The U.S. Food and Drug Administration (FDA) has approved Botox Cosmetic (OnabotulinumtoxinA) for use to temporarily improve the appearance of moderate to severe canthal lines, commonly referred to as crow’s feet. To date, Botox Cosmetic is the only FDA approved drug treatment for the condition.

In 2002 the FDA approved Botox Cosmetic to temporarily improve glabellar lines, the wrinkles between the eyebrows often called frown lines. The drug works by keep the muscles in the area from tightening which makes wrinkles appear less prominent.

“This additional indication will provide people with a new FDA approved treatment option for those seeking a smoother appearance by temporarily minimizing the appearance of crow’s feet at the sides of the eyes,” said Susan Walker, M.D., director of the Division of Dermatology and Dental Products in the FDA’s Center for Drug Evaluation and Research.

Botox Cosmetic is delivered via intramuscular injection. Treatment for frown lines and crow’s feet lines can be administered at the same time.

The safety and effectiveness of the drug for treatment of lateral canthal lines was established in two clinical efficacy and safety studies. More than 800 adult participants with moderate to severe lateral canthal lines were randomly assigned either the drug or a placebo. Results showed that participants who received Botox showed greater improvement of lateral canthal lines in comparison to those who received the placebo.

The most common adverse reaction associated with the drug during treatment for lateral canthal lines has been eyelid edema. Eyelid edema is when the eyelids swell and contain excessive amounts of fluid.

OnabotulinumtoxinA is marketed as Botox and Botox Cosmetic. The FDA has approved the drug for treatment of chronic migraines, severe underarm sweating, eyelid spasms and misalignment of the eyes.

The drug comes with a warning on the box that the effects of the botulinum toxin could spread from the injection site to other areas of the body, resulting in symptoms similar to those of botulism. Those symptoms include difficulty swallowing and breathing difficulty that could potentially be life threatening. To date, there has been no confirmed case of any serious toxin spread when Botox or Botox Cosmetic have been used at a recommended dosage for an approved treatment.

Botox Cosmetic is manufactured by Allergan Inc. based in Irvine, Calif.