The childhood condition of visual difficulties caused by brain damage, commonly termed cortical or cerebral visual impairment (CVI), is well established but has no internationally accepted definition. Clarification of its core features is required to advance research and clinical practice. This systematic review aimed to identify the definitions of childhood CVI in the original scientific literature to describe and critically appraise a consensual definition of the condition. MEDLINE, EMBASE, PsychINFO, CINAHL and AMED databases were searched in January 2017. Studies were included if they (1) were published original research, (2) contained a childhood CVI sample, (3) contained a definition of CVI and (4) described their CVI identification/diagnostic method. Thematic analysis identified concepts within definitions and narrative synthesis was conducted. Of 1150 articles, 51 met inclusion criteria. Definitions were subdivided according to detail (descriptive definition, description not reaching definition status and diagnostic/operationalising criteria). Three themes concerning visual deficits, eye health and brain integrity were identified (each containing subthemes) and analysed individually across definitions. The most common themes were visual impairment' (n=20), 'retrochiasmatic pathway damage'(n=13) and 'normal/near normal eye health' (n=15). The most consensual definition identified here may not be the best quality for advancing our understanding of CVI. We argue for the alternative definition: verifiable visual dysfunction which cannot be attributed to disorders of the anterior visual pathways or any potentially co-occurring ocular impairment. We propose reporting guidelines to permit comparison across studies and increase the evidence base for more reliable clinical assessment and diagnosis.

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.

Aim To investigate the effects of home‐based early intervention in children with severe visual impairment (SVI) using the Developmental Journal for babies and young children with visual impairment (DJVI). Method A longitudinal observational study was undertaken with a national cohort (OPTIMUM) of infants with congenital disorders of the peripheral visual system (CDPVS) and profound‐SVI; and followed up after 12 months and 24 months. Intervention was categorized according to the practitioner diary records of their usual practice over 12 months from baseline comparing those receiving the DJVI and those receiving ‘Other Support’. Outcome measures of cognition and language, behaviour difficulties, parenting stress, and satisfaction with parent–practitioner partnership were collected. Results In the 54 children (26 males, 28 females, baseline mean age 13.5mo, SD 2.3mo, range 8–17mo) with ‘total’ CDPVS (including 16 ‘complex’ and 38 ‘simple’ with or without known brain disorder respectively), linear mixed effects pointed towards acceleration in sensorimotor understanding and expressive language especially in the ‘simple’ subsample (11.72 developmental quotient, 95% confidence interval −1.17 to 24.61, p>0.05) in those receiving the DJVI. Vision level also predicted outcomes (p<0.05). The DJVI group showed improvements in behavioural withdrawal (η2=0.20, p=0.02, ‘simple’) and parenting stress (d=0.78, d=0.92, p=0.02 total and ‘simple’ respectively) and perceived practitioner–parent relationship (η2=0.16, p=0.01). Interpretation Infants and young children with visual impairment receiving home‐based early intervention using the DJVI with a structured developmental approach had better outcomes than those receiving ‘other’ home‐based early interventions. Moderate to large effect improvements were found in child cognition and language, behaviour and parenting stress and the perceived practitioner‐parent relationship, although cognition did not reach 5% significance level. What this paper adds Early intervention using the Developmental Journal for babies and young children with visual impairment was associated with enhanced developmental outcomes compared to other approaches. Improvements were also found in child behaviour, parenting stress, and perceived parent practitioner outcomes. Type and complexity of visual impairment also influenced outcomes.

Mothers of infants with visual impairment are at increased risk of parenting stress. Parenting stress was higher in mothers of children with profound visual impairment than those with severe visual impairment. High levels of parenting stress and lower infant vision at 1 year of age predicted higher parenting stress at 2 years of age.

Background: This study investigated mother-infant interactions, including maternal maintaining of infant attentional focus and sensitivity, with infants with congenital severe and profound visual impairment (VI) and the association with developmental trajectories from one to three years. Method: Fifty-five infants and mothers were video-recorded playing together with a standard set of toys at Time 1 (T1) mean age 12.95 months (8.13-17.05 months). Maintain was categorized as the mother following and maintaining the child's focus, and Sensitivity, the mother's responsiveness and contingency to infant behaviour. Vision level was measured using the Near Detection Scale. Cognition and language were measured at T1, 12 months later (T2) and 24 months later (T3) using the Reynell-Zinkin Scales. Results: Cross-sectional analyses showed that mothers of infants with severe VI (basic form vision) produced higher rates of Maintain compared to those with children with profound VI (light perception at best). Linear mixed-effects models examining developmental progression from T1 to T3 (controlling for vision level) showed an average increase of 5 DQ points (CI 95%: 1.03-9.08) in verbal comprehension for higher Sensitivity. No significant findings were found for Maintain. Conclusions: The findings suggest that mother-infant interactions (maternal Maintain) are associated with level of vision at infancy, but only maternal Sensitivity has a long-term positive association with advances in verbal comprehension from infancy to about three years. They highlight the need for incorporating strategies related to parent-infant interactions, including increased sensitivity, into early intervention for children with visual impairment.