Featured Research

from universities, journals, and other organizations

Brain holds early signs of glaucoma

Date:
March 1, 2010
Source:
Vanderbilt University Medical Center
Summary:
Researchers are now a step closer to deciphering a leading cause of blindness in the United States -- glaucoma. They found that the first sign of injury in glaucoma actually occurs in the brain. The findings show that glaucoma is very much like other neurodegenerative central nervous system diseases.

Researchers at the Vanderbilt Eye Institute are now a step closer to deciphering a leading cause of blindness in the United States -- glaucoma.

Related Articles


In a recent study, David Calkins, Ph.D., director of Research at the VEI, discovered that the first sign of injury in glaucoma actually occurs in the brain.

Glaucoma is generally considered a disease of the eye in which sensitivity to ocular pressure causes damage to the retina and optic nerve, which are components of the central nervous system and do not regenerate. The damage begins in the peripheral visual field and progresses toward the center resulting in complete blindness unless detected early. For this reason, degeneration in glaucoma is often hard to detect.

The report this week in the Proceedings of the National Academy of Sciences describes recent experiments in which Calkins' laboratory shows that glaucoma is very much like other central nervous system diseases.

"This is a paradigm shift on how we think about this disease," said Calkins, associate professor of Ophthalmology at VEI and a member of the neuroscience program. "This will have global implications. This information opens up an entirely new domain of nerve-derived therapeutics."

Combining this new understanding of where the first neuronal injury for glaucoma occurs, with the fact that the incidence of injury increases with age, researchers now have insight into how the loss of sensory function occurs in normal aging.

Traditionally, glaucoma therapies have focused on lowering ocular pressure within the eye. But the recent PNAS study gives credence to taking a new direction of study focusing on neuronal activity in the middle of the brain where the optic nerve forms its first connections.

"This is very exciting work that demonstrates that we must consider not just the eye, but also the brain, in our efforts to understand blinding diseases such as glaucoma," said Paul Sternberg, M.D., chair of Ophthalmology and Visual Sciences and director of VEI. "We are optimistic that Dr. Calkins' neurobiological approach will lead to new targets for potential treatment of this devastating condition."

Calkins explained that in other age-related diseases, like Alzheimer's and Parkinson's, the most significant contributor to neuronal susceptibility to injury is age.

"In these diseases, the injury to neurons occurs very early in the distal projections in a process called dying back. In dying back, the neuronal axon loses its ability to communicate with the target.

"In the case of glaucoma, we have showed that the axons in the optic nerve lose their ability to communicate with their projection site in the mid-brain."

Calkins' team expected to find a loss of communication in the optic nerve of the eye, but what they also discovered was that the connectivity between the optic nerve and the brain was dying first.

Using animal models with high pressure glaucoma, the team was able to see that a very early mechanism of vision loss involves the loss of communication between the optic nerve and the mid-brain, where sensory information about sound, heat, cold, pain and pressure originate.

"If you followed the disease long enough, eventually the optic nerve, then the retina, show signs of degeneration," said Calkins. "So the degeneration works in reverse order. It starts in the brain and works its way back to the retina so that in the very latest stages of the disease, the earliest structures, the ones nearest the eye, are the last to go."

Now the team is working on finding drugs that can improve or restore the connectivity between the optic nerve and the mid-brain. Using both synthetic compounds and natural nerve growth factors such as Brain-Derived Neurotrophic Factor (BDNF), the team is examining how to restore communication in the pathway.

According to National Eye Institute projections, by the year 2020, 80 million people worldwide will have glaucoma. The risk of vision loss in glaucoma cases increases sevenfold after the age of 55.

Since 1915 there have been fewer than a dozen articles about glaucoma published in PNAS, said Calkins.

"People really thought we were crazy when we first suggested that the first signs of injury for glaucoma were in the brain," he said. "What this discovery does is to allow us to view this disease through the same lens that we view other age-related neurodegenerative disorders."

The study, which also introduces the possibility of using MRI scans as an early diagnostic tool, was funded by the Glaucoma Research Foundation and the National Eye Institute.

Sam Crish, Ph.D., a staff scientist in the Calkins laboratory, is the paper's first author.


Story Source:

The above story is based on materials provided by Vanderbilt University Medical Center. Note: Materials may be edited for content and length.


Journal Reference:

  1. Samuel D. Crish, Rebecca M. Sappington, Denise M. Inman, Philip J. Horner, and David J. Calkins. Distal Axonopathy with Structural Persistence in Glaucomatous Neurodegeneration. PNAS, March 1, 2010 DOI: 10.1073/pnas.0913141107

Cite This Page:

Vanderbilt University Medical Center. "Brain holds early signs of glaucoma." ScienceDaily. ScienceDaily, 1 March 2010. <www.sciencedaily.com/releases/2010/03/100301151919.htm>.
Vanderbilt University Medical Center. (2010, March 1). Brain holds early signs of glaucoma. ScienceDaily. Retrieved December 21, 2014 from www.sciencedaily.com/releases/2010/03/100301151919.htm
Vanderbilt University Medical Center. "Brain holds early signs of glaucoma." ScienceDaily. www.sciencedaily.com/releases/2010/03/100301151919.htm (accessed December 21, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Sunday, December 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

The Best Tips to Curb Holiday Carbs

The Best Tips to Curb Holiday Carbs

Buzz60 (Dec. 19, 2014) It's hard to resist those delicious but fattening carbs we all crave during the winter months, but there are some ways to stay satisfied without consuming the extra calories. Vanessa Freeman (@VanessaFreeTV) has the details. Video provided by Buzz60
Powered by NewsLook.com
Sierra Leone Bikers Spread the Message to Fight Ebola

Sierra Leone Bikers Spread the Message to Fight Ebola

AFP (Dec. 19, 2014) More than 100 motorcyclists hit the road to spread awareness messages about Ebola. Nearly 7,000 people have now died from the virus, almost all of them in west Africa, according to the World Health Organization. Video provided by AFP
Powered by NewsLook.com
Researchers Test Colombian Village With High Alzheimer's Rates

Researchers Test Colombian Village With High Alzheimer's Rates

AFP (Dec. 19, 2014) In Yarumal, a village in N. Colombia, Alzheimer's has ravaged a disproportionately large number of families. A genetic "curse" that may pave the way for research on how to treat the disease that claims a new victim every four seconds. Duration: 02:42 Video provided by AFP
Powered by NewsLook.com
The Best Protein-Filled Foods to Energize You for the New Year

The Best Protein-Filled Foods to Energize You for the New Year

Buzz60 (Dec. 19, 2014) The new year is coming and nothing will energize you more for 2015 than protein-filled foods. Fitness and nutrition expert John Basedow (@JohnBasedow) gives his favorite high protein foods that will help you build muscle, lose fat and have endless energy. Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins