||Last Updated: Nov 17th, 2006 - 22:35:04
Master Proteins Dictate Retinal Differentiation Timetable
The embryonic construction of the vertebrate retina is a highly ordered affair. Following a precise timetable, six different specialized cell types emerge from a mass of identical, proliferating cells. The process of retinal cell differentiation, when so-called progenitor cells stop dividing and choose among the six fates, depends primarily on homeobox genes, major regulators of embryonic patterning. How these genes control the timing of retinal cell differentiation has remained an open question—until now.
Aug 16, 2006, 08:41
Yellow plant pigments lutein and zeaxanthin reduce risk of age-related macular degeneration
Women younger than age 75 years who eat diets rich in the yellow plant pigments lutein and zeaxanthin may have a reduced risk of developing the eye disease age-related macular degeneration, according to a report in the August issue of Archives of Ophthalmology, one of the JAMA/Archives journals. Age-related macular degeneration (AMD) occurs when the macula, the area at the back of the retina that produces the sharpest vision, deteriorates over time. The condition is the leading cause of blindness in aging Americans, according to background information in the article. There is no cure for AMD and limited treatment options are available to slow its progression, so research on preventive measures is essential. Previous studies have suggested a potential link between AMD and lutein and zeaxanthin, plant pigments known as carotenoids and found in leafy green vegetables, corn, egg yolks, squash, broccoli and peas. These compounds may reduce the risk of AMD by absorbing blue light that could damage the macula, by preventing free radicals from damaging eye cells and by strengthening eye cell membranes.
Aug 15, 2006, 11:41
Objective way to diagnose diseases of colour perception
Pictures of brain waves that reveal our ability to see colour could provide a new objective way to diagnose and monitor diseases that affect human colour perception. The research finding by a Universiy of New South Wales PhD student, Ms Mei Ying Boon, has earned her a nomination in this year's Fresh Science Awards.
Aug 10, 2006, 14:59
Onchocerciasis treatment reduces prevalence and intensity by 38%
Onchocerciasis, river blindness or craw craw is an endemic disease in Bioko Island, Equatorial Guinea. This pathology causes a weakening in affected individuals, most of them within the labour force population, making this disease one of the limiting factors for the economic development of the island.
Jul 31, 2006, 11:45
Antioxidants may slow retinal degeneration
Scientists at Johns Hopkins have successfully blocked the advance of retinal degeneration in mice with a form of retinitis pigmentosa (RP) by treating them with vitamin E, alpha-lipoic acid and other antioxidant chemicals.
Jul 20, 2006, 20:22
Hormone Therapy Does Not Affect Age-Related Vision Loss
Postmenopausal hormone therapy does not appear to increase or decrease the overall risk of AMD among women, although combination hormones may slightly reduce the chances of developing certain risk factors or types of the condition, according to a report in the July issue of the Archives of Ophthalmology, one of the JAMA/Archives journals.
Jul 12, 2006, 05:59
Eating Fish Protects Against Macular Degeneration
In a study, Brian Chua, B.Sc., M.B.B.S., M.P.H., Westmead Millennium Institute and Vision Co-operative Research Centre, Syndney, Australia, and colleagues examined the association between dietary fat intake and AMD risk in 2,895 Australians age 49 years or older, beginning in 1992-1994. At the beginning of the study and again five years later, participants had a comprehensive eye exam that included photographs of the retina. They also filled out a questionnaire with data about food types and portion sizes consumed, including specific information about margarines, butters, oils and supplements.
Jul 12, 2006, 05:53
Research Highlights Risk Factors For Age-Related Vision Loss
Eating fish frequently may be associated with decreased chances of developing age-related macular degeneration, while smoking nearly doubles the risk for this common cause of vision loss and hormone therapy appears to have no effect, according to three articles in the July issue of the Archives of Ophthalmology, one of the JAMA/Archives journals.
Jul 12, 2006, 05:50
How Thalamic Neurons Grab Your Attention
Certain salient features in a visual scene grab our attention, such as a tiger emerging from a field of tall grass, after which we may spend more time taking in the details. Both ways of experiencing the world are automatic, and the neurons that make up the brain's visual system switch between these two modes continuously. But the exact neurons and mechanisms responsible are still a mystery to neuroscientists.
Jul 12, 2006, 05:27
FDA approves ranibizumab for the treatment of wet age-related macular degeneration
The Food and Drug Administration (FDA) today approved Lucentis (ranibizumab injection) for the treatment of patients with neovascular (wet) age-related macular degeneration (AMD). Lucentis is the first treatment which, when dosed monthly, can maintain the vision of more than 90 percent of patients with this type of AMD.
