Featured Research

from universities, journals, and other organizations

Optic Nerve Disease May Cause Sleep Disorders

Date:
February 3, 2004
Source:
Washington University School Of Medicine
Summary:
Young people with eye diseases that damage the inner part of the retina and optic nerve are significantly more likely to have sleep disorders than those with other types of eye disease or those with normal vision, according to researchers at Washington University School of Medicine in St. Louis.

St. Louis, Feb. 1, 2004 -- Young people with eye diseases that damage the inner part of the retina and optic nerve are significantly more likely to have sleep disorders than those with other types of eye disease or those with normal vision, according to researchers at Washington University School of Medicine in St. Louis.

In the February issue of the journal Ophthalmology, the investigators report on a study involving 25 students, ages 12 to 20, from the Missouri School for the Blind and 12 students with normal sight from the Thomas Jefferson School, a boarding school in suburban St. Louis. The visually impaired students were divided into two groups: Those whose visual problems were related to optic nerve disease and those whose vision loss did not involve the optic nerve. The optic nerve is made up of ganglion cells, the type of cells targeted by eye diseases such as glaucoma.

Participants with optic nerve disease were 20 times more likely to be pathologically sleepy (napping 20 or more minutes per day) than those with normal sight. They also were nine times more likely to have pathologic sleepiness than children who were blind from non-optic nerve diseases.

"We suspect these patients have difficulty using daylight to synchronize their internal rhythms to the outside world," says senior investigator Russell N. Van Gelder, M.D., Ph.D., assistant professor of ophthalmology and visual sciences and of molecular biology and pharmacology at the School of Medicine.

In recent research, Van Gelder found that the retina contains not only the photoreceptor cells called rods and cones, which translate light into vision, but it also houses non-visual photoreceptor cells called intrinsically photosensitive retinal ganglion cells (ipRG cells) that function as the eye's "light meter."

In a camera, the light meter helps a photographer determine how to set the shutter speed and whether to use a flash. By determining light levels, ipRG cells help synchronize the body's sleep/wake cycle, reset the internal body clock, control the pupil of the eye's response to light and regulate the release of hormones such as melatonin. These ipRG cells continue to gather and use information about light even in animals that otherwise are visually blind.

"In our basic research, we have demonstrated that animals that lack rods and cones in the retina still have very normal circadian, or body clock, functions," he says. "But animals that lack the ganglion, or 'light meter' cells cannot synchronize their clocks to the outside world."

The ipRG cells that act as the eye's light meter are concentrated together at the head of the optic nerve, so Van Gelder's team wondered whether children with optic nerve disease might have problems regulating their internal body clocks. To measure the impact of the loss of those cells, first author Raymond Wee, a graduate student in Van Gelder's laboratory, had participants wear a device known as a wrist-worn actigraph. Worn like a watch, the actigraph measures every movement a person makes. A sophisticated computer algorithm then uses this movement information to determine whether a person was awake or asleep, active or inactive. Children in the study wore the actigraphs every day for two weeks.

Those with optic nerve disease had highly variable wake-up times and also had trouble falling asleep, compared to blind children without optic nerve damage and sighted children. Those sleep problems led them to nap more frequently, and children with optic nerve disease napped, on average, about 28 minutes a day.

None of the children in the study had any other conditions that might contribute to sleep disorders. None took sedative drugs, had attention-deficit hyperactivity disorder (ADHD) or were being treated with stimulant medications. So, the researchers believe the sleep problems these children experienced were directly related to their eye disease.

"Taken together, these results lead to the unexpected conclusion that eye disease can be a risk factor for sleep disorders, and the health of the optic nerve strongly influences risk," Van Gelder says.

In future studies, Van Gelder hopes to test whether treatment with melatonin helps regulate sleep patterns in children with optic nerve disease. Melatonin is a naturally occurring hormone that helps regulate the circadian clock. Its release is related to the eye's light meter function.

But even before he learns whether it's possible to help these patients to synchronize their internal clocks to the outside world, Van Gelder believes it is important for health professionals to begin considering the impact of eye disease on sleep.

"Physicians and other health-care professionals should be sensitive to the possibility of daytime sleepiness or insomnia, particularly in patients with severe optic nerve disease," Van Gelder says. "Your eye doctor might want to make a point of asking how you've been sleeping."

###

Wee R, Van Gelder RN. Sleep disturbances in young subjects with visual dysfunction. Ophthalmology, 111:2 pp. 297-302, Feb 2004.

This research was supported by grants from the Doris Duke Foundation, Research to Prevent Blindness, the Becker/Association of University Professors of Ophthalmology/Research to Prevent Blindness Physician-Scientist Award, the Culpepper Physician-Scientist Award, the National Alliance for Schizophrenia and Affective Disorders and the National Eye Institute of the National Institutes of Health.


Story Source:

The above story is based on materials provided by Washington University School Of Medicine. Note: Materials may be edited for content and length.


Cite This Page:

Washington University School Of Medicine. "Optic Nerve Disease May Cause Sleep Disorders." ScienceDaily. ScienceDaily, 3 February 2004. <www.sciencedaily.com/releases/2004/02/040202064949.htm>.
Washington University School Of Medicine. (2004, February 3). Optic Nerve Disease May Cause Sleep Disorders. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/2004/02/040202064949.htm
Washington University School Of Medicine. "Optic Nerve Disease May Cause Sleep Disorders." ScienceDaily. www.sciencedaily.com/releases/2004/02/040202064949.htm (accessed July 28, 2014).

Share This




More Health & Medicine News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

$15B Deal on Vets' Health Care Reached

$15B Deal on Vets' Health Care Reached

AP (July 28, 2014) A bipartisan deal to improve veterans health care would authorize at least $15 billion in emergency spending to fix a veterans program scandalized by long patient wait times and falsified records. (July 28) Video provided by AP
Powered by NewsLook.com
Traditional African Dishes Teach Healthy Eating

Traditional African Dishes Teach Healthy Eating

AP (July 28, 2014) Classes are being offered nationwide to encourage African Americans to learn about cooking fresh foods based on traditional African cuisine. The program is trying to combat obesity, heart disease and other ailments often linked to diet. (July 28) Video provided by AP
Powered by NewsLook.com
West Africa Gripped by Deadly Ebola Outbreak

West Africa Gripped by Deadly Ebola Outbreak

AFP (July 28, 2014) The worst-ever outbreak of the deadly Ebola epidemic grips west Africa, killing hundreds. Duration: 00:48 Video provided by AFP
Powered by NewsLook.com
Trees Could Save More Than 850 Lives Each Year

Trees Could Save More Than 850 Lives Each Year

Newsy (July 27, 2014) A national study conducted by the USDA Forest Service found that trees collectively save more than 850 lives on an annual basis. Video provided by Newsy
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:
from the past week

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