Cortical Visual Impairment Across a Range of Neurodevelopmental Disorders: Clinical Characterization, Diagnostic Tool Evaluation, and Association with Developmental Outcomes

Cortical visual impairment is particularly relevant in children with neurodevelopmental disorders yet remains underdiagnosed. This study assessed the prevalence and severity of cortical visual impairment in 4 neurogenetic conditions: STXBP1, SLC6A1, Ring 14, and 8p-related disorders. We also evaluated the CDKL5 -Clinical Severity Assessment–Clinician vision subdomain as a diagnostic tool and examined the association between cortical visual impairment and developmental outcomes. A retrospective chart review of 85 patients found cortical visual impairment in 44%, most commonly in 8p (54%) and STXBP1 (50%); no cases were seen in SLC6A1 . The CDKL5 -Clinical Severity Assessment–Clinician vision subdomain effectively distinguished cortical visual impairment cases (mean score 25.9 vs 2.6, P < .0001). A cutoff score ≥11 showed high specificity (95.9%) and positive predictive value (94.3%). Cortical visual impairment was significantly associated with greater developmental impairment, with higher overall CDKL5 -Clinical Severity Assessment–Clinician scores and lower Vineland Adaptive Behavioral Scales–Third Edition scores. Early identification of cortical visual impairment is critical for ensuring access to appropriate therapies and therefore should be more systematically evaluated for in neurogenetic conditions.