"Are we doomed by ignorance in refractive surgery to repeat forever the sight robbing mistake that the true grandfather of refractive surgery Sato made, by incising a tissue whose function he did not even begin to understand?...I now give you Bowman's layer whose function is still not understood."


"Dr. Svyatoslav Fyodorov told us that RK wounds were like any other incisions and that in a year they were going to be basically very strong. I think there is some doubt about that at this time." 

"I think we have an obligation to warn these RK patients to protect themselves for, at the very least, several years and probably for the rest of their lives. They need to be lovers and not fighters."

Maurice E. John Jr, MD, Dissection of Radial Keratotomy International Symposium -1985

"I think it is appropriate for us to re-examine RK at this time. It has now been more than 50 years since Professor Sato at Juntendo University in Tokyo began operating on normal corneas using both anterior and posterior incisions to modify the shape in order to achieve a reduction in myopia. Since that time, there has been a revolution of RK techniques. An assembly line approach was observed in Russia with modifications of the earlier technique. RK was introduced in this country in 1978.  Many of the people on our panel and here in the room were instrumental in organizing the US PERK study. This mutlicentered study tried to determine the effectiveness of RK using a single method. The initial data were very encouraging. But there were some problems that became apparent in the PERK study with respect to the relative predictability of RK and the stability of refraction. There was some bothersome fluctuating acuity for some patients, possibly due to the effect of changes in intraocular pressure on an unstable cornea. Later, the potential for development of progressive hyperopia, that a significant number of patients with RK experienced, was observed with the analysis of the 10-year PERK data. Certainly, the overall PERK results were still very good for low myopia, but the data are not as satisfactory as the operation was pushed more for individuals having moderate and high myopia."

Richard L LIndstrom, MD, Cornea and Refractive Surgery 1997

The History of Radial Keratotomy


Keratotomy for myopia (nearsightedness) and astigmatism (football shaped cornea) has developed during the past century in three major phases.  In the first phase surgeons in Europe and the United States defined the principles of keratotomy (surgical reshaping of the cornea) in the late 1800s. In the second phase surgeons in Japan detailed the effects of anterior (outside of cornea) and posterior (inside the cornea) keratotomy in the 1940s and 1950s. And in the third phase ophthalmologists in the Soviet Union, the United States, Europe, and Latin America refined modern refractive keratotomy between 1976 and the present.


Professor Sato was an astute clinician who drew lessons from his observations.  In fact he observed that spontaneous breaks in Descemet's  (inner eye) membrane in keratoconus (bulging cornea disease) produced flattening of the cornea as the breaks healed.  This provided hints for his idea of posterior  corneal incisions.   He did posterior keratotomy in 10 eyes of eight keratoconus patients, reporting his observations in his first paper on keratotomy in 1939.

In the 1930s there were no effective treatments for keratoconus.   A posterior keratotomy seemed simple and effective, and Professor Sato operated on some 200 keratoconus cases between 1938 and 1943.

Every day Sato and his staff performed careful operations on rabbits.  The staff members took turns for nightly shifts and worked around the clock.  Their efforts were rewarded with great success.  And with the accumulation of sufficient data from the animal experiments, Sato decided to apply his anteroposterior (inside and outside the cornea) keratotomy technique to humans.

Myopic surgery was performed most frequently in the early 1950s.  The surgeons would operate on one patient after another.  If the eye contents leaked despite the many precautions that were taken, the doctors would immediately stop, operate on the next patient on the neighboring table, and then return to the first patient to complete the operation.  The ophthalmic surgeons at Juntendo University operated on 861 eyes up to 1959.

This decade of creative work produced numerous publications, two of which stand out as important summaries of Professor Sato's work.  One, published in the American Journal of Ophthalmology in 1953, described Sato's experience with anterior and posterior half incisions in 32 eyes, with the conclusion that this new surgical approach is a proven, safe method which definitely cures or adequately alleviates over 95% of all cases of myopia in Japan.  This claim was eventually disproved.

