Clinical features of ocular motility in cerebral visual impairment (CVI)

Objectives. The Authors describe ocular motility in a sample of 56 patients affected by cerebral visual impairment (CVI) of hypoxic-ischemic origin. Methods. Fifty-six patients were selected from a large sample of cerebropathic subjects referred to our Institute from 1995 to 2000 for encephalopathy due to pre-perinatal anoxic-ischemic lesion. Cerebral damage was diagnosed by MRI. Mean age was 7.1 years ± 4 SD; mean gestational age was 34 weeks. In all cases, the etiology determining the lesion was perinatal ischemia-hypoxia. Most of our subjects showed severe neurological sequelae. Results. We observed paroxysmal ocular deviations in 78% of the subjects, variable angle strabismus in 86% and defective coordination of saccades in 93%. Nystagmus was also present. Conclusions. Disordered initiation and performance of saccades, absence of smooth pursuit, vergence abnormalities, nystagmus beats, instability of fixation, difficulty in the systematic exploration of the environment were the most significant features of ocular motility in CVI. These abnormalities characterize the lack of gaze coordination found in children with brain damage. As CVI subjects are often children with multiple disabilities, an early and detailed evaluation of their ocular motility is in order to facilitate rehabilitation.