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Introduction | Procedure | Risks | Side effects | Candidate requirements

Introduction

Radial keratotomy, which was developed in the '70s, was designed to reduce or eliminate myopia. It is used to treat nearsightedness and some forms of astigmatism. RK can correct up to six diopters of myopia.

Procedure

The surgeon flattens the cornea with four to eight incisions made from near the center of the cornea to its outer edge. The incisions form a design that looks like the spokes of a wheel. The incisions are made to a depth of eighty to ninety percent of the thickness of the cornea. The peripheral area of the cornea bulges microscopically, which allows the center to flatten.

The surgeon uses a diamond knife calibrated to the eye's measurements. The number and length of the incisions are based on the amount of correction needed and the person's age. As the incisions heal, the cornea flattens, changing the refraction to reduce the patient's degree of myopia.

Risks

RK leaves the eye structurally compromised. Trauma could cause the eye to rupture at one of the incision points. If the pupil enlarges beyond the edge of the scars, scattered light can cause glare problems at night. Since RK is a manual procedure, it is not as precise as laser surgery. Additionally, there is a small risk of infection. The patient will be given antibiotic eyedrops to prevent that possibility.

Side effects

There are some side effects associated with radial keratotomy. Patients often experience discomfort and irritation. They may be sensitive to light and have blurred or fluctuating vision. This tends to decrease with time. They may also experience glare or see starbursts around lights at night. These symptoms may make it difficult to drive at night.

If there is an undercorrection, the patient may require additional RK surgery for further enhancements. In ten to thirty percent of cases, there is an overcorrection and the patients need glasses. Some patients develop astigmatism and some experience a regression of their vision. Rarely there is a loss of vision. If a patient requires contacts after RK surgery, it may be difficult to fit the contact lenses.

Candidate requirements

Patients must be eighteen years old. They should have stable vision and no abnormalities of the cornea or external eye.