“The old order changeth, yielding place to new” – Lord Alfred Tennyson
And this is exactly what is seen in corneal transplants. What was earlier the norm of the day – full thickness transplants, is now giving way to partial thickness transplants, one of which is DALK. Read on to find out why:
The cornea is the front clear surface of your cornea. It is made up of 5 layers viz. outer epithelium, bowman’s layer, stroma, descemet’s layer and inner most endothelium.
Deep Anterior Lamellar Keratoplasty (DALK) is a surgical procedure (an advanced type of corneal transplant) that is done to treat corneal diseases. This is a type of partial thickness graft in which two inner most layers of the cornea are preserved namely Descemet’s membrane and endothelium.
• Keratoconus (a disease in which there is thinning and bulging of your cornea)
• Corneal Dystrophy (a rare genetic disorder in which abnormal material accumulates in your cornea)
• Corneal scars not involving the deeper layers of the cornea
• Diseases of your eye surface like Steven Johnson Syndrome, Chemical / Thermal burns, Ocular Pemphigoid (an auto-immune blistering skin disease) leading to superficial scarring of the cornea layers
The entire procedure may take between one to one and a half hours. Usually it is done under local anesthesia.
The descemet’s membrane of the donor’s cornea are removed to prepare a donor corneal button.
The front surface of your cornea is cut. The stromal layers are separated from the descemet’s membrane. Fluid or air is injected to separate the layers. The diseased corneal tissue is removed and the donor corneal tissue is placed with fine stitches. The eye is then covered with a pad or a bandage soft contact lens is used.
• Tearing of the delicate endothelial layer and descemet’s membrane may occur. This may result in leaking of fluid from inside the eye causing it to be waterlogged. It may heal on its own or may need additional surgery.
• The stitches may become loose causing irritation.
• Other than that, infection, bleeding and raised eye pressure are other risks too.
You will be required to spend an hour in the recovery area after which you can go home.
Your eye may be red, sensitive to light and watery after the surgery.
You may be asked to use antibiotic and steroid eye drops to prevent infection and graft rejection.
Avoid rubbing your eyes. Wear a night shield for a couple of weeks to prevent this.
Your vision would have improved significantly by 3 months. You can expect to see improvement in vision 6 months to 1 year after your operation.
Only the diseased upper layers of your cornea are removed leaving the healthy inner layers intact. This reduces the risk of rejection to a great extent.
A large incision to the eye is avoided along with the risks associated.
Faster healing as compared to traditional corneal transplant