Musculus levator palpebrae superioris
The levator palpebrae superioris originates from the orbital periosteum dorsal to the optic foramen and inserts on the upper eyelid (tarsal plate and skin). Its action is to elevate the upper eyelid and open the palpebral fissure. It is innervated by the oculomotor nerve (CN III).
Origin: Orbital periosteum dorsal to the optic foramen
Insertion: Upper eyelid (tarsal plate and skin)
Action: Elevates the upper eyelid; opens the palpebral fissure
Innervation: Oculomotor nerve (CN III)
Dysfunction (ptosis) can occur with oculomotor nerve injury or other neurologic disease. Part of a full ophthalmic or neurologic examination.
Damage to CN III (from head trauma, EPM, or space-occupying lesions) causes the upper eyelid to droop. May be part of Horner syndrome if sympathetic innervation to the smooth muscle component (Müller'
A drooping upper eyelid after trauma or with other neurologic signs should be evaluated.
Damage to CN III (from head trauma, EPM, or space-occupying lesions) causes the upper eyelid to droop. May be part of Horner syndrome if sympathetic innervation to the smooth muscle component (Müller's muscle) is affected. Signs include: Drooping upper eyelid on one side; eye appears partially closed; may be accompanied by miosis (constricted pupil) and enophthalmos in Horner syndrome; facial sweating on the affected side (unique to horses with Horner syndrome).
Dysfunction (ptosis) can occur with oculomotor nerve injury or other neurologic disease. Part of a full ophthalmic or neurologic examination.
A drooping upper eyelid after trauma or with other neurologic signs should be evaluated.
See the Levator Palpebrae Superioris on our interactive 3D horse model. Open 3D Model