n 1978, Dr. Leo Bores, founder and director of the Bores Eye Institute (Scottsdale, AZ), was the first American to perform a radial keratotomy operation in the United States. Since then, he has perfected many of the techniques and tools used in the surgery, making him one of the two leading radial keratotomy specialists in the world.

To find out more about radial keratotomy, continue reading, as Dr. Bores answers questions concerning this unique and fascinating new area in eye care.

A question often asked is: What is Radial Keratotomy and why do I need it? In the first place you don't need it, but it is available if you want it.

Q. If glasses and contact lenses are capable of restoring an individual's sight, why is surgery necessary?

A. Because glasses and contact lenses only serve as temporary solutions. The moment you take them off, your vision is blurry again. In addition, many people cannot wear contact lenses for various reasons, such as an allergic reaction. And of course there are times when only surgery can restore vision.

Q. With all these types of surgery, why should I consider radial keratotomy?

A. Because radial keratotomy is a simpler technique and involves fewer complications than other types of surgery. Besides — most individual's myopia is in the range covered by this surgery.

Q. How do I know if radial keratotomy is right for me?

A. You must ask yourself if you really need surgery. If you are well-corrected with your glasses or contact lenses and are happy with that correction, you shouldn't consider the surgery. But, if you can't wear contacts and you don't want to wear glasses, or if your job requires good vision without glasses, such as a firefighter's, radial keratotomy is something to look into.

Q. How long has this surgery been around?

A. Radial Keratotomy was begun in 1973 after a chance observation of corneal flattening after eye trauma in a child. Svyatoslav N. Fyodorov, was at that time, director of The Clinic for Experimental Eye Surgery in Moscow, USSR. Professor Fyodorov was already well known for his pioneering work in intraocular lens implant surgery. In 1976, Dr. Leo Bores, founder and director of the Bores Eye Institute, was the first American to perform a radial keratotomy operation. He began to work with the Soviet inventor to refine this surgery and in 1978 introduced it into this country. Since then, he has further refined the technique and invented many of the methods and instruments used in this surgery throughout the world (including Russia). Doctor Bores also performs the intricate keratomileusis operation and other types of refractive surgery. He is recognized as one of the leading radial keratotomy and refractive surgery specialists in the world. Along with Professor Fyodorov he has the longest experience of anyone. (see also: Evolution of RK)

The surgery works by causing temporary peripheral weakening of the corneal tissue. This is accomplished by making radiating, partial thickness incisions into the corneal stroma from the epithelial surface. These incisions are varied in length, number, and depth to vary the resultant correction (Figures).

The technique is quick and relatively painless making it ideally suited for the out-patient surgical facility. In addition, the recovery period is relatively short and most patients return to normal activity within hours. While seemingly easy to perform, the technique requires careful attention to pre-operative details and nuances of surgical technique. It is truly “microsurgery” in its strictest sense as a few microns of incision depth can affect the outcome. The seeming simplicity of the technique has led to variations or “improvements” in the technique not bolstered by experimental evidence or clinical experience. “Good” results have been reported with these variations but they are not optimal as further study has revealed.

Q. Who can have this surgery?

A. Anyone who is nearsighted (myopic) and wants it.

Q. Who cannot have the surgery?

A. This surgery is not recommended for the very young or for those patients who have eye disease. Also patients with certain types of systemic diseases are not candidates.

Q. Suppose that my myopia is greater than -6.50 diopters or I'm farsighted. Is there anything that can be done for me?

A. Yes there is. In very high degrees of myopia and hyperopia, a procedure known as keratomileusis can be performed. This is a type of corneal transplant except that the patient's own cornea is used instead of a donor. See below under Lamellar Refractive Keratoplasty for further details. Or you might be a candidate for LASIK. And just because you have myopia over -6.5D doesn't mean that you can't have RK. It just means that you will probably not get a complete correction but it might be enough to get you into thinner glasses or disposable contacts.

Q. I've been told that I am “farsighted”. What does this mean and why can't I have radial keratotomy?

A. If you are able to see in the distance better than you can see up close or very near the same — you are said to be farsighted. Some farsighted people see well enough not to need glasses. Some however are just as bad off as nearsighted people. Radial keratotomy works by making you farsighted. If you are already farsighted — it will make you worse. There is a surgery — Hyperopic Lamellar Keratotomy — that has been developed to correct this problem (see below).

Q. Can this surgery correct astigmatism?

A. Yes. As a matter of fact, radial keratotomy, or some variant, is the only type of surgery that can get rid of astigmatism effectively. This may be done by grouping incisions together or by changing the shape of the optic zone, the clear window of the cornea, from a circle to an oval.

Q. Does a radial keratotomy operation really make it possible for a person to never wear glasses again?

A. In many instances, yes. In other cases, glasses with a weaker prescription might be needed, but you would only have to wear them when you read. Or if you could never wear contact lenses before, because of severe myopia, after the operation you may be able to.

