Descemet’s Stripping Endothelial Keratoplasty (DSEK) is a modern, specialized technique in corneal transplantation. This procedure replaces only the diseased inner lining of the cornea, unlike older methods that replaced the entire thickness of the tissue. DSEK offers a less invasive, targeted repair for patients suffering from specific types of corneal clouding.
Defining DSEK: The Targeted Layer of the Cornea
The cornea is a transparent, multi-layered structure that acts as the eye’s outermost lens. DSEK targets the innermost layer, the endothelium, which is a single layer of cells resting on Descemet’s membrane. Endothelial cells function like pumps, actively removing fluid to maintain the cornea’s clarity and thinness. When these cells fail, the cornea swells with water, causing cloudiness and blurred vision. DSEK selectively replaces the damaged Descemet’s membrane and endothelium with a healthy donor graft, which includes a small amount of the donor’s posterior stroma.
Conditions Requiring DSEK
DSEK is primarily needed for conditions causing the failure of endothelial pump cells. The most common diagnosis is Fuchs’ Endothelial Dystrophy, a hereditary condition where these fluid-pumping cells gradually die off. As the cell population diminishes, the cornea thickens with fluid, causing foggy or hazy vision, often noticed most severely in the morning. Another frequent indication is pseudophakic or aphakic bullous keratopathy, a form of corneal swelling that can occur following complex cataract surgery. In these cases, the compromised inner layer causes the cornea to lose transparency because it cannot regulate its fluid content.
How the DSEK Procedure Works
The DSEK procedure is performed through a small surgical incision, typically measuring three to five millimeters. The surgeon first removes the patient’s damaged Descemet’s membrane and endothelium, a step known as descemetorhexis, leaving the rest of the cornea intact. The donor tissue, consisting of a healthy endothelium, Descemet’s membrane, and a thin layer of stroma, is prepared by being gently folded or rolled. This prepared tissue is then inserted through the small incision into the anterior chamber of the eye.
Once inside, the surgeon carefully unfolds and positions the donor tissue against the back surface of the patient’s remaining cornea. The graft is secured not with sutures, but by injecting a large air or gas bubble into the eye. This temporary bubble presses the new endothelial layer against the recipient’s cornea, allowing the natural biological adhesion process to begin. The air bubble remains in place for several days, acting as an internal splint to ensure the donor tissue bonds securely.
Recovery and Post-Operative Care
Immediate post-operative care is specific to ensure the donor tissue adheres properly to the back of the cornea. For the first 24 to 48 hours, the patient must lie flat on their back, facing the ceiling, for the majority of the time. This supine positioning allows the injected air or gas bubble to float upward and maintain continuous pressure on the transplanted tissue. Patients are permitted to sit up only briefly for meals and bathroom use.
The air bubble causes vision to be very blurry or completely obscured in the initial days, often described as seeing underwater. Steroid and antibiotic eye drops are prescribed for many months to prevent infection, reduce inflammation, and minimize the risk of graft rejection. Vision gradually starts to clear as the bubble naturally dissipates and is absorbed by the body, typically taking one to two weeks. While improvement is noticeable within a few weeks, the final visual outcome may take several months to achieve.
DSEK vs. Traditional Corneal Transplants
DSEK represents a major advance over the traditional full-thickness corneal transplant, known as Penetrating Keratoplasty (PKP). PKP replaces all five layers of the cornea, requiring a large circular incision and numerous sutures to secure the donor tissue. This extensive suturing often leads to significant, irregular astigmatism, making clear vision difficult to achieve.
In contrast, DSEK is minimally invasive, using a much smaller incision that results in less induced astigmatism and a more predictable visual result. The absence of a large wound also provides greater structural stability to the eye, lowering the risk of rupture from trauma. DSEK offers a much faster visual recovery, often measured in weeks to a few months, compared to the year or more required for vision to stabilize after PKP.