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September 8, 2008, 7:35 PM CT

Spirituality is important to eye patients

Spirituality is important to eye patients
Patients visiting an ophthalmologist report that prayer is important to their well-being and that God plays a positive role in illness, as per a report in the recent issue of Archives of Ophthalmology, one of the JAMA/Archives journals.

"Ethical medical practice includes doctor behavior, beyond technical competence, that promotes healing and optimizes the patient's welfare," the authors write as background information in the article. "The doctor who respects the patient as a person with dignity must acknowledge the patient's value system to establish a relationship that permits conversations that nourish trust for joint therapeutic decision making. For a number of patients, religion and spirituality is important to their value system and may represent a unique source of motivation and coping with life events, including the experience of personal illness (illness refers to the response of a patient to a disease)".

Gina Magyar-Russell, Ph.D., of the Johns Hopkins School of Medicine, Baltimore, and his colleagues distributed a brief questionnaire to 124 patients visiting the office of one ophthalmologist. The 14-question survey was completed by the patient and collected without any identifying information, so patients could be assured the answers would not affect their care.........

Posted by: Mike      Read more         Source


July 23, 2008, 4:37 PM CT

Human visual system could make powerful computer

Human visual system could make powerful computer
Since the idea of using DNA to create faster, smaller, and more powerful computers originated in 1994, researchers have been scrambling to develop successful ways to use genetic code for computation. Now, new research from a professor at Rensselaer Polytechnic Institute suggests that if we want to carry out artificial computations, all we have to do is literally look around.

Assistant Professor of Cognitive Science Mark Changizi has begun to develop a technique to turn our eyes and visual system into a programmable computer. His findings are published in the latest issue of the journal Perception

Harnessing the computing power of our visual system, as per Changizi, requires visually representing a computer program in such a way that when an individual views the representation, the visual system naturally carries out the computation and generates a perception.

Ideally, we would be able to glance at a complex visual stimulus (the software program), and our visual system (the hardware) would automatically and effortlessly generate a perception, which would inform us of the output of the computation, Changizi said.

Changizi has begun successfully applying his approach by developing visual representations of digital circuits. A large and important class of computations used in calculators, computers, phones, and most of today's electronic products, digital circuits are constructed from assemblies of logic gates, and always have an output value of zero or one.........

Posted by: Mike      Read more         Source


July 22, 2008, 8:30 PM CT

How carrots help us see the color orange

How carrots help us see the color orange
One of the easiest ways to identify an object is by its color -- perhaps it is because children's books encourage us to pair certain objects with their respective colors. Why else would so a number of of us automatically assume carrots are orange, grass is green and apples are red?

In two experiments by Holger Mitterer and Jan Peter de Ruiter from the Max Planck Institute for Psycholinguistics, perception of color and color constancy (the ability to see the same color under varying light conditions) were examined using different hues of orange and yellow. By using these hues on different objects, the scientists hoped to show that knowledge of objects can be used to identify color.

In one experiment, half of the participants saw traditionally-colored orange objects in their respective hue, while the other participants saw the same objects in an ambiguous hue between yellow and orange. The participants that saw the ambiguous hue on traditionally-colored orange objects later called the item with that ambiguous hue "orange". Apparently, seeing the ambiguous hue on a traditionally-colored orange objects led participants to redefine that hue to be proper "orange".

In the second experiment, participants saw the same hues, but now on objects that could be any color (e.g., a car). Some participants were shown objects that ranged from the ambiguous color from the first experiment to a strong yellow hue, while others were shown objects in a range of strong orange hues to the ambiguous color. Just as in the first experiment, participants then had to identify a sock that had been colored with an ambiguous hue. This second experiment revealed no differences between the two groups, showing conclusively that it was only the knowledge of how objects are naturally colored that made them redefine the colors in the first experiment.........

Posted by: JoAnn      Read more         Source


June 23, 2008, 7:16 PM CT

Retinal hemorrhaging and motor vehicle crashes

Retinal hemorrhaging and motor vehicle crashes
The severity of retinal hemorrhaging for young children in motor vehicle crashes is closely corcorrelation to the severity of the crash, as per a new study by scientists at the Medical College of Wisconsin in Milwaukee. Retinal hemorrhages occur when the blood vessels lining the retina rupture, resulting in bleeding onto the surface of the retina.

The study, by Jane Kivlin, M.D., and Kenneth Simons, M.D., professors of ophthalmology at the Medical College, is reported in the recent issue of Archives of Ophthalmology

"The severity of the retinal injuries is similar to that seen in nonaccidental childhood neurotrauma, or shaken baby syndrome," as per Dr. Kivlin, a pediatric ophthalmologist and lead author, who sees patients at Children's Hospital of Wisconsin. "A number of perpetrators of shaken baby syndrome have confessed to violently shaking the child, subjecting the child to severe rotational force".

