B-99, Bharat Ram Road, Opp. Commercial School, Darya Ganj, New Delhi, India

Descemet Membrane Endothelial Keratoplasty (DMEK)

Replaces the patient’s endothelium with a transplanted disc of posterior stroma/Descemets/endothelium (DSEK) or Descemets/endothelium (DMEK). This relatively new procedure has revolutionized treatment of disorders of the innermost layer of the cornea (endothelium). Unlike a full thickness corneal transplant, the surgery can be performed with one or no sutures. Patients may recover functional vision in days to weeks, as opposed to up to a year with full thickness transplants.

During surgery the patient’s corneal endothelium is removed and replaced with donor tissue. With DSEK, the donor includes a thin layer of stroma, as well as endothelium, and is commonly 100-150 microns thick. With DMEK only the endothelium is transplanted. In the immediate post operative period the donor tissue is held in position with an air bubble placed inside the eye (the anterior chamber). The tissue self adheres in a short period and the air is adsorbed into the surrounding tissues.

Complications

Complications include displacement of the donor tissue requiring repositioning (‘refloating’). This is more common with DMEK than DSEK. Folds in the donor tissue may reduce the quality of vision requiring repair. Rejection of the donor tissue may require repeating the procedure. Gradual reduction in endothelial cell density over time can lead to loss of clarity and require repeating the procedure.

Patients with endothelial transplants frequently achieve best corrected vision in the 20/30 to 20/40 range, although some reach 20/20. Optical irregularity at the graft/host interface may limit vision below 20/20.

Risks

The risks are similar to other intraocular procedures, but additionally include graft rejection (lifelong), detachment or displacement of lamellar transplants and primary graft failure. There is also a risk of infection. Since the cornea has no blood vessels (it takes its nutrients from the aqueous humor) it heals much more slowly than a cut on the skin. While the wound is healing, it is possible that it might become infected by various microorganisms. This risk is minimized by antibiotic prophylaxis (using antibiotic eye drops, even when no infection exists).

Graft failure can occur at any time after the cornea has been transplanted, even years or decades later. The causes can vary, though it is usually due to new injury or illness. Treatment can be either medical or surgical, depending on the individual case. An early, technical cause of failure may be an excessively tight stitch cheese wiring through the sclera.

Cost for the surgery – Charges for Keratoplasty are Rs 50,000/- for keratoplasty and if other procedures are also required charges may go upto Rs.70,000/- per eye.

Authored By Dr. Neera Agrawal