Ocular myasthenia gravis mainly or solely affects the eyes.

Generalized myasthenia gravis causes muscle weakness throughout the body.

A person may initially experience eye symptoms and later develop symptoms affecting other body parts.

Myasthenia gravis occurs when the immune system attacks the neuromuscular junction.

The neuromuscular junction is a tiny space where neurotransmitter chemicals flow between a nerve and a muscle. These neurotransmitters allow a person to make voluntary movements since the nerves pass a signal to the muscles through neurotransmitters.

Signs and Symptoms of Ocular Myasthenia Gravis

Ocular myasthenia gravis happens when the immune system creates autoantibodies that attack the neuromuscular junction’s specific receptors, including the:

• Nicotinic acetylcholine receptors
• Muscle-specific kinase
• Lipoprotein-related protein 4

Infection or immunization may lead to the start of symptoms.

Factors that may cause or worsen symptoms once ocular myasthenia gravis develops include:

• An anesthetic
• Certain medications or drugs
• Fatigue
• Illness
• Surgery recovery

COVID-19 may cause ocular myasthenia gravis in some people. Less often, the COVID-19 immunization can also lead to the disorder.

Congenital myasthenia gravis is a rare form of the disorder that results from specific mutations. A person with this form is born with it, which may affect the eyes.

A doctor can often diagnose ocular myasthenia gravis based on the presence of classic signs and symptoms, though blood tests can confirm the diagnosis.

However, they usually perform a physical examination and review personal and family medical history. They may ask about recent medication use or infections.

A doctor typically performs clinical testing, which can include:

• Ice test: The doctor fills a surgical glove with ice and places it on the drooping eyelid for about 2 minutes. After removing the glove, they might observe a noticeable improvement in the drooping.
• Sleep or rest test: The person rests their eyes for 30 minutes. They may see improvements in drooping eyelids or double vision, with a return to symptoms in 5 to 30 minutes.
• Cogan lid twitch sign: For this test, the person focuses their gaze downward for a period. The upper eyelid moves to an exaggerated position, twitches a bit, and returns to the usual position.
• Forced eyelid closure test: In this test, a person squeezes their eyes shut for about 10 seconds. They then open their eyes and focus on an object. The test is positive if the upper eyelid opens too wide and then slowly drifts back into position.

The doctor may then order a blood test to check for the presence of one or more autoantibodies associated with myasthenia gravis. The results can confirm the diagnosis.

Treatment for Ocular Myasthenia Gravis

Ocular myasthenia gravis is an autoimmune disorder that causes muscle weakness around the eyes. Symptoms include double vision, fatigue, and droopy eyelids.

Some medications may help a person manage symptoms of ocular myasthenia gravis. In some cases, a doctor may also recommend surgery.

People with ocular forms of the disorder can sometimes develop a generalized form, which may cause additional symptoms in different body parts.