Ultrastructure of the levator muscle of the eyelid in ptosis due to third nerve palsy.

This paper deals with the histopathology of the levator muscle of the upper eyelid obtained in three cases of ptosis due to 3rd nerve palsy. Light- and electron-microscopy show muscle fibers decreased in number and altered, showing vacuolation, mitochondrial degeneration, large glycogen amounts, disorientation of myofibrils and Z-line changes. The findings are discussed and compared to the data reported by others.