The cause of blepharospasm is most often unknown. It affects women more than men and tends to occur in families. Rarely, blepharospasm may be secondary to eye disorders, including those that cause ocular irritation (eg, trichiasis Trichiasis Trichiasis is an anatomic misalignment of eyelashes, which rub against the eyeball, in a patient with no entropion. Trichiasis is most often idiopathic, but known causes include blepharitis... read more , an inward growing eye lash), corneal foreign body, keratoconjunctivitis sicca Keratoconjunctivitis Sicca Keratoconjunctivitis sicca is chronic, bilateral desiccation of the conjunctiva and cornea due to an inadequate tear film. Symptoms include itching, burning, irritation, and photophobia. Diagnosis... read more
(dry eye), and systemic neurologic diseases that cause spasm (eg, Parkinson disease Parkinson Disease Parkinson disease is a slowly progressive, degenerative disorder characterized by resting tremor, stiffness (rigidity), slow and decreased movement (bradykinesia), and eventually gait and/or... read more ).
Symptoms are involuntary blinking and closing of the eyes; in severe cases, people cannot open their eyes. Spasms may be made worse by fatigue, bright light, and anxiety.
Treatment of blepharospasm involves injecting botulinum toxin type A into the eyelid muscles; treatment must be repeated in most instances. Anxiolytics may help. Surgery to cut the periorbital muscles is also effective but, because of potential complications, is considered only if botulinum toxin is ineffective. Sunglasses help decrease the light sensitivity that may cause or accompany blepharospasm. Temporary relief can also be obtained by alleviating maneuvers such as touching the face, covering the eyes, singing, or yawning (1 General reference Blepharospasm is spasm of muscles around the eye causing involuntary blinking and eye closing. The cause of blepharospasm is most often unknown. It affects women more than men and tends to occur... read more ).
General reference
1. Kilduff CLS, Casswell EJ, Salam T, et al: Use of alleviating maneuvers for periocular facial dystonias. JAMA Ophthalmol 134:1247-1252, 2016. doi: 10.1001/jamaophthalmol.2016.3277