Doctors previously thought that ophthalmoplegic migraine was a form of migraine, but they now know that it is a nerve issue that affects the eyes.

The new name for this condition is recurrent painful ophthalmoplegic neuropathy (RPON).

RPON is rare, affecting about 0.7 per 1 million people every year. It causes the muscles in and around the affected eye to become weak or paralyzed because of nerve damage or pressure.

The condition usually begins with one-sided head pain, with paralysis around the eye typically following.

This article takes a closer look at RPON, including the causes, symptoms, and treatment options. It also explores the differences between RPON and ocular migraine.

A person experiencing an opthalmoplegic migraine.Share on Pinterest
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Ophthalmoplegic migraine is a rare condition. It typically causes muscle paralysis around the affected eye and painful headaches that can sometimes be disabling. The headaches may affect just one side of the head. People may also experience blurred vision and other issues with their sight.

In 2018, The International Classification of Headache Disorders, 3rd Edition (ICHD-3) officially reclassified ophthalmoplegic migraine as RPON because it is not a form of migraine. Instead, it is an issue with at least one of the nerves that control how the eyes move and take in visual information.

Experts do not know exactly why RPON occurs, but they suspect that it involves:

  • loss of the protective fatty tissue around the nerves
  • inflammation
  • nerve compression
  • blood flow issues

Even though the exact cause remains unknown, doctors have identified risk factors, including:

  • living with migraine
  • having a family history of migraine
  • being younger than 10 years of age
  • being male

Doctors also note that in Nigerian populations, a link exists between abnormal hemoglobin and RPON.

The main symptoms of RPON include:

  • pain around or behind the eye
  • visual disturbances, such as double vision or blurred vision
  • loss of peripheral vision
  • pupil dilation, known as mydriasis
  • drooping eyelid, or ptosis
  • nausea and vomiting
  • light sensitivity

These symptoms usually only affect one eye at a time.

For example, people might experience paralysis in their left eye while their right eye remains functional. Paralysis typically happens on the side where the person starts experiencing pain.

However, in some cases, head pain can happen before muscle paralysis. People might also feel dizzy during an episode. This dizziness is due to a loss of peripheral vision.

There is no single diagnostic test for RPON. Instead, doctors must first rule out other conditions with similar symptoms, including diabetes, cancer, infections, and inflammatory diseases.

If all other possible causes seem unlikely, and a person has had at least two episodes of symptoms, the doctor may diagnose RPON.

The process usually also involves a headache workup, during which the doctor asks questions about the headache’s characteristics, intensity, and triggers. They will also thoroughly review the person’s medical and family history and perform a physical examination of the eyes.

Although few tests exist to diagnose RPON, a doctor might sometimes order an MRI scan to look for tumors or nerve compression.

They may also use a nerve conduction study, which detects the speed and strength of electrical signals in nerves and helps doctors evaluate nerve problems.

RPON episodes may resolve on their own. If a person needs treatment, some options are available to help manage and prevent RPON symptoms.

The exact treatment depends on someone’s overall health and how they respond to treatment.

For example, IV steroids such as prednisone may help some people but provide no relief for others. A person should work with their doctor to find the best option for managing RPON symptoms.

Some treatment options include:

Additionally, people should try to identify and avoid anything that triggers episodes, such as fatigue and stress.

Migraine and ocular migraine are conditions that share some symptoms with RPON despite not causing the same medical issues.

It is important that people understand how migraine and ocular migraine differ from RPON so that they know when to seek medical care.

The reason for this is that in 30% of RPON cases, recurrent episodes may be severe enough to cause permanent neurological damage. A potential complication of retinal migraine is also irreversible visual loss.

During a migraine attack, pain typically occurs on one side of the head at a time. Migraine episodes — which typically last about 4–72 hours — can cause intense head pain, nausea, vomiting, and sensitivity to light.

The American Migraine Foundation reports that up to 3 in 10 people with migraine experience vision changes, such as blurred vision, during an episode.

However, the other symptoms associated with RPON, such as loss of peripheral vision or eye drooping, do not typically affect people with migraine.

Ocular migraine may refer to either migraine with aura or retinal migraine. Migraine with aura causes visual disruptions with or without a headache. Although it typically lasts less than an hour, it lasts longer in about 20% of people.

With retinal migraine, visual symptoms occur in one eye before or during the headache phase of an episode. Retinal migraine symptoms often affect people more than aura symptoms.

It can be challenging to tell the difference between migraine with aura and retinal migraine.

According to the National Headache Foundation, people should seek medical attention if over-the-counter pain relievers do not ease the headache or they need to take them more than twice a week.

People should also seek medical assistance if their headache:

  • is new
  • happens regularly
  • does not go away

People should seek emergency medical attention if:

  • they experience the worst headache or migraine episode they have ever had
  • they have a headache with other symptoms, including fever, vision loss, vomiting, confusion, loss of consciousness, and a stiff neck
  • they have a headache for 72 hours with less than 4 hours free of pain

Recurrent painful ophthalmoplegic neuropathy (RPON) is the new name for ophthalmoplegic migraine. RPON is a rare nerve issue that affects the eyes. It causes intense headaches and paralysis around an eye.

Doctors do not fully understand what causes RPON, and there is no cure, but treatments such as steroids and nerve medications may ease the symptoms.

A person should seek the advice of a doctor if they have new, regular, or severe headaches that do not go away with pain relievers.