TABLE 1. The frequency of neuro-ophthalmological features in 115 paediatric patients with chronic ataxia.

Neuro-ophthalmological features	Frequency (%)
Afferent visual system abnormalities
Decreased visual acuity	17 (9.2)
Abnormal optic discs	16 (8.7)
Abnormal pupillary examination	5 (2.7)
Abnormal visual fields	2 (1.1)
Efferent visual system abnormalities
Strabismus	54 (29.3)
All types of pathological nystagmus	51 (27.7)
Gaze-evoked nystagmus*	27 (14.7)
Impaired smooth pursuit	43 (23.4)
Hypometric saccades	19 (10.3)
Hypermetric saccades	4 (2.2)
Impaired ductions	3 (1.6)

*Subset of all patients with nystagmus.