Radial Keratotomy (RK)
Radial
keratotomy (RK) is surgical procedure that has been used since the late 1970's
to reduce myopia by changing the curvature of the cornea.
Using
a microscope, microsurgical instruments and a diamond blade, the surgeon makes
several deep incisions (keratotomies) in the cornea in a radial or spoke-like
pattern. People with myopia have difficulty with distance vision because the
cornea has too much power and focuses light rays in front of the retina. RK
weakens the support of the cornea, flattening it and reducing its power. This
allows the light rays to focus directly on the retina.
RK
takes fifteen minutes and may be performed with the patient awake. Eyedrops
anesthetize the cornea, eliminating pain during the procedure. Following
surgery, people are moderately uncomfortable and often require oral pain
medication. Antibiotic eyedrops need to be taken for approximately one week.
Clear vision can be present the day following surgery.
Postoperative
complications include glare, halos, undercorrection, overcorrection and
astigmatism that may not be able to be corrected with glasses. The major
disadvantage of RK compared to laser procedures is it permanently weakens the
cornea. Radial keratotomy is currently being used to correct low levels of
myopia.