Thermal Keratoplasty for Farsightedness - Topic Overview
Thermal keratoplasty is a type of refractive surgery that uses heat
to change the shape of the
cornea. The surgeon uses a device to shrink the
collagen fibers in the cornea. This causes a lasting scar on the cornea. Though the treatment is
not effective for severe
farsightedness (hyperopia), it has been shown to correct mild to moderate farsightedness. Thermal keratoplasty
can be applied through a laser (noncontact) or probes (contact).
Laser thermokeratoplasty (LTK) involves applying pulses of laser
light in ring formation to the cornea. This heats the collagen and changes the
shape of the cornea. Actual treatment time is only a few seconds for each eye.
LTK has been approved for people over 40 years of age who have
mild hyperopia of 2.5
diopters or less. There is some discomfort after the procedure,
including expected initial overcorrection of vision.
During a cornea transplant, an eye surgeon removes a portion of your cornea and replaces it with a new section of cornea from a donor.
The procedure is also called a corneal transplant or a keratoplasty. About 40,000 cornea transplants are performed in the U.S. every year.
You may need a cornea transplant if your cornea no longer lets light enter your eye properly because of scarring or disease.
Conductive keratoplasty (CK) is a relatively new technique that can treat mild to moderate farsightedness. A contact probe delivers radiofrequency energy to multiple
locations on the cornea, shrinking the collagen and steepening the central
cornea. Treatment takes less than 1 minute for each eye.
Disadvantages of the procedure include an initial overcorrection,
inability to treat
astigmatism, scarring of the cornea, and a possibility of inducing
astigmatism. Also, the correction may not last, so you may need to have the