The retrospective study examined ten cases of children younger than three years taken from autopsies performed by the Milwaukee County medical examiner from January 1, 1994, to December 31, 2002. All patients died in motor vehicle crashes as passengers or pedestrians. They were subjected to extremely severe forces involving rapid deceleration with a rotational, or whiplash-like, component.........

Posted by: Mike      Read more         Source


May 15, 2008, 8:23 PM CT

Visual System Equipped With "Future Seeing Powers"

Visual System Equipped With
Catching a football. Maneuvering through a room full of people. Jumping out of the way when a golfer yells "fore." Most would agree these seemingly simple actions require us to perceive and quickly respond to a situation. Assistant Professor of Cognitive Science at Rensselaer Polytechnic Institute Mark Changizi argues they require something more - our ability to foresee the future.

It takes our brain nearly one-tenth of a second to translate the light that hits our retina into a visual perception of the world around us. While a neural delay of that magnitude may seem minuscule, imagine trying to catch a ball or wade through a store full of people while always perceiving the very recent (one-tenth of a second prior) past. A ball passing within one meter of you and traveling at one meter per second in reality would be roughly six degrees displaced from where you perceive it, and even the slowest forward-moving person can travel at least ten centimeters in a tenth of a second.

Changizi claims the visual system has evolved to compensate for neural delays, allowing it to generate perceptions of what will occur one-tenth of a second into the future, so that when an observer actually perceives something, it is the present rather than what happened one-tenth of a second ago. Using his hypothesis, called "perceiving-the-present," he was able to systematically organize and explain more than 50 types of visual illusions that occur because our brains are trying to perceive the near future. His findings are described in May-recent issue of the journal Cognitive Science.........

Posted by: Mike      Read more         Source


May 12, 2008, 10:09 PM CT

High blood pressure and high cholesterol

High blood pressure and high cholesterol
Hypertension and high cholesterol levels appear to be risk factors for retinal vein occlusion, a condition that causes vision loss, as per a report in the recent issue of Archives of Ophthalmology, one of the JAMA/Archives journals.

Retinal vein occlusion occurs when one or more veins carrying blood from the eye to the heart become blocked, as per background information in the article. Bleeding (hemorrhage) or fluid buildup (edema) may follow, damaging vision.

Paul R.A. OMahoney, of the Royal College of Surgeons in Ireland, Dublin, and his colleagues conducted a meta-analysis of 21 previously published studies involving 2,916 individuals with retinal vein occlusion and 28,646 control participants without the condition. The scientists pooled data from all the studies and estimated the population-attributable risk, or the percentage of cases of retinal vein occlusion that could be attributed to high blood pressure (high blood pressure), diabetes and hyperlipidemia (high cholesterol).

Of patients with retinal vein occlusion, 63.6 percent had hypertension, compared with 36.2 percent of controls; those with hypertension had more than 3.5 times the odds of having retinal vein occlusion. High cholesterol levels were more than twice as common among patients with retinal vein occlusion as those without (35.1 percent vs. 16.7 percent), and those with high cholesterol levels had an approximately 2.5-fold higher risk of retinal vein occlusion. Diabetes was slightly more prevalent among those with retinal vein occlusion than among those without (14.6 percent vs. 11.1 percent).........

Posted by: Mike      Read more         Source


May 12, 2008, 9:50 PM CT

Vision therapy appears to improve visual function

Vision therapy appears to improve visual function
A low-vision treatment program that includes a home visit, counseling, assistive devices such as magnifiers and assignments to practice using them appears to significantly improve vision in veterans with diseases of the macula (the area of the retina with the sharpest vision), as per a report in the recent issue of Archives of Ophthalmology, one of the JAMA/Archives journals.

Low vision, chronic visual impairment that limits everyday function, is one of the 10 most prevalent causes of disability in America, the authors write as background information in the article. In addition to affecting daily function, low vision increases the risk of depression, injury and an overall decline in health. Most diseases that cause low vision are not curable. In most cases, impaired vision cannot be corrected and rehabilitation is the only option for regaining lost function for the patient with low vision. Low-vision rehabilitation aims to restore functional ability, the ability to perform tasks modulated by visual impairment.

