Oculopharyngeal muscular dystrophy (OPMD)

Overview

Oculopharyngeal muscular dystrophy (OPMD) is a rare genetic condition causing progressive weakness, mostly in the muscles around the eyes and throat, though arm and leg weakness can develop too. Symptoms typically don't appear until after 40, with 50 being a fairly typical age of onset.

Symptoms

The first sign is usually either drooping eyelids (ptosis) or difficulty swallowing (dysphagia). As the eyelid-lifting (levator) muscle weakens, the eyelid gradually droops further, eventually covering part of the pupil and narrowing the visual field, even though the eye itself still works normally. Weakness in the muscles that move the eyes can mean needing to turn the head more to look around, and some people tilt their head back or use their forehead muscles to compensate; double vision is possible too, and reduced vision or double vision together can affect balance.

Swallowing difficulty tends to develop gradually, often starting with dry or tougher foods like meat, sometimes needing a sip of water to help food go down; coughing, choking, or drooling from delayed swallowing can follow, and severe cases can affect liquids and even saliva. This can make it harder to eat a varied, nutritious diet, and food occasionally 'goes the wrong way', raising the risk of chest infections.

Many years after the first eye or swallowing symptoms, limb weakness can develop too — usually starting around the shoulders, then the hips — often mild, but sometimes progressing enough to affect mobility.

Inheritance and cause

OPMD is caused by a change in the PABPN1 gene, leading to an abnormal version of the PABPN1 protein that builds up, particularly in the eye and throat muscles, causing the weakness described above. It's autosomal dominant — a single changed copy is enough — so a child of someone with OPMD has a 1 in 2 chance of inheriting it, though some people who carry the changed gene never go on to develop symptoms themselves.

Getting a diagnosis

A GP can refer to a neurologist or clinical genetics service, particularly where there's a suggestive family history. Diagnosis is usually confirmed with a genetic blood test; muscle biopsy used to be common but is now rarely needed given how accurate and straightforward genetic testing has become.

Management and outlook

There's no cure for OPMD, but lifestyle adjustments and, where needed, surgery can meaningfully improve the main symptoms, managed through a multidisciplinary team.

For ptosis, a small 'prop' or 'loop' device that attaches to glasses can hold the eyelids up without surgery; alternatively, an ophthalmologist or oculoplastic surgeon can perform eyelid surgery (usually under local anaesthetic) to shorten the muscles and tendons that lift the eyelid, aiming to reduce drooping while keeping both eyes symmetrical and able to close properly.

For swallowing difficulty, a speech and language therapist can teach safer swallowing techniques and a dietitian can advise on food and drink choices — softer foods, thickened liquids, supplements or high-calorie drinks are common suggestions, and eating slowly without talking can help. A feeding tube is an option in severe cases; where therapy alone isn't enough, an ENT surgeon may offer a procedure to widen the oesophagus (cricopharyngeal myotomy) or temporary Botox injections.

For limb weakness, staying active matters — specialist neuromuscular physiotherapy can help maintain function, and an occupational therapist can suggest practical adaptations and mobility aids as day-to-day tasks become harder.