Normal blinking occurs every 2 to 10 seconds to lubricate the eyes but for people with blepharospasm, uncontrolled twitching and blinking can cause the eyelids to flutter or even stay closed, causing functional blindness.
Blepharospasm is defined as abnormal, involuntary blinking or spasm of the eyelids. The correct name for this condition is benign essential blepharospasm, or BEB. “Benign” categorizes the condition as non life threatening. “Essential” is a medical term used to indicate that the cause of the condition is not known.
Blepharospasm Symptoms
Symptoms of BEB usually begin gradually. A patient may blink more often, as though the eyes are irritated. Other symptoms including squinting, difficulty keeping the eyes open and sensitivity to light. Symptoms are usually worse during the day and disappear during sleep. In the early stages, some patients report that certain causes of stress including bright lights, fatigue, and emotional tension can trigger a spasm attack. Over time, eyelid spasms occur more often and last longer. This can cause substantial disruption of vision and may result in functional blindness if the eyelids are forced to remain closed for long periods of time. BEB can occur in both men and women, but is most common in middle-aged and elderly women.
Causes of Blespharospasm
Doctors are not sure what causes BEB, but they believe a portion of the brain called the basal ganglia may be malfunctioning. The basal ganglia are collections of nerve cells located at the base of the brain. These cells play a role in coordinated movements of the body. While there is no recognized cause that triggers the start of BEB, researchers have noted that patients with BEB often have symptoms of dry eye. BEB can also be caused be certain medications, including those used to treat Parkinson’s disease. When medication is the cause, reducing the dose relieves the symptoms.
Treating Blepharospasm
At the present time, there is no cure for BEB. However, several treatments are available to help reduce the symptoms.
• Botulinum toxin –Marketed under the brand name BOTOX, this toxin can be injected into the tissue above and below the eyelid. It acts by paralyzing the muscles of the eyelids, which calms the spasms. BOTOX can provide substantial relief of symptoms, but may also have some side effects including drooping eyelids, blurred or double vision, and dry eye. Injections wear off and need to be repeated after approximately 3 to 4 months.
• Oral medication – Some medicines are available to treat BEB, but the results are typically hard to predict. Medications tend to work in only about 15 percent of cases and the results are short-lived.
• Myectomy – Surgeons can remove parts of the nerves and muscles that control the movement of the eyelids. This procedure helps in 75 to 80 percent of patients and is typically used for patients who do not respond well to BOTOX treatments.
Sources:
National Eye Institute
National Institute of Neurological Disorders and Stroke
Benign Essential Belpharospasm Research Foundation
‘BOTOX’ is a registered trademark of Allergan.