
Everything you need to know about ocular myasthenia
10 November 2022
Myasthenia gravis is a chronic autoimmune neuromuscular disease that causes weakness in the voluntary muscles, which are responsible for functions related to breathing and movement of parts of the body, including the arms and legs.
Ocular myasthenia is a form of myasthenia gravis in which the extraocular muscles, which control the eyes and eyelids, become easily fatigued and weakened.
If you have ocular myasthenia, you have probably experienced double vision (diplopia) and/or drooping eyelids (ptosis). Your eyes do not move together in balanced alignment, causing you to see "double" images. One or both eyelids may also droop down to cover all or part of the pupil of the eye, thus obstructing vision.
Eye weakness often changes from day to day, and throughout the day. Eye problems often worsen at the end of the day or after you have used your eyes for a prolonged period of time. Your eye problems may temporarily improve if you rest your eyes by closing them for several minutes when symptoms bother you.
If you have ocular myasthenia, you will not have difficulty swallowing, speaking or breathing, nor will you experience weakness in your arms and legs.
The most important difference between the muscles of the eyes and eyelids, compared to those of the rest of the body, is that they respond differently to immune attack.
They are structurally different from the muscles of the body and limbs, and have fewer acetylcholine receptors. In addition, eye muscles contract much faster than other muscles, so they are more likely to fatigue anyway.