Microstructural differences in visual white matter tracts in people with aniridia.

Area of Science:

• Neuroscience
• Ophthalmology
• Genetics

Background:

• Aniridia is a panocular disorder primarily affecting the iris, often due to PAX6 gene mutations impacting eye and brain development.
• Previous research noted global brain volume and functional connectivity differences in aniridia, but white matter structure remains understudied.

Purpose of the Study:

• To investigate white matter structural differences in individuals with aniridia using diffusion-weighted imaging.
• To identify specific white matter tracts affected by aniridia and their potential implications for neural alterations.

Main Methods:

• Diffusion-weighted imaging was employed to assess white matter structure.
• Quantitative anisotropy (QA), an index of white matter tract density, was calculated and compared between 11 individuals with aniridia and 11 matched healthy controls.

Main Results:

• Lower quantitative anisotropy (QA) was observed in individuals with aniridia compared to controls.
• Affected regions included the bilateral optic tract, bilateral optic radiation, forceps major, bilateral superior longitudinal fasciculus, and right posterior corona radiata.

Conclusions:

• White matter structure is significantly altered in individuals with aniridia.
• These alterations are present in both visual tracts and associated posterior visual pathways, suggesting widespread neural impact.