Did you know that there are more than 30 different types of muscular dystrophy? Oculopharyngeal muscular dystrophy (OPMD) is a type that mainly affects the eye and throat muscles. As the disease progresses, it may also lead to muscle weakness in the arms and legs. There’s currently no cure for OPMD, but you can take steps to manage your symptoms.

This article will cover what OPMD is, who it affects, and how it develops. We’ll also discuss common symptoms and ways to treat this disorder. To learn more about OPMD, talk to your healthcare provider or a neurologist or neuromuscular specialist.

What Is Oculopharyngeal Muscular Dystrophy?

OPMD is a rare genetic disorder that progressively affects the muscles supporting the eyes and throat. Over time, muscle weakness can spread to other parts of the body. Overall, OPMD affects about 1 in every 100,000 people in the U.S. and Europe.

Certain groups of people are more likely to develop OPMD. The Muscular Dystrophy Association notes that OPMD is more common in French-Canadians and Bukhara Jewish people from Israel. It’s also more frequent among Hispanic people living in New Mexico.

What Age Does Oculopharyngeal Muscular Dystrophy Occur?

OPMD usually develops in adulthood. According to the National Organization for Rare Disorders, most people are diagnosed with OPMD between the ages of 40 and 60. Symptoms can appear at different ages. On average, ptosis (droopy eyelids) begins at 48 years old. Dysphagia (difficulty swallowing) starts appearing in people at an average of 50 years old.

What’s the Difference Between OPMD and OPDM?

If you search the condition “OPMD,” you may come across another muscle disease with a similar acronym. Oculopharyngodistal myopathy (known as OPDM) causes similar symptoms to oculopharyngeal muscular dystrophy.

People with both conditions can experience eye and throat problems. However, people with oculopharyngodistal myopathy may also have:

• A nasal or hoarse voice
• Hearing loss
• Breathing problems due to muscle weakness
• Muscle weakness in the lower arms and legs

Both OPMD and OPDM are rare genetic diseases. However, they each affect different genes. Oculopharyngeal muscular dystrophy develops in people with mutations (changes or variations) in the PABPN1 gene. Oculopharyngodistal myopathy forms in those with changes in several other genes. Each affects how cells make different proteins important for muscle function.

What Causes Oculopharyngeal Muscular Dystrophy?

OPMD is a rare genetic condition caused by a variation in the PABPN1 gene. The PABPN1 protein is important for creating messenger RNA (mRNA). The mRNA then acts as instructions for making new proteins.

In people with OPMD, the mutated PABPN1 gene makes abnormal clumps of PABPN1 proteins. These clumps can be seen in muscle cells using powerful microscopes. Researchers think they interfere with muscle cell function.

Genes are passed down through family members. Everyone inherits two copies of each gene — one from each parent. Scientists classify genes as dominant and recessive.

A person needs only one altered copy of a dominant gene to develop the associated disease. For recessive genes, it takes two altered copies. This means if you have a parent with a dominant genetic disorder, you have a 50 percent chance of developing it yourself. If both of your parents carry the recessive gene for a disorder, there’s a 25 percent chance you will develop the condition.

OPMD can be passed down as either a dominant or recessive disorder. Most people have the dominant form, meaning one of their PABPN1 genes has the variation for OPMD. However, some people can inherit two altered copies of the PABPN1 gene, and they typically have more severe symptoms. They’re also more likely to develop symptoms at a younger age.

Oculopharyngeal Muscular Dystrophy Symptoms

OPMD most commonly affects the muscles around the eyes and the throat. The term “oculopharyngeal” refers to the ocular (eye) muscles and the pharyngeal (throat or pharynx) muscles.

One of the first symptoms of OPMD is eyelid drooping, which usually affects both eyes. It can impair your vision if your upper eyelids droop over most of your eyes. You may try tipping your head back to see better. It’s also possible to develop double vision while living with OPMD.

Another early warning sign of OPMD is choking on food or drinks because of trouble with swallowing and muscle weakness in the throat. People with OPMD need to be careful when eating and drinking. If they inhale any particles of food, it could lead to aspiration pneumonia. This refers to an infection and inflammation in the lungs.

As OPMD progresses over time, some people may notice more muscle weakness in certain parts of the body. This is due to atrophy or muscle wasting, which may appear in the shoulders, upper arms, or upper legs. Eventually, the weakness can spread to the lower arms and legs, although this is less common.

Other symptoms of OPMD include:

• Atrophy and muscle weakness affecting the tongue
• Weak facial muscles
• Wet or garbled speech from saliva collecting in the mouth

Diagnosing Oculopharyngeal Muscular Dystrophy

If your healthcare provider thinks you may have OPMD, they’ll order some tests. An OPMD diagnosis usually includes a physical exam and taking your medical history. Be sure to let your healthcare provider know if you have a family history of OPMD. They’ll also run a blood test (genetic test) to look for changes in the PABPN1 gene and tests to examine the muscle cells.

Oculopharyngeal Muscular Dystrophy Treatment

OPMD treatment mainly focuses on addressing symptoms to improve your quality of life. Your treatment options depend on what muscles are affected.

Treatments for Dysphagia

If you’re having trouble swallowing or you’re choking on food, you’ll likely need some tests. A speech-language pathologist can evaluate your swallowing abilities. They’ll make recommendations based on how severe your dysphagia is. Your speech-language pathologist may suggest using thickeners to make swallowing liquids easier. Changing your position or holding your head differently can also help.

For advanced cases of OPMD, doctors may recommend surgery to stretch the throat open. During another procedure called a cricopharyngeal myotomy, the surgeon makes a small cut in the throat muscle. This relaxes your throat, allowing food and drink to pass through easily. You may also need a feeding tube to make sure you’re getting enough nutrients. These approaches are usually saved for people with severe swallowing problems.

Treatments for Ptosis

Drooping eyelids from ptosis can affect your vision. Your healthcare provider may recommend surgery to raise your eyelids so you can see better. For some people, surgery for ptosis can prevent your eyelids from fully closing. Your healthcare provider can discuss the side effects and complications of the procedure.

If you don’t want to have surgery, you have other options for treating ptosis. Eyelid crutches attach to glasses to help hold your eyes open. Your eye doctor can make suggestions for where to buy these devices.

Treatments for Muscle Weakness

Muscle weakness from OPMD may affect your mobility — especially if it affects your legs. Doctors recommend using assistive devices to support your body while you move. Canes, walkers, and leg braces can all help.

What Is the Life Expectancy With Oculopharyngeal Muscular Dystrophy?

People with OPMD usually have a typical lifespan compared to those without the disorder. Some of your symptoms can negatively impact your quality of life. It’s important to work closely with your doctor to avoid complications. Some problems — like aspiration pneumonia and choking — can be life-threatening if left untreated.

Connect With Others Who Understand

On myMDteam — the social network for people living with muscular dystrophy and their loved ones — members share their experiences, ask questions, and find support from others who understand the challenges of living with MD.

Are you living with oculopharyngeal muscular dystrophy? What symptoms do you experience? How have you managed your disorder? Share your experiences in the comments below, or start a conversation by posting on your Activities page.