Thursday, October 28, 2010

Experimental Synthetic Cornea May Provide Alternative To Cadaver Corneas.

By Fiona MacRae from the UK Daily Mail

Button-shaped artificial corneas have restored the sight in men and women in danger of going blind.
The man-made corneas were just as good at improving eyesight as those usually obtained from donors.
In time, the transparent implants could help ease the dire shortage of donated corneas.
Around 3,000 transplants are carried out in the UK each year but hundreds more could have benefited from the surgery.
Worldwide, 1.5million people go blind each year because they cannot have corneal transplants.
Damage to the cornea, the collagen-based transparent outermost layer of the eye, is one of the most common causes of blindness. It affects ten million people around the world and can be caused by genetics, surgery, burns, infection or chemotherapy.
Previous attempts to develop synthetic implants have had limited success. To create an implant that is as close as the real thing as possible, the North American and Swedish researchers grew a synthetic form of human collagen in the lab and moulded it into wafer-thin button-like shapes.
Ten men and women with corneal disease had the damaged tissue scraped away from the surface of the eye and replaced with a man-made cornea in a half-hour operation.
Over time, the patients were able to blink and cry and the nerves severed by the surgery mended.
Fitted with contact lenses, the patients were able to see as well as people who had conventional corneal transplants, the journal Science Translational Medicine reports. Two years after the op, the lab- grown corneas were still working well.
Using ' biosynthetic' corneas removes the risks of disease and rejection associated with corneas taken from donors after death.
Dr May Griffith, of the University of Ottawa in Canada and Linkoping University in southern Sweden, said: 'This study is important because it is the first to show that an artificially fabricated cornea can integrate within the human eye and stimulate regeneration.
' With further research, this approach could help restore sight to millions of people who are waiting for a donated cornea for transplantation.
The journal reported: ' The see-through nature of the cornea is easily destroyed by trauma or infection but replacement human corneas can be inserted and reliably restore vision.
'The problem is that the shortage of donated corneas leaves millions of people likely to go blind. An alternative source of corneas could make a big difference.
'These biosynthetic corneas may soon allow patients who need transplants but do not have donors to regain normal sight.'
Barbara McLaughlan, of the Royal National Institute of Blind People, said: 'This is potentially an exciting new development for patients with corneal blindness where currently transplant from a human donor is the only treatment opt ion available.
'The first results of this small scale trial in humans seem very encouraging, however mor e research is needed to determine if this could work for all types of corneal blindness and become a widely available treatment.
'RNIB is committed to reducing the number of people who lose their sight unnecessarily, and will follow developments in the hope that the potential of biosynthetic corneas to save sight can be realised.'

Friday, October 22, 2010

Sunglasses Rival Lotions as Vital for Safety

UV rays threaten the eyes as much as the skin, experts warn

By Dennis Thompson
HealthDay Reporter

FRIDAY, Aug. 20 (HealthDay News) -- Folks have been taught to slather on sunscreen, slip on a shirt and clap a hat on their heads to protect their skin from the sun's harmful ultraviolet rays.

That's all good. But not adding a pair of good sunglasses to the ensemble still leaves people at risk, eye doctors say.

Ultraviolet, or UV, rays can cause significant damage to unprotected eyes, resulting in a number of illnesses and disorders that can rob people of their sight.

"People are more aware of skin cancer. There's more awareness of exposing your skin to the sun," said Dr. J. Alberto Martinez, a practicing ophthalmologist in Bethesda, Md., and a clinical professor of ophthalmology at Georgetown University Medical School. "But at the same time, the eyes suffer dramatically from ultraviolet exposure. UV exposure is a public health problem, and, as an ophthalmologist, I see the continuous, serious problems that are caused by UV."

Both short- and long-term exposure to UV rays can cause vision problems and eye damage, according to the U.S. Environmental Protection Agency's Office of Air and Radiation.

People exposed to bright sunlight for even short periods can develop a "sunburn of the eye" in the form of either photokeratitis or photoconjunctivitis.

Photokeratitis is an inflammation of the cornea, the transparent front part of the eye that covers the iris, pupil and lens, according to the World Health Organization. "The sun can cause superficial cells on the front of the cornea to become damaged and die off," said Dr. Lee Duffner, an ophthalmologist in Hollywood, Fla. Photoconjunctivitis is a similar inflammation that affects the conjunctiva, the membrane lining the inside of the eyelids and the eye socket. Both conditions can be very painful, but people tend to recover quickly from them with no long-term damage to their vision.

