Blepharospasm means involuntary blinking or involuntary shutting of eyelids. Blepharospasm is a progressive nervous disorder which mostly occurs among the elderly and middle-aged women. The most common form of blepharospasm is "benign essential blepharospasm" which is represented by frequent and involuntary closing of eyelids.
Blepharospasm is in fact a kind of dystonia, which is characterized by frequent, sustained and involuntary contractions in one muscle or a group of muscles.

How Does Blepharospasm Begin?

Blepharospasm usually bigins gradually. At first, the person may have dry eye or light sensitivity, but no involuntary muscular contraction. After a while, eye irritation (for example, by sunlight, cool wind, noise, quick movements of head and eyes) and stress lead to the beginning of blepharospasm attacks. As the disease progresses, the intensity and frequency of the attacks increase so that eyes sometimes shut for several hours and the person is practically blind for some hours. This state is sometimes so severe that causes the person's disability and shame of being in public; thus, the person is virtually isolated. In such a state, there is the possibility of depression.
Generally, stress and mental pressure- like presence in unfamiliar environments- intensifies blepharospasm. It usually stops during sleep. In addition, concentration on a specific activity reduces blepharospasm attacks.

What Causes Blepharospasm?

It seems that blepharospasm is caused by a kind of problem in the function of "brain basal ganglia". Basal ganglia include a section of brain that coordinates movement of muscles. In fact, it is not precisely known what causes blepharospasm. In most cases, blepharospasm is generated spontaneously and without a definite cause. Of course, in many people, eye dryness is a stimulating factor which initiates blepharospasm in sensitive people. Sometimes, blepharospasm or other types of dystonia occur in members of a family. Therefore, genetic and hereditary background may affect its incidence. 

How Is Blepharospasm Diagnosed?

Blepharospasm is diagnosed based on clinical symptoms. To diagnose blepharospasm, there is no need for special tests or images. Paraclinical measures are necessary only to rule out accompanying problems (like tumors). 

Medical treatment: Since the main cause of blepharospasm is unknown, there are no specific drugs to treat it. Anticonvulsants, tranquilizers and antidepressants are usually used for controlling blepharospasm. Different people respond differently to these drugs and it cannot be predicted which medication is best for a particular person. It is often required for the individual to try different drugs under the supervision of a doctor in order to determine the best drug for him/her. Nevertheless, medical treatment is not so effective in blepharospasm. At best, using drugs only result in relative and temporary improvement. In addition, many patients do not have an appropriate response to medical treatment.

Botox Injection: Currently, the best treatment for blepharospasm is Botox injection which is supplied in Iran under the brand name Dysport. Botox is the trade name of a complex protein which is extracted from a bacterium called clostridium botulinum. After injection, Botox is absorbed by the nerve endings which give orders muscles. In these endings, Botox prevents the release of a chemical called acetylcholine which is responsible for muscular contractions. As a result, a kind of temporary paralysis is generated in the muscles, which lasts for 3 to 6 months. 
When Botox is temporarily injected into muscles which close eyelids, these muscles are paralyzed and cannot contract. Consequently, symptoms of blepharospasm disappear. The effect of injection usually appears one or two weeks later and lasts for 3 to 6 months. After this period, it is necessary to re-inject Botox. In fact, in some patients, the symptoms disappear after two or three times of injection. However, this is not common and it is usually required to inject Botox every 3 to 6 months. Botox injection is a very effective method for controlling the symptoms of blepharospasm so that in more than 90 to 95% of cases, they are significantly improved. In fact, Botox injection can have complications like drooping of eyelids, blurred vision or diplopia, but all of these complications are transient and resolve within 6 months.

Surgery: Surgery is usually used for cases that do not respond to Botox injection or the person is not interested in having frequent shots. The most common surgery used for treating blepharospasm is to remove the muscle, which is called myectomy. In this method, some of the muscles responsible for blinking are surgically removed. In 70 to 80% of the cases, this method improves the symptoms of blepharospasm; however, the complications of this surgery are more than those of Botox injection. In addition, complications of Botox injection are reversible but those of surgery are not.

Supportive Therapies : As mentioned before, stress and nervous pressure usually exacerbate blepharospasm. Training patients and their family plus effective family support can have helpful results in controlling blepharospasm symptoms.
It should be considered that severe attacks of blepharospasm can make the person blind for several hours. It is very important to make their living environment safe to avoid the risks in case such conditions occur.
Blepharospasm can cause anxiety, depression and isolation of the person. Treatment of depression and anxiety in such conditions can improve the person's function.
Using dark sunglasses helps the patients with blepharospasm in two ways. First, sunglasses prevent eye irritation by blocking intense light from getting into the eye and thus prevents from blepharospasm attacks. Second, dark glasses cover the eye and prevent others from seeing the abnormal blinking of the patient. As a result, it is easier for the person to join the society. 
Using artificial tear drops and eye moisturizers for treating dry eye and blepharitis may help control blepharospasm attacks by reducing irritation of eye surface.
Considering the chronic nature of this disease and the problems it causes in social relations of the person, there are supportive groups for the patients with blepharospasm in some countries. In Iran, unfortunately, no such organizations have been developed yet.