Oculopharyngeal muscular dystrophy (OPMD) is a rare form of muscular dystrophy that causes progressive muscle weakness predominantly in the eye (oculo) and throat (pharyngeal) muscles.

Patients usually appear healthy before the onset of disease symptoms, typically between ages 40 to 60.

OPMD is a genetic condition that is most commonly inherited in an autosomal dominant manner (a mutated gene inherited from one parent is disease-causing), although more rare autosomal recessive inheritance is known. People with the autosomal recessive form of OPMD often have a milder form of the disease that starts much later in life.

The genetic mutations responsible for both inherited forms of OPMD are on the PABPN1 gene. They cause the production of abnormal protein clumps in certain groups of muscles their impair their function.

Weakness in eye muscles

A first symptom of OPMD is often droopy eyelids, a condition known as ptosis. It usually affecting both eyes. Patients have difficulty keeping their eyes open, and this may obstruct their vision. They often adopt a posture of tilting their head back and raising their eyebrows in an effort to see clearly.

Muscles directly connected to the eyeball can also weaken, restricting eye movement.  Such problems can cause double vision, or diplopia.

Weakness in throat muscles

Difficulty swallowing, or dysphagia, occurs early in the disease, typically following ptosis. Patients with mild dysphagia may only feel like something is sticking to their throat. As the condition progresses, they can find it difficult to swallow solid and dry foods. Eventually, even swallowing liquids — including saliva — may become a challenge.

Dysphagia puts patients at risk of poor nutrition and aspiration pneumonia, an infection resulting from food or saliva being breathed into the lungs.

Muscle weakness elsewhere

Muscles closer to the center of the body, called proximal muscles, may also be affected in OPMD. This particularly affects the hip and upper leg muscles. As the disease progresses, muscles farther away from the trunk — such as the arms and calves — may begin to weaken as well.

Muscle weakness becomes more severe over time, and patients may find it difficult to bend down, climb stairs or squat. Some may need to use a cane or walker to move about. But it is rare for torso and leg muscles to become so weak that a wheelchair will be necessary.

OPMD primarily affects voluntary muscles (muscles under conscious control), sparing involuntary muscles such as those of the heart and many other organs.

Living with OPMD

While no cure for OPMD currently exists, symptoms can be managed with surgery to correct ptosis as well as speech and occupational therapy to overcome muscle weakness in the throat and limbs. Life expectancy with such symptom management is generally close to normal for people with OPMD.

***

Muscular Dystrophy News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.