Common drug for boosting memory may protect patients against glaucoma
NEW YORK — A new study finds that a pill taken by millions for its memory-boosting abilities may also hold the key to curing glaucoma. Researchers in New York say citicoline, a natural chemical in the body, can also protect against one of the leading causes of blindness worldwide.
In experiments, the compound restored optic nerve signals between the brain and eye to near-normal levels in rats. The disease occurs when fluid inside the eye does not drain properly, causing a build-up of pressure. Eye drop medications are the main current treatment, but they don’t reverse the condition.
“Our study suggests that citicoline protects against glaucoma through a mechanism different from that of standard treatments that reduce fluid pressure,” says senior author Dr. Kevin Chan from New York University in a release. “Since glaucoma interrupts the connection between the brain and eye, we hope to strengthen it with new types of therapies.”
Citicoline has several different uses
The supplement is available commercially across the world. It is said to sharpen thinking by increasing blood flow to grey matter in the brain. Patients with Alzheimer’s disease, Parkinson’s disease, and even bipolar disorder take citicoline supplements.
Glaucoma affects around three million people in the United States and can lead to total vision loss if left untreated. Researchers believe the condition may involve more than just eye pressure since citicoline typically protects nerve cells.
When the eye’s vital watery fluid builds up in glaucoma patients, it wears down cells and the nerves connecting them to the brain. However, the irreversible condition continues to worsen even after the pressure has been controlled, with the link remaining poorly understood. Dubbed “the silent thief of sight,” it can develop slowly over many years and doesn’t always cause symptoms at first.
In the lab rodents, glaucoma was reversed after the animals ingested citicoline in their food and drink. The chemical produces choline, an essential nutrient in membranes that line nerve cells and enhance communication. While elevated eye pressure fuels glaucoma, citicoline appears to treat it in a different way.
The results, appearing in the journal Neurotherapeutics, shed fresh light on how the neurochemical works.
Slowing nerve degeneration due to eye disease
Previous studies show humans and rodents with glaucoma have lower than normal levels of choline in the brain. Until now, there has been little concrete evidence of the effectiveness of supplements as a therapy or why choline is reduced in patients.
Over three weeks, giving rats oral doses of citicoline protected nerve tissues and reduced vision loss sustainably. The effect continued even after the treatment stopped for another three weeks. Researchers simulated glaucoma in dozens of rats using a clear gel to build up eye pressure without otherwise blocking their vision. Study authors measured the structure, function, and physiological activity of the visual pathway using MRI brain scans.
Dr. Chan and his colleagues also tracked the animals to test the clarity of sight of each eye. In those with mildly elevated eye pressure, tissues that connect the eye and brain, including the optic nerve, decayed for up to five weeks after the injury occurred.
Meanwhile, nerve structure breakdown in the citicoline-treated rodents slowed by as much as 74 percent. Chan adds scientists need to do more work before turning to citicoline supplements into a true glaucoma treatment. Commercial drugs have yet to be proven fully effective in clinical trials.
The researchers now plan to investigate the origin of choline decline in people with glaucoma, as well as how citicoline works to repair the damage. Patients taking these drugs to slow the onset of dementia or Parkinson’s usually tolerate them well. Some side-effects can include nausea and diarrhea.
SWNS writer Mark Waghorn contributed to this report.