Eye Movements of Congenital Nystagmus

Thirty five patients with congenital horizontal nystagmus (except nystagmus alternans and latent nystagmus) were examined electronystagmographically. All patients underwent the following tests of eye movements:gaze test, optokinetic pattern test (OKP), eye tracking test (ETT) and pendular rotation test (PRT) while gazing at a stationary target point. If the nystagmus had the element of saccade at least in the uni-directional gaze test, we defined it as "jerky type", and when the nystagmus had no saccade in the bilateral gaze test, we defined it as "pendular type". 1. Five patients had pendular type and 30 patients had jerky type nystagmus. 2. One patient who showed no response in the OKP test had pendular type nystagmus and another with inversion of OKP clearly had jerky type. 3. We considered that lateral gaze nystagmus and inversion or no response in the OKP test are related to the direction of eye movement. 4. Disorders of smooth pursuit in ETT were much better compensated in PR T while gazing at a stationary target point in patients with jerky type than in those with pendular type congenital nystagmus. 5. Rehabilitation is considered to be of value for patients with congenital nys-tagmus, especialy of the jerky type.