What is corneal ring implantation?

Corneal ring implantation is a surgical procedure for inserting a ring of plastic into the middle layer of your cornea. This can correct certain problems with your cornea and enable you to see clearly.

The cornea is your eye’s outermost layer. It is a clear, layer that caps the front of your eye. It helps protect the rest of your eye from germs and debris. It also helps focus light into your eye. Different conditions can damage your cornea’s shape. If your cornea isn’t the right shape, light rays don’t focus exactly where they should. If this happens, you may have poor vision even when using glasses.

Why might I need corneal ring implantation?

Your healthcare provider might recommend corneal ring implantation to treat poor vision due to keratoconus. In keratoconus, your cornea gradually becomes cone-shaped for unknown reasons. Your provider also may use corneal ring implantation to treat pellucid marginal degeneration. This is another condition in which the cornea thins abnormally.

Another use for corneal ring implantation is to treat myopia, also known as nearsightedness. If you have myopia, you are not able to see things at a distance without the help of glasses or contact lenses. In myopia, light rays entering the eye focus in front of your retina instead of on your retina, as they should. This can happen because of an abnormally shaped eyeball, cornea, or lens of your eye.

If you have corneal ring implantation for myopia, you might not need glasses or contact lenses anymore. The procedure may work best if you have mild or moderate myopia.

Corneal ring implantation offers an alternative to other procedures that can help correct myopia or nearsightedness, like LASIK (laser in situ keratomileusis) surgery or radial keratotomy. People often choose to undergo these procedures so that they no longer need to wear corrective lenses. Each of these procedures has its own risks and benefits. Ask your eye healthcare provider why corneal ring implantation might make sense for you.

Both LASIK and radial keratotomy occasionally cause abnormal swelling of your cornea. This can cause new vision problems. If this happens to you, your healthcare provider might recommend corneal ring implantation to try to stabilize your cornea and correct some of the changes that have happened.

What are the risks of corneal ring implantation?

Most people do well with their corneal ring implantation. But complications can happen. Possible complications include:

• Keratitis
• Perforation of your eye
• Extrusion of your ring (when the ring comes out of the cornea)
• Eye swelling
• Movement of your ring
• Night halos or glare
• Chronic eye pain
• Infection

There is also a risk that the surgery might not correct your vision as much as you would like, or that it might cause another vision problem, like astigmatism, where the curvature of the cornea becomes irregular. Some people who have corneal ring implantation may need an adjustment surgery to get a better outcome.

Your risk of complications may differ based on your age, your other medical conditions, and the reason for your corneal implant. Ask your eye healthcare provider about your risks for corneal ring implantation.

How do I get ready for corneal ring implantation?

Ask your eye healthcare provider what you need to do to prepare for corneal ring implantation. Ask whether you need to stop taking any medicines before the procedure. You may need to avoid eating after midnight before the day of the procedure.

Your eye healthcare provider may want to use special instruments to shine a light in your eye and examine your cornea. You may need to have your eyes dilated for this eye exam. You also might need computerized corneal mapping, which will give your eye healthcare provider even more information about your cornea.

What happens during corneal ring implantation?

Talk to your eye healthcare provider about what will happen during your surgery. The details may vary somewhat. In most cases, you will only have one eye treated in a single procedure. In general, during the procedure:

• Most people are awake. You may receive a medicine to help you relax. Your eye healthcare provider may use anesthetic eye drops and injections to make sure you don’t feel anything.
• You might get anesthesia to put you to sleep, although this is less common. If this is the case, you will sleep deeply through the surgery and won’t remember it afterwards.
• Your surgeon will make small cuts in the outer edge of your cornea.
• Next, he or she will make tunnels under the outer layer of your cornea.
• Your surgeon will insert the sections of the ring into these tunnels.
• He or she will surgically close the cut with very fine stitches.
• The plastic rings help flatten and reshape your cornea.
• This helps the light rays focus at the right location, improving your vision.
• An antibiotic ointment may be applied to your eye to help prevent infection.
• Your eye will be patched and covered.

What happens after corneal ring implantation?

Ask your eye healthcare provider what you should expect after your surgery. In most cases, you will be able to go home the same day. Plan to have someone go home with you after the procedure.

Be sure to follow your eye healthcare provider’s instructions about eye care and medicines. You may need to take eye drops with antibiotics to help prevent infection. Your eye may be a little sore after the procedure, but you should be able to take over-the-counter pain medicines. You may need to wear an eye patch for a day or so. Ask your eye healthcare provider if there are any activities you should avoid as you recover. Avoid rubbing your eyes.

You will need close follow-up care so your eye healthcare provider can see whether the procedure was effective, and monitor you for complications. You may have a scheduled appointment the day after the procedure. Be sure to tell your eye healthcare provider right away if you have decreased vision or increased eye redness, swelling, or pain.

Some people may not need to wear corrective lenses after their corneal ring implantation. Others may still need to wear lenses, even though their vision will have improved overall.

Next steps

Before you agree to the test or the procedure make sure you know:

• The name of the test or procedure
• The reason you are having the test or procedure
• What results to expect and what they mean
• The risks and benefits of the test or procedure
• What the possible side effects or complications are
• When and where you are to have the test or procedure
• Who will do the test or procedure and what that person’s qualifications are
• What would happen if you did not have the test or procedure
• Any alternative tests or procedures to think about
• When and how will you get the results
• Who to call after the test or procedure if you have questions or problems
• How much will you have to pay for the test or procedure