Botox® (onabotulinumtoxin A) is a well-studied neurotoxin that has been used since the 1970s to treat eye misalignment (strabismus, struh-biz-muss). Strabismus is a common symptom of thyroid eye disease (TED). Botox is approved to treat strabismus in those 12 years old and older.1,2
What are the ingredients in Botox?
Onabotulinumtoxin A is the active ingredient in Botox.1
How does Botox work?
Botox is a neuromuscular blocking agent. These types of drugs block certain chemical signals from the nerves that cause muscle contraction. Once injected into the affected muscles, Botox starts to work after 1 to 2 days after treatment. Muscles that have been treated with Botox will regain normal function after 3 to 4 months because the nerve signals to the muscle cells are repaired over time.2
What are the possible side effects?
Botox injections for TED are considered relatively safe when performed by an experienced TED specialist. The most common side effects of Botox include:1,3
- Injection site reaction with pain, swelling, or bruising
- Headache or feeling generally unwell
- Droopy or uneven eyelids or eyebrows, depending on the site of injection
Retrobulbar hemorrhage has occurred in those receiving injections for strabismus. This is a rare but sight-threatening emergency of arterial bleeding in the bony orbit behind the eye. Be sure to receive your Botox injections from a skilled TED specialist who can quickly recognize and treat this condition.1,3
Botox has a boxed warning, the strictest warning from the US Food and Drug Administration (FDA). It has this warning because the effects of Botox can spread from the area of injection to distant areas in the body. Although very unlikely, this can lead to life-threatening problems with breathing and swallowing. This complication can occur hours to weeks after the injection. There have been rare reports of death related to this complication. Call your doctor or seek immediate medical attention if you notice any of the following effects after receiving Botox:1
- Speaking or swallowing problems
- Breathing problems
- Muscle weakness outside of the treatment area
- Vision problems
- Loss of bladder control
These are not all the possible side effects of Botox. Talk to your doctor about what to expect when using Botox. You also should call your doctor if you have any changes that concern you when using Botox.
Other things to know
Botox injections for strabismus in TED should only be given by a doctor or TED specialist who is skilled and properly certified to do so.3
Before an injection of Botox, tell your doctor or TED specialist if you take any medicines or supplements. For example, if you take blood thinner drugs, you may need to stop before your injection. However, do not stop or start medicines without first talking to your doctor.1,3
Your doctor will place numbing eye drops in your eye before injecting Botox.1
Your TED specialist will use electromyography (EMG) to guide the placement of your Botox injection. This device helps to ensure that the injection of Botox goes directly into the muscle that needs to be treated. For strabismus in TED, the muscles treated are the muscles around the eye (extraocular muscles).1
The number of injections you will need depends on many factors, including the severity of your symptoms and the area treated.1
You will likely have another appointment 7 to 14 days after your Botox injection so your doctor can assess your condition and the effectiveness of the dose.1
Botox may cause harm to an unborn baby. If you plan to breastfeed, talk to your doctor about your options. Scientists do not know whether Botox can affect your ability to produce breastmilk. They also do not know whether Botox can travel through the breastmilk to your nursing baby.1
Before beginning treatment for TED, tell your doctor about all your health conditions and any other drugs, vitamins, or supplements you are taking. This includes over-the-counter drugs.
For more information, read the full prescribing information of Botox.