Learn how the medication known as Botox may reduce eyelid spasms, help crossed eyes, and treat other eye problems such as blurred vision (diplopia).
Helpful medical treatments can come from the strangest places. For a good example, you don’t have to look further than a toxin involved in a scary kind of food poisoning that’s now being used to treat some eye problems. The drug form of botulinum toxin — called Botox — is probably best known as a treatment for facial wrinkles. However, the Food and Drug Administration has now approved it for strabismus (crossed eyes) and a side effect known as diplopia (blurred vision). It may also help with another eye problem called blepharospasm (eyelid spasms).
Botox is found in a rare but serious form of food poisoning called botulism. It occurs when food contaminated with a kind of bacteria known as Clostridium botulinum is eaten (it also sometimes occurs when a wound is contaminated with these same bacteria). Clostridium botulinum produce botulinum toxin — and eating food contaminated with this toxin can cause your muscles to become paralyzed. People with botulism may be unable to move their arms or legs or breathe on their own.
The toxins do this by preventing nerves from sending signals to muscles to make them move. The muscles then become paralyzed. Eventually the nerves regain their ability, but it takes a few months for them to make new connections to the muscles.
Researchers Focus on Botox for Eye Problems
Scientific research led doctors to the discovery that botulinum toxin could be medically useful because of its effects on paralyzing — or relaxing — abnormally tight muscles.
In the early 1980s, an eye doctor promoted botulinum toxin as a way to treat an eye problem called strabismus that can affect children and adults. Strabismus causes the eyes to look in different directions; one eye may look inward, creating a cross-eyed appearance, or one eye may look outward. Strabismus can cause vision loss, trouble with depth perception, or double vision (which doctors call diplopia).
Why Botox Helps Ease Eye Problems
Each of your eyes has six muscles, and two of the muscles move the eye from side to side, explains Daniel Neely, MD, an associate professor of ophthalmology at Indiana University-Purdue University in Indianapolis whose interests include the use of Botox for eye problems. These muscles keep the gaze straight by working against each other, with equal strength, each pulling the eye in opposite directions.
If one of those muscles grows weak, the stronger muscle will pull the eye the opposite way. As a result, your eyes can end up looking in different directions. Strokes and nerve damage can also cause this problem, Neely says. Because the stronger muscle in the eye is always contracting, it can become permanently tight, he says. So when eye doctors treat strabismus with Botox, they inject the drug into the stronger muscle to relax it. This gives the weaker one a chance to recover.
In some people who have eye problems such as eyelid spasms (blepharospasms), the issue can be so severe that they can’t open their eye and, as a result, can’t perform common daily activities such as driving. “For people with this problem, it’s life-altering to have access to this treatment,” Dr. Neely says.
Botox as a Medical Treatment: Some Caveats
Though Botox can be helpful, it’s important to know that it will not cure these conditions, nor does it serves as a permanent treatment. The effects will last a few months, and then you’ll need another shot. Before using Botox, your doctor should check for underlying eye problems that could be causing your symptoms. Dry eyes, for instance, can sometimes cause eyelid spasms.
Before receiving any Botox injections, also be sure to tell your doctor if you’ve ever had eye or facial surgery that could put you at risk for side effects. Tell your doctor about any medications you are taking, because the dose may need to be adjusted when you are given Botox. Health experts also urge you to call your doctor if you have any of the following symptoms during the first few weeks after an injection: shortness of breath or trouble swallowing; vision problems; trouble holding up your head or moving your face; fainting; seizures; rash or hives; or chest pain or an irregular heartbeat.
The good news is that, when used safely, Botox can improve common vision disorders and provide relief for many people with these eye problems.