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aamukherjee A Slice of Entropie -
alchymista Alchymista -
crownedrose Fading Like A Dead Star -
expose-the-light Quarks to Quasars -
ikenbot CWL -
abluegirl A Blue Girl -
perscientiamlibertas A Matter of the Most Pleasant Fraternal Confidence
IMPLANTABLE TELESCOPE LENS TO TREAT MACULAR DEGENERATION
Retired entrepreneur Willis “James” Hindman, 77, always enjoyed raising and watching thoroughbred race horses run on his farm in Westminster, Md. “There is nothing more beautiful than seeing a horse in motion and at full speed. It’s something very special to me,” says Hindman.
But when severe age-related macular degeneration (AMD) destroyed Hindman’s vision to the point where he couldn’t read, see faces of family and friends or watch his horses, he says he became depressed and a “captive of my limitations.”
Hindman, founder and former CEO of Jiffy Lube International, is one of the approximately two million Americans who have the advanced form of AMD, which affects the region of the retina responsible for central, detailed vision, and is the leading cause of irreversible vision loss and legal blindness in people over the age of 65.
Now, a relatively new device, essentially an implantable telescope, is available to people like Hindman, who underwent his implantation in December 2012, is offering hope for those “aging eyes.” The U.S. Food and Drug Administration approved the Implantable Miniature Telescope (IMT), which works like the telephoto lens of a camera, in 2010.
The surgical procedure involves removing the eye’s natural lens, as with cataract surgery, and replacing the lens with the IMT. The tiny telescope is implanted behind the iris, the colored, muscular ring around the pupil.
“While it doesn’t cure AMD, it will help improve the vision of patients, like Mr. Hindman, and help them resume their favorite activities and independence,” said Oliver D. Schein, M.D., M.P.H., M.B.A., Burton E. Grossman Professor of Ophthalmology and director of the Comprehensive Eye Service at The Wilmer Eye Institute at Johns Hopkins.
The Wilmer Eye Institute is the first place in Maryland to implant the IMT since its approval by the FDA. Schein, who performed the surgery on Hindman, led the Wilmer Eye Institute’s participation in a four-year, multi-center FDA study that provided long-term data on the efficacy of the IMT in patients with end stage age AMD.
Hindman is one of three (two from the trial, one post-FDA approval) Wilmer patients in Maryland to have the telescope implanted to date. The device itself costs approximately $15,000, which does not include the cost of surgery and rehabilitation. However, Schein says that the IMT is covered by Medicare for eligible patients. Schein says that after the IMT implantation, patients participate in an extensive rehabilitation program that involves training them to effectively use the device. Rehabilitation postsurgery takes about six months to a year.
Hindman, who is currently receiving therapy at Wilmer’s Low Vision Rehabilitative Services from a visual rehabilitation specialist, is still learning how to use his enhanced eye.
“After surgery, the therapy is the most critical component. You need months of training in helping to reteach the brain to learn how to use each eye differently for a specific task,” explains Judith Goldstein, O.D., FAAO, assistant professor of ophthalmology and rehabilitative medicine and chief of the Low Vision and Visual Rehabilitation Service at the Wilmer Eye Institute at Johns Hopkins. “The telescope eye sees things centrally and the non-telescope eye basically sees things peripherally. It’s unlike anything they’ve ever experienced.”
Hindman says the change in his life has been dramatic over the past four months.
“The services I have been provided at Johns Hopkins have just been tremendous. They’ve been inspiring. They make me want to get up in the morning,” says Hindman. “I have started becoming more interested in working with my horses because I can see.”
Schein cautions though that the surgery is not for everyone and in keeping with FDA guidelines potential candidates must be 75 years of age or older, have irreversible dry AMD and no longer be a candidate for drug treatment. The guidelines also exclude those who have had previous cataract surgery in the eye to be implanted.
(Image: The Implantable Miniature Telescope (IMT)technology reduces the impact of the central vision blind spot due to End-Stage AMD and projects the objects the patient is looking at onto the healthy area of the light-sensing retina not degenerated by the disease. Photo courtesy of of VisionCare Ophthalmic Technologies CentraSight treatment program)
neuromorphogenesis
If optimists see the world through rose-colored lenses, some birds see it through ultraviolet ones. Avians have evolved ultraviolet vision quite a few times in history, a new study finds.
