New Treatment For Age-Related Macular Degeneration Within Sight

With 8 million people at high risk for advanced age-related Macular Degeneration, researchers from Harvard and Japan discovered that the experimental drug, endostatin, may be the cure. A research report describes how giving endostatin to mice significantly reduced or eliminated abnormal blood vessel growth within the eye, which is ultimately why the disease causes blindness.

"Our study provides intriguing findings that may lead to a better treatment of age-related Macular Degeneration," said Alexander Marneros, the first author of the report, "but clinical studies in patients with age-related Macular Degeneration are still necessary."

In this study, researchers describe testing the effects of endostatin on mice lacking this naturally occurring substance. The mice without endostatin were about three times more likely to develop advanced age-related Macular Degeneration (AMD) than normal mice. Then the researchers administered endostatin to both sets of mice. In the mice lacking endostatin, the number of abnormal blood vessels that cause AMD were reduced to normal levels. In control mice with normal levels of endostatin, the number of abnormal blood vessels were practically undetectable.

"With Baby Boomers reaching advanced ages, new treatments are desperately needed to keep age-related Macular Degeneration from becoming a national epidemic," said Gerald Weissmann, MD, Editor-in-Chief of The FASEB Journal. "This research provides hope for those at risk for blindness, and it gives everyone another glimpse of how investments in molecular biology will ultimately pay off in terms of new treatments and cures."

AMD is a progressive disease that affects the part of the eye that allows people to see fine details. The disease gradually destroys sharp, central vision, and in advanced stages ultimately leads to total blindness. Abnormal blood vessel growth, also known as angiogenesis, is a hallmark of advanced AMD. These faulty blood vessels leak fluids and blood, causing catastrophic vision loss.

As the name implies, risk for age-related Macular Degeneration increases with age, and 8 million people are considered to be at high risk for the disease. Of these individuals, approximately 1 to 1.3 million will develop advanced AMD within the next five years. Endostatin is an experimental drug, which is currently being tested to stop cancer in people by restricting the formation of abnormal blood vessels supply blood to tumors. Endostatin is a protein in collagen, and while collagen is used in a range of products for skin care to gelatin desserts, consumption or use of these products does not have any effect on tumors or AMD.

Weissmann added, "This research proves once and for all that endostatin functions as the body's own natural inhibitor of new blood vessel growth as Judah Folkman of Harvard predicted."

This research was published in the December 2007 issue of The FASEB Journal.

http://www.sciencedaily.com/releases/2007/11/071129142449.htm

Story Source:

The above story is reprinted from materials provided by Federation of American Societies for Experimental Biology, via EurekAlert!, a service of AAAS.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

New Light Shed On How Retina's Hardware Is Used in Color Vision

New Light Shed On How Retina's Hardware Is Used in Color Vision

Biologists at New York University and the University of Würzburg have identified, in greater detail, how the Retina's cellular hardware is used in color preference. The findings, published in the latest issue of the Proceedings of the National Academy of Sciences (PNAS), enhance our understanding of how eyes and the brain process color.

Light can serve as an attractive or repulsive landmark for orientation -- we identify an object or a light source at a certain location in visual space, then approach it or retreat from it. This process, called phototaxis, was the focus of the PNAS study.

Conducted by biologists at New York University's Center for Developmental Genetics and the Department of Genetics and Neurobiology at the University of Würzburg in Germany, the research specifically examined the photoreceptor cells in the Retinas of the fruit fly Drosophila. Drosophila is a powerful model for studying the color vision process as it is amenable to very specific genetic manipulations, allowing researchers to analyze how its visual system functions when different elements of its Retina are affected.

The visual systems of most species contain photoreceptors with distinct spectral sensitivities that allow animals to distinguish lights by their spectral composition (i.e., color). In Drosophila, six of these (R1-R6) are responsible for motion detection and are sensitive to the brightness or dimness of a broad spectrum of light. Two others (R7 and R8) are used for color vision by comparing ultraviolet light (UV), detected by R7, with green or blue light detected by two types of R8. The NYU and University of Würzburg biologists investigated how photoreceptor types contribute to phototaxis by blocking the function of either R7 or R8, or a combination of a range of photoreceptors (R1-R6, R7 and/or R8).

In the study, they constructed two sets of "Y-shaped mazes" with two different types of light at the ends of each: UV and blue in one and blue and green in the other. Under this arrangement, the fly would show a preference for certain type of light (UV vs. blue in one maze; blue vs. green in the other) by moving toward it. The researchers could then link specific preferences to the make-up of each fly's visual system.

In a "UV vs. blue" choice, flies with only R1-R6 and flies with only R7/R8 photoreceptors preferred the blue to the UV light. This finding suggested that these two sets of photoreceptors (R1-R6 and R7/R8) function separately in phototaxis as flies with only one of these sets showed similar preferences. In addition, flies without a functioning R7 photoreceptor preferred the blue to the UV light, whereas flies without R8 preferred UV. In the "blue vs. green" maze, flies without a functioning blue R8 photoreceptor preferred green, whereas those with a defective for green R8 photoreceptor preferred blue. This shows that each subclass of photoreceptors [R1-R6, R7, R8 (blue), R8 (green)] is used by the fly to distinguish colors and setup its innate color preference. In a previous work, the same authors had shown that motion detection only involves R1-R6 and not R7 and R8, suggesting that there are two independent channels in the fly visual system -- one for motion and one for color.

