ABSTRACT
DEFINITION Blepharoptosis is drooping of the upper lid margin to a position that is lower than normal. (Normal upper lid position is at the level of the upper limbus.)
LEVATOR APONEUROSIS n Origin: Lesser wing of the sphenoid n Insertion: Orbicularis oculi, dermis, tarsus n Innervation: Superior division of oculomotor nerve (CN III) n Action: Provides 10-12 mm of eyelid elevation n Embryology: Develops in the third gestational month from the superior rectus muscle n Anterior lamella of the levator muscle forms aponeurosis
Fig. 93-1 Differences between normal and ptotic upper eyelid anatomy.
