Exploring cerebral visual impairment: functional vision classification and caregiver concerns

Abstract

Cerebral Visual Impairment (CVI) is a spectrum of visual impairment resulting from abnormalities of the brain and visual processing pathways, characterized by lower- and/or higher-order visual deficits and functional vision impairment that cannot be fully explained by coexisting ocular conditions. Children with CVI experience difficulties in visual processing that can impact perception, mobility, learning, and interaction with their surroundings. Early diagnosis is often difficult because the clinical presentation is variable and conventional visual acuity assessments may not adequately reflect functional visual limitations. Functional assessment tools such as the CVI Range, together with caregiver-reported observations, provide important insights into everyday visual performance. However, data exploring the relationship between parental concerns and functional vision in children with CVI remain limited in low-resource settings such as Nepal. This cross-sectional study included children diagnosed with CVI at a tertiary pediatric ophthalmology clinic. Caregiver-reported visual concerns were recorded, and functional vision was assessed using the CVI Range to classify children into three functional phases. Visual acuity and contrast sensitivity were measured using age-appropriate methods, and their associations with CVI phase and caregiver-reported concerns were analyzed. A total of 70 children with CVI were included, with a mean age of 4.66 ± 4.65 years; 67.1% were male. Nearly half (48.6%) were classified as Phase 1, 18.6% as Phase 2, and 32.9% as Phase 3, with mean age increasing across phases. The most common parental concern overall was difficulty maintaining eye contact (37.1%), followed by academic concerns (17.1%) and failure to look directly at objects (17.1%). Parental concerns varied by CVI phase, shifting from deficits in visual attention in Phase 1 to academic, mobility, and distance vision difficulties in later phases. Parental concerns also varied across age groups, with visual attention and fixation difficulties predominating in younger children, while academic, mobility, and distance-viewing concerns were more common in older children. Visual assessment methods also varied by phase, with fixation and following predominating in Phase 1 (79.4%), grating acuity in Phase 2 (76.9%), and Snellen visual acuity in Phase 3 (60.9%). Mean grating acuity improved across phases, while contrast sensitivity was poorer in Phase 1 compared with later phases. However, differences in grating acuity, contrast sensitivity, and LogMAR visual acuity across phases were not statistically significant (p > 0.05). Caregiver-reported concerns differed descriptively across age groups and functional vision phases. Integrating caregiver observations with functional vision assessment may provide a more comprehensive understanding of visual difficulties and support individualized rehabilitation planning in children with CVI.