Oculomotor dysfunction in cerebral visual impairment following perinatal hypoxia

Abstract

The aim of the study was to describe ocular motility in a sample of 56 patients affected by cerebral visual impairment (CVI) of hypoxic‐ischemic origin. The sample consisted of 56 participants (37 males and 19 females), ranging in age from 2 to 16 years. In all cases CVI was associated with MRI‐verified damage of the cerebral visual system. A complete ophthalmologic and neurological assessment was performed. Behaviour of gaze was studied in four conditions: during scanning of the surrounding environment, during fixation, execution of saccades, and pursuing. In addition, strabismus, nystagmus, and paroxysmal ocular deviations were evaluated. Ocular motility was studied by video recording the patients’eye motility during orthoptic examination. Each pattern of ocular motility studied revealed profound alterations in all the individuals examined. Typical features of ocular motility in CVI were: paroxysmal ocular deviations (present in 78%); the presence of variable angle strabismus (86%); and defective coordination of saccades (93%). Exploration of the environment and fixation were also impaired (88% and 84%, respectively). Disorders of initiation and performing saccades, absence of smooth pursuit, vergence abnormalities, nystagmus beats, instability of fixation, and difficulty in the systematic exploration of the environment were observed. These abnormalities characterize lack of gaze coordination found in children with brain damage. An early and detailed evaluation of ocular motility in individuals with CVI is important, especially when rehabilitation intervention is intended.

Visual assessment in children with cerebral palsy: implementation of a functional questionnaire

“…These results concur with the findings of other studies performed in children with neurological impairments, although some report an even higher prevalence of CVI. 12,[20][21][22] Of the participants diagnosed with CVI, 88.46% were classified at VCS levels 1 to 3, as were 84% of those participants diagnosed with optic atrophy. The group without visual impairment were all classified at level 4 and 5.…”

Effects of visual processing and congenital nystagmus on visually guided ocular motor behaviour

“…However, nystagmus is an eye movement disorder that also commonly occurs in individuals with CVI. 21,22 Thus, RTF delays in the group with CVI could originate from either visual processing impairments or ocular motor instabilities. These instabilities were quantified and it was found that GFA values were only moderately increased in the group with CVI compared with the group with congenital nystagmus and the comparison group.…”

Visual field defects in prematurely born patients with white matter damage of immaturity: a multiple‐case study

“…Individuals with WMDI can exhibit a wide spectrum of visual symptoms, ranging from early onset esotropia to severe cerebral visual impairment (Cioni et al 1997). Findings of subnormal but slowly improving VA, crowding (Pike et al 1994) and eye motility disorders (Salati et al 2002) have also been described within this spectrum of symptoms, as has damage to higher visual functions that may result in difficulties in visuospatial analysis, recognition, simultaneous perception and visual memory (Koeda & Takeshita 1992).…”