Birds depend on their color vision for selecting mates, hunting or foraging for food, and spotting predators. Until recently, ultraviolet vision was thought to have arisen as a one-time development in birds. But a new DNA analysis of 40 bird species, reported Feb. 11 in the journal BMC Evolutionary Biology, shows the shift between violet (shorter wavelengths on the electromagnetic spectrum) and ultraviolet vision has occurred at least 14 times.
“Birds see color in a different way from humans,” study co-author Anders Ödeen, an animal ecologist at Uppsala University in Sweden, told LiveScience. Human eyes have three different color receptors, or cones, that are sensitive to light of different wavelengths and mix together to reveal all the colors we see. Birds, by contrast, have four cones, so “they see potentially more colors than humans do,” Ödeen said.
Birds themselves are split into two groups based on the color of light (wavelength) that their cones detect most acutely. Scientists define them as violet-sensitive or ultraviolet-sensitive, and the two groups don’t overlap, according to Ödeen. Birds of each group would see the same objects as different hues.
The specialization of color vision has its advantages. For instance, a bird with ultraviolet-sensitive vision might have spectacularly bright plumage in order to impress a female, but that same plumage might appear dull to predator birds that see only in the violet range.
ikenbot
The revolutionary ‘contact lens’ loaded with stem cells that restores sight - by helping the eye heal itself naturally
A ‘contact lens’ loaded with stem cells could be a way to naturally repair or retain sight. Scientists hope the biodegradable implant loaded with stem cells that then multiply will allow the body to heal the eye naturally.
Stem cells are the building blocks of tissue growth. They can transform into any other type of cell the body is built from and so should be able to repair everything from the brain to the heart. The scientists at the University of Sheffield who developed the implant now hope the new technique could help millions of people across the world retain or even regain - their sight.
The technology has been designed to treat damage to the cornea, the transparent layer on the front of the eye, which is one of the major causes of blindness in the world. With the new implant, by mimicking structural features of the eye, the researchers have developed a new method for producing very delicate thin membranes to help graft stem cells onto the eye itself.
Using a series of complex techniques, the researchers are able to make a disc of biodegradable material that can be fixed over the cornea. The disc is loaded with stem cells that then multiply, allowing the body to heal the eye naturally. Standard treatments for corneal blindness are corneal transplants or grafting stem cells onto the eye using a donated human membrane as a temporary carrier to deliver these cells to the eye.
But for some patients, the treatment can fail after a few years as the repaired eyes do not retain these stem cells, which are required to carry out repair of the cornea. A key feature of this new disc is that it contains small pockets to house and protect the stem cells, to keep them in the eye and also grouped together.
‘The disc has an outer ring containing pockets into which stem cells taken from the patient’s healthy eye can be placed,’ said Dr Ílida Ortega Asencio, from Sheffield’s Faculty of Engineering.
‘The material across the centre of the disc is thinner than the ring, so it will biodegrade more quickly allowing the stem cells to proliferate across the surface of the eye to repair the cornea.’
Without this constant repair, thick white scar tissue forms across the cornea causing partial or complete sight loss. The researchers said another advantage of the disc is that it is biodegradable and made from the same material already used in sutures, so it will not cause a problem in the body.Laboratory tests have shown that the membranes will support cell growth. As a result, clinical trials are expected to begin shortly in India, as the Sheffield scientists are working in conjunction with researchers at the LV Prasad Eye Institute in Hyderabad.
Commenting on the disc, Dr Frederick Claeyssens, lecturer in biomaterials at the University of Sheffield, said: ‘We also believe that the overall treatment using these discs will not only be better than current treatments, it will be cheaper as well.’
The research is published in the journal Acta Biomaterialia.
Woah.
Jeepers, Peepers: Why Spiders Have So Many Eyes
Is it their eight creepy-crawly legs or their eight beady eyes that make spiders a spooky Halloween staple? Either way, new research suggests all those extra pairs of spider peepers have their own roles to play in keeping the arachnids safe.