The increasing popularity of contact lenses around the world in the 1950s shifted the emphasis of treatment of myopia and astigmatism from surgical correction to correction with contact lenses and glasses.  In addition, Sato began to sense that the inner lining of the cornea, the endothelium was important.  Corneal transplantation was becoming popular worldwide, and it was becoming apparent that the endothelium played an important role in the survival of a corneal graft.  Throughout his life Sato had focused his interest on Descemet's membrane as important in keratotomy and gave the endothelium little thought in relationship to keratotomy.  He died unaware of the long-range complications of corneal swelling and imflamation (edema).

In 1965, 5 years after Professor Sato 's death , Jiro Inoue, M.D., of Tokyo University reported bullous keratopathy ( a condition in which small vesicles, or bullae, are formed in the cornea due to endothelial dysfunction which undergo painful ruptures releasing their fluid content to the surface. These bullae disrupt vision and create pain sensations) that developed in a patient 12 years after the Sato procedure for myopia was performed  on him .  Of course no one at the time the procedures were being performed could have possibly foreseen the development of bullous keratopathy from endothelial damage, since no one at the time knew the function of the endothelium in preserving corneal clarity.

Unfortunately, the damage done to the corneal endothelium by posterior incisions frequently produced corneal opacification (clouding) that only appeared 10 to 24 years later.  In addition there were certain technical deficiencies that resulted in many low corrections that did not warrant the risk of the surgery. Consequently, the surgery was abandoned.

Kanai, working at Juntendo University in Tokyo— the school where Sato was a professor— followed 80 of the eyes of 50 patients (of 281 myopic eyes on which Dr. Sato performed the operation after 1951) from 1971 through 1980.  Sixty of the 80 eyes (75%) developed bullous keratopathy.   It is assumed (without any evidence) that the remaining 581 eyes shared the same fate.

As the number of cases of corneal edema increased, every member of Professor Sato's research team expressed sincere regret at having made these patients suffer such a fate.  The shock caused by consequences of Professor Sato's operation lingered for decades in the Japanese ophthalmologic profession and fueled the controversy about anterior radial keratotomy when it reemerged in the early 1980s.


In 1960 shortly after Sato's death Svyatoslav Fyodorov, M.D., attended the Japanese Ophthalmological Society Conference in Niigata, Japan.  After the conference Fyodorov tried Sato's technique in four cases of myopia and two cases of astigmatism but found it difficult to place the full number of posterior incisions without flattening the anterior chamber.

Pureskin and  Durnev and  also repeated some of Sato's work on rabbits and at least once in a human subject, verifying most of Sato's findings, including a tremendous corneal reaction not reported by the Japanese surgeon.   Consequently, posterior incisions were rejected out of hand.




Important contributions to modern anterior refractive keratotomy were made during the 1970s and 1980s by S.N. Fyodorov and his colleagues in Moscow.  Fyodorov started performing surgery in humans in 1974 using a freehand razor blade fragment in a blade holder, checking the depth of the incision with a depth gauge, and deepening the incisions as needed.

He stated he specifically refrained from reporting his early results so that he could have a reasonable follow-up on many patients.  Throughout his oral and written presentations Fyodorov has remained enthusiastically optimistic about keratotomy for myopia and astigmatism, extolling its virtues and minimizing its drawbacks. His results supported his enthusiasm: 100% of 230 eyes with baseline refractions of -1.0 0 to -6.0 0 D, achieving a final refraction within ±0.50 D of emmetropia (good vision) 1.5 years after surgery.  No other surgeons have been able to replicate these extraordinary results.


