Astigmatic Keratotomy (AK)
Astigmatic keratotomy or AK is a non-laser refractive surgery procedure useful for correcting astigmatism. In AK, the refractive surgeon uses a hand-held, bladed instrument to create incisions (cuts) in the peripheral cornea. These cuts penetrate approximately 90% of the total corneal thickness. As the incision(s) heal, they flatten the cornea in specific meridians to make the curvature of the cornea more symmetrical, thereby correcting astigmatism.
In the hands of a skilled surgeon, AK is effective and can achieve predictability that rivals the correction of astigmatism with LASIK or other laser procedures. And because the central cornea is not treated in AK, it may even produce sharper vision than laser eye surgery. AK is often a useful enhancement procedure following cataract surgery if significant astigmatism remains after that procedure.
Since the corneal incisions in AK are deep, a perforation of the eye is possible if the blade cuts too deeply. In this instance, fluid inside the eye could leak outward, creating a risk of an intraocular infection or other serious complications. Should a perforation occur during AK, the surgeon may need to apply temporary stitches over the wound to stop the leak.
AK is similar to another non-laser refractive procedure called radial keratotomy (RK), which was a popular surgery for the correction of myopia (nearsightedness) in the 1980s. But in AK, only one or two incisions are usually required. In RK, 8 or more incisions were frequently used. Because AK and RK are performed using a blade to make cuts in the corneal, they are referred to as "incisional" refractive surgery procedures.