Jul 6, 2006, 02:23
High Body Mass Index Increase the Genetic Risk of AMD
Current cigarette smoking was associated with a fivefold increased risk and high BMI (30 or higher) was associated with a twofold higher risk of AMD. The homozygous risk genotype (CC) plus smoking conferred a tenfold higher risk of AMD, compared with non-smokers with the non-risk (TT) genotype, while the risk genotype plus higher BMI increased risk of AMD almost sixfold. Gene plus environment risk scores provided an area under the receiver operating characteristic (ROC) curve of 0.70-0.75. The attributable risks for the combination of genes and environment were 69% to 73%.
Jul 1, 2006, 17:41
Ranibizumab Approved for Wet Age-Related Macular Degeneration
The Food and Drug Administration (FDA) approved Lucentis (ranibizumab injection) for the treatment of patients with neovascular (wet) age-related macular degeneration (AMD). Lucentis is the first treatment which, when dosed monthly, can maintain the vision of more than 90 percent of patients with this type of AMD. Lucentis is a new molecular entity (NME), meaning it contains an active substance that has never before been approved for marketing in any form in the United States. Lucentis will be the first FDA--approved product to provide prescription information in the new format for prescription drug package inserts, to provide professionals and consumers clear and concise prescription information.
Jul 1, 2006, 16:41
Statins reduce incidence of nuclear cataract
The use of statins is linked with a lower incidence of nuclear cataract, the most common type of age-related cataract, according to a study in the June 21 issue of JAMA. Statins are widely used to decrease serum cholesterol for cardiovascular disease prevention. Statins have also been shown to have antioxidant activity. Oxidative stress (a condition in which antioxidant levels are lower than normal) has been thought to be a risk factor for age-related cataract, particularly nuclear cataract (the most common type of age-related cataract, which occurs in the center of the lens). Some evidence has suggested an association between nutritional intake of antioxidants and age-related cataract, according to background information in the article.
Jun 21, 2006, 15:22
Limitations of human visual system hinders goalkeepers
Professional goalkeepers fail to stop free kicks because of shortcomings in their visual system, according to new research by Cathy Craig and colleagues, from Queen’s University Belfast, Northern Ireland. The projected trajectory of a ball following a curved flight path is more difficult to judge because our visual system is not sensitive enough to gauge a change of direction at speed, mid-flight. The research is published in Springer-Verlag’s journal Naturwissenschaften.
May 22, 2006, 03:20
First look at the 'birth' of a retina cell
Scientists at the University of Michigan Kellogg Eye Center have gained new insight into the way an embryonic retina cell develops and then commits itself to a specific role. They have observed a small window of opportunity during which a cell has been designated to play a particular role, but has not yet begun to function as such.
May 7, 2006, 15:25
New genetic discovery explains 74 percent cases of age-related macular degeneration
A new study, led by researchers at Columbia University Medical Center, pinpoints the role that two genes – Factor H and Factor B – play in the development of nearly three out of four cases of age-related macular degeneration (AMD), a devastating eye disease that affects more than 10 million people in the United States. Findings indicate that 74 percent of AMD patients carry certain variants in one or both genes that significantly increase their risk of this disease.
Mar 6, 2006, 17:31
Just two genes, Factor H and Factor B, cause blindness in millions
Just two genes cause blindness in millions of older people across the globe, a discovery that scientists say could aid the development of new treatments for the condition.
Mar 6, 2006, 16:56
Marijuana for Diabetic retinopathy ?
Scientists have discovered a compound in marijuana that could protect against eye damage in diabetics.
Feb 28, 2006, 21:26
Controlling SPARC levels key to controlling angiogenesis in macular degeneration
For the second time in a week Dr. Jayakrishna Ambati, UK HealthCare physician and associate professor and vice chair of the Department of Ophthalmology and Visual Sciences, announced a discovery from his lab that will affect the future of macular degeneration treatment and research.
Feb 3, 2006, 16:08
Microsaccades are indeed responsible for most of our visual experience
For more than 40 years, a scientific controversy has raged over whether microsaccades, rapid eye movements that occur when a person's gaze is fixated, are responsible for visibility.
Jan 20, 2006, 15:36
Making new blood vessels: keeping the lines of sight open
The creation of new blood vessels, known as angiogenesis, is a process used to supply oxygen and nutrients at sites of tissue injury. Angiogenesis is known to be stimulated during hypoxia (low oxygen conditions, when new vessels are needed). However, the mechanisms by which hypoxia leads to new vessel formation is poorly understood.
