Issue: March 1, 2002
March 01, 2002
3 min read

Dr. Sadun honored for work during blindness epidemic in Cuba

Alfredo Sadun, MD, and colleagues found that a vitamin deficiency contributed to an epidemic of optic neuropathy that affected 50,000 Cubans.

Issue: March 1, 2002
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HAVANA — A researcher whose team helped stop a puzzling epidemic of blindness in Cuba during the early 1990s received an award here for his contributions. The Decade Medal of Honor was given to Alfredo Sadun, MD, PhD, for “valor in scientific accomplishment,” by the Cuban National Academy of Sciences.

The award, issued only once a decade, acknowledges the work of Dr. Sadun and a team of U.S. and U.N. researchers who helped solve the mystery of the epidemic and initiated treatment.

The team determined that Cuban government food rations and nutritional guidelines instituted in the early 1990s led to folic acid and other vitamin deficiencies that ultimately damaged the optic nerves of 50,000 Cubans. They recommended wide distribution of B vitamins, which largely ended the epidemic.

Dr. Sadun, a professor of ophthalmology and neurosurgery at the University of Southern California School of Medicine, was honored here by the Cuban National Academy of Sciences. His American coinvestigators were James Martone, MD, and Lillie Reyes, along with Benjamin Caballero, MD, and Gustavo Roman, MD, of the Pan-American Health Organization, an arm of the United Nations. Rosarlis Santiestaban, MD, was the principal Cuban medical scientist with whom the group worked.

Dr. Sadun and his colleagues on the research team had a reunion at an international symposium here last year for one final discussion of the epidemic and the results of their treatment. They determined that the epidemic had successfully ended and that vision had been partially restored to some of those affected by the condition.

“Because of the [U.S.] embargo, and because the Russians had stopped their support of Cuba not too long before, there were some major problems with the economy and proper nutrition” in the early 1990s, Dr. Sadun said.

The nutritional repercussions from these factors resulted in widespread malnutrition, Dr. Sadun said. Because of food shortages and lack of calories in the diets of the Cuban population, the government was encouraging the consumption of rice, beans and potatoes — a dietary shift that led to widespread dietary deficiencies, especially of folic acid.

The final straw

On a recent trip to Cuba, Dr. Sadun and colleagues met with Fidel Castro. From left to right: Jim Martone, MD; Dr. Sadun; Gen. Castro; and Lillie Reyes, Dr. Sadun’s head technologist.

“The final straw may have been when Castro decided to discourage Cubans from consuming their own rum. He needed American dollars for it (via exportation). As a consequence, some of the Cubans were making homebrew. This was not badly made rum, it just wasn’t aged very long, so it had trace amounts of methanol in it,” Dr. Sadun said.

Methanol metabolizes to formate, which can damage the optic nerve. In healthy people, Dr. Sadun said, the formate would have been detoxified by folic acid. But because the Cubans had depleted their systems of folic acid, the formate damaged the optic nerves of many people.

The cases of blindness began near the end of 1992 and grew exponentially, Dr. Sadun said. The rapid growth of the condition led the Cuban Minister of Health to appeal to the United Nations for help. He delivered a speech in which he told the world that 50,000 Cubans had gone blind, and they did not know why. At the time they believed the condition was caused by a virus, and they could not determine a treatment for it. The speech was both a call for help and a warning; it was thought that the virus might spread to other countries.

Dr. Sadun was recommended for the task force as an expert who had done work on the optic nerve. (The Cuban Ministry of Health had suspected that the condition was related to the optic nerve, and the researchers found this was correct.) In May 1993, Dr. Sadun and his colleagues spent a week in Cuba examining patients and deliberating over the cause of the disease. The disease was dubbed the Cuban epidemic of optic neuropathy (CEON).

The researchers recommended the distribution of folic acid and B-vitamin supplements to all residents. Dr. Sadun returned in September of that year to re-examine the patients and found that the spread of the epidemic had effectively been stopped.


“One of the most surprising letters I got was from Fidel Castro, 6 weeks after I got back from the first trip. He told me that I had correctly prophesied that the epidemic would be stopped with folic acid. But he said I was incorrect because I had also said that the people who had gone blind would never get their vision back, and many had,” Dr. Sadun said. “Castro was half right. Their vision had improved but had not returned to normal.”

Partial vision returned because some of the nerve fibers had not been completely damaged, Dr. Sadun determined.

After making several trips to Cuba, the researchers met for the last time in August 2001. All the field reports indicated that there are no more cases of CEON.

“It was very promising to hear from all of the Cuban provinces and hear that the epidemic was over,” Dr. Sadun said.

It was at that final meeting where Dr. Sadun was surprised to learn he was to be awarded the Cuban National Academy’s Medal of Honor.

For Your Information:
  • Alfredo Sadun, MD, PhD, can be reached at Doheny Eye Institute, University of Southern California, 1450 San Pablo St., Los Angeles, CA 90033; (323) 442-6417; fax: (323) 442-6407; e-mail: