Ophthalmoplegia

Ophthalmoplegia is a condition that affects the muscles controlling your eye movements, causing weakness or paralysis that can lead to drooping eyelids, double vision, and difficulty moving your eyes. Understanding this condition and its various forms is essential for proper diagnosis and treatment.

Table of contents

• What is Ophthalmoplegia?
• Types of Ophthalmoplegia
• Symptoms
• Causes and Risk Factors
• Diagnosis
• Treatment Options
• Outlook and Recovery

What is Ophthalmoplegia?

Ophthalmoplegia is the paralysis or weakness of the eye muscles. It can affect one or more of the six muscles that hold the eye in place and control its movement^[1]. The condition may affect any of the six external eye muscles that control eye movement or the three internal eye muscles that control pupil size and help the eye focus^[2].

Generally, ophthalmoplegia occurs due to an issue in the brain that interferes with signals being sent to the eye muscles^[2]. This condition is generally caused by disruption of the messages that are sent from the brain to the eyes^[1].

Ophthalmoplegia usually involves the third (oculomotor), fourth (trochlear), or sixth (abducens) cranial nerves. These are the nerves responsible for controlling different eye movements. Double vision is the characteristic symptom in all three cases^[5].

Types of Ophthalmoplegia

There are two main types of ophthalmoplegia: chronic progressive external ophthalmoplegia and internuclear ophthalmoplegia^[1].

Chronic Progressive External Ophthalmoplegia

Chronic progressive external ophthalmoplegia typically appears in adults between the ages of 18 and 40 years^[1]. It typically begins with drooping eyelids and difficulty controlling the muscles that coordinate the eyes^[1].

The condition is characterized by weakness of the eye muscles. The first sign of progressive external ophthalmoplegia is typically drooping eyelids, known as ptosis, which can affect one or both eyelids^[4]. As ptosis worsens, affected individuals may use the forehead muscles to try to lift the eyelids, or they may lift up their chin in order to see^[4].

Another characteristic feature of progressive external ophthalmoplegia is weakness or paralysis of the muscles that move the eye. Affected individuals have to turn their head to see in different directions, especially as the ophthalmoplegia worsens^[4].

People with progressive external ophthalmoplegia may also have general weakness of the muscles used for movement, particularly those in the neck, arms, or legs. The weakness may be especially noticeable during exercise, a condition called exercise intolerance. Muscle weakness may also cause difficulty swallowing, known as dysphagia^[4].

When the muscle cells of affected individuals are stained and viewed under a microscope, these cells usually appear abnormal. These abnormal muscle cells contain an excess of cell structures called mitochondria and are known as ragged-red fibers^[4].

Internuclear Ophthalmoplegia

Internuclear ophthalmoplegia is the medical term for one or both of your eyes not moving when you look to the side. When you look to one side, your affected eye won’t move past center or be able to turn all the way in the direction you’re looking^[3].

Internuclear ophthalmoplegia is caused by nerve damage to the nerve fibers that coordinate lateral eye movement. This leads to double vision^[1]. It happens when something damages your medial longitudinal fasciculus, which is the pathway that holds nerves that regulate your eye movements^[3].

Internuclear ophthalmoplegia is an ocular movement disorder caused by a lesion of the medial longitudinal fasciculus. It is characterized by impaired adduction of the ipsilateral eye with nystagmus of the abducting eye^[6]. This means that as one eye tries to move, it cannot turn inward properly, while the other eye may make involuntary, rapid movements.

Internuclear ophthalmoplegia can affect one of your eyes, called unilateral internuclear ophthalmoplegia, or both eyes at the same time, called bilateral internuclear ophthalmoplegia^[3].

Symptoms

People affected by ophthalmoplegia may have double or blurred vision. They may also experience an inability to position the eyes in sync. Some may also have a hard time moving both eyes in every direction, and many will have drooping of their eyelids^[1].

For internuclear ophthalmoplegia, the most obvious symptom is one eye not moving when you look to the side. Other common symptoms include diplopia (double vision), especially when you’re looking to the side, and sometimes when you look up. People may also experience blurry or worsened vision and dizziness^[3].

If ophthalmoplegia is associated with a systemic disorder, other symptoms may include difficulty swallowing and general muscle weakness^[1].

In oculomotor paralysis, the muscles controlling the eye are affected in such a way that the eye drifts outward and slightly downward and has difficulty turning inward and upward. In addition, the upper eyelid of the affected eye usually droops, and the pupil may be enlarged^[5].

Causes and Risk Factors

General Causes

This condition can be congenital, meaning present at birth, or develop later in life^[1].

External ophthalmoplegia is usually caused by muscle disorders or mitochondrial diseases such as Graves’ disease or Kearns-Sayre syndrome^[1].

Other common causes include migraines, thyroid disease, stroke, brain injury, brain tumor, and infection^[1].

Causes of Internuclear Ophthalmoplegia

Internuclear ophthalmoplegia is often caused by multiple sclerosis, trauma, or infarction^[1]. About a third of the cases of internuclear ophthalmoplegia are caused by infarctions and are commonly unilateral and seen in older individuals^[6].

Demyelinating disorders like multiple sclerosis account for another third of cases and are mostly bilateral and seen in young adults and adolescents. Some studies have shown that internuclear ophthalmoplegia is seen in about 23% of MS patients^[6].

The most common causes of internuclear ophthalmoplegia include multiple sclerosis, strokes (especially ones that affect the brainstem), hemorrhage, arteriovenous malformation, encephalitis (especially when it happens because of infections like Lyme disease, HIV and herpes zoster), traumatic brain injuries, and autoimmune diseases including lupus and Sjögren’s syndrome^[3].

Other causes of internuclear ophthalmoplegia include trauma, tentorial herniation, infections (like HIV, syphilis, cysticercosis, tuberculoma), tumors (medulloblastoma, glioma, lymphoma, metastases), vasculitis (systemic lupus erythematosus, Sjogren syndrome), iatrogenic injury, and brainstem hemorrhage^[6].

Causes of Progressive External Ophthalmoplegia

Progressive external ophthalmoplegia is a condition caused by defects in mitochondria, which are structures within cells that use oxygen to convert the energy from food into a form cells can use^[4].

Progressive external ophthalmoplegia can result from mutations in one of several different genes. In some cases, mutations in nuclear DNA are responsible for the condition, including mutations in the POLG, TWNK, RRM2B, and SLC25A4 genes, among others. These genes are critical for the production and maintenance of mitochondrial DNA^[4].

In other cases, the condition is caused by a single large deletion of mitochondrial DNA that is not associated with a mutation in a nuclear DNA gene^[4].

Risk Factors

Ophthalmoplegia is slightly more likely to occur in people with diabetes. Men with diabetes who are over the age of 45 and have had type 2 diabetes for more than 10 years were recently identified as a higher risk category for developing ophthalmoplegia^[1].

People that have a condition that affects their muscle control, such as multiple sclerosis or Graves’ disease, are more at risk than others^[1].

In general, there are no lifestyle choice factors that contribute to being at risk for ophthalmoplegia^[1].

Diagnosis

A healthcare provider will diagnose internuclear ophthalmoplegia with a physical exam. They’ll look at your eyes and watch how they move. They’ll ask you to perform movements that will help evaluate eye function^[3].

A comprehensive eye exam can reveal problems with eye coordination, focus, or peripheral vision, which might signal the onset of ophthalmoplegia. Your eye doctor will conduct additional tests to eliminate other possible causes. You may need a referral to other specialists for neurological scans and blood tests^[20].

The diagnosis of chronic progressive external ophthalmoplegia is made based on the symptoms, history (including age of symptom onset) and physical exam, especially when there is a family history of this condition. Certain other tests, including blood tests and certain imaging tests, may be done to evaluate for other conditions, and a biopsy of one of the affected eye muscles may be done in some cases to confirm the diagnosis^[19].

Treatment Options

Treatment for Internuclear Ophthalmoplegia

For internuclear ophthalmoplegia or one-and-a-half syndrome, treatment and prognosis (whether the disorder abates or eventually resolves) depends on the disorder that caused it^[7].

Treatment for Progressive External Ophthalmoplegia

At present, there are no specific treatments for chronic progressive external ophthalmoplegia. Severe symptoms may be treated, such as surgery for severe ptosis, and other supportive care may be helpful^[19].

Several small studies have shown evidence of clinical improvement in patients treated with CoQ10. A decrease in serum levels of pyruvate and lactate were observed, and general neurologic function was noted to improve^[13].

For ptosis, adhesive tape and lid crutches can be used to assist patients with advanced chronic progressive external ophthalmoplegia^[13].

Bell phenomenon is absent in many patients with chronic progressive external ophthalmoplegia; therefore, ptosis surgery often is contraindicated. Because a silicone sling is reversible, it could be a possibility for some patients^[13].

Strabismus surgery can be helpful in carefully selected patients if diplopia occurs and the patient has had a stable deviation for several months^[13].

Non-Surgical Management

If you do have ophthalmoplegia, your eye doctor can recommend any of several effective treatment strategies. In many cases, treatment for an underlying disorder can help reduce your vision issues. For instance, surgical removal of a brain tumor can often ease intraocular ophthalmoplegia symptoms^[20].

While other doctors address the underlying cause of your condition, your eye doctor can take immediate steps to aid your eyesight. You may benefit from special glasses, including glasses designed to prop up drooping eyelids. If you suffer from blurred vision, the use of an eye patch may help correct this symptom^[20].

The goal of non-surgical treatment is usually management of symptoms, and the primary tool used is prism. Results of recent studies in the neurorehabilitation literature have suggested that eye muscle exercise may do more than compensate for symptoms of ophthalmoplegia. They may accelerate recovery for those conditions in which recuperation is possible, and restore ocular mobility in chronic and degenerative conditions^[11].

Outlook and Recovery

Some people with internuclear ophthalmoplegia make a full recovery. Others have symptoms for the rest of their life. How long it takes you to recover depends on many factors, especially what caused it^[3].

Nearly half of all cases of internuclear ophthalmoplegia resolve within one year^[6].

The overall prognosis for isolated chronic progressive external ophthalmoplegia (when the condition only involves the eye muscles) is good; a normal life expectancy is typical, although the eye symptoms may limit some aspects of the patient’s life^[19].

Mitochondrial disease that becomes symptomatic in the teenaged or early adult years can be devastating. An otherwise healthy child can progress from normal functionality to impairment, possibly severe enough to result in death. Genetic counseling is necessary in carrier families to ascertain the risks^[13].

It is imperative that patients with chronic progressive external ophthalmoplegia receive regularly scheduled follow-up care in all areas^[13].

If you develop droopy eyelids, whether you notice it or friends and family point it out to you, you should see your doctor to be evaluated. There are many possible causes of ptosis, and medical evaluation can help identify possible diagnoses, and hence guide what further testing and treatment may be needed (even if the initial treatment is “watch and wait” to see if symptoms change or other symptoms develop)^[19].