What is the prognosis of an isolated cranial nerve III palsy caused by ischemia from microvascular disease in the vasa nervosa?

Good. After several weeks, most patients regain full function of their ocular muscles.

For a nice review of ocular nerves and their respective functions, check out this awesome website.


Source

Goodwin, J. "Oculomotor Nerve Palsy" Emedicine. 2 Dec 2008.

Yanoff & Duker: Opthalmology, 3rd ed.