Medicines for Nystagmus

What it is

Nystagmus is a condition in which the eyes make repetitive, involuntary (uncontrolled) movements — typically a rhythmic to-and-fro movement, which can be side-to-side, up-and-down, or circular. Because the eyes are constantly moving, nystagmus can reduce the sharpness of vision and affect how steady the vision seems, though many people with long-standing nystagmus do not experience the world as moving. There are two broad situations. "Early-onset" (congenital or infantile) nystagmus develops in the first months of life; it may occur on its own, or be associated with reduced vision or other eye or developmental conditions, and people with it usually adapt and do not perceive movement. "Acquired" nystagmus develops later in life and is important because it can be a sign of an underlying condition affecting the brain, the balance system, or the nerves controlling eye movement (such as neurological conditions, inner-ear problems, certain medicines or substances, or other causes) — so new nystagmus in an older child or adult, particularly with other symptoms (such as a sense of the world moving, dizziness, or other neurological symptoms), needs assessment to find the cause. Nystagmus varies widely in its impact, and understanding the type and cause guides the approach.

How it is treated

The approach depends on whether the nystagmus is long-standing (early-onset) or new (acquired), and on finding any underlying cause. Assessment by eye specialists (and, where appropriate, other specialists such as neurologists) aims to characterise the nystagmus, check the vision and eyes, and, particularly for acquired nystagmus, look for an underlying cause — which may involve examination, and investigations such as brain scans where a neurological cause is suspected. For early-onset nystagmus, there is often no "cure" for the eye movements themselves, and management focuses on optimising and supporting vision — correcting any refractive error (glasses or contact lenses), managing any associated eye conditions, and providing low-vision support, aids, and educational support where vision is reduced; some people benefit from particular treatments or, in selected cases, surgery to improve a head posture they adopt to see best. For acquired nystagmus, the priority is identifying and treating the underlying cause, which may improve or resolve the nystagmus, and, where the eye movements themselves are troublesome, certain treatments (including some medicines) can sometimes help. Support for vision, daily living, and (in children) education and development is important throughout, along with practical and emotional support. The reassuring message is that nystagmus is assessed to determine its type and cause — with support to optimise vision for long-standing nystagmus, and identification and treatment of any underlying cause for new (acquired) nystagmus, which should be checked.