A new study sheds light on how amblyopia affects the brain’s visual pathways. Researchers from the University of Wisconsin-Madison used diffusion-weighted imaging to map three pathways known to carry visual information between the eyes and the brain. They discovered water diffusing more easily down the brain’s visual pathways in patients with amblyopia. 

The investigators speculate the conductive sheath of myelin around neurons becomes thinner, providing less insulation. With less myelin in the way, the water diffuses more easily.

This study may improve treatments for amblyopia and other disorders in which patients have trouble judging distance and location of objects, investigators hope.

“This diffusion-weighted imaging approach will help us understand whether, and how much, brain training treatments work,” says Bas Rokers, a University of Wisconsin-Madison psychology professor, in a press release. “You can put patients in the scanner and see if your treatment actually has an effect.” 

Allen B, Spiegel DP, Thompson B, et al. Altered white matter in early visual pathways of humans with amblyopia. Vision Research. 2015;114:48.