Can Myasthenia Gravis Affect the Eyes? | Myasthenia Gravis Awareness Month

Myasthenia gravis is a rare autoimmune disease that affects the muscles. In people that have myasthenia gravis, the immune system releases an antibody that interferes with the nerve impulses that cause muscle contraction. The antibody blocks or destroys the nerve receptor sites, which leads to gradual muscle weakness. 

​

June is Myasthenia Gravis Awareness Month and it’s a good time to bring attention to the disease. Myasthenia gravis can affect most of the muscles of the body, including the muscles that control the eyes.

The cause of myasthenia gravis is not known. It does not appear to be an inherited condition. But there may be a genetic predisposition to developing certain types of autoimmune diseases.

Although myasthenia gravis is somewhat rare, it appears to be increasing. According to the Genetic and Rare Diseases Information Center, the number of people with myasthenia gravis has increased in the last 20 years. But the increase may be due to increased lifespan in people affected or earlier diagnosis. 
​

Symptoms

The muscles that control eye movement, talking, and swallowing are often affected. Symptoms of myasthenia gravis include:

• Muscle weakness
• Difficulty swallowing
• Shortness of breath
• Impaired speech
• A change in facial expressions

​

​How Myasthenia Gravis Can Affect the Eyes

It’s very common for myasthenia gravis to affect the muscles that control eye movement. In fact, for a large percentage of people, eye-related changes are one of the first symptoms of myasthenia gravis. Because of the lack of signals to the nerves, changes to the eyes may include:

• Drooping eyelids
• Trouble lifting the eyebrows
• Difficulty focusing the eyes
• Double vision

When eye-related symptoms occur, they can affect one or both eyes. Symptoms also vary in severity. People that have generalized myasthenia gravis will also develop muscle weakness in other areas of the body, such as the arms and legs. 
​

Ocular Myasthenia Gravis 

In some cases, myasthenia gravis only affects the muscles that control the movement of the eyelids and eyes. When this form of the disease develops, it is called ocular myasthenia gravis.

According to the Myasthenia Gravis Foundation of American, visual and eye changes are the first symptoms for about 50 percent of people with generalized myasthenia gravis. Roughly 15 percent of people have ocular myasthenia gravis and do not develop muscle weakness anywhere else but the eyes. 
​

How is Ocular Myasthenia Gravis Diagnosed 

Ocular myasthenia gravis may share similar symptoms with other types of diseases. Since generalized muscle weakness does not occur with ocular myasthenia gravis, a diagnosis is sometimes delayed while other conditions are ruled out.
​
In addition to medical history, an eye exam is helpful to determine if symptoms are due to another eye condition. There are also specific tests an eye doctor can perform to make a diagnosis. According to the American Academy of Ophthalmology, there is no one best test to diagnose ocular myasthenia gravis. Instead, various tests, such as an ice test or sleep test to access eyelid drooping and eye muscle weakness, may be used. 
​

Treating Ocular Myasthenia Gravis and Keeping the Eyes Healthy

Currently, there is no cure for myasthenia gravis. But there are treatments to manage symptoms. Treating the condition may decrease eye and visual symptoms. Medications might be prescribed. 

There are two main classifications of medications used to treat myasthenia gravis, including steroids and cholinesterase inhibitors. Steroids suppress the function of the immune system. Decreasing the immune system may cause the body to produce fewer antibodies that interfere with the nerve signals to the muscles. Steroids can have side effects including weight gain, irritability, and sleeplessness, so they might not be given long-term.

Cholinesterase inhibitors improve communication between the muscles and the nerves. This type of medication is usually most effective in people that have mild symptoms of myasthenia gravis.

Double vision that might occur due to myasthenia gravis can be helped by wearing an eye patch to block one eye.  It’s also vital for people with myasthenia gravis to get regular eye exams. As with the general population, other eye conditions can also develop in people with myasthenia gravis, which can make vision even worse. It’s helpful for an eye doctor to monitor the progression of eye symptoms.

If you have any questions about ocular myasthenia gravis or you would like to make an appointment with our eye doctors, give our office a call at 508-746-8600.