What is Blepharospasm?
Involuntary muscular spasm and contraction of eye muscle are known as blepharospasm. Blepharospasm is also referred to as benign essential blepharospasm. Blepharospasm is not a life-threatening condition and its cause is not known.
How Does Blepharospasm Affect the Vision?
Blepharospasm is a form of functional Dystonia. It starts with one eye initially, but eventually both the eyes get affected with blepharospasm. The spasms often leave the eyelids completely closed, causing functional blindness even though the vision and the eyes are completely normal.
In many cases, the spasm and the twitching from blepharospasm appear in the day time and disappear when the affected person is sleeping. The symptoms of blepharospasm reappear when the person wakes up the next morning.
What are the Causes of Blepharospasm?
The cause of blepharospasm is not known, but according to researchers, it has something to do with the functioning of the basal ganglia (a group of structures located at the base of the brain). It is also believed that some defect in the neuronal circuit leads to blepharospasm. There are also some chances of blepharospasm being inherited.
Secondary causes of blepharospasm may be due to some organic disease, few of which are. Multiple sclerosis, dry eye, eye trauma, conjunctivitis, Tourette syndrome, tardive dyskinesia, cerebral palsy, atypical parkinson’s disease, brain tumor, blepharitis, glaucoma and infections, such as viral encephalitis, tuberculosis and AIDS.
Types of Blepharospasm
Blepharospasm is of two types:
In primary blepharospasm, the dystonia is characterized by involuntary contractions of the muscles of the face, which closes the eyelids. The muscles of face responsible in this movement disorder are the orbicularis oculi. In primary blepharospasm the patient experiences flickering of the eyelid and is also often linked to apraxia (difficulty in the opening) of the eyelid. Primary Blepharospasm is the most common type of blepharospasm.
Secondary blepharospasm occurs due to external factors, such as exposure to certain drugs, physical trauma, neurological and metabolic diseases, and sometimes brain lesions. Some conditions, which lead to secondary blepharospasm, are.
Meige’s Syndrome. Forceful movement of jaw and tongue can lead to secondary blepharospasm.
Brueghel Syndrome. It is a condition which leads to neck, tongue, facial muscles twitching along with jaw clamping and blepharospasm.
Extrapyramidal Disorder. This disorder is characterized by abnormal movements, such as neck rigidity and tics in the extremities causing secondary blepharospasm.
Reflex Blepharospasm. Reflex blepharospasm is an involuntary reflex caused by irritation from light or dry eye.
Management & Complications of Blepharospasm
Blepharospasm almost always affects both the eyes. With time the patient observes an increase in the frequency of the blepharospasm symptoms, which leads to narrowing of the opening of the two eyelids. As there is no exact cause of blepharospasm, the treatment options are designed to manage the symptoms. Leaving blepharospasm untreated for long can land you in a serious complication, such as functional blindness. Some people even experience loss of facial expressions due to paralysis of the facial muscles. Malposition of the eyelids is also a most experienced deformity due to blepharospasm.
- “Blepharospasm.” Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/blepharospasm/symptoms-causes/syc-20355023
- Jankovic, J. (2006). Treatment of hyperkinetic movement disorders. The Lancet Neurology, 5(9), 845-854.
- Defazio, G., Berardelli, A., & Hallett, M. (2007). Do we agree on the definition of blepharospasm—Can a Consensus be reached? Parkinsonism & Related Disorders, 13(Suppl 1), S181-S183.