Jumping spiders, a group of spiders that actively hunts its prey rather than trapping it in webs, have four pairs of eyes (as do most spiders). A new study finds that while the center, or principal, pair of eyes is good at picking out details, one of the side pairs is crucial for warning spiders when something is coming their way.
This “looming response” is the equivalent of a human ducking and covering when a baseball flies toward his or her face. But humans rely on just one pair of eyes to both avoid the baseball and see the details of its stitching. Jumping spiders use four eyes for the same tasks.
Space Flight Squishes Astronaut’s Eyeballs
Trips to weightlessness can squash the eyeballs of astronauts, swell the optic nerves and blur vision — changes that often persist long after the astronauts return to weightbound Earth. That is one more health effect that NASA will have to worry about before astronauts venture farther out into the solar system..Myopia seems a small price to pay for “boldly going” where very few men and women have gone before.
(via TYWKIWDBI (“Tai-Wiki-Widbee”): Astronaut’s eyeballs get squished)
Incredible close-up photos of animals’ eyes by Suren Manvelyan
expose-the-light
Eyes move constantly when we think, when it might make more sense to look straight at whatever we are looking at. Now scientists are teasing apart what causes our eyes to move when we are thinking and not looking.
Past research suggests that rightward shifts, which are linked with the left…
Eyes That Tell Stories
The Singapore Eye Research Institute commissioned Jorg Sundermann to capture these abstracted photos of eyes to help raise awareness for eye research. See the entire series over on Behance.
New Look at Mouse Eyes
Photograph courtesy Bryan William Jones, University of Utah
A cross-section of a mouse eye reveals complex signs of metabolism—chemical changes in cells that release energy—in the eye’s tissues. The picture won first place in the contest’s photography category.
To create the image, Bryan William Jones “assigned” colors to three organic molecules found in mouse eyes: taurine (red), glutamine (green), and glutamate (blue).
The resulting range of hues comes from different molecular concentrations in the more than 70 classes of cell in the eye. For instance, the deep blue in the middle is optic fiber, while concentric rings of pink represent photoreceptor cells.
“Some of the muscles that move the eye can be seen on the outer, leftmost portion of the image as a golden color, while the sclera—which is normally the white part of your eye—is shown in green,” Jones, of the University of Utah’s Moran Eye Center, said via email.
(See “Mice Get ‘Human’ Vision in Gene Experiment.”)
One of the best pictures of 2011 Published February 1, 2012 in National Geographic
Psychologists Decipher Brain’s Clever Autofocus Software
It’s something we all take for granted: our ability to look at an object, near or far, and bring it instantly into focus. The eyes of humans and many animals do this almost instantaneously and with stunning accuracy. Now researchers say they are one step closer to understanding how the brain accomplishes this feat.
In an attempt to resolve the question of how humans and animals might use blur to accurately estimate distance, Geisler and Burge used well-known mathematical equations to create a computer simulation of the human visual system. They presented the computer with digital images of natural scenes similar to what a person might see, such as faces, flowers, or scenery, and observed that although the content of these images varied widely, many features of the images—patterns of sharpness and blurriness and relative amounts of detail—remained the same.
The duo then attempted to mimic how the human visual system might be processing these images by adding a set of filters to their model designed to detect these features. When they blurred the images by systematically changing the focus error in the computer simulation and tested the response of the filters, the researchers found that they could predict the exact amount of focus error by the pattern of response they observed in the feature detectors. The researchers say this provides a potential explanation for how the brains of humans and animals can quickly and accurately determine focus error without guessing and checking. Their research appears online this week in the Proceedings of the National Academy of Sciences.
(via ikenbot)
cwnl:
New Vessels
People with diabetes are 25 times as likely as others to lose vision. This is thought to be because the retinas of diabetics are damaged through oxygen starvation associated with the disease. To diagnose the disease, doctors look for new blood vessels created by the retina to compensate for the lack of oxygen. Sodium fluorescein is injected intravenously, and blue light is used to visualise the retinal blood vessels.
Image: Chris Barry
