The Lowdown on Benign Eyelid Myokymia

From Primary Care Optometry News March 2006:
Benign Eyelid Myokymia (BEM)is a benign twitching of the obicularis oculi muscle. Usually unilateral, self-limiting, and last from several hours to several weeks.
Causes: Not well understood, but precipitating factors include fatigue, stress, excessive alcohol/caffeine/nicotine intake.
History: Ask about antipsychotic medication usage, past CN VII palsy and prior injection around the eye. Observe for other neurological symptoms.
Biomicroscopy: Rule out trichiasis, blepharitis, keratitis, dry eyes, corneal abrasion, recurrent corneal erosion, and foreign body. In most cases, BEM will not be observed during the course of the examination.
Rule out Superior Oblique Myokymia(SOM) by having the patient look down and in towards their nose while viewing the suspected eyelid with the slit lamp. If SOM is present, the lid will demonstrate subtle oscillations lasting less than 10 seconds.
Differential diagnosis of BEM: Blepharospasm, hemifacial spasm, Meige syndrome, aberrant regeneration of CN VII, trigeminal neuralgia, Tourette syndrome, spastic-paretic facial contracture, and SOM.
Treatment: Reassurance that condition is self-limiting. If patient desires treatment, the condition does not improve, or oscillopsia is present topical antihistamines have shown to be effective in some cases. Emadine, Patanol, Elestat, Zaditor, Optivar are among the choices. Botox injections are used in severe cases.