Nystagmus

Dr Ben Wild

Overview

The eyes are connected in many different ways to themselves and different parts of the body. These connections can include the inner ear, brain, or many different parts of the eye sharing neural networks. If any of these fragile connections becomes disturbed, it can affect the eyes in many ways.

Nystagmus is the involuntary oscillation of one or both eyes either left and right (most common), up and down, or rotationally. It involves a drift of the eyes away from their target and a fast snap back to their target. Nystagmus can be physiological (normal) or pathological (caused by disease).

Physiological nystagmus can be noticed in some people when they look very far to the right or the left (extreme gaze). They can also be induced by looking at a moving repetitive target or through the vestibulo-ocular reflex (VOR). Briefly, a VOR can be stimulated by spinning in circles quickly thereby making the fluid in the semi-circular canals of the inner ear spin. When a person stops spinning the inner ear fluid continues to spin for a few seconds and the person experiences a nystagmus during that time because the movement of this fluid affects eye movement.

Pathological nystagmus is most commonly congenital (born with nystagmus) and is associated with many conditions that cause decreased vision. These can include improper development of the eye, albinism, very high prescription, congenital cataracts, etc. Acquired nystagmus can be from a stroke, trauma, Multiple Sclerosis, brain tumors, inflammation of inner ear, certain anti-epileptic drugs, central nervous system diseases and more.

Frontal view indicating different nystagmoid movements, either left-right, up-down, or rotating inwards-outwards.

Signs and Symptoms

Signs

Very fast eye movement either from left-right, up-down, or rotation inwards-outwards, possible torticollis (head tilt/turn) as some patients get some relief from their nystagmus when they look to the side.

Symptoms

Congenital	Blurred vision, usually no other symptoms.
Acquired	Oscillopsia (world is spinning), blurred vision, nausea, poor balance, dizziness.

Causes and Risk Factors

Causes

Congenital	Improper development of the eye.
Acquired	Central nervous system disease or medication side effects.

Risk Factors

Congenital	Albinism, very high prescription, congenital cataracts.
Acquired	Stroke, trauma, Multiple Sclerosis, brain tumors, inflammation of inner ear, certain anti-epileptic drugs, central nervous system diseases and more.

Prevention and Treatment

Prevention

There are no known preventative measures.

Treatments

· Cataract surgery or fix refractive error (eye prescription).

· Prism glasses to lower nystagmus in primary gaze (straight ahead gaze).

· Surgery to lower nystagmus in primary gaze.

· Contact lenses so the patient is always looking through the center of their lenses.

· Low vision aids like magnifying glasses, telescopes, etc.

· Baclofen or gabapentin to lower nystagmus.

· Botox.

Prognosis

People with congenital nystagmus will live their whole lives with this condition. It will likely affect their ability to get a driver’s permit, may restrict career path, but will not affect their ability to be an independent individual. Acquired nystagmus needs immediate attention as it could be a sign of a life-threatening condition. In some cases, once this condition is diagnosed and treated, the nystagmus will disappear, in other cases, it is permanent.