Q. I have heard that the Japanese did this surgery in 1956 and it failed. Some patients even lost their sight. Is this true?

A. The Japanese DID NOT do radial keratotomy but another type of surgery altogether. In the beginning, this surgery was confused, possibly deliberately, with a similar technique espoused by T. Sato, M.D. of Japan, in 1953. Although the incisions look the same they are different in many ways. In the Sato procedure, the incisions were made from the inside of the eye without the use of a surgical microscope. In addition they made 50-60 incisions and these incisions were very short. Because the incisions were made into the undersurface of the cornea — they destroyed a delicate cell layer (endothelium) which caused the clear cornea to become white. Many patients lost their vision as a consequence.

Q. How does radial keratotomy differ from the Japanese operation?

A. The incisions are made on the outside of the clear cornea of the eye in RK. The surgery is done under microscopic enlargement allowing precise placement and control of the incisions. The corneal thickness is measured with an ultrasonic probe accurate to 3 decimal places. At the BEI, the blades are set with precision optical gages. The Japanese guessed. The blades used at the BEI are the sharpest ever produced by man -- some have an edge thickness of 1/3 the wave length of light -- and were made to Doctor Bores’ particular specifications from sapphire and diamond.

Q. How many people have lost vision from radial keratotomy?

A. To the best of my knowledge only two — both from infection (out of 600,000+ cases). Some patients experience a slight loss of best corrected vision after the surgery but this is seldom severe and rarely lasting.

Q. What other problems have occurred after RK?

A. All patients experience glare, especially at night from oncoming headlights. Fluctuation, or changing vision from morning to night is also common but rarely severe. Both of these side-effects disappear in time and practically never prevent normal activities including night driving.

Q. I've heard that the vision gets worse in time.

A. In some of the early cases this happened to a few patients but is not common now. Once the incisions are made, the effect produced is permanent.

Q. Is it possible that the surgery could make me farsighted?

A. There is a tendency for patients over 40 years of age to get more correction for a given amount of surgery. This could lead to an over-correction. However, because age is one of the factors taken into consideration by experienced eye surgeons BEFORE the surgery, over correction is not a common worry. In addition, there is good scientific evidence to show that, in most studies, there has been no progression of the effect over time. It must be kept in mind that the method of surgery used in the PERK study is NOT the method used to perform RK in private practice. In fact, the surgery used in the government funded PERK study is NOT used by anyone in clinical practice to our knowledge.

Q. If I wanted the surgery, how would I know if I'm a candidate?

A. You must be examined in the Clinic. If you are in good health and your myopia does not exceed 7 diopters, you are probably a candidate for the procedure. (A diopter is a unit for measuring the light bending power of a lens.)

Q. My vision without glasses is 20/200. Doesn't that make me a candidate?

A. Not necessarily. It is a common misconception that the degree of vision is somehow related to the severity of the refractive error. This is not true. The fraction 20/200 merely means that at 20 feet you can see a letter that a person with "normal” vision (20/20) can see at 200 feet. While this is pretty bad vision, it could be caused by nearsightedness, farsightedness and/or astigmatism. The 20/200 merely measures the vision not the refraction.

Q. How successful is RK?

A. Very. The overall success rate in patients whose myopia ranges from -1.00 to -6.50 diopters is 85%. That means that almost 90% of operated patients have their vision improved to the point that they can drive a car without glasses — day or night and in any state. In the lower ranges of myopia (where most people are), the success rate is even higher, in some ranges the percent attaining 20/20 (normal) vision is almost 95%.

Q. Are there any examinations or tests needed before the radial keratotomy?

A. Yes, there are. Every radial keratotomy is different from another. Various tests are required to obtain information that might alter the procedure done in each operation. This information includes how much myopia or astigmatism is present, the degree of corneal curvature and the thickness of the cornea A thorough examination of your eyes is also done to determine if there are any medical problems that might interfere with surgery.

Q. Are there some things that might prevent me from having this surgery even if my nearsightedness is in the proper range?

A. Yes there are some conditions that might prevent you from having this surgery:

1: If you have keratoconus (a peculiar type of astigmatism associated with abnormal corneal tissue) — you should not have RK or any other refractive surgical procedure.

2: If you have irregular astigmatism for any reason — such as a corneal scar — you should not have this surgery. If you do — it could make your condition worse. It depends upon where the scar is. If it's off to the side and nowhere near the center of your vision, then it may not effect the outcome. On the other hand, if it's near your visual center and if there's thinning of the cornea (there almost always is) it could cause your condition to get worse instead of better. If you are considering such surgery seek out an expert before consenting to any procedures.

3: If you've ever had a Herpes keratitis (or dendritic ulcer) you should not have this surgery — ever.

4: A history of recurrent corneal erosions, while not an absolute contraindication, could cause problems with delayed healing and increased glare. Map-Dot changes are not a contraindication nor are dry eyes.