Study Reveals That Brain Pressure Controls Eye Pressure, Providing New Ways To Treat Glaucoma
Source: Thailand Medical News Jan 14, 2020 4 years, 11 months, 1 week, 1 day, 23 hours, 42 minutes ago
Medical researchers at the University of South Florida (USF) have discovered a novel feedback pathway from the
brain to the
eye that modulates
eye pressure, a significant advancement in the effort to diagnose and treat
glaucoma.
Glaucoma is associated with increased
pressure in the
eye due to a reduce ability of the
eye to maintain proper fluid drainage. The heightened pressure applies mechanical strain to the optic nerve as the nerve exits the
eye, resulting in vision loss and potential blindness.
For a long time, it has long been hypothesized that
brain pressure might also play a role in
glaucoma because the amount of strain on the optic nerve depends not just on
eye pressure, but the difference in
pressure between the
eye and
brain. The groundbreaking study published in the
Journal of Physiology shows, for the first time, that
eye and
brain pressure are physiologically connected. The neuroscientists came to this conclusion by altering
brain pressure in animal models and noting changes in the fluid drainage properties of the
eye that could be blocked by chemicals that eliminate feedback signals from the
brain. Interestingly, the
eye's ability to clear fluid changed in a manner that restored a healthy
pressure difference across the optic nerve.
Dr Chris Passaglia, Ph.D., Professor in the USF Department of Medical Engineering told
Thailand Medical News, "The drainage control system may service to protect the optic nerve from swings in
eye or
brain pressure. Its discovery offers a new target for
glaucoma treatment, wherein the modulatory mechanisms of the system might be exploited to help lower
eye pressure and impede disease progression in
glaucoma patients."
Currently,
Glaucoma is the leading cause of blindness in people over the age of 60. Since symptoms often don't arise until the condition has advanced,
ophthalmologists check the
eye pressures of patients during routine exams by administering an "air puff test." However, Passaglia says there are more complex aspects of the disease that make diagnosis a challenge. Some patients exhibit symptoms of
glaucoma yet have normal
eye pressure. While others with high
eye pressure, don't always show signs of the condition.
Medical researchers are now trying to pinpoint the location of t
he
brain cells that are sending signals to the
eye and find which nerve fibers in the
eye are being mediated by the
brain. This will help physicians better diagnose
glaucoma and have a greater understanding of what's causing it to develop.
Reference : Intracranial pressure modulates aqueous humour dynamics of the eye, Journal of Physiology., Kayla R. Ficarrotta , Christopher L. Passaglia, https://doi.org/10.1113/JP278768