Long-term UV exposure can do cumulative eye damage over time, causing more insidious and dangerous threats to a person's vision, including:

Pterygium. An abnormal growth of the conjunctiva caused by sun damage that can become so large it grows over and obstructs the cornea, partially blocking vision. Surgery may be required to restore vision. "The bad ones have a tendency to come back, even after they're removed surgically," Duffner said. "They're a real nuisance."
Cataracts. These involve clouding of the eye's lens. Ultraviolet rays are believed to play a part in the process.
Macular degeneration. UV rays that penetrate deep into the eyeball are believed to do damage to the retina, the sheet of nerves along the back wall of the eye that perceive light. The macula, at the center of the retina, is responsible for perception of fine details and a person's central field of vision. "Chesapeake Bay sailors who wear sunglasses and a hat have a much lower incidence of cataracts and macular degeneration than those who don't," Martinez said, citing research.
Cancer. People can develop skin cancer of the eyes as a result of UV damage, according to the WHO. The eye tends to develop melanoma, while the eyelids usually are inflicted with basal cell carcinoma. In both cases, surgery may be necessary.
Of course, such damage doesn't occur just in the summer, or even just when you're standing in sunshine. Bright reflected sunlight from sidewalks, aluminum, snow and other surfaces can cause UV damage just as easily as direct sunlight. In fact, one of the more well-known forms of photokeratitis is snow blindness, which occurs when skiers and climbers are exposed to high levels of UV radiation from light reflected off snow.

So how to protect yourself? Sunglasses. It's that simple, the experts say. A wide-brimmed hat wouldn't hurt, but sunglasses are key.

The sunglasses should be rated to absorb 99 to 100 percent of both UV-A and UV-B radiation. Read the labels. And keep in mind that how much you pay may not guarantee protection.

"It's not really price-related," Duffner said. "I've seen very expensive sunglasses that are not good ultraviolet absorbers, and I've seen cheap sunglasses that were great ultraviolet absorbers."

Also, toss fashion sense out the window, the eye experts say. Small, stylish sunglasses will allow UV radiation to reach the eyes. "If possible, buy wrap-around sunglasses," Duffner said. "With a standard pair of glasses, a fair amount of sunlight still strikes the eye from the side."

The worst forms of UV-related eye disease come from accumulated damage, making it important to start protecting kids' eyes so they will have a better chance of maintaining their vision in their old age.

The bulk of exposure occurs in the first 18 years of life," Martinez said. "The more sun damage you have, the more sensitive you are to later exposure. The trick is to try to get kids to wear sunglasses. It's difficult, but you must try."

Thursday, October 14, 2010

New Gel May Help Speed Healing Of Chronic Wounds, Serious Eye Injuries.

From the Huffington Post:

LONDON — For three years, Connie McPherson had debilitating leg ulcers that were so painful she sometimes couldn't sleep. Despite repeated surgery, antibiotics, steroids and other treatments, nothing helped.

Then last year, she took part in a trial for a new gel aimed at chronic wounds.

"It was the answer to my prayers," said McPherson, 58, a real estate agent in Tulsa, Oklahoma. Within weeks, McPherson said the ulcer treated was completely healed. "I tried everything possible and this is the only thing that worked."

The gel used to treat McPherson was developed by a team led by David Becker, a professor of cell and developmental biology at University College London. The gel, named Nexagon, works by interrupting how cells communicate and prevents the production of a protein that blocks healing. That allows cells to move faster to the wound to begin healing it.

Though it has only been tested on about 100 people so far, experts say if it proves successful, the gel could have a major impact on treating chronic wounds, like leg or diabetes ulcers, and even common scrapes or injuries from accidents.

In most chronic wounds, Becker said there is an abnormal amount of a protein involved in inflammation.

To reduce its amount, Becker and colleagues made Nexagon from bits of DNA that can block the protein's production. "As that protein is turned off, cells move in to close the wound," Becker said. The gel is clear and has the consistency of toothpaste.

In an early study on leg ulcers, scientists at the company Becker co-founded to develop the gel found that after four weeks, the number of people with completely healed ulcers was five times higher in patients who got the gel versus those who didn't. The average leg ulcer takes up to six months to heal and 60 percent of patients get repeated ulcers.

Other experts said the gel appeared promising. "It looks like the gel has a good effect in getting the outer layer (of skin) to restore itself," said Phil Stephens, head of tissue engineering and repair at Cardiff University. Stephens is not linked to Becker's research.

Care in Pennsylvania. Serena has no financial ties to Nexagon, but is one of the primary investigators for a U.S. trial of the product.

Another study is planned soon which experts said should answer more questions like the right dosage of the gel and any side effects.

In the U.S., there are 70 million people with chronic wounds. With increasing rates of obesity, experts predict there will soon be many more people suffering from diabetic ulcers.

