Nystagmus is the involuntary and oscillatory movement of the eyes, which can happen even if the head is still, and can result in some symptoms, such as nausea, vomiting and imbalance, for example.
The movement of the eyes can happen from side to side, being called horizontal nystagmus, from top to bottom, receiving the name of vertical nystagmus, or in circles, this type being called rotary nystagmus.
Nystagmus can be considered normal, when it happens with the objective of following the movement of the head and focusing on an image, for example, but it can also be considered pathological when it happens even with the head still, and can be the result of labyrinthitis, neurological changes or side effect of medication, for example.
How to identify nystagmus
Nystagmus is characterized mainly by the involuntary movement of the eyes, which can be normal or due to some condition of the person, in which case it is called pathological nystagmus. Nystagmus consists of two movements, one slow and one fast. The slow movement happens when the eyes follow the movement of the head, focusing on a fixed point. When the eyes reach their limit, the rapid movement returns them to their starting position.
When the slow and fast movement happens even when the head is stopped, the movements of the eyes become more noticeable, this condition being called pathological nystagmus.
In addition to involuntary eye movements, nystagmus can be noticed due to the appearance of some symptoms, such as imbalance, nausea, vomiting and dizziness.
Main causes
According to the cause, nystagmus can be classified into two main types:
- Physiological nystagmus, in which the eyes move normally in order to focus an image when we turn our heads, for example; Pathological nystagmus, in which eye movements happen even with the head still, being normally indicative of changes in the vestibular system, which is a system responsible not only for hearing and maintaining balance, but also for sending electrical impulses to the brain and regions that control eye movement.
In addition to the classification in physiological and pathological, nystagmus can also be classified as congenital, when it is perceived shortly after birth, or acquired, which happens due to several situations that can happen throughout life, being the main causes:
- Labyrinthitis; Neurological changes in currents of tumors or blows to the head, for example; Loss of vision; Nutritional deficiencies, such as vitamin B12, for example; Stroke; Excessive consumption of alcoholic beverages; Side effect of medications.
In addition, people with Down syndrome or albinism, for example, are more likely to have nystagmus.
The diagnosis is made by the ophthalmologist by observing eye movements, in addition to performing specific tests, such as electro-oculography and video-oculography, for example, in which involuntary eye movements are observed in real time and in a more precisely.
How the treatment is done
The treatment for nystagmus is done with the objective of reducing the occurrence of involuntary eye movements, so the treatment of the cause can be indicated by the ophthalmologist, and suspension of the drug responsible for nystagmus or vitamin supplementation may be recommended, when it happens due to nutritional deficiencies.
In addition, the ophthalmologist may recommend the use of some drugs that can act directly on the neurotransmitter system, in addition to the use of contact lenses.
In more severe cases, when involuntary movements are very frequent and happen regardless of the position of the head, surgery may be necessary to change the position of the muscles that are responsible for moving the eye, thus improving the ability to focus on objects, in addition to improving visual ability.
