Is there a role for optokinetic nystagmus testing in contemporary orthoptic practice? Old tricks and new perspectives.

Optokinetic nystagmus is a physiological oscillation of the eyes that requires intact development of motion perception, pursuit function, and saccadic function to be smoothly executed. Neuro-ophthalmological disorders often produce distinct perturbations in optokinetic responses that can be used to unmask the clinical diagnosis. With the advent of modern neuroimaging, optokinetic testing has slowly become a lost art in clinical examination. The purpose of this paper is to review the conditions wherein optokinetic testing provides a critical neurodiagnostic role, and to revitalize interest in this simple and valuable clinical tool.