All about Cornea Transplant Surgery (Keratoplasty) - Indications, Types (PK, DALK, DSAEK, DMEK), and Risks of Corneal Transplant Surgery
What is Cornea transplant?
Cornea transplant (also called as Keratoplasty) is a surgical procedure to replace the damaged or diseased cornea with healthy corneal tissue from a deceased human donor. Cornea is the clear, dome shaped front layer of the eye. The cornea works in tandem with the lens of the eye to focus light that enters the eye so that one can have clear vision.
What are the different types of Cornea transplant surgeries?
Based on the condition of patient’s cornea and results from various diagnostic tests, a surgeon will choose from the following cornea transplant procedures:
Penetrating Keratoplasty (PK)
Also called a full thickness cornea transplantation, Penetrating Keratoplasty (PK) procedure has evolved over 100 years. In this procedure the surgeon uses a small circular blade called as trephine for the removal of the entire center part of the damaged cornea. It is then replaced with a healthy same-shaped piece of donor cornea. The surgery generally takes 1 to 2 hours, and it can be performed under Local Anesthesia or General Anaesthesia (depending on the indication, age and other health parameters of the patient).
Deep Anterior Lamellar Keratoplasty (DALK)
Also called partial thickness cornea transplantation, Deep Anterior Lamellar Keratoplasty (DALK) procedure is conducted when the middle and outer layers of the cornea are damaged, but the innermost layer of the cornea is healthy. In this procedure, surgeon removes the middle and outer layers of cornea and replaces it with healthy corneal tissue. It has been observed that patients who have Keratoconus are mostly good candidates for DALK. This is so because those patients with Keratoconus are generally younger and have healthy endothelium.
Endothelial Keratoplasty (EK)
Endothelial Keratoplasty (EK) procedure is conducted when the inner most layer of the cornea (also called Endothelium) is damaged. Surgeons perform two types of endothelial keratoplasty surgeries - DSAEK and DMEK
Descemet Stripping Automated Endothelial Keratoplasty (DSAEK)
Descemet Stripping Automated Endothelial Keratoplasty (DSAEK) is the most common type of EK procedure. In this procedure the back 20-30% of the donor cornea is implanted into the patient’s eye. For patients can usually achieve average vision of 20/30 or even better within a few months, provided those patients who do not have any other kind of eye problems.
Descemet Membrane Endothelial Keratoplasty (DMEK)
Descemet Membrane Endothelial Keratoplasty (DMEK) is a relatively new type of Endothelial Keratoplasty (EK) procedure which uses extremely thin donor cornea tissue (just 5% of corneal thickness). It helps patients with 20/20 or 20/25 vision when compared with DSAEK
Each of these procedure, i.e. DSAEK and DMEK, removes damaged endothelial tissue and replaces it with healthy donor tissue. Unlike the other keratoplasty procedures, fewer or no stitches are needed with the endothelial keratoplasty procedures. The difference between DSAEK and DMEK is the thickness of the donor cornea – DSAEK is thicker, while DMEK is thinner.
When is Corneal Transplant surgery required? What are the indications for Cornea transplant?
A cornea transplant is most often used to restore vision to a person who has a damaged cornea. A cornea transplant may also relieve pain or other signs and symptoms associated with diseases of the cornea. There could be multiple symptoms, the most common being poor vision, whitish appearing cornea, eye pain due to corneal infection or other causes or worsening vision after a complicated cataract surgery etc which may lead to a recommendation for a Cornea transplant by your doctor.
A number of conditions can be treated with a cornea transplant, including:
Keratoconus - it is a disease that causes the cornea to thin and slowly bulge out to be cone-shaped instead of dome-shaped
Fuchs' dystrophy - it is a disease of the cornea in which the inner layer (endothelial) cells of the cornea die, which cause the cornea to swell and thicken. It leads the vision to become blurred. Funch’s dystrophy affects both the eyes and can cause the gradual worsening of your vision with time. Generally, the disease starts in 30s and 40s. However, there has been cases where patients have developed symptoms in their 50s and 60s.
Thinning of the cornea
Cornea scarring, caused by infection or injury
Clouding of the cornea
Bullous Keratopathy - it is a disease in which the cornea is permanently swollen. It causes eye discomfort, pain, and blurred vision. It occurs when the inner layer (endothelial) of the cornea is damaged and in not pumping fluid as per the need. The damage could have been due to the result of trauma, Glaucoma or inflammation after an eye surgery
Corneal ulcers, including those caused by infection
Complications caused by previous eye surgery
How will Cornea transplant affect my vision post-surgery?
Patients’ eyesight should gradually improve a few weeks after this procedure. However, the period of recovery and achieving stable vision can vary between a couple of months to a year.
During the period of recovery, one can expect the operated eye to be red, have irritation and have sensitivity towards light. One can also expect some pain, which can be controlled with over-the- counter pain reliever as prescribed by surgeon. For example, eye drops and ointments are prescribed. They are usually both antibiotics (to prevent infection) and corticosteroids (to reduce swelling, inflammation, and to prevent rejection). Stitches may need to be removed depending on the type of stitches and surgical technique used.
What are the major risks associated with Cornea Transplant?
One of the most concerning complications of cornea transplant is organ (cornea) rejection. Rejection means the patient’s immune system identifies the donated cornea as foreign and tries to fight off the transplant. The patient will be needed to take eye drops for at least a year following surgery to reduce the risk of rejection.
Risk of rejection varies based on the surgical technique used and the condition of the eye. For example, in the case of DSEK, it could vary between 12 to 20 percent. While in case of DMEK, the rate of rejection can be as low as 1 percent. Chance of rejection increases with conditions such as dry eye, blood vessels growing in the cornea, and eye infections
Some the other key risks/ complications of cornea transplant surgery include the following:
Infection – in the cornea or inside the eye
Fluid leakage from your cornea
Visual acuity problems (sharpness of the vision) caused by an irregular curve in the shape of the cornea
Detachment of the transplanted cornea
Experience Safe and Advanced Cornea Transplant Surgery at Krishna Netralaya - Best Eye Hospital in Gurgaon. We have state-of-the-art operation theatre equipped with the best ophthalmic equipment from world's leading companies.
Have more questions about Cornea Transplant? Schedule a consultation with our Cornea Super Specialist Dr. Aditi Agarwal
Disclaimer: All information, provided above is for informational purposes only and is not intended to serve as a substitute for the consultation, diagnosis, and/or medical treatment of a qualified physician or healthcare provider.