Joan A. Stelmack, O.D., M.P.H., of the Edward E. Hines Jr. VA Hospital, Hines, Ill., and the University of Illinois at Chicago College of Medicine, and his colleagues studied 126 patients (average age 78.9, 98 percent male) with low vision and diseases affecting the macula who were eligible for Veterans Affairs (VA) services. Between November 2004 and November 2006, participants were randomly assigned to one of two groups. In one, patients received a vision treatment program incorporating a low-vision examination, counseling, assistive devices such as magnifiers and five weekly sessions provided by a low-vision therapist to teach use of the assistive devices and other adaptive strategies. They were also assigned homework to ensure they used the devices outside of treatment. The other group was placed on a wait list for the treatment program and received no therapy for four months, an amount of time veterans might normally wait to receive such services.........

Posted by: Mike      Read more         Source


April 21, 2008, 6:07 PM CT

Sharper imags: sports vision clinic

Sharper imags: sports vision clinic
The Dynavision is a peg board that requires athletes to hit the red buttons as they light up. The Sports Vision Performance Center uses the machine to determine reaction time, peripheral awareness and accuracy of movement.

Photo courtesy of University Eye Institute.
The standard eye chart only covers letters and numbers, but athletes need above average vision to track balls hurtling toward them at alarming speeds. To test those special skills, a University of Houston optometrist has founded the Sports Vision Performance Center, a facility where athletes perform while a strobe light is flashing, play tag with a board of lights and engage in other activities designed to improve their visual abilities.

The biggest problem that athletes face is not knowing they can potentially see much better than 20/20 vision, said Kevin Gee, a Fellow of the American Academy of Optometry and an assistant clinical professor with the UH College of Optometry. Gee opened the Sports Vision Performance Center in January to individual athletes and teams from various sports, and utilizes a range of tests to analyze what is called the visual system.

The visual system is more than just whats the smallest line on the chart you can see, Gee said. The visual system consists of a number of things, but specifically for sports, depth perception, color, speed and accuracy of movements and contrast sensitivity or the ability to detect an object off a background.

To assess these skills, Gee and his staff use instruments, such as a 3-D movie projected on a computer screen with shimmering objects that pop up to measure depth perception, a lighted batting test that can time up to one-thousandth of a second to gauge timing and accuracy, and a Dynavision board a vertical lighted peg board that determines reaction time, peripheral awareness and accuracy of movement.........

Posted by: Mike      Read more         Source


April 17, 2008, 7:43 PM CT

MU researchers find clue to cataract formation

MU researchers find clue to cataract formation
It is the No. 1 line-item cost of Medicare reimbursement and affects more than 20 million people in the United States. Cataracts, which can have devastating effects on the eye, affect 42 percent of the population between the ages of 70 and 80, and 68 percent of the population over the age of 80, as per the National Eye Institute. Now, a University of Missouri professor has identified an important step in how cataracts form. This discovery, published in a recent edition of The Journal of Biological Chemistry, could lead to a better therapy or cure for cataracts in the future.

In his study, K. Krishna Sharma, professor of ophthalmology at MU, observed that a specific type of protein begins to lose function as the eye ages. As the protein loses function, small peptides, made of 10 to 15 amino acids, start forming and accelerate cataract formation in the eye.

It is very helpful to track the formation of these peptides, Sharma said. The next step is to work on preventing their formation. If we are successful, we could delay the aging process in the eye. A ten-year delay in the onset of cataracts could decrease the number of cataract surgeries by 45 percent, thus significantly decreasing vision care cost. Currently, 1.5 million to 2 million cataract surgeries are completed yearly.........

Posted by: Mike      Read more         Source


April 7, 2008, 10:50 PM CT

When poor communication pokes you in the eye

When poor communication pokes you in the eye
Cataract in human
The ocular lens belongs to the optical apparatus and focuses incidental beams of light onto the retina. Now, a research team led by Professor Dr. Jochen Graw of the Institute of Developmental Genetics, of the Helmholtz Zentrum M√ľnchen, has been able to decipher a genetic defect responsible for small eyes and an incomplete, clouded lens in the so-called Aey12 mouse mutants. These results lead to conclusions concerning cataracts in humans, because, in this case too, the lens loses its transparency.

The development of the eye in mammals (and this naturally includes humans) is an extraordinarily complex process beginning in an early embryonic phase. The same applies also to the formation in healthy eyes of elastic and transparent lenses, which focus light beams. With the aid of the ciliary muscles, the lens can change its degree of curvature and thus set itself on varied, far distant objects. As a result, a pin sharp image is created on the retina. "As with humans, with mice too, the development of the lens starts with the formation of a spherical, hollow sac," Graw says. "That is the lens vesicle, the cover of which is surrounded by the lens epithelium, composed of a layer of cells. The vesicle is then filled in with fiber cells. In the following course of development, additional fibers originate in the equator of the lens. These scale up the diameter of the lens: a process that lasts a lifetime."........

Posted by: Mike      Read more         Source



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