Surgery Overview
Corneal ring implants are clear pieces of acrylic that can be
surgically implanted into the clear, dome-shaped bulge at the front of the eye
called the
cornea. The implants flatten the cornea and reduce
nearsightedness. The implants are shaped like
crescents or half-circles. Two implants are inserted in each eye, along the
sides of the cornea. They do not cover the central portion of the
cornea.
Corneal implants are intended to be permanent, but they can be
surgically removed if you are not happy with the results or if you have
problems with night vision.
What To Expect After Surgery
Surgical insertion of corneal ring implants is done on an
outpatient basis (you do not have to stay overnight in the hospital). The
visual effects of the implants are immediate.
Why It Is Done
The U.S. Food and Drug Administration (FDA) has approved corneal
ring implants for use in adults age 21 and older with mild nearsightedness (1
to 3
diopters) who have mild or no astigmatism (1 diopter
or less) and whose vision has been stable for at least 1 year. Corneal ring
implants can also be used to treat certain diseases of the cornea (such as
keratoconus and thinning of the cornea).
How Well It Works
Corneal ring implants appear to be very effective for correcting
mild nearsightedness. A year after having corneal ring implants inserted, 88%
of people had uncorrected vision (without glasses or contact lenses) of 20/40
or better.1
They have not been studied or approved for use in treating
moderate or severe nearsightedness. There is no information about the long-term
results of corneal ring implants.
Risks
Complications of corneal ring implants may include:
- Infection.
- Glare or
halos.
- Night vision problems.
- Overcorrection or
undercorrection.
Experts do not yet know the long-term risks of corneal ring
implants.
What To Think About
Some people have had the implants removed because of unacceptable
side effects, such as severe glare, or because they were not happy with the
vision provided by the implants (overcorrection or undercorrection).
One advantage that corneal ring implants have over laser surgery is
that the procedure can be reversed by having the rings removed at any
time.
If you are considering having surgery to improve nearsightedness,
consider the different options, which include corneal ring implants,
intraocular lens implants, PRK, LASIK, and radial keratotomy. Talk about these
different options with your doctor.
Complete the
surgery information form (PDF)
(What is a PDF document?)
to help you prepare for this surgery.