DSAEK Corneal Transplantation
The Basics
Before we explain what DSAEK corneal transplantation isand how an experienced corneal surgeon like Dr. Goosey performs this surgery, let’s cover the basics. The cornea is the clear, living tissue on the very front of the eye. Light passes through the cornea to reach the retina at the back of the eye, making the cornea critical for clear vision. Sometimes referred to as the “window” to the eye, the cornea can become damaged due to disease or injury. When this happens, light can no longer pass through effectively, leading to reduced vision. In such cases, a corneal transplant procedure may be necessary to replace the damaged cornea with a clear donor cornea. This procedure is a delicate microsurgery performed by specialists like Dr. Goosey.
What Is DSAEK?
DSAEK (Descemet’s Stripping Automated Endothelial Keratoplasty) is an advanced corneal transplant technique where the unhealthy, diseased, posterior portion of the cornea is replaced with healthy donor tissue from an eye bank. Unlike conventional corneal transplantation surgery known, known as Penetrating Keratoplasty (PKP), the DSAEK procedure requires a smaller surgical incision and does not involve corneal sutures. This results in faster visual recovery and reduces the risk of sight threatening complications such as intraoperative expulsive hemorrhage or post-operative traumatic wound rupture.
Who Is a Candidate?
DSAEK is typically recommended for patients with corneal conditions affecting the posterior endothelial layer of the cornea. The endothelial layer is a thin monolayer of cells attached to a basement membrane called Descemet’s membrane. Healthy endothelial cells are small, hexagonalin shape, and maintain a density of 2500 to 3000 cells/mm2.
Figure 1a –
Healthy monolayer of endothelial cells attached to Descemet’s membrane.
Red line in the leftmost figure represents Descemet’s membrane and endothelium. The middle diagram represents an enlargement of a cross section that from top to bottom includes the epithelial layer (a), stromal layer (b), Descemet’s membrane with attached monolayer of endothelial cells © and anterior chamber (d). The rightmost diagram illustrates normal size and shape of healthy endothelial cells.
Healthy Cornea Function:
When functioning properly, the endothelial cells act as a “pump-leak system” allowing nourishing fluids from inside the eye (aqueous humor) to leak to enter the cornea. After the corneal cells have been nourished, the endothelial cells pump the fluid out of the cornea, maintaining clarity.
When this “pump” function is compromised, the cornea becomes overhydrated and cloudy, leading to vision impairment. This is most commonly occurs seen in patients who have a history of trauma to the endothelial layer (such as during complicated cataract surgery) or in patients who have an inherited disease known as Fuchs’ Endothelial Dystrophy.
Fuch’s Endothelial Dystrophy and DSAEK
In patients with Fuch’s Endothelial Dystophy, the endothelial cells become larger and more spars. As the endothelial cell density falls below 1000 cells/mm, the pump function can no longer maintain a clear cornea. This condition leads to corneal swelling and thinickening, making the cornea appearmore opaque. Over time, patients may feel like they are looking through wax paper.
For individuals with severe endothelial cell damage or Fuchs’ dystrophy, DSAEK is an excellent option to restore vision and prevent further deterioration.
If you are experiencing vision problems and believe you may benefit from DSAEK corneal transplantation, to schedule an appointment with Dr. Goosey.
Figure 1b – Unhealthy monolayer of endothelial cells attached to Descemet’s membrane.
The middle diagram illustrates a cross section of an over hydrated swollen cornea. The top layer of epithelial cells has formed bullae or blisters (a) and the stroma is thickened with vacuolated spaces (b) both of which are the result of over hydration. A sparse covering of stressed endothelial cells lies over a thickened Descemet’s membrane ©. The rightmost figure depicts large, low density, irregularly shaped endothelial cells.