Latent nystagmus is commonly associated with infantile esotropia.

• A. Spasmus nutans
• B. Latent nystagmus
• C. Gaze-evoked nystagmus
• D. Convergence-retraction syndrome

Answer: (B)

Latent nystagmus is the type of nystagmus that appears when one eye is covered, revealing binocular circuitry that isn’t normally engaged during binocular viewing. In infantile esotropia, the early disruption of binocular fusion leads to an abnormal development of the oculomotor system, so a horizontal nystagmus becomes evident on monocular viewing. The phenomenon reflects the brain’s adaptation to imperfect alignment and sensory fusion from infancy, and it typically diminishes when both eyes are open or when fusion is attempted.

Spasmus nutans presents with pendular nystagmus accompanied by head nodding and often a torticollis, which is a distinct clinical picture from latent nystagmus and isn’t specifically tied to infantile esotropia. Gaze-evoked nystagmus arises from a faulty neural integrator and occurs when looking in a particular direction, usually in the context of neurologic issues rather than early-onset infantile strabismus. Convergence-retraction syndrome involves dorsal midbrain pathology with inappropriate convergence and globe retraction on attempted upward gaze, not the typical association seen with infantile esotropia.