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October 9, 2006, 9:08 PM CT

Laser Surgery Safer Than Contacts

Laser Surgery Safer Than Contacts
Traditional assumptions have held that contact lenses are safer than laser surgery to correct vision problems. Now, an Oregon Health & Science University Casey Eye Institute physician, comparing data from several recent studies, has observed that belief may not be true.

William Mathers, M.D., professor of ophthalmology in the OHSU School of Medicine, evaluated several large, peer-evaluated studies and found a greater chance of suffering vision loss from contact lenses than from laser vision correction surgery, also known as "refractive" surgery. His findings appear in a letter in today's issue of Archives of Ophthalmology.

"Several times a year, I have patients who lose eyes from complications because they've been wearing contacts and they've gotten an infection. By this I mean their eyes have to be physically removed from their bodies," said Mathers, an eye surgeon with a strong background in contact lens issues and former president of the Contact Lens Association of Ophthalmologists. "It's not that contacts aren't good. They're better than they've ever been. But one cannot assume contacts are safer".

The risks linked to laser surgery versus contact lenses can not be compared directly, partly because complications from contact lenses accumulate over years of use, and complications from surgery occur soon after the surgery.........

Posted by: Mike      Permalink         Source


September 14, 2006, 5:57 PM CT

Predicting Spread Of Eye Cancer To Liver

Predicting Spread Of Eye Cancer To Liver This is a map of several class 2 tumors showing the simultaneous expression of many genes
Researchers at Washington University School of Medicine in St. Louis have developed a method to predict whether melanoma of the eye will spread to the liver, where it quickly turns deadly. They also believe the molecular screening test may one day help determine the prognosis of patients with some types of skin melanoma.

J. William Harbour, M.D., the Paul A. Cibis Distinguished Professor of Ophthalmology and Visual Sciences and associate professor of cell biology and molecular oncology, reported on the screening test today at the American Academy of Cancer Research meeting in Chicago.

"About half of patients with ocular melanoma develop metastasis in the liver," says Harbour, who directs the ocular oncology service at the School of Medicine. "Ocular melanoma has a strong propensity to spread to the liver, and when it does, it commonly leads to death within a very short time."

Doctors have known for a number of years that patient age, tumor size and location and shape of tumor cells all could help predict whether ocular melanoma was likely to spread. But none of those factors were accurate enough to influence therapy decisions in individual patients.

Now Harbour and his colleagues have observed that a particular molecular signature - that is, the pattern of activation of a group of genes in the tumor cells - accurately predicts risk for metastasis. Rather than analyzing a single protein or molecular factor, the test looks at how several factors work together.........

Posted by: Mike      Permalink         Source


September 11, 2006, 10:20 PM CT

An Artificial Cornea In Sight

An Artificial Cornea In Sight
If eyes are "the windows of the soul," corneas are the panes in those windows. They shield the eye from dust and germs. They also act as the eye's outermost lens, contributing up to 75 percent of the eye's focusing power. On Sept. 11 in San Francisco at the annual meeting of the American Chemical Society, chemical engineer Curtis W. Frank will present a novel biomimetic material that's finding its way into artificial corneas. It's a hydrogel, or polymer that holds a lot of water. That material may promise a new view for at least 10 million people worldwide who are blind due to damaged or diseased corneas or a number of millions more who are nearsighted or farsighted due to misshapen corneas.

Called DuoptixTM, the material can swell to a water content of 80 percent--about the same as biological tissues. It's made of two interwoven networks of hydrogels. One network, made of polyethylene glycol molecules, resists the accumulation of surface proteins and inflammation. The other network is made of molecules of polyacrylic acid, a relative of the superabsorbent material in diapers.

"Think of a fishnet, but think of a 3-D fishnet," says Frank, the W. M. Keck, Sr. Professor in Engineering and a professor, by courtesy, of chemistry and of materials science and engineering. "It's a strong, stretchy material." That makes it able to survive suturing during surgery. The biocompatible hydrogel is transparent and permeable to nutrients, including glucose, the cornea's favorite food.........

Posted by: Mike      Permalink         Source


September 6, 2006, 7:50 PM CT

Progress In Macular Degeneration

Progress In Macular Degeneration
A dart-like molecule that adheres to proteins in the eye is the key that turns on the uncontrolled growth of blood vessels, as per scientists at Case Western Reserve University and the Cleveland Clinic Cole Eye Institute. Uncontrolled blood vessel growth is a major contributor to the development of age-related macular degeneration (AMD), the leading cause of blindness among people over 65 in the United States.

Robert Salomon and his graduate students Kutralanathan Renganathan and Liang Lu of Case's Department of Chemistry in the College of Arts and Sciences, observed that the molecule, Carboxyethylpyrroles (CEPs), attaches to proteins found in the eye, triggering the uncontrolled growth of blood cells.

The Case scientists teamed up with Quteba Ebrahem Jonathan Sears, Amit Vasanji, John Crabb and Bela Anand-Apte and Xiaorong Gu (a Salomon group alumna), of Cleveland Clinic, to complete the study titled Carboxyethlpyrrole oxidative protein modifications stimulate neovascularization: Implications for age-related macular degeneration." .

The results of their collaborative work were reported in the recent Proceedings of the National Academy of Science (PNAS).

AMD is a progressive disease that results in the severe loss of vision. The early stages of AMD are characterized as "dry," with the disease advancing to the "wet form" as the retina, the part of the eye responsible for central vision, becomes infused with fluid from leaky new blood vessels, during a process called neovascularization. The unchecked blood vessel growth, or angiogenesis, in the retina accounts for 80% of the vision loss in the advanced stages of AMD.........

Posted by: Mike      Permalink         Source


August 29, 2006, 9:52 PM CT

New device may improve vision

New device may improve vision
Researchers at Schepens Eye Research Institute, an affiliate of Harvard Medical School, say a visual aid they invented promises to improve the visual abilities of people with tunnel vision. In the first study to evaluate this small high tech device, the research team saw a significant increase in the effectiveness and speed with which visually impaired individuals found objects. The study -- in the recent issue of the Journal of Investigative.

Ophthalmology & Visual Science -- shows that this device, which combines a tiny camera, pocket-sized computer and transparent computer display on a pair of glasses, may offer the most effective assistance to date for this patient population.

"We are very pleased with the results of this first evaluation and hope that with further study and refinement, we may soon make this device available for the public," says low vision expert Dr. Eli Peli, the inventor, a senior scientist at Schepens, and a professor of ophthalmology at Harvard Medical School and the senior author of the study, .

About one in 200 Americans over age 55 suffers from tunnel vision, as a result of diseases such as retinitis pigmentosa (RP) and glaucoma. RP can begin to affect vision in one's teen years and may become quite severe tunnel vision by middle age. Residual tunnel vision occurs when peripheral or side vision is destroyed, leaving only a small window of central vision. The field of view of these patients can be likened to looking through the tube of a roll of paper towels. Thus, tunnel vision can often cause the individual to bump into or trip over obstacles. "Navigating city streets or buildings can be quite challenging," says Dr. Gang Luo, the study's first author, adding that for a person with tunnel vision, finding a misplaced item is like searching for a key in a dark room using a tiny flashlight. Luo is a research associate at Schepens Eye Research Institute and an instructor in Ophthalmology at Harvard Medical School.........

Posted by: Mike      Permalink         Source


August 27, 2006, 7:06 PM CT

How brain cells categorize images?

How brain cells categorize images?
Socks in the sock drawer, shirts in the shirt drawer, the time-honored lessons of helping organize one's clothes learned in youth. But what parts of the brain are used to encode such categories as socks, shirts or any other item, and how does such learning take place?

New research from Harvard Medical School (HMS) researchers has identified an area of the brain where such memories are found. They report in the advanced online Nature that they have identified neurons that assist in categorizing visual stimuli. They observed that the activity of neurons in a part of the brain called the parietal cortex encode the category, or meaning, of familiar visual images and that brain activity patterns changed dramatically as a result of learning. Their results suggest that categories are encoded by the activity of individual neurons (brain cells) and that the parietal cortex is a part of the brain circuitry that learns and recognizes the meaning of the things that we see.

"It was previously unknown that parietal cortex activity would show such dramatic changes as a result of learning new categories," says lead author David Freedman, PhD, HMS postdoctoral research fellow in neurobiology. "Some areas of the brain, especially the frontal and temporal lobes, have been linked to visual categorization. Since these brain areas are all interconnected, an important next step will be to determine their relative roles in the categorization process".........

Posted by: Daniel      Permalink         Source


August 23, 2006, 5:18 AM CT

Serious Eye Infection With Certain Contact Lens Solutions

Serious Eye Infection With Certain Contact Lens Solutions
Scientists have additional information concerning the recent outbreak of the corneal infection Fusarium keratitis, which was linked to use of a specific contact lens solution, as per a research studyin the August 23/30 issue of JAMA. After preliminary findings from this investigation were released in May, the product was withdrawn from the market worldwide.

