Botulinum toxin

Botulinum toxin (btx) Injection

What is Botulinum toxin?

Btx is a purified protein toxin produced by the clostridium botulinum bacteria, a potent substance known for its ability to paralyse muscles and nerves.  Since 1973 doctors have deliberately exposed patients to the effects of this chemical for muscular and nerve disorders such as squints, chronic eyelid twitch and muscle spasms such as those seen in cerebral palsy.  More recently (since 1988) it has been used for cosmetic purposes.  Although Botox is technically a toxin, there have been no serious side effects recorded. This is because, for the treatment described, it is used in extremely small amounts and does not spread throughout the body.

Where can Btx be injected?

The lines we know as frown lines and crow's feet are lines of facial expression. They are created by the repeated action of very specific facial muscles and the lines become more apparent over time. The muscles creating the frown lines are called the corrugator muscles and the procerus muscles and they are located above the eyebrows and in the middle of the bridge of the nose.
The orbicularis oculi muscles create the crow's feet at the corners of the eyes. These muscles are easily identified and their movements can be minimized with the technique of Btx injection.

What is involved?

First, the muscles to be treated are identified by observing the patient making different facial expressions. Btx, which comes frozen and dried, is reconstituted and diluted to a very specific strength. A few drops of Btx are injected with a tiny needle into the muscle that creates the wrinkle.  When Btx is injected into a muscle, it blocks the nerve impulse from reaching that area, and as a result, the muscle weakens. As the muscle weakens, the skin overlying the muscle relaxes and the wrinkle in the skin gradually softens and often disappears.  When Btx is injected there is an initial minor sting for a few seconds. Once the injection is complete, there is usually no discomfort.  The procedure itself usually takes less than 10 minutes.  There is no immediate response to the Btx injection. It takes several days for the muscles to be affected, at which time, one will notice the gradual loss of ability to frown or to create the lines affected by the treated muscles.

How long does a Btx treatment last?

The effects of Btx usually last three to five months, at which time another injection is required. After several treatments, the effects of Btx may begin to last longer, sometimes up to six to eight months. We recommend treatment every three months for the first year, then repeat treatment as needed.

Does it work for everyone?

No. About 2% of patients have pre-existing antibodies to Btx, which render it ineffective.  Unfortunately there is no way of identifying this small group of people beforehand.

What are the risks?

Btx has been used safely and successfully in ophthalmology for over 20 years and for wrinkle therapy for over 10 years. In the amounts used for wrinkle therapy, the only possible side effects are temporary and localized to the area of injection. In rare cases this may cause a droopy eyelid or eyebrow. This seems to occur because some of the material injected finds its way into those muscles unknowingly. The problem usually goes away in two or three weeks and may be expedited by taking eye drops. Allergic reactions to Btx are extremely rare.  Other possible side effects are temporary bruising, pain or headache and double vision, which is extremely rare and will usually disappear within two weeks.

Does Btx affect other facial expressions or create numbness?

Btx doesn't affect the sensory nerves, so there is no numbness in the area of the injection. Also, the effect of the Btx is only in the immediate area of the injection. Therefore, the muscles related to other expressions are unaffected.

Is the treatment for everyone?

There are very few restrictions regarding Btx treatments. Patients who are pregnant, have a neurological disease, or are taking antibiotics should not be treated.