Researchers at the University of British Columbia and the University of Toronto have discovered a drainage route at the back of the eye. In experiments with mice, it appeared to carry fluid and waste into the lymphatic system, a network that removes waste, balances fluid and supports the body's defences. The researchers call it the POLO pathway.
The retina, the light-sensitive tissue at the back of the eye, uses considerable energy to turn light into signals for the brain. This activity produces waste that needs to be cleared. A build-up of fluid and waste is associated with diseases that can cause permanent sight loss, including glaucoma and age-related macular degeneration.
To follow fluid movement, the team used imaging methods and molecules that gave off light. These markers reached nearby lymph nodes within minutes. The discovery could help researchers investigate new ways to protect sight. However, they still need to establish how the pathway works in humans and whether changing its activity would be safe. Possible treatments remain future possibilities, not established medical care.
