What Is DALK Surgery?
DALK surgery is a partial-thickness corneal transplant procedure that removes the diseased or damaged stromal layers of the cornea while leaving the healthy endothelium intact. The cornea consists of five layers, with the stroma being the thickest. In many corneal conditions, the damage is limited to the outer layers, making it unnecessary to replace the endothelium. DALK focuses on replacing only the affected layers, preserving the patient’s healthy tissue.
The surgery involves carefully dissecting and removing the damaged layers of the cornea and replacing them with donor tissue. Unlike traditional full-thickness transplants, known as penetrating keratoplasty (PK), DALK preserves the patient’s own endothelial cells, which play a crucial role in maintaining corneal clarity and function.
Who Is a Candidate for DALK?
DALK is an effective treatment option for patients with corneal diseases that do not involve the endothelium. Some of the most common conditions treated with DALK include:
- Keratoconus: A progressive eye disease that causes thinning and bulging of the cornea into a cone-like shape, resulting in visual distortions.
- Corneal Scarring: Scars on the cornea caused by trauma, infections, or previous surgeries that impair vision.
- Corneal Dystrophies: Genetic disorders, such as lattice or granular dystrophy, that affect the stroma while leaving the endothelium intact.
- Corneal Ectasia: A condition characterized by corneal thinning and distortion, often occurring after refractive surgeries like LASIK.
By preserving the endothelium, DALK minimizes the risk of complications associated with endothelial cell damage, making it an ideal option for patients with healthy inner corneal layers.
The DALK Procedure
DALK is performed under local or general anesthesia, depending on the patient’s preference and the surgeon’s recommendation. The procedure involves several key steps:
- Preparation: The surgeon carefully removes the diseased outer layers of the cornea, leaving the endothelium intact. This step requires precision to avoid damaging the healthy endothelial cells.
- Donor Graft: A donor corneal graft is prepared, matching the size and shape of the area being replaced. The graft is typically obtained from an eye bank.
- Graft Placement: The donor tissue is meticulously placed onto the patient’s cornea and secured with sutures. The graft integrates with the remaining layers of the patient’s cornea over time, restoring clarity and function.
The entire procedure usually takes one to two hours, depending on the complexity of the case.
Advantages of DALK Surgery
DALK offers several significant advantages over traditional penetrating keratoplasty:
- Reduced Risk of Rejection: Since the patient’s own endothelium is preserved, the immune system is less likely to reject the donor tissue. This significantly reduces the risk of graft failure.
- Faster Recovery: Patients undergoing DALK typically experience faster visual recovery compared to full-thickness transplants. The preservation of the endothelium allows the eye to heal more quickly.
- Long-Term Stability: By retaining the patient’s endothelium, DALK ensures long-term corneal clarity and reduces the likelihood of complications such as chronic edema or endothelial failure.
- Lower Risk of Infection: DALK is a less invasive procedure than full-thickness transplants, reducing the risk of infections and other postoperative complications.
- Improved Visual Outcomes: Many patients achieve excellent visual acuity following DALK, with fewer postoperative issues such as astigmatism or irregular healing.
Recovery and Aftercare
Recovery after DALK surgery involves a period of adjustment as the eye heals and the graft integrates with the patient’s cornea. Patients may experience some discomfort, redness, or sensitivity to light during the initial days following surgery. Eye drops are prescribed to prevent infection, reduce inflammation, and promote healing.
Regular follow-up visits with the surgeon are essential to monitor the healing process and ensure the graft remains clear and functional. Stitches are typically removed after several months, depending on the healing rate.
Conclusion
DALK surgery is a revolutionary technique that offers a less invasive, safer, and more effective alternative to traditional corneal transplants for patients with specific corneal conditions. By preserving the endothelium, DALK significantly reduces the risk of complications and provides faster recovery times, making it a preferred option for many surgeons and patients.
As advancements in surgical techniques and technology continue, the success and accessibility of DALK are expected to improve further, providing even better outcomes for patients worldwide. For individuals suffering from keratoconus, corneal scarring, or other non-endothelial diseases, DALK represents a promising path to restored vision and improved quality of life.