A New Approach for Endothelial Transplantation: Deep Lamellar Endothelial Keratoplasty

Endothelial dysfunction is one of the leading causes of corneal visual deficit. Although Fuchs’ endothelial dystrophy is the leading natural cause of endothelial cell loss, surgical misadventure during cataract surgery and anterior chamber artificial lenses have been major iatrogenic causes of endothelial cell loss leading to surgical repair over the last 30 years. The only method of endothelial replacement for nearly 100 years has been full-thickness, penetrating keratoplasty (PK) surgery. While great strides have been made in the instrumentation and techniques of PK leading to clear grafts and better survival of tissue, the full-thickness aspect of PK is relatively indiscriminate and replaces all layers of the cornea while only the endothelium is sick or damaged. The technique of modern PK involves a full-thickness vertical stromal wound and employs multiple passes of nylon suture in order to achieve a watertight wound. These aspects of the procedure incur significant liabilities in the postoperative period for a transplant patient. The stroma is avascular and, therefore, requires prolonged wound healing before the sutures can be removed; even after years of healing, the wound is relatively fragile, with poor tectonic strength and protection from even mild blunt trauma. First-year success of 20/20 vision after transplant surgery can be turned into the failure of a ruptured globe and loss of the eye from minor trauma even years after the surgery. The sutures of PK surgery must compress the wound to seal it, but this compression leads to irregular astigmatism and poor corneal topography initially, limiting the visual potential in many patients in the first postoperative months. Later, as the wound heals, the sutures can become loose and exposed above the epithelial layer. When this happens, the sutures can induce epithelial breakdown, ulceration, infection, and vascularization, all of which can lead to graft rejection or loss of the graft (or both). When sutures are removed after sufficient wound maturity, the topography of the donor sur-