Introduction
Research studies in India indicate that corneal blindness is the leading cause of blindness in the country with over 10 lakh people blind in both eyes (2019). Corneal blindness can be corrected with a cornea transplant. Healthy eyes, donated soon after death, can be transplanted to replace the damaged cornea of a blind person. “Corneal blindness can be corrected with cornea transplant and such surgeries are highly successful. Unfortunately, eye donation is not very popular in the country” says, Dr Jugal Shah. Let us understand the cornea and its function.
What is a cornea and its function?
The human eye consists of three layers, sclera, choroid, and retina. The anterior portion of the sclera is known as the cornea. The cornea is a thin, clear piece of tissue at the front of the eye. It is the part of the eye that a contact lens sits on. To see your best, it must be clear and compact so that you can easily see through it. Should it become swollen, hazy, or scarred, your vision would decrease dramatically.
The main function of the cornea is the refraction of light and focusing. It is responsible for about two-thirds of the focusing power of the eye.
A normal, healthy cornea should be clear and transparent. If it gets damaged due to any disease or trauma, vision is impaired or lost completely. The only treatment to restore vision is a corneal transplant.
Traditionally, full-thickness corneal transplants used to be performed. More recently, DSAEK has become an option. With a DSAEK, instead of replacing the entire cornea, we replace only the damaged endothelial cells of your cornea.
DSAEK has revolutionized the way we think about corneal transplants. DSAEK is the newer, less invasive way of performing a corneal transplant. It involves a much smaller incision and very few stitches since it replaces the damaged tissue only.
How is the Cornea DSAEK surgery performed by the doctor?
Descemet’s Stripping Automated Endothelial Keratoplasty (DSAEK) involves surgically replacing diseased cornea tissue with donor cornea tissue. First, we obtain a healthy donated cornea. Next, we take a thin slice of the inner layer of the donor cornea (which includes the endothelial cells) and insert them into your eye. Once the new cells are transplanted into your eye, the goal is for them to attach to your native cornea and start working as your own cells. These new, healthy cells can clear up your own, natural cornea.
Patients who would benefit from a DSAEK are ones who have permanent damage or loss to the cells that line the inner layer of the cornea, known as the endothelium. Damage to the endothelial cells results in a thickened, hazy cornea that becomes difficult to see through. Since a single thin layer of cells is replaced, there is a greater chance of success and better visual recovery. Besides, we retain those healthy parts of the cornea that do not require replacement.
This technique is superior to traditional corneal transplants and is preferred by ophthalmologists as it is hassle-free, safe and gives better results.
DSAEK is an outpatient procedure. No hospitalization is required. The entire surgery, including prepping the eye, usually takes between 45 and 60 minutes.
The donor tissue takes about 24 hours to get fixed in the recipient’s eye.
Who is eligible for a cornea DSAEK?
All corneal transplants cannot be done with DSAEK. Only those corneas with defects and damage limited to the inner cornea layer (endothelium) are candidates for DSAEK. Other patients will need full corneal transplant surgery.
DMEK is best suited for diseases that cause corneal swelling by affecting the innermost layer of the cornea such as:
- Fuchs’ endothelial dystrophy
- Posterior polymorphous membrane dystrophy
- Congenital hereditary endothelial dystrophy
- Bullous keratopathy
- Iridocorneal endothelial (ICE) syndrome
- Failed previous corneal transplants
How is the recovery after DSAEK surgery?
Full recovery takes about three months. Initially, the vision will be blurry. Gradually, it will improve in about one to two weeks.
For the first few days after surgery, you will be instructed to lay flat on your back to help the graft attach to your cornea. Our doctors recommend lying flat for 45 minutes out of every hour for the first few days after surgery. Eye drops are used for several weeks to help prevent infection and control inflammation. You will use a steroid eye drop (once daily) to prevent rejection of the transplant for a long time. It is important to not rub or bump the eye and to use protective eyewear when engaged in any activity which may cause eye injury. Swimming or diving underwater and lifting heavy weights should be avoided for some time.
What are the risks of DMEK surgery?
DMEK surgery is highly successful. If the graft is not fully attached, a small procedure may be needed to place an additional air bubble in the eye. Significant, sight-threatening complications like intraocular infection, retinal detachment, corneal or retinal oedema or haemorrhage are exceedingly rare. Abnormalities of pupil size, shape, or function may rarely result from corneal surgery.