Corneal Ring Implants
What is corneal ring implantation?
Corneal ring implantation is surgery to place a ring of plastic into the middle layer
of your cornea. This can correct certain problems with your cornea and help you see
The cornea is your eye’s outer layer. It is a clear layer that covers 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 eye care provider might advise this surgery if you can't see well due to keratoconus.
With keratoconus, your cornea slowly becomes cone-shaped for unknown reasons. Your
provider also may use this procedure to treat pellucid marginal degeneration. This
is another condition in which the cornea thins abnormally.
Corneal ring implantation is also used to treat nearsightedness (myopia). If you have
myopia, you can't see things at a distance without using glasses or contact lenses.
With 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 cornea
If you have corneal ring implantation for myopia, you might not need glasses or contacts
anymore. The procedure may work best if you have mild or moderate myopia.
This surgery is an alternative to other procedures that can help correct myopia. These
include LASIK (laser in situ keratomileusis) or radial keratotomy. People often have
these procedures so that they don't need to wear corrective lenses. Each of these
procedures has its own risks and benefits. Ask your eye care provider why corneal
ring implantation might make sense for you.
Both LASIK and radial keratotomy can sometimes cause abnormal swelling of your cornea.
This can cause new vision problems. If this happens to you, your eye care provider
may advise corneal ring implantation. This may stabilize your cornea and correct some
of the changes that have happened.
What are the risks of corneal ring implantation?
All procedures have risks. Some possible risks of this procedure include:
A small hole (perforation) in your eye
The ring comes out of the cornea (ring extrusion)
The ring moves
Night halos or glare
Long-term (chronic) eye pain
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, such as astigmatism. This
is when the curve of the cornea becomes irregular. Some people who have this procedure
may need an adjustment surgery to get a better result.
Your risk of complications may be different based on your age, your other health conditions,
and the reason for your corneal implant. Ask your eye care provider about your risks
for corneal ring implantation.
How do I get ready for corneal ring implantation?
Ask your eye care provider what you need to do to get ready for the surgery. Ask if
you need to stop taking any medicines before the procedure. Follow any directions
you are given for not eating or drinking before the surgery.
Your eye care provider may want to use special tools 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. This will give your provider even
more information about your cornea.
What happens during corneal ring implantation?
Talk with your eye care provider about what will happen during your surgery. The details
may vary a bit. 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 be given a medicine to help you relax. Your eye care
provider may use anesthetic eye drops and shots (injections) to make sure you don’t
You might get general anesthesia to put you to sleep. This is less common. But if
this is the case, you will sleep deeply during the surgery. You won’t remember it
Your surgeon will make small cuts (incisions) in the outer edge of your cornea.
Next, he or she will make tunnels under the outer layer of your cornea.
Your surgeon will place the sections of the ring into these tunnels.
He or she will surgically close the cut with very fine stitches.
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 care provider what to expect after your surgery. In most cases, you will
go home the same day. Plan to have someone go home with you after the procedure.
Follow your 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 care provider if there
are any activities you should not do as you recover. Don't rub your eyes.
You will need close follow-up care so your eye care provider can see if the procedure
was effective, and watch you for complications. You may have a scheduled appointment
the day after the procedure. Tell your provider right away if you have reduced vision
or more eye redness, swelling, or pain.
Some people may not need to wear corrective lenses after this surgery. Others may
still need to wear lenses. But their vision will be improved overall.
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