently, we are able to just transplant the thin inner layer containing the pumps to provider much faster vision recovery (several weeks) and lower risk of rejection compared to the traditional surgery. Patients with normal eye anatomy are typically great candidates for the DMEK procedure and patient’s whose eye anatomy is compromised or the view into the eye is limited typically do better with the DSAEK.
What is the goal of the surgery?
The goal of the partial thickness corneal transplant is to restore vision lost due to swelling of the cornea. It cannot fix problems and restore vision loss due to glaucoma, macular degeneration, or irregular astigmatism.
How is the procedure performed?
The surgery is performed on an outpatient basis with local anesthesia. Due to the small incision of the surgery, there is no longer a need to put patients to sleep. The procedure is typically performed in 30-45 minutes and an air bubble is injected into the eye at the very end to attach the transplant to the cornea. In order to allow the transplant to take, the patient is required to spend 36 hours after surgery laying on their back (with intermittent bathroom breaks). Vision is limited for a few weeks while the new cells start working but gradually improves every day. The transplants can last up to 10 years or longer and may be repeated in the future as needed.