The cornea is a very unique surface structure that focuses light and protects the internal structures of your eye. A normal cornea allows light to be focused onto the retina, the light sensitive layer in the back of the eye. A properly shaped cornea and healthy lens are key to providing focused vision. It is also important that the cornea remain clear because a clear cornea permits light to smoothly pass through to the retina without being interrupted. If the cornea becomes hazy or cloudy, or if the shape of the cornea becomes irregular, vision is impaired. Age, trauma, and disease are common causes of corneal problems. If vision becomes impaired and affects one’s daily functioning, the cornea can be partially or completely replaced by a corneal transplant procedure.
Anterior Corneal Transplant (DALK)
DALK – Deep Anterior Lamellar Keratoplasty
Deep Anterior Lamellar Keratoplasty (DALK) is a newer method of cornea transplant for anterior corneal disease such as keratoconus, corneal scars and stromal dystrophies. Only the diseased anterior layers of the cornea are replaced and the innermost layer of the recipient, the endothelium, is retained. Because the inner layer is retained, the body does not recognize the donor tissue, hence there is less risk of rejection and the corticosteroid medications can be discontinued after only 6 weeks. A lesser degree of suture related postoperative astigmatism has also been reported with DALK compared to full thickness grafts. The standard full thickness transplant lasts an average of 20 years and then often will fail and need to be repeated. By retaining the endothelial layer with DALK, the corneal transplant should last much longer.
Anterior Corneal Transplant (DALK) Advantages
Maintaining an intact endothelium obviates or reduces several of the major challenges and vulnerabilities associated with corneal transplantation. “Theoretically, DALK leaves the patient with a stronger wound because you have not violated Descemet’s membrane, the strongest layer of the cornea.
