FDA OKs Use of Botulism Toxin for Treatment of Eye Disorders

The government on Friday approved a type of food poisoning bacteria for use as a treatment for crossed eyes and another eye disorder that renders its victims legally blind.

The Food and Drug Administration said a sterile, purified botulism toxin was approved as an injection therapy to treat strabismus, or cross-eye, and blepharospasm, a muscle disorder that makes the eyes close involuntarily.

“This is seen as the first successful treatment for both conditions,” said Eva Kemper, an FDA spokeswoman.

When eaten in improperly handled food, the toxin can cause botulism, or food poisoning, an ailment that can lead to paralysis or death.

“However, in clinical studies, the injected form was used safely in thousands of men and women to weaken muscles that pulled an eye in or out, or to reduce spasms in muscles that pull the eyelid closed,” the agency said in a written statement.

“With the blepharospasm, patients are legally blind because they can’t hold their eyelids open,” Kemper said.

Strabismus can be the commonly known cross-eye, in which the eyes look inward at each other, or wall-eye, in which they look out.

Doctors would inject the drug, botulinum toxin type A, into muscles near the eye, not the eye itself, to aid in “turning off” the muscle, the FDA said. The injection would take effect in a day or two and would last for about three months.

FDA approval requires product labeling that indicates it is not recommended for use for children under age 12 and an advisory to physicians that sedentary patients treated with the drug resume activity slowly.

“At least two patients who had been incapacitated and sedentary because of their previous condition apparently over-exerted too quickly and died of cardiac collapse,” the agency said.

“The most common side effects are that some patients’ eyelids may droop or their eyes may feel irritated,” it said.

The product, which will be sold as Oculinum, is expected to be available in about 30 days.