Visual training after central retinal loss limits structural white matter degradation: an MRI study

Area of Science:

• Neuroscience
• Ophthalmology
• Vision Science

Background:

• Macular degeneration affects 8% of the global population, causing blindness.
• Central retinal lesions in cats were used to study visual system degradation.
• Motion perception training was explored as a method to mitigate vision loss.

Purpose of the Study:

• To evaluate the impact of visual training on behavioral performance and white matter structure in cats with retinal lesions.
• To assess if motion perception training can limit visual system degradation.
• To integrate a novel motion-acuity test into a training regimen.

Main Methods:

• Cats were divided into retinal-lesioned, retinal-lesioned trained, and control trained groups.
• A 10-week motion perception training program was implemented, culminating in a new motion-acuity test.
• 7 Tesla MRI scans were performed pre- and post-lesioning, followed by Fixel-Based and Fractional Anisotropy Analysis.

Main Results:

• Trained cats with retinal lesions outperformed untrained cats in motion tasks, even those relying solely on acuity.
• Motion training led to more localized and reduced white matter degradation in specific brain regions (dLGN, caudate nucleus, hippocampus).
• Fractional Anisotropy values in visual regions showed differential changes between trained and untrained lesioned groups, with area V5/PMLS remaining unaffected.

Conclusions:

• Early motion training post-retinal loss demonstrated a stabilizing effect on white matter structure.
• The findings suggest that early motion-acuity training can facilitate brain plasticity.
• This approach, targeting intact retinal peripheries, may promote better vision outcomes in low vision patients.