Radial keratotomy (RK) has been referred to by some as the “grandfather” of refractive surgery. It involved making radial incisions in the cornea sometimes as deep as 80% of the total thickness of the cornea in an attempt to flatten the tissue. Astigmatism was treated with specific incisions placed in strategic parts of the cornea. The astigmatic incisions were made first, since they created more myopia, and when they healed, the radial ones were made. The optical zone around the pupil varied according to the degree of myopia that had to be corrected.
Having seen many thousands of patients who have had this procedure, I can say with confidence that the majority complained of glare and the vast majority regressed and required glasses shortly after surgery. That period ranged from several months to many years. RK’s “father” was Dr. Fyedorov, who did his research and perfected his technique on thousands of “very willing” citizens of the Soviet Union. During that time in the 70’s and 80’s the reported results of him were outstanding. To date it is very difficult to find negative results or complaints about his work. Obviously, the Soviet Union may have had something to do with its reported clinical data for public consumption.
RK was brought to the United States by 5 American eye surgeons, two of the best known being Dr. Norman Stahl and Dr. Jerry Zelman. They both traveled to Moscow to study with Dr. Fyedorov, and I even had the pleasure of being in the office with Dr. Stahl when Dr. Fyedorov visited him in his office in Garden City, Long Island. Dr. Stahl was a noted physician and surgeon, personally performing many thousands of RK procedures. In the short term, most patients were happy with the results. Yet where are these patients today? How do they see and how do their corneas look so many years after surgery?
I have had the pleasure of examining several of these same patients years after their procedure. Most, if not all, of these people I examine require an eyeglass prescription. Most are farsighted and also have a significant degree of astigmatism. Their prescriptions are generally unusual and they have acquired unconventional astigmatism. Another very common finding is the presence of a brown semicircular ring in the lower half of the cornea. The innermost layer of the cornea is only one layer thick, and when RK was performed, that layer was stretched to cover a larger area. Its function is to pump fluid out of the cornea and keep it at the proper hydration level. However, as this thin layer was stretched, its function was negatively affected. As a result, heavier materials were left behind; Iron. Therefore, this brown deposit is iron left behind in the cornea by a weakened endothelial layer. It doesn’t seem to have any visual effect, nor does it create any physiological determination, but it is a constant. What the future holds for these patients remains a question mark.
The big question is why all these patients have farsightedness and what can be done about it. The answer to the first question remains a mystery. It is possible that they were deliberately overcorrected to compensate for the regression or, more likely, the corneas were so weakened by RK that they became flatter over time and distorted causing astigmatism. Unfortunately, both Dr. Stahl and Dr. Zelman are deceased and are not available for consultation on this matter. A weakened cornea is free to change without any guidance, as internal and external pressures can reshape it. The one constant is that everyone needs refractive help. In fairness to all RK surgeons, current technology was not available to them. There were no surveyors, no Orbscans, and many other measuring instruments that we routinely use today. In addition, surgical calculations were performed on a regular refraction. The FDA and all surgeons did not require cycloplegic refractions which eliminate any spasm of the focusing system abnormalities affecting pre-surgical stones.
Many of these patients are having PRK as a way to correct their vision and improve their distorted vision. At least today’s technology has corrected the mistakes of the past. One has to wonder if in 20 years we will have problems with LASIK or PRK.