Other gels are on the market, but don't work for everyone. Bioengineered skin, a protein that regulates cell growth and division, and even maggots are among the few other treatments that have been found to speed up healing.

Brad Duft, president of CoDa Therapeutics, which is developing the new gel, would not say how much Nexagon currently costs to make, for proprietary reasons.

He said the gel is still a couple of years away from being on the market and the price will drop significantly when that happens. Some leg ulcer patients spend about $30,000 a year or more on treatment. Duft said the new gel would cost a fraction of that.

For McPherson, the experience of being treated with Nexagon was so positive she asked to be included in the gel's next trial, to treat an even larger ulcer that wasn't eligible for the first study.

"To have something that works would change my life," she said.

Friday, October 8, 2010

Epilepsy drug valproic acid could help in retinitis pigmentosa, study finds

A small preliminary study has found that valproic acid--a drug already used to treat epileptic seizures, migraines and bipolar disorder--may halt or even reverse the loss of vision produced by retinitis pigmentosa, researchers said Thursday. A team from the University of Massachusetts Medical School in Worchester is now organizing a clinical trial to confirm its observations.

Retinitis pigmentosa, commonly known as RP, is a group of eye diseases marked by degeneration of the retina, the part of the eye that captures images, leading to loss of peripheral vision and night vision. At least 40 genes have been linked to the condition and the particular manifestation of the disease depends on which genes are involved. The only effective treatment involves high levels of vitamin A palmitate, which can slow the progression of the disorder but not halt it. About one in 4,000 people is affected by RP, with many going blind by the age of 40.

Virtually all forms of the disease are characterized by inflammation and cell death. Dr. Shalesh Kaushal, a professor of ophthalmology and cell biology at the university, reasoned that valproic acid, which is known to affect both conditions, might slow the progression of RP, and tissue culture experiments suggested that was the case.

Kaushal and his colleagues then treated seven patients with an early stage of RP with 500 to 750 milligrams of valproic acid per day over the course of two to six months. The team reported in the British Journal of Ophthalmology that vision improved in five of the patients even though they were at a stage when vision loss normally progressed rapidly.

Kaushal is now organizing a three-year, $2.1-million clinical trial of the approach to test it against a placebo. The trial will be funded by the Foundation Fighting Blindness and the National Neurovision Research Institute. The clinical trials will be easier that they would be with an experimental compound because the safety of the drug has already been demonstrated.

Thomas H. Maugh II / Los Angeles Times

Friday, October 1, 2010

What's Lurking in Those Supplements?

Jeannine Stein

Los Angeles Times

August 3, 2010

Do you really know what's in the dietary supplements you're taking? Consumer Reports tells what might be in those pills and powders in a new report. They focus on the less-than-desirable ingredients that could be lurking in the supplements people often take as part of their diet and exercise regimen or for sexual enhancement.

Consumer Reports worked with experts from the independent research group Natural Medicines Comprehensive Database to identify 12 ingredients in supplements that may have potential health risks, possibly leading to problems with cardiovascular, kidney or liver health. Those ingredients are: aconite, bitter orange, chaparral, colloidal silver, coltsfoot, comfrey, country mallow, germanium, greater celandine, kava, lobelia, and yohimbe. Some of the ingredients, according to the report, have had a previous FDA warning.

The Food and Drug Administration is taken to task by the report for what they say is the agency's lack of oversight in making sure supplements are safe. The report also argues that the FDA has not fully used its limited authority granted by the Dietary Supplement Health and Education Act to ban supplement ingredients that may be dangerous.

"Supplements are marketed with very seductive and sometimes overblown sales pitches for increasing your performance in the bedroom, slimming down or boosting your athletic prowess," said Nancy Metcalf, senior program editor for Consumer Reports, in a news release. "And consumers are easily lulled into believing that supplements can do no harm because they're ‘natural.' However, some natural ingredients can be hazardous, and on top of that the FDA has repeatedly found hazardous ingredients, including synthetic prescription drugs, in supplements."

The FDA also got dinged for not inspecting Chinese factories where many of the raw materials for supplements originate.

Consumers are cautioned to check with their doctor or pharmacist before taking any supplements, to be especially careful with weight-loss, sexual-enhancement and strength-building supplements, not to overdo supplements and to report any symptoms or side effects to a physician. The "USP Verified" mark on products indicates that the manufacturer has had U.S. Pharmacopeia verify the ingredients. USP is a nonprofit, private company that sets standards for prescription and over the counter medication and healthcare products manufactured or sold in the U.S.

The report also suggests not believing everything you hear or read about a product. "If a claim sounds too good to be true," it says, "it probably is."