Corneal Transplant: Why is it Needed, Types, Risks Factors, What to Expect After Corneal Transplant, Success Rate

Corneal transplant is an approach in which the affected cornea is replaced with a new one to get the vision to normal. A corneal transplant becomes necessary when the problem cannot be fixed by eyeglasses or contact lenses or if the medications can’t help resolve this condition. Corneal transplant can be done by 3 different styles depending on the specific need of the patient. Like any other surgery, Corneal transplant also has some risks. Corneal transplant has a very high success rate thanks to modern eye banking and surgical techniques.

Cornea is a clear outermost membrane of the eye. It has multiple layers. This works as a windshield of your car. Due to various reasons like bacterial infections, hereditary reasons, scars due to injury etc. can cloud the layers of cornea causing a loss of vision. Corneal transplant is an approach in which the affected cornea is replaced with a new one to get the vision to normal. In this surgery, the scarred cornea is replaced with a healthy cornea taken from a donor. This procedure is also known as keratoplasty or corneal graft.

When the cornea is damaged because of different reasons, it becomes less transparent or its shape can change. This prevents the light reaching the retina and causes the picture transmitted to the brain to be distorted or unclear. A corneal transplant becomes necessary when the problem cannot be fixed by eyeglasses or contact lenses or if the medications can’t help resolve this condition. There are conditions which put you at a high risk of a corneal failure. These include.

• Scarring due to infections like herpes involving the eyes or fungal keratitis.
• Trichiasis (a condition where the eyelashes grow inwardly causing scarring in the cornea)
• Fuchs’ dystrophy
• Advanced keratoconus
• Irregular corneal shape or thinning of the cornea
• Chemical burns or eye damage caused by an injury
• Edema of the cornea
• Graft failure from a previous transplant surgery

As a patient, if your vision impede your job performances, if your vision isn’t getting better with special contact lenses, if can you take enough time off from work to recover fully or not, are a few considerations you must take and discuss with your doctor in detail before going for a corneal transplant surgery.

Full Thickness Corneal Transplant. In cases where cornea is affected due to a disease such as keratoconus, infection, or previous eye surgery, a corneal transplant is sometimes necessary to restore functional vision. In this type of corneal transplant, the entire cornea is removed and replaced with a donor cornea.

Partial Thickness Corneal Transplant. In some cases full thickness corneal transplant may not be needed to treat corneal damage or disease. Some patients may benefit from a partial thickness corneal transplant, in which only the affected layers of the corneal tissue are replaced with a healthy one.

Endothelial keratoplasty. This is a newer version of the procedure. The cornea has five layers; the innermost layer is called the endothelium. In some conditions, this layer is damaged causing the cornea to swell leading to affected vision. This can be done in two different ways. Descemet’s Stripping Endothelial Keratoplasty (DSEK) and Descemet’s Membrane Endothelial Keratosplaty (DMEK).

The patient will undergo a thorough eye exam to look for conditions that may cause complications after the surgery. Your name is placed on a list at a local eye bank.

You may need to wait for suitable tissues from a donor. Your doctor measures what size donor cornea you will need. You might have to stop taking certain medications that you were taking routinely before the surgery. The doctor will guide you about it. If you are suffering from other eye problems like infection or inflammation, your eye doctor will treat them before the surgery as they may reduce the chances of a successful corneal transplant. You can visit your primary care doctor for physical exams to make sure if you are healthy enough to go through the transplant surgery.

Corneal transplant procedure generally takes about an hour and is performed under general or local anesthesia on an outpatient basis. Your surgeon decides how to transplant the healthy donor cornea based on your specific need. After the anesthesia has taken effect, an instrument called lid speculum is used to keep the eyelid open throughout the surgery. During the most common type of corneal transplant that is penetrating keratoplasty, your surgeon cuts through the entire thickness of the abnormal or diseased cornea to remove the affected corneal tissue. The donor cornea, cut to fit, is placed in the opening. Your surgeon then uses a fine thread to stitch the new cornea into place. The stitches may be removed at a later visit when you see your eye doctor. In patients who are not eligible to accept a donor cornea, an artificial cornea is placed.

After a corneal transplant surgery, you will be discharged with an eye patch for at least a day. Your eyes may be red and sensitive to light. It may also hurt or feel sore.

Your eye doctor will prescribe recovery from a corneal transplant may take time up to a year or longer. You will be given eye drops and sometimes oral medications to help control infection, swelling, and pain. You must use the eye drops exactly as prescribed.

Refrain from rubbing or pressing the eye after a corneal transplant. You must follow up with your doctor to look for complications in the first year of the surgery. You should not drive, operate machinery, or drink alcohol for at least 24 hours after corneal transplant surgery. The sedative will take this long to fully wear off. Before it does, it may make you very sleepy and unable to think clearly. You will be advised to limit activities that could make you fall or put pressure on your eyes. Avoid heavy lifting, stay away from dust and blowing sand.

There is a risk of graft rejection in corneal transplant surgeries. It can occur in about 1 out of 3 patients in the first five years. Rejection can be controlled by steroid eye drops. Warning signs that shows that your body is rejecting the cornea are.

• Pain in the eye
• Extra sensitivity to the light (photophobia)
• Redness to the eye
• Cloudy vision

You must inform your ophthalmologist about these signs so that he might be able to stop the rejection with medicines.

Corneal transplant can cause some other problems like.

• Infection
• Bleeding
• Retinal detachment
• Glaucoma
• Cataracts
• Loss of vision
• Scarring of the eye
• Corneal swelling
• Astigmatism
• Uveitis

Corneal transplant has a very high success rate thanks to modern eye banking and surgical techniques. In most cases, vision returns gradually. The patient must understand that the healing process varies from patient to patient. While some patients can experience improved vision in few weeks, others may have to wait up to a year.

Lastly, your ophthalmologist is the best person to decide whether you need the surgery or not. He is also the right person to decide which type of corneal transplant will be suitable for you.