Long-term outcome of children with cortical visual impairment

Abstract

Cortical visual impairment (CVI) is now the most common cause of visual impairment in children. Little is known about the long-term visual outcome. This study evaluates the outcome of children with congenital CVI. Using medical records, 423 children (225 males, 198 females) were identified with congenital CVI. Of these children, 259 had follow-up visual acuity assessments. The children's gestational age varied with 32 weeks or less representing 15.9%; 33 to 36 weeks representing 10.7%; 37 to 42 weeks representing 61.2%; and 43 weeks or greater representing 0.9% (11.3% of patients' gestational age was unrecorded). Clinical data were extracted and information regarding outcome was gathered. The majority of children showed improvement in their visual acuity levels after 2 or more years of follow-up. For the 194 children initially assessed before 3 years of age, 97 had improved, 75 were unchanged, 18 had deteriorated, and 4 had sub-optimal assessments. For the 74 children initially assessed at 3 or more years of age, 23 had improved, 44 remained unchanged, 3 had deteriorated, and 4 had sub-optimal testing. Children with better visual acuity levels at follow-up were more likely to have favourable cognitive outcomes (non-mental retardation) in 12.2% versus 2.8% (p<0.01). Similarly, favourable motor outcomes (independent ambulation) were present in 20.1% for those with better visual acuities versus 7.9% for those with poorer visual acuities (p<0.01). Our study demonstrates that the majority of children with CVI underwent improvement in visual acuity. Additional disabilities were common, but those children with better visual acuity outcomes faired better. Given the frequency of comorbid conditions, appropriate diagnostic assessment services are needed.

Epidemiology of blindness in children

“…Demonstrable improvements in visual function in some children with CVI have resulted in suggestions that various ‘visual stimulation’ therapies may be of benefit, but the population who improve may be a separate subgroup in whom CVI is a manifestation of a delayed or interrupted rather than aborted trajectory of ‘normal’ visual development 54. Further research into pathogenesis, or the identification of therapeutic targets, is hampered by the absence of a clinically meaningful taxonomy with which to classify the different CVI phenotypes.…”

Is there consensus in defining childhood cerebral visual impairment? A systematic review of terminology and definitions

“…‘Diagnostic/operationalising criteria’ were often similar to the descriptive definition but were classified as explicit statements of how the participants were diagnosed or allocated into the CVI group. Examples of how such criteria were identified are ‘CVI was diagnosed clinically…’,49–53‘…clinical characteristics consistent with CVI…’30 and ‘…diagnosis of CVI was based on…’ 43. Most articles contained both a descriptive definition of CVI (either explicit definition or implicit description not reaching definition status) and diagnostic/operationalising criteria for CVI.…”

“…This is important for guiding clinicians in selecting age-appropriate and developmentally appropriate assessments for more accurate diagnosis 13 28 29. However, as there is currently no international consensus on the definition of childhood CVI which covers the range of childhood developmental abilities and age, there is consequently no universally accepted diagnostic assessment framework 30. The diagnostic process may be based on ophthalmological examination, basic vision examination, standardised neuropsychological assessment, neuroimaging or any combination of these.…”

Quantitative Fiber Tracking of the Optic Radiation Is Correlated with Visual-Evoked Potential Amplitude in Preterm Infants

“…Children with cerebral visual impairment often have comorbid neurological impairments, including mental retardation, cerebral palsy, and hearing loss 5 .…”