Ophthalmoplegia, (กล้ามเนื้อตาอ่อนแรง, which is the term in Thai) is a type of weakness of our eye muscles which are responsible for our eye movements. It is also known as eye-paralysis. It can be caused due to congenital abnormalities, viral infections, disorders of various eye parts or also due to our nervous system.
There are two types: Chronic progressive external ophthalmoplegia and internuclear ophthalmoplegia. Chronic progressive external can be witnessed among people between 18 to 40years of age. It refers to the movements of extraocular muscles only.
The Internuclear one is a certain kind of impairment of horizontal eye movement. It is caused by nerve fiber damage in the brain stem which controls lateral eye movement.
Causes and Symptoms
- This disorder can be inborn or it may also develop in later life. The internuclear one is a result of multiple infarctions, sclerosis, and trauma. External one usually results from muscular disorders or mitochondrial diseases.
- Migraine, brain tumor, and injury, thyroid ailments are also responsible for this. Sometimes, double eyelid surgery causes eye muscle weakness.
- The main symptoms of this disease are drooping eyelids, difficulties in controlling eye coordinating muscles and double or blurred vision are.
- Another form of this same disorder is known as One-and-a-half syndrome. It can be observed when the affected eye seems to look straight ahead while staring on the other side. But its up and down movements are hardly affected.
Diagnosis and Various Risk Factors
It can be diagnosed by minutely observing the eye movements or by MRI or CT scan. In cases of nerve disorders or thyroid issues, blood tests are also required. Most people above 45years of age with diabetes are also its sufferers. Also, in Internuclear one, horizontal eye movements are impaired, but vertical eye movements are not.
Treatment and Preventions
Although the treatment and prognosis depend on the cause of impaired horizontal eye movements, still there are some ways to resolve it. Depending upon the symptoms and reasons of ophthalmoplegia, the treatment varies is different. Wearing special glasses, treatment of weak eye muscles and migraine, double eyelid surgery are some of them.
To conclude, 6 eye muscles control various movements of our eyes. These muscles often tend to be weak and hidden under our eyelids. And that is why when we look at the mirror or sometimes take pictures by the camera, one of our eyes seem to be smaller than the other. Also, there is a slight chance of developing a genetic syndrome after diagnosis.
