Ptosis

A deficiency of levator tonus produces the clinical sign called blepharoptosis or ptosis

Blepharospasm

Blepharospasm is an involuntary closure of the eyelids evoked by contraction of the orbicularis oculi

Essential Blepharospasm and the Blepharospasm-Oromandibular Dystonia Syndrome

Blepharospasm is an involuntary closure of the eyelids evoked by contraction of the orbicularis oculi

Eyelid Retraction

Inappropriate and excessive elevation of the eye lids-eyelid retraction-makes a patient appear to be staring and also produces an illusion of exophthalmos

Walsh & Hoyt: Anatomy of the Eyelid System

The eyelids contain three main muscles innervated by three different neural networks. The oculomotor nerve provides innervation to the levator palpebrae superioris muscle that keeps the eyelids open, a function assisted somewhat by Mullers muscle which is innervated by the sympathetic nervous system. Eyelid closure is achieved by contraction of the orbicularis oculi muscle, innervated by the facial nerve

Walsh & Hoyt: Excessive or Anomalous Eyelid Closure

Unlike insufficient eyelid closure, which can be caused by neurologic, neuromuscular, or myopathic causes, excessive or inappropriate eyelid closure usually is neurologic in origin. Essential blepharospasm and the blepharospasm-oromandibular dystonia syndrome (Meige syndrome; Brueghel syndrome). Blepharospasm associated with lesions of the brainstem and basal ganglia. Blepharoclonus and reflex blepharospasm. Ocular blepharospasm. Blepharospasm associated with drug-induced tardive dyskinesia. Facial tics and Tourette syndrome. Nonorganic blepharospasm. Focal seizures. Lid-triggered synkinesias. Facial myokymia (with and without spastic paretic facial contracture). Facial myokymia with peripheral neuropathy. Hemifacial spasm. Excessive eyelid closure of neuromuscular origin. Excessive eyelid closure of myopathic origin

Facial Tics and Tourette Syndrome

In contrast to the sustained, dystonic movements typical of blepharospasm, facial tics are usually brief, clonic, and jerk-like

Walsh & Hoyt: Anatomy of the Muscles of Eyelid Closure

The primary muscle responsible for eyelid closure, the orbicularis oculi, is a typical striated muscle. It completely covers the orbital opening, forming concentric rings around the palpebral fissure and surrounding bone. It is responsible not only for active eyelid closure but also for much of the facial expression around the eyes. It can be divided into three parts: orbital, preseptal, and pretarsal

Insufficiency of Eyelid Closure from Peripheral Facial Nerve Palsy

The insufficiency or weakness of eyelid closure associated with lesions of the facial nerve is usually combined with weakness of other facial muscles supplied by that nerve

Abnormalities of Eyelid Closure

As with eyelid opening, insufficient eyelid closure can be neuropathic, neuromuscular, or myopathic in origin