1. TESTING FOR NYSTAGMUS IN THE DARK.
1. TESTING FOR NYSTAGMUS IN THE DARK.
The aim of the clinical examination is to detect the presence of nystagmus, which would indicate vestibular asymmetry. Nystagmus involves slow eye movements with rapid intermittent phases in the opposite direction. For diagnosis, the patient must be sitting and then lying down with videonystagmoscopy goggles, thus being placed in the dark to prevent inhibition by fixation. The goggles are equipped with a camera and monochrome infrared light, and the idea is to detect the iris imprint. A 3D study of the components of spontaneous nystagmus is essential. Is the nystagmus horizontal or vertical? Is there a torsional component? Is it inhibited by ocular fixation? Lastly, is it triggered by certain head movements?