"This simple insect can achieve sophisticated color discrimination and detect a broader spectrum of colors than we can, especially in the UV," said NYU biologist Claude Desplan, one of the study's authors. "It is a great model system to understand how the Retina and the brain process visual information.
The research was supported by a grant from the National Institutes of Health.
http://www.sciencedaily.com/releases/2010/03/100308151051.htm

The above story is reprinted from materials provided by New York University, via EurekAlert!, a service of AAAS.
Note: Materials may be edited for content and length. For further information, please contact the source cited above.

New Glaucoma Test Allows Earlier, More Accurate Detection

Cumbersome Glaucoma tests that require a visit to the ophthalmologist could soon be history thanks to a home test developed by a UA engineer.

Phoenix ophthalmologist Dr. Gholan Peyman demonstrates a prototype Glaucoma test instrument that's noninvasive and simpler to use than current procedures. It can also be used in situations that are difficult or impossible with current tests. (Credit: Image courtesy of University of Arizona College of Engineering)

The self-test instrument has been designed in Eniko Enikov's lab at the UA College of Engineering. Gone are the eye drops and need for a sterilized sensor. In their place is an easy-to-use probe that gently rubs the eyelid and can be used at home.

"You simply close your eye and rub the eyelid like you might casually rub your eye," said Enikov, a professor of aerospace and mechanical engineering. "The instrument detects the stiffness and, therefore, infers the intraocular pressure." Enikov also heads the Advanced Micro and Nanosystems Laboratory.

While the probe is simple to use, the technology behind it is complex, involving a system of micro-force sensors, specially designed microchips, and math-based procedures programmed into its memory.

Enikov began working on the probe four years ago in collaboration with Dr. Gholan Peyman, a Phoenix ophthalmologist. "We went through several years of refinement and modifications to arrive at the current design," Enikov noted.

The National Science Foundation has funded the work, and Enikov and Peyman now are seeking investors to help fund final development and commercialization of the product.

In addition to screening for Glaucoma, an eye disease that can lead to blindness if left untreated, the device corrects some problems with the current procedure, and can be used to measure drainage of intraocular fluid.

"Eye pressure varies over a 24-hour cycle," Enikov said. "So it could be low at the doctor's office and three hours later it might be high. With only a single test, the doctor might miss the problem. Having the ability to take more frequent tests can lead to earlier detection in some cases."

Once the diagnosis is made, several treatments are available. The question then is: How effective are they? Patients could use the probe at home to trace how much the pressure decreases after using eye drop medications, for instance.

"One of the reasons pressure builds up in the eye is because fluid doesn't drain properly," Enikov noted. "Currently, there are no methods available to test drainage."

Current tests require applying pressure directly to the cornea, but only very light pressure is safe to use, and it doesn't cause the fluid to drain.

"Our technique allows us to apply slightly greater pressure, but it's still not uncomfortable," he said. "It's equivalent to rubbing your eye for a brief period to find out if the pressure changes. If it does, we know by how much and if there is a proper outflow of intraocular fluid."

Sometimes, a surgical shunt is used to help fluid drain from the eye. "The problem with Glaucoma shunts is they can plug up over time," Enikov noted. "Or if they're not properly installed, they may drain too quickly. So you would want to know how well the shunt is working and if it is properly installed. Our device could help answer those questions."

In another scenario, certain patients cannot be tested for Glaucoma using currently available procedures. "If a patient had cataract surgery or some other surgery through the cornea, the cornea sometimes thickens," Enikov said. "The cornea's structure is different, but our test remains accurate because it's not applied to the cornea."

Instead, it presses the entire eyeball, much as you might press a balloon to determine its stiffness.

"The innovation with our device is that it's noninvasive, simpler to use and applies to a variety of situations that are either difficult to address or impossible to test using the current procedures," Enikov said. "That's why we're so excited about this probe. It has great potential to improve medical care, and significant commercial possibilities, as well."

http://www.sciencedaily.com/releases/2011/01/110104101331.htm

The above story is reprinted from materials provided by University of Arizona College of Engineering. The original article was written by Ed Stiles.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Caring For Your New Eyeglasses

Caring For Your New Eyeglasses

Those new glasses look great on you, and you'll want to keep that look fresh and bright. Theses simple steps will ensure your satisfaction.

Have your glasses adjusted if they slip, feel tight or look crooked. If your temples won't stay open, have the screws tighteded. Put on and remove your glasses with both hands to avoid stretching the fit.

If your frame has nosepads, the color should be clear. Have them repladed annually so they won't appear discolored.

During the daily cleaning, use your microfiber drying cloth to buff the frame so it gleams.

When not worn, store your glasses in a hard case. They will become scratched and dull in your pocket or purse. Add a drying cloth to the case to gently dust away snowflakes that appear throughout the day.