Cornea transplants: Restoring sight with donor tissue

A healthy cornea — the transparent outer surface of your eye — is an essential component of sharp, clear vision. It accounts for a large part of your eye's focusing power. Any condition that distorts or diminishes the transparency of your cornea can harm your vision — sometimes severely. One treatment option may be a cornea transplant (keratoplasty).

Cornea transplants are one of the most common organ and tissue transplants performed in the United States. Nearly 40,000 people undergo the procedure each year — many of them older adults. Find out who might benefit from a cornea transplant and what's involved in the procedure.

The role of your cornea

Your cornea makes up the outside, dome-shaped layer on the front of your eyeball. It serves two important purposes:

• Protecting your eye. Your cornea guards your eye from germs and harmful particles, such as dust. Your cornea also filters out ultraviolet (UV) light from the sun to protect the inside of your eye.
• Focusing your eye. As light enters your eye, your cornea begins the focusing process. Parts of your eye behind the cornea do the rest to focus a clear image on your retina.

Five layers of tissue make up your cornea. The cornea tissue is unique in that it doesn't require blood vessels for nourishment. Nourishment for your cornea comes from your tears and the aqueous humor — the clear fluid that fills the space between your iris and cornea. Your cornea is transparent, allowing light to pass through much like clear glass.

Anatomy of your eye

Anatomy of your eye

Your cornea is the clear dome-like covering over the front of your eye.

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Cornea transplant can restore vision

A number of diseases and conditions can be treated with a cornea transplant, including:

• Thinning of the cornea
• Cornea scarring, caused by infection or injury
• Clouding of the cornea
• Swelling of the cornea
• Corneal ulcers, including those caused by infection

Most cornea transplants are used to restore vision. Whether you'll rely on glasses after cornea transplantation or have perfect vision will depend on your disease or condition. In other instances you might receive a cornea transplant to restore the structure of your eye, for instance if your cornea becomes very thin or uneven, or to relieve pain if you have an infection.

Cornea transplants provide cosmetic changes, as well. Although new technology, such as colored contact lenses, has made cosmetic transplants less common, people with eye conditions that change how their eye looks might opt for a cornea transplant. For instance, corneal scarring can appear grey or white.

What to expect during cornea transplant surgery

In a cornea transplant, a surgeon replaces a portion of your cornea with a different one from a donor. Donor corneas (grafts) become available when families donate the eyes of a deceased loved one. Just about anyone can donate corneas and, unlike other organ and tissue donations, there isn't a waiting list for people who want cornea transplants.

Before surgery you'll receive a sedative, which means you aren't asleep during the procedure. Some people drift off during surgery and don't remember the procedure afterward, while others stay aware of their surroundings and can communicate with the surgical team. Either way, you won't feel any pain because your eye is completely numbed with a local anesthetic. Though you won't be able to see the surgery being performed on your eye, you may notice when the surgeon moves instruments in and out of the light in front of your eye.

Keeping your eye protected after cornea transplant surgery

After surgery you'll be taken to a recovery room to rest for an hour or so until you're ready to go home. The protective shield remains over your eye to protect it from injury. It's important to keep this shield over your eye until your doctor allows you to remove it — generally within three days of surgery.

You'll receive eyedrops to control swelling and guard against infection. If your eye feels dry, talk to your doctor about using artificial tears. Never rub or put direct pressure on your eye.

You'll meet with your eye doctor the next day to check for any postoperative problems. Expect to visit your eye doctor every week or two for the first month after surgery and then every two weeks for about three months.

It takes about a year for your eye to heal completely. In many cases, you might notice improved vision before your eye heals completely.

Until your eye heals, take precautions to keep your eye safe from injury. For at least the first month after surgery:

• Shield your eye. Wear glasses or a patch during the day. Wear your protective shield at night.
• Keep water out of your eye. Avoid getting water directly in your eye. Wear your protective shield when you wash your hair.
• Avoid dust and sand. Stay away from dusty and sandy environments. These particles can irritate your healing eye.
• Reduce pressure on your eye. Take a break from activities such as exercising, dancing or jogging to avoid putting excess pressure on your eye. Avoid lifting heavy objects.

Move slowly and carefully since your vision may be altered temporarily as your eye heals. When you can return to work depends on what your job involves. Office workers may be comfortable going back to work in as little as a week. Wait six to eight weeks before returning to a manual labor job. When you return to work also depends on your level of vision. If you must wait for vision to return to your operated eye, it may take several months to a year.

Weigh the risks of cornea transplant surgery

Cornea transplants are relatively safe and have been performed for many years. But, like any surgery, cornea transplants carry the risk of complications. Common signs and symptoms that might represent complications include:

• Decreased vision
• Increased reddening of your eye
• Pain
• Sensitivity to light
• Light flashes or floaters

If any of these symptoms develop and persist for more than six hours, call your eye doctor immediately. Prompt treatment is essential. Without treatment, complications can lead to the need to replace your transplanted cornea.

Consider your options

Carefully weigh the risks and benefits of cornea transplant surgery to help you decide whether this procedure is right for you. Discuss your concerns with your eye doctor. Cornea transplants are common in the United States and as technology improves, they're becoming safer.