Optic radiation microstructure as a biomarker of visual function in paediatric Bardet-Biedl Syndrome

Motivation: While the molecular pathology of Bardet-Biedl Syndrome (BBS), a genetic condition, is increasingly understood, its impact on brain structure and function remains unexplored. Goal(s): Given retinal degeneration is the most prevalent symptom of BBS, we investigate optic radiation (OR) microstructure in paediatric patients versus age- and sex-matched healthy controls to identify structural changes that may relate to vision loss. Approach: Probabilistic tractography was used to reconstruct the ORs. Diffusion tensor and NODDI measures were statistically compared between groups. Results: Paediatric BBS patients have significantly lower FA and higher RD than healthy controls, reflecting white matter damage to the visual pathways in BBS. Impact: In BBS, optic radiation tractography and diffusion-based microstructural measures can serve as biomarkers of visual system structural integrity, potentially reflecting disease progression and treatment efficacy. This is promising for monitoring clinical outcomes, particularly in future clinical trials for BBS.