Latent nystagmus

This code represents a form of nystagmus that is typically absent when both eyes are open and fixating, but becomes evident or more pronounced when one eye is occluded. It is often associated with congenital strabismus and amblyopia, and the nystagmus beats with its fast phase directed towards the viewing eye.

Use this code when documentation clearly indicates the presence of nystagmus that is latent, meaning it is only observed or significantly amplified when one eye is covered. This condition is frequently identified during ophthalmological examinations, especially in pediatric patients with a history of early-onset eye misalignment.

• Differentiate from manifest nystagmus (H55.01) where the nystagmus is present with both eyes open.
• Ensure documentation specifies "latent" or describes the characteristic appearance upon monocular occlusion.
• Consider co-occurring conditions such as strabismus (H49.-) or amblyopia (H53.0-) and code them appropriately.