Thanks to smaller incisions, less eye trauma and faster patient recoveries, Descemet's stripping with endothelial keratoplasty (DSEK) is quickly replacing penetrating keratoplasty as the preferred method for treating endothelial dysfunction in the cornea. Let's take a closer look at the technique that is fast becoming the gold standard in corneal transplant surgery.

During penetrating keratoplasty, the entire cornea is removed and replaced with a complete donor cornea, which is secured in place by a series of sutures. Recovery is slow and tedious. The stitches are removed gradually over several years and patients must commit to a lifetime of eye medications and regular exams to ensure the donor tissue remains intact and viable. DSEK, on the other hand, involves the removal of the diseased endothelial cells that line the cornea — often caused by Fuchs' Dystrophy. The diseased cells are removed through small incisions in the eye and replaced with a graft of donor tissue. Before implantation, the graft is shaped and cut to the required diameter with a trephine.

Some surgeons choose to dissect the donor tissue manually or with a microkeratone. We buy precut grafts. They're a little more expensive, but getting tissue that's a step closer to being implanted takes a time-consuming step out of the procedure, one that can take even longer if you don't perform DSEK on a regular basis. Make sure the grafts you purchase have no signs of infectious diseases and contain healthy tissue by looking for endothelial cell counts of 2,500 or more. Working with healthy tissue helps prevent complications and increases the likelihood that the patient's body will accept the graft and that it will perform as intended.

Just as you'd prep cataract patients, prep DSEK patients with antibiotic and 5% betadine eye drops. At the start of the procedure, the surgeon often marks the corneal epithelium with a trephine and makes paracentesis wounds in the anterior chamber. A reverse Sinskey hook is commonly utilized to perform a descemetorhexis and remove the diseased corneal endothelium through the paracentesis wound under an air tamponade. Injecting Trypan blue into the anterior chamber will stain the cornea and serve as an indicator that you've completely removed the targeted cells.

A 4mm to 5mm clear corneal incision is performed next using a keratome. Some physicians opt to further scrape the corneal posterior stromal tissue to help the new donor tissue adhere. The surgeon then uses forceps to fold the graft and carefully guide it through the incisions in the anterior chamber. Devices that enable a "pull-through" technique are available to help with the preparation, handling and insertion of the graft. These systems include forceps, bases to hold the graft tissue as it's being prepared, and cartridges and applicators to slide the graft into place with minimal endothelial damage.

Once the graft is properly placed, the surgeon pumps sterile air into the anterior chamber to create a tiny air bubble, which opens the graft and compresses it against the posterior surface of the cornea, replacing the diseased endothelial cells with the graft's additional stroma and endothelial. The air bubble is left in place (it will gradually dissipate over several days) as the patient lies flat in the OR for about 10 minutes to ensure the graft sticks to the cornea's tissue.

The procedure's movements and techniques are challenging, especially for inexperienced surgeons. More seasoned physicians can perform the procedure in as little as 30 minutes, but it's more realistic to allow for up to an hour. After the procedure, give patients topical steroids and antibiotic drops. Instruct patients, once home, to lie on their backs overnight to ensure the air bubble remains in place and the graft tissue is fully compressed against the cornea.

Patients are able to recover in 1 or 2 months after DSEK with a small amount of astigmatism, much faster than they would following full-thickness corneal transplantation, which can take up to a year. DSEK is less invasive and doesn't reshape the cornea as much as penetrating keratoplasty does. It also reduces the risk of post-op glaucoma developing and lessens the likelihood of graft rejection. In addition, patients don't need to take as many steroids during recovery. Post-op vision is typically restored to 20/30; not quite as good as can be achieved following full-thickness corneal transplantation, but really quite acceptable when you consider the procedure's other post-op recovery benefits.

DSEK might not be a high-volume moneymaker for your center, but it's a significant step up from penetrating keratoplasty and will provide a valuable service for patients in your community.