Monocular Elevation Deficiency, also known by the older term Double Elevator Palsy, is an inability to elevate one eye, usually resulting in one eye that is pointed downward relative to the other eye (hypotropia) [See figure 1].
This entity is not known to be hereditary (inherited). It is a rare condition, and can be congenital (present at birth) or acquired after birth.
Yes. The eyelid on the involved side is droopy (ptosis) 25% of the time while 75% of cases have pseudoptosis. In this case, the pseudoptosis is the appearance of ptosis caused by the eye being hypotropic (downward deviation).
The inability to elevate the eye most commonly results from restriction of the inferior rectus muscle on that side (70%). The cause is not precisely known for those cases without restriction of the inferior rectus. A hypothesized cause is an abnormal cranial nerve development with secondary muscle fibrosis (scarring).
25% of those with Monocular Elevation Deficiency and Congenital Ptosis have a phenomenon called Marcus Gunn jaw-winking. This a condition in which the cranial nerve that usually controls eyelid movement is mis-wired with the cranial nerve that controls chewing or sucking thus creating a "wink" when chewing or sucking.
There is no known association between Monocular Elevation Deficiency and systemic or neurological diseases. Other disorders can occur in conjunction with Monocular Elevation Deficiency, but they are not directly related.
The treatment of Monocular Elevation Deficiency is surgery, which is indicated if there is a significant hypotropia , amblyopia and/or a chin-up head posture. The type of surgery depends on the cause of the elevation deficit. Surgery is usually performed on the effected eye, but rarely, surgery on a muscle in the opposite eye is necessary to fully correct the deficit.
Patching is sometimes necessary to treat amblyopia (weak vision) that can result from misalignment of the eyes. Patching will not realign the eyes; it is done to help strengthen the vision in the eye that has amblyopia.
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