Microvascular cranial nerve palsy is one of the most common causes of double vision in older people. It occurs more often in patients with diabetes and high blood pressure and is often referred to as a “diabetic” palsy.
Microvascular cranial nerve palsy occurs when the blood flow is blocked to one or more of the nerves that control the eye muscles. Injury to the abducens nerve will cause your eye to not be able to move toward the outside. This creates double vision with side-by-side images. If the trochlear nerve is affected the double vision will be vertical (one image on top of another). And if the oculomotor nerve is affected there may be drooping of the eyelid along with double vision.
Although it is not clear what blocks the blood flow, diabetes and high blood pressure are often associated with this condition.
Symptoms of microvascular cranial nerve palsy include blurred or double vision, drooping of an eyelid, or enlarged pupil.
Although there is no known treatment for microvascular cranial nerve palsy, double vision may be treated by patching either eye or placing a prism in the patient’s spectacles. If the double vision persists surgery of the eye muscles may be indicated.
In the majority of patients normal function and vision will return in six to twelve weeks.