Botulinum toxin provides many cosmetic, functional uses

Cleveland-Comprehensive ophthalmologists who understand the mechanism of botulinum toxin type A (Botox, Allergan) and the underlying anatomy can find many functional and cosmetic uses for botulinum toxin in their practices, said Julian D. Perry, MD.

"As ophthalmologists, we have been pioneers in the field of botulinum toxin use. I think we need to continue to lead the community and not to trivialize it," said Dr. Perry, section head, oculoplastic and orbital surgery, The Cole Eye Institute, Cleveland Clinic Foundation, Cleveland.

"I think it's important to discuss with patients what botulinum toxin can and can't do," he added. "Botulinum toxin works for dynamic rhytides, basically by chemodenervating the muscles around the wrinkle. It does not work for static wrinkles, it doesn't treat actinic damage or skin texture, and it doesn't address periorbital fat deflation and volume."

Mechanism of action A brief overview of the mechanism of action of botulinum toxin is necessary for working in the periocular area, Dr. Perry said. Botulinum toxin first binds to the nerve terminal, then is incorporated into the cell via receptor-mediated endocytosis. It then blocks the fusion and release of acetylcholine vesicles. The effect of botulinum toxin wanes as new nerve terminals sprout.

Contraindications for botulinum toxin include use in patients who are hypersensitive to human albumin or have a history of neuromuscular diseases, and it should not be used in pregnant women or in patients who are sensitive to aminoglycoside antibiotics.

Dr. Perry also discussed some of the techniques he uses in his practice. He noted that while the manufacturer recommends using nonpreserved saline for reconstitution, several studies in the dermatology literature have shown that preserved saline can improve patient comfort because the benzyl alcohol preservative may act as an anesthetic.

Dr. Perry's preferred approach to reconstitution in most patients is to use 2 ml of preserved saline, which allows for 0.1 ml to equal 5 units. However, in some cases he uses different dilutions for the same patient, such as 2.5 ml, which allows 0.1 ml to equal 4 units, or 4 ml, which allows 0.1 ml to equal 2.5 units.

"It depends on the location and what we're trying to achieve," he explained.

The only FDA-approved cosmetic use for botulinum toxin is for treatment of glabellar folds, although there are numerous off-label uses. Various injection patterns can be used to treat glabellar folds. A typical pattern involves three injections of about 10 units each, one in the procerus and one on either side of the corrugator supercili complex.

"I pinch the brow between my thumb and forefinger to isolate the corrugator and avoid ptosis from weakening of the levator muscle," Dr. Perry said.

Off-label uses A few of the off-label facial aesthetic uses for botulinum toxin in ophthalmology include forehead furrows, crow's feet, brow lift, and perioral wrinkles. For treatment of forehead furrows, Dr. Perry uses a gridlike pattern with one or two layers and delivers about 10 units of botulinum toxin on each side. He seldom uses a large quantity of botulinum toxin in the central forehead because the frontalis muscle is not significant in this area in most patients, he noted.

For crow's feet, Dr. Perry often uses about three injections along the orbital rim of 4 to 5 units each to chemodenervate the orbicularis muscle.

"A good rule of thumb when you're starting out is to stay at or outside the orbital rim to avoid any lid malposition," Dr. Perry said.

He also shared tips on brow lifts, pointing out that injection of 2.5 to 5 units of botulinum toxin into the lateral orbicularis weakens this brow depressor muscle and can help achieve an attractive brow elevation.

In the perioral area, only a tiny amount of botulinum toxin is needed, Dr. Perry said. He recommended using 1 to 1.5 units in two or three areas just above the vermilion border to smooth out perioral rhytides.