Evaluation of the Child With Nystagmus: What to Do in the Age of Genetic Testing.

Childhood nystagmus is a complex clinical presentation with diverse underlying mechanisms. While eye movement characterization aids description, it is often insufficient for establishing etiology. Accurate diagnosis relies on a structured evaluation that integrates careful clinical assessment with ancillary testing and genetic analysis. Recent advances in genetic testing have reshaped the diagnostic paradigm, allowing identification of molecular causes in an increasing proportion of children, refining prognostic counseling, and influencing clinical management. Ancillary studies-including electrophysiology, optical coherence tomography, and neuroimaging-remain essential in guiding and interpreting genetic results. This review outlines a practical neuro-ophthalmic framework for evaluating children with nystagmus, emphasizing the complementary role of genetic testing within a comprehensive, clinically driven diagnostic approach.