Fyodorov actively exported anterior keratotomy to the United States, but the start was slow. He visited the United States a number of times in the mid- and late 1970s to speak about his iris-fixated Sputnik intraocular lens, popularizing it in the Northeast.  He also extolled the virtues of keratotomy, but, like Sato, he found only American indifference.  However, once the news media began to describe the pinwheel surgery that lets you throw away your glasses, the eruption of interest created an unprecedented surgical, ethical, and socioeconomic upheaval in American ophthalmology.

Colleagues are encouraged to go to Moscow in order to learn the technique.  In this context I would like to cite a letter to the editor of the Times (London) from November 25, 1985:

More than meets eye

From Mr. D.P. Choyce .

Sir, Peter Kellner, in an article on September 11, praised the Moscow Institute

for Eye Microsurgery, under its director, Professor Svyatoslav Fyodorov. There is

another side of Professor Fyodorov's activities of which Mr. Kellner appears to be


What happens when a Western ophthalmologist wishes to go to Moscow to

learn from the master? He has to sign an agreement with Licensintorg, the licensing

bureau. I have a copy in front of me. The salient features are these:

1. The tuition fees, payable in advance in US dollars, range from US dollars 920

for three days to US dollars 5,680 for one month, in a group; 30 per cent more if

the instruction takes place on a one-to-one basis.

2. He must use the correct trademark; he must use Fyodorov's instruments, artificial

lenses and surgical techniques. He must make no changes to any of these.

3. He must report his results every year and if his success rate falls below 80 per

cent he automatically loses the franchise.

4. He is allowed to do 50 operations "for free"; thereafter he must pay a 5 per

cent royalty on every operation he performs to the agency, again in US dollars. He

has to agree to open his practice accounts at least once a year to an auditor appointed

by the agency to enable it to keep a check on his earnings.

5. He is not allowed to instruct others in the techniques he will have learned in

Moscow. .

6. The agreement runs for seven years.

7. Should there be any disagreement between the parties the dispute will be referred

to the Foreign Trade Arbitration Commission at the All-Union Chamber of

Commerce and Industry, Moscow, whose decision shall be binding on both signatories.

Altogether a very remarkable document, about as far removed as possible from

the ethics enshrined in the Hippocratic oath upon which Western medicine is

based. It is ironic that it takes a citizen of the USSR to think up something which is

unacceptable to his colleagues in capitalist countries.

Yours faithfully,

D. P. Choyce (Past President, International Intraocular

Implant Club and United Kingdom Intraocular Implant Society)

I agree with Mr. Choyce that there certainly are different ways of how to interpret the Hippocratic oath in different parts of the world. . . .

From Tengroth B: Acta Ophthalmol 1987;65:1.


Development of Refractive Keratotomy in the United States,


In contrast to the development of refractive keratotomy in Japan and the Soviet Union, which centered largely on two prominent individuals, its development in the United States from 1978 to the present (1990) has been a convoluted jumble of social, economic, political, and scientific forces— a paradigm of modern medicine.

Social: Refractive keratotomy was introduced to the United States largely through the mass media, creating intense public interest.

Economic: A few entrepreneurial ophthalmologists competed for the potential millions of dollars in fees.  Management firms established refractive keratotomy-oriented practices around the country. Optimistic advertising and direct public sales created the most intense commercialization of ophthalmic surgery in the history of the profession.

Political: Numerous organizations that were centered on refractive keratoplasty in general and refractive keratotomy in particular sprang up; relations between these organizations were more acrimonious and litigious than cooperative.

Scientific: Laboratory investigation and clinical modification of the techniques continued in the hands of individual surgeons and collaborative groups.  By the mid-1980s much of the fuss had died down, the social, economic, political, and scientific elements smoldered along……..


I believe the history books of refractive surgery will use the contents of this site as the basis to write the rest of the history of Radial Keratotomy in North America until it’s inevitable, appropriate death………

(this historical retrospective was derived from the texts Refractive Keratotomy, by Dr George Waring III who founded the PERK study and Refractive Eye Surgery- Second Edition, by Dr Leo Bores who brought RK to North America in 1976.)