Among the estimated 34 million contact lens wearers in the United States, microbial keratitis (corneal infection) is a rare but serious complication that may lead to permanent vision loss or the need for corneal transplantation. The annual occurence rate of microbial keratitis is estimated to be 4 to 21 per 10,000 soft contact lens wearers depending on overnight wear, as per background information in the article. Fusarium is a filamentous fungus usually found in soil and plants and is the major cause of fungal keratitis in certain tropical or subtropical regions. Beginning in March 2006, the Centers for Disease Control and Prevention received multiple reports of Fusarium keratitis among contact lens wearers in the US.

Douglas C. Chang, M.D., of the Centers for Disease Control and Prevention, Atlanta, and his colleagues conducted a study to determine the specific activities, contact lens hygiene practices, or products linked to this outbreak. Data for cases that occurred after June 1, 2005, were obtained by patient and ophthalmologist interviews for case patients and neighborhood-matched controls by trained personnel.........

Posted by: Mike      Permalink         Source


August 20, 2006, 2:21 PM CT

Immune cells protect retina from damage

Immune cells protect retina from damage Abnormal blood vessels and hemorrhage underneath the retina in the wet form of age-related macular degeneration
Eventhough some recent studies have suggested that inflammation promotes retinal damage in age-related macular degeneration (AMD), new work from Washington University ophthalmology scientists has observed that a particular type of inflammation, regulated by cells called macrophages, actually protects the eye from damage due to AMD.

The scientists report in the Aug. 15 issue of Public Library of Science (PLoS) Medicine that in a mouse model of AMD, macrophages help prevent the formation of blood vessels that grow underneath the retina and cause the majority of severe vision loss linked to AMD.

Age-related macular degeneration is the leading cause of blindness in the United States in people over the age of 50. It accounts for more than 40 percent of blindness among the institutionalized elderly, and as baby boomers get older, the problem is expected to grow, with at least 8 million cases of AMD predicted by the year 2020.

There are two varieties of AMD: a "dry" form and a "wet" form. Most patients have the dry form of the disease, and eventhough this can progress and cause severe vision loss in some, between 80 and 90 percent of the blindness and severe vision loss occurs in the wet form of the disease, as per the paper's first author Rajendra S. Apte, M.D., Ph.D.........

Posted by: Mike      Permalink         Source


July 31, 2006, 10:58 PM CT

One Of 50 Most Influential Women In Optical

One Of 50 Most Influential Women In Optical Sarita Soni
P. Sarita Soni, professor of optometry and vice provost for research at Indiana University Bloomington, was named among the 50 most influential women in optical in a report released by Vision Monday magazine, a national news and analysis service for eye care professionals.

Soni joined the School of Optometry in 1978 and has developed and taught many courses in optometry, vision science and optometric technology. She is also the founder and co-director of the IU Borish Center for Ophthalmic Research, which has been involved in numerous clinical trials under her direction. Soni has published more than 70 research articles on corneas, contact lenses and refractive error corrections over the span of her career. She has also served in various consulting roles for the Food and Drug Administration, Federal Trade Commission and National Institutes of Health.

The report honored women who had made a difference in the optical industry through their leadership and service. This was the fourth year that Vision Monday has compiled this list of influential women in optical. View the report online at http://cms.visionmonday.com/articles/details.asp?ID=15727.

To speak with Soni, contact Elisabeth Andrews, 812-855-2153 or ecandrew@indiana.edu.........

Posted by: Mike      Permalink         Source


July 26, 2006, 4:54 PM CT

how much the eye tells the brain

how much the eye tells the brain
Scientists at the University of Pennsylvania School of Medicine estimate that the human retina can transmit visual input at about the same rate as an Ethernet connection, one of the most common local area network systems used today. They present their findings in the recent issue of Current Biology. This line of scientific questioning points to ways in which neural systems compare to artificial ones, and can ultimately inform the design of artificial visual systems.

Much research on the basic science of vision asks what types of information the brain receives; this study instead asked how much. Using an intact retina from a guinea pig, the scientists recorded spikes of electrical impulses from ganglion cells using a miniature multi-electrode array. The researchers calculate that the human retina can transmit data at roughly 10 million bits per second. By comparison, an Ethernet can transmit information between computers at speeds of 10 to 100 million bits per second.

The retina is actually a piece of the brain that has grown into the eye and processes neural signals when it detects light. Ganglion cells carry information from the retina to the higher brain centers; other nerve cells within the retina perform the first stages of analysis of the visual world. The axons of the retinal ganglion cells, with the support of other types of cells, form the optic nerve and carry these signals to the brain.........

Posted by: Daniel      Permalink         Source



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