What is Nystagmus? An involuntary back-and-forth, up-and-

down, or oscillatory rhythmical movement of

the eyeballs. Many people with this condition suffer from

partial sightedness and some are considered legally blind.

There are approximately 45 different types of nystagmus.

Types Nystagmus can be classified into two

general types:-Physiological -Pathological

It can also be classified into according eye movement patterns:

- pendular -jerky -rotatory

General Types Physiological- A normal response that is

induced because of excessive demand or imbalance in the vestibular or ocular motor system.

Pathological- An abnormal response that occurs spontaneously or appears in an individual looking at a stationary object.

-Congenital (early infancy-6 months) -Acquired (after 6 months)

Eye Movement Patterns Pendular

(congenital or acquired)-thought to be a result of a delay in messages to the brainstem-characterized by eye movements that are equally paced in each direction

Jerk (physiological or pathological)-characterized by an FEM in one direction and a slower movement in the opposite direction-thought to result from extra input to the oculomotor system from the brainstem.

Causes

1- Ocular nystagmus

A. nystagmus due to defective central vision

B. Nystagmus due to blindness

C. Congenital idiopathic nystagmus

D. Spasmus nutans

E. Miners disease

2- vestibular nystagmus :

A. Lesion of labyrinth B. Lesion of vestibular nerve

3- central nystagmus due to lesion of :

A. Brain stem B. Cerebellum C. Spinal cord

4-Toxic/metabolic

A. Alcohol intoxication

B. Amphetamines

C. Barbiturates Benzodiazepines

D. Ketamine

E. Phenytoin

5-other

A. Aniridia

B. Brain tumors "Medulloblastoma, Astrocytoma"

C. Head trauma

D. Lateral medullary syndrome

Effects of Nystagmus Nystagmus affects people in different ways.

The most significant effect is the reduced visual acuity and binocular vision.

Factors such as stress, tiredness, and nervousness can cause changes in ability to focus.

Distance visual acuity is poorer than near vision.

Balance may be affected due to poor depth perception or due to vestibular problems.

Head nodding is common. Also, most sufferers have a null point where eye movement decreases and vision improves

Social Impact One major difficulty individuals suffering from

nystagmus face is the lack of knowledge about the disorder, from the outside community.

In conversation, sufferers with involuntary head movement may cause people to think they are disagreeing with what they are saying.

Reading speed is likely to be affected because of the extra time and effort it takes to scan words.

Some people are unable to get their driver’s license. “alcohol”

People with the disorder find it difficult to play sports, especially those involving good hand to eye coordination.

Treatment At the moment, there is no cure for nystagmus. Many treatments have been tried, but the success

varies from person to person.

Some of the treatments include eye muscle surgery, anti parkinsonian drugs , Baclofen , Gabapentin , optical and acupuncture.

In a medical journal, it was recorded that tenotomy of the horizontal muscles in horizontal nystagmus with no null point was very effective in improving or eliminating horizontal eye movement.

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