Jan 20, 2006, 13:56
Sudden severe loss of vision linked with impotency drugs
Viagra and Cialis, the drugs used to treat impotency, may be associated with an increased risk of optic nerve damage in men with a history of heart attack or high blood pressure, suggests a small study in the British Journal of Ophthalmology.
Jan 17, 2006, 19:09
Antioxidants reduce risk of age-related macular degeneration
A diet with a high intake of beta carotene, vitamins C and E, and zinc is associated with a substantially reduced risk of age-related macular degeneration in elderly persons, according to a study in the December 28 issue of JAMA. Age-related macular degeneration (AMD) is a degenerative disorder of the macula, the central part of the retina, and is the most common cause of irreversible blindness in developed countries, according to background information in the article. Late-stage AMD results in an inability to read, recognize faces, drive, or move freely. The prevalence of late AMD steeply increases with age, affecting 11.5 percent of white persons older than 80 years. In the absence of effective treatment for AMD, the number of patients severely disabled by late-stage AMD is expected to increase in the next 20 years by more than 50 percent to 3 million in the United States alone. Epidemiological studies evaluating both dietary intake and serum levels of antioxidant vitamins and AMD have provided conflicting results. One study (called AREDS) showed that supplements containing 5 to 13 times the recommended daily allowance of beta carotene, vitamins C and E, and zinc given to participants with early or single eye late AMD resulted in a 25 percent reduction in the 5-year progression to late AMD.
Dec 28, 2005, 18:23
Successful tests of new treatments for Leber congenital amaurosis (LCA)
A team led by Krzysztof Palczewski, Ph.D., chair of pharmacology at the Case Western Reserve University School of Medicine, has taken the first steps in treating an eye disease causing irreversible congenital blindness in millions of people worldwide by successfully testing two new treatments in mice.
Nov 2, 2005, 11:21
First-ever Images of Living Human Retinas Sprung a Surprise
First-ever images of living human retinas have yielded a surprise about how we perceive our world. Researchers at the University of Rochester have found that the number of color-sensitive cones in the human retina differs dramatically among people—by up to 40 times—yet people appear to perceive colors the same way. The findings, on the cover of this week's journal Neuroscience, strongly suggest that our perception of color is controlled much more by our brains than by our eyes.
Oct 27, 2005, 00:32
Dietary Fat Intake Linked to Dry Eye Syndrome in Women
More than eight million people in the United States, predominantly women, suffer from dry eye syndrome, a painful and debilitating eye disease. In the first study of its kind to examine modifiable risk factors, researchers from Brigham and Women’s Hospital (BWH) and Schepens Eye Research Institute (SERI) found that the amount, type and ratio of essential fatty acids in the diet may play a key role in dry eye prevention in women.
Oct 20, 2005, 23:11
Neural wiring in brain's visual system is not dismantled by visual deprivation
New research findings led by Thomas Krahe and Ary S. Ramoa of Virginia Commonwealth University School of Medicine offer two pieces of good news for treating children with amblyopia. First, the researchers have found evidence that the neural wiring in the brain's visual system is not dismantled by visual deprivation--for example, due to a cataract--during what is known as the "critical period" of vision development. Rather, the wiring is merely deactivated, capable of being rapidly reactivated when vision is restored. And secondly, the researchers wrote in an article published in the October 20, 2005, issue of Neuron, their findings suggest that allowing children with amblyopia to use both eyes--rather than patching the stronger eye to encourage use of the weaker one--enables better recovery. Such findings are clinically important because about three percent of people suffer loss of visual acuity in one eye during early development.
Oct 20, 2005, 16:02
VISION - VEGF Inhibition Study in Ocular Neovascularization Exploratory Analysis
Age-related macular degeneration (AMD) is the leading cause of blindness in older patients in the developed world. Vascular endothelial growth factor is one of the key mediators stimulating the abnormal blood vessel growth and leakage characteristic of the exudative (wet) form of the condition. Pegaptanib sodium (Macugen) is a new treatment for exudative AMD, and has been shown to stabilize vision in approximately 70 percent of cases.
Oct 8, 2005, 05:57
Why do pictures look same from different angles?
University of California at Berkley and RIT release new findings on visual perception
Sep 27, 2005, 18:28
Potential role of amyloid-beta in the pathogenesis of age-related macular degeneration
Age-related macular degeneration (AMD) is the main cause of blindness in patients over the age of 60. In these AMD patients, choroidal neovascularization (CNV) is the most common cause of visual loss.
Sep 27, 2005, 01:21