Radial Keratotomy, or RK, changes the shape of the cornea by making incisions with a surgical knife to flatten, steepen, or alter the contour of the front of the eye.

Radial Keratotomy was developed in the Soviet Union, and became a common surgery worldwide in the 1970's.

Corneal incisions are very effective at changing the shape of the eye, but because these incisions go almost all the way through the cornea, and because the healing process varies greatly among individuals, complications are substantially more common with RK than with laser refractive surgery.

The great majority of patients who have had RK have obtained markedly improved vision.  However, it is quite common for RK patients to notice variable vision through the course of each day, due to weakening of the cornea and resultant fluctuation in its shape in an ongoing basis.

Some people who have had RK have also experienced progressive changes in their vision over years after their surgery, so that the initial improvement fades with time.  Even more serious complications, including severe scarring requiring further corneal surgery, or constant blurring not treatable with contact lenses or glasses, have occurred on an infrequent basis.

While RK may still be recommended for certain selected situations, it is rapidly being supplanted by laser surgery for almost all vision correction applications.  Fortunately, laser surgery is much safer and more predictable than RK, and eliminates completely the rare but more serious complications of surgery such as those described above.

Most surgeons feel that while RK was a valuable step in the development and evolution of vision correction surgery, it will likely no longer be used as laser surgery continues to improve and expand its horizons.