Visual function subtyping in children with early-onset cerebral visual impairment.

AIM: To develop a data-driven subgrouping method to identify and profile subtypes of early-onset childhood cerebral visual impairment (CVI). METHOD: Sixty-three children with suspected or diagnosed congenital CVI were recruited (28 males, 35 females, median age=8y, range=5-16y). Cognitive, basic, and higher-order vision functions were assessed and quality of life, functional vision questionnaire, neurodevelopmental, and ophthalmological data were collected. Cluster analysis and other statistical analyses were undertaken to determine and validate the subgrouping. RESULTS: Forty-three participants completing the full test battery were included in cluster analysis, revealing two subgroups. Group A1 (n=15) showed selective visual perception and visuomotor deficits. Group A2 (n=28) showed more severe and broader visual perception and visuomotor deficits, and variable visual acuity. A third, lower-functioning group, Group B (n=20), was differentiated and showed significant visual acuity reduction compared with Group A (p<0.001, V=0.69). External validation showed significant cooccurring ophthalmological (e.g. strabismus p<0.001, V=0.59) and motor impairment differences (χ2 =16.26, p<0.001, V=0.51) between the three groups. All groups had lowered parent-reported quality of life and everyday functional vision. INTERPRETATION: Statistical analyses revealed three subgroups with differentiated vision function characteristics on a gradient of severity. The subgrouping method provides the first steps in developing a novel classification system to underpin future clinical diagnostics and profiling of early-onset CVI. WHAT THIS PAPER ADDS: Three data-driven subgroups of vision function deficits were identified. A similar severity gradient was shown in cooccurring cognitive and neurodevelopmental deficits. Reported quality of life and functional vision difficulties were low across all groups.