Children with nystagmus should be referred for further evaluation. This is usually done most efficiently by initially referring the child to an ophthalmologist. Nystagmus that presents in infancy and early childhood is usually due to either congenital motor nystagmus or is secondary to an underlying ocular disorder. Acquired nystagmus in older children is more likely to be associated with an underlying neurological disorder. Older children with nystagmus may need to be evaluated by both an ophthalmologist and a neurologist.

What Shouldn’t Be Missed

Sensory nystagmus in infants may be due to septo-optic dysplasia. This is often associated with pituitary gland dysfunction. Affected infants may not be able to mount a normal stress response and are therefore at risk for decompensating with minor illnesses. If this diagnosis is suspected, the infant’s family should be warned of this possibility while waiting for an endocrinological evaluation.

• 1. Congenital motor nystagmus (infantile nystagmus syndrome). In congenital motor nystagmus, the eyes themselves are fine. The nystagmus results from abnormalities of the ocular motor system. Despite the nystagmus, most children see surprisingly well (Table 12–1).
  
• 2. Sensory nystagmus. Any disorder that affects the vision in both eyes during infancy may present with nystagmus in the first few months of life. The prognosis for vision depends on the underlying disorder. Common etiologies include albinism, optic nerve hypoplasia (septo-optic dysplasia), and Leber’s congenital amaurosis (Table 12–2).
  
• 3. Acquired nystagmus in older children. Acquired nystagmus is relatively rare in childhood. Unlike infantile nystagmus, older children with acquired nystagmus may complain of oscillopsia, the sensation of the world moving back and forth. Acquired nystagmus may result from central nervous system lesions or as a side effect of medication (Table 12–3).
  
• 4. Voluntary nystagmus. Some patients are able to voluntarily elicit nystagmus. This is a high-frequency horizontal oscillation. It cannot be sustained longer than a few seconds.
  
• 5. Latent nystagmus (fusion maldevelopment nystagmus). Patients with infantile esotropia develop nystagmus when one of their eyes is covered. The nystagmus is usually not visible when both eyes are opened. It is the strabismus, rather than nystagmus, that usually brings the patient to medical attention.
  
• 6. Normal newborn. Occasionally, normal infants may have episodes of abnormal eye movements, including nystagmus or tonic gaze deviations, during the first 1 to 2 months of life. This is uncommon, and usually such infants require ophthalmic evaluation to rule out other problems.