What is the difference between RK and PRK?

While radial keratotomy (RK) sounds similar to photorefractive keratectomy (PRK), the two procedures are different and should not be confused. In RK, a surgeon reshapes the cornea by using a hand-held blade to make a pattern of incisions in the cornea that look like the spokes of a wheel. Those incisions cut through more than 90% of the thickness of the cornea and weaken the structure of the eye. This weakening permits the cornea to flatten, thus shortening the length of the eye and correcting the refractive error.

PRK, or Photorefractive Keratectomy, does not include an incision on the cornea. Instead, an excimer laser carefully shapes or sculpts the corneal surface by ablating or removing tissue from the corneal surface. The thickness of tissue removed is often less than that of a human hair. Laser vision correction with PRK involves the removal of less than ten percent of the corneal tissue because the excimer laser is so precise. The end result is a re-sculpting of the cornea, allowing light to properly focus on the retina. PRK was studied in clinical trials for six years before approval in the United States. It uses a computerized laser to correct nearsightedness(myopia) and farsightedness(hyperopia).

What is LASIK?

LASIK (Laser in-situ keratomileusis) also utilizes the excimer laser to remove corneal tissue in order to reshape the cornea. With LASIK, the surgeon first creates a flap on the cornea with a device called a microkeratome. He then uses the excimer laser to reshape the cornea below the corneal flap. The corneal flap is then placed back into position and healing begins with good surface integrity in 12 hours.

What is an Excimer Laser?

A laser is an instrument that can produce and control a powerful beam of light. Laser light can be directed and controlled more precisely than normal light, and it can be delivered in extremely brief, intense pulses. The excimer laser produces a beam of ultraviolet light in pulses that last only a few billionths of a second. Each pulse removes a microscopic amount of tissue by evaporating it, producing very little heat and leaves underlying tissue virtually unchanged.

Is laser vision correction the same as Radial Keratotomy (RK)?

No. While both treatments are designed to correct nearsightedness, RK and laser vision correction are not the same. The revolution in eyecare - changing the shape of the cornea itself - began with radial keratotomy (RK). Although successful with some types of nearsightedness, RK is an invasive surgical procedure involving the use of scalpels to make a series of corneal incisions, cutting into as much as 95% of the cornea. Laser vision correction uses a state-of-the-art, computerized excimer laser to reshape the cornea with no incisions. During the last decade, physicians worldwide have turned increasingly to laser vision correction and have performed the treatment over one million times.

What can I expect from the laser vision correction procedure?

Prior to treatment, the physician administers anesthetic eyedrops to the patient to numb the cornea. After the eye drops have had a chance to take effect, the patient is positioned in a comfortable chair centered underneath the laser and is asked to focus on a small bright light. Once the laser is properly aligned and the patient feels comfortable focusing, the actual treatment may begin. Depending upon the amount of correction required, the laser treatment itself takes about 15-40 seconds. The patient remains awake throughout the treatment. The treatment itself is painless, although the patient may notice a "gritty" sensation in the eye or some discomfort in the first 24-48 hours. Medication may be provided to minimize any discomfort. Typically, the patient will notice improved vision within 3-5 days and can usually resume normal activities in 1-3 days. Often patients prefer to be treated on a Thursday or Friday afternoon to reduce time away from work. Vision may fluctuate over the next few weeks, and usually stabilizes within three months.

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How do I know if I'm a good candidate for laser vision correction?

A large majority of all nearsighted (myopia) and farsighted (hyperopia) people are potential candidates for the laser treatment. Typically, patients who are at least 18-21 years of age who have mild to high myopia (up to -14 diopters of nearsightedness), astigmatism (up to 5 diopters of astigmatism), and farsightedness (up to +6 diopters of farsightedness). The excimer laser is FDA approved for nearsightedness, astigmatism, and farsightedness with PRK. Recently, November 1999, the FDA also approved the excimer laser for LASIK. Patients may be required to meet certain medical and visual criteria. The best candidates tend to be people who are dissatisfied with their contact lenses or glasses and are motivated to make a change , whether it's due to occupational or lifestyle reasons. However, only an eye doctor who is specially trained in laser vision correction can evaluate a patient's suitability for the treatment.

How do I know if it's safe?

The excimer laser has proven to be safe and effective for the treatment of the vast majority of nearsighted and farsighted prescriptions. In the U.S. clinical trials' three-year follow-up, no sight-threatening complications have occured. Over 3,000,000 treatments with the excimer laser have been performed worldwide.

Can I afford the treatment?

There are several ways for you to carefully evaluate whether or not this treatment will be 'affordable' for you. First, consider the costs associated with maintaining your eyeglasses or contact lenses. Depending on the type used some can be costly, especially when adding in the cost of solutions and other accessories. While it is harder to place a dollar value on lifestyle, we recommend that you consider this factor as you assess affordability. Ability to actively participate in a hobby, sports or your profession without the aid of glasses or contacts might be very important to you. Most centers and doctors offer a range of payment options to meet your needs.

What are the risks and side effects that I should be aware of?

As with any medical procedure, there are risks and side effects involved. Each patient must understand that a specific result cannot be guaranteed; however, results can be closely predicted based on data from thousands of previous cases. Serious complications are very rare, and the most likely is an infection, which is treatable with medication. Some possible complications include haze, perforation of the cornea, induced astigmatism, and under- or over-correction. However, thousands of refractive procedures have been performed in the United States, and they are recognized as some of the most successful and gratifying procedures performed. Since risks and side effects vary from patient to patient and are very important to consider, your refractive surgeon will cover these issues with you on a one-to-one basis.