Macular Degeneration Treatment Tips

Lets take a quick look at a couple of these reports in the context of macular degeneration treatments.

The March 4 issue of the ‘Journal of Neuroscience’ carries a study on how the brain changes when its inputs change.

"Neurons seem to ‘want’ to receive input: when their usual input disappears, they start responding to the next best thing,” said Nancy Kanwisher, at the McGovern Institute for Brain Research at MIT, and senior author of the above study.

This study and others found that when neurons in the visual cortex no longer receive input from central vision, they can start to respond instead to other areas receiving light stimuli.

"If scientists could one day develop technologies to replace the lost light-sensitive cells in the fovea, patients might be able to recover central vision since the neurons there are still alive and well", according to a Newswise press release on this report.

You can read the whole press release at http://www.newswise.com/articles/view/549515/

Another study that appeared in the December issue of ‘Restorative Neurology and Neuroscience’ was run by the Georgia Institute of Technology. It tested how volunteers with macular degeneration made up for their loss of central vision by focusing with other parts of their visual field (known as preferred retinal locations).

The conclusion was that the brain reorganized itself.

This was the first study which directly showed that this ‘brain remapping’ in people with eye degeneration disease related to their own behavior. In other words, the very way in which macular degeneration patients tried to see with areas outside their central vision helped their brains to reorganize. They ‘retrained’ the visual cortex in their brains.

This sounds encouraging. The Georgia Tech research group are now studying how long such a process takes, and whether ‘low-vision training’ can further support it.

Certainly it’s worth exploring these possibilities. There’s more than one way to approach macular degeneration treatments. We keep looking into what’s being developed, as well as continuing with the known improvers of vision: diet and macular vitamins.

The use of your own stem cells for retinal regeneration has been suggested before, but at E10,545 or equivalent for both eyes it is very expensive. The price and elite availability of such procedures puts it out of reach for most of us.

Now an article published in The Guardian on January 30, 2009 suggests stem cell therapy for macular degeneration may become affordable.

The article continues: "But it is likely that the first embryonic stem cell therapy to become widely available will come from Britain … enabling those who were going blind to see. The work being done by Coffey, who is based at the University College London Institute of Ophthalmology, has the beauty of simplicity. Age-related macular degeneration (AMD) is caused by the deterioration of retinal pigment epithelial (RPE) cells at the back of the eye. These cells form a layer that processes light, and do not need to be linked in to the nervous system and the brain. "We’re not having to reconnect cells to a neural network," says Coffey. "This is a carpet of cells." He and his team have done it very successfully in animals, he says. They have persuaded embryonic stem cells to turn into RPE cells and in effect laid a new carpet.

"We’re now manufacturing the cells to clinical standard so we can go into trials in 2010/11," he says, adding with enthusiasm that it is do-able because they need relatively few. "We only need 40,000 cells. It sounds an awful lot but if you think of a computer mouse," he says, looking around the room for something the right size, "if you grew the cells in it you could provide easily enough for 100,000 patients. The scale-up is relatively simple."

Coffey thinks this therapy has a good chance of success. A quarter of pensioners will hope he is right. That’s how many over-65s get AMD. And while there is a new (very expensive) drug called Lucentis for one form of the disease, it is not a cure. AMD is, as he says, "a huge problem".

But funding has not been easy. Coffey was kept afloat by the UK’s Macular Disease Society, which gave him £50,000 at a tricky point. Otherwise the money has come from philanthropic donors in the US, of whom Bush’s ban made sure there was no shortage.

Interestingly, if it proves to be a cure for macular degeneration, this therapy is likely to be affordable. Not only that, it will save the NHS a lot of money. The costs of surgery, Coffey reckons, will be about £4,000-£5,000, but the patch of cells itself could cost as little as £250. Lucentis costs £800 to £1,500 for each injection every four to six weeks. "But this is a cure - not like Lucentis," says Coffey. That’s the argument that has at last caused the big pharma companies to sit up and take notice. For years they steered clear of biotechnology. Living tissue was of far less interest to them than chemical compounds that patients would take for years. But a new reality is dawning. Stem cell therapies could drive their drugs off the market.

Other new treatment technologies currently under research include a computer chip implant in the retina, and gene technology.

The macula is a tiny area in the centre of the retina.

The retina, the light-sensitive tissue at the back of the eye, processes all visual images. Photoreceptor cells in the retina are called ‘rods’ and ‘cones’. Rods are used for peripheral vision and seeing in dim light, while cone cells are needed for sharp sight in bright light.

The macula is packed with cone cells. It gives us detailed and color vision. Thanks to the macula we can see accurately when we look straight ahead. It’s also thanks to the macula we are able to drive, do fine work, recognize faces and read. You are using your macula to read this print.

The macula has a highly specialized blood and nerve supply. And more messages reach the brain from the macula than from any other separate part of the body.

So you see how vital this tiny bit of the eye is to our understanding of the world.

The macula is normally a slightly darker color in the middle because of more pigment in the RPE. It may also look yellowish because of luteal pigment in the inner layers of the retina. This pigment protects the macula from light damage.

If your eyes lose pigment, macular health is threatened and so is your sight. Aging eyes have less pigment, and so do blue or pale-colored eyes.

That’s why we’ve written about the different things you can do to look after your eyes and specifically the macula. Things like wearing good sunglasses, eating vision-friendly foods, and testing your sight. It’s also important to give up smoking and to do some exercise if you can. And you can support your vision by taking a daily supplement formulated for macular health.

Make sure it contains Lutein and Zeaxanthin, as well as other eye nutrients. For more information read our posts on "Lutein Vitamins", "Antioxidant Nutrition" and "Eye Health Nutrients" (see category on right).

Why are Lutein and Zeaxanthin important for macular health? They:

    •    shield the macula from harmful UV light
    •    improve macular pigmentation
    •    have powerful antioxidant properties
    •    have an affinity with the macula
    •    are naturally present in high concentrations in a healthy macula

The good news is that both Lutein and Zeaxanthin are now available for you to take in supplement form. They can be made from ground-up marigold petals or else synthesized. So if your natural levels of these carotenoids have depleted, you can replace them.

Avastin and Lucentis are both distributed in the US by the same company Genentech. As we discussed in our previous post Avastin Macular Treatment Warning Lucentis is the approved Macular Degeneration drug but is far more expensive than the similar drug Avastin. Both Macular Degeneration drugs are administered by eye injection. In December 2008 Genentech released a report to eye doctors advising them that some patients had suffered eye inflammation after treatment with Avastin.

Now the US National Eye Institute has announced a new Macular Degeneration Research trial comparing the safety and effectiveness of both drugs.

Participants are being recruited now!

The National Eye Institute is looking for 1200 participants to get involved in the trials. If you are interested you can expect to be treated with an injection every four weeks for up to two years.

The Lucentis-Avastin Trial  schedule is as follows:

1.    Injection of Lucentis on a fixed schedule of once every four weeks for one year, with the patient being assigned randomly in the second year to either an injection of Lucentis every four weeks or on a variable schedule depending on the patient’s response to treatment;

2.    Injection of Avastin on a fixed schedule of once every four weeks for one year, with the patient being assigned randomly in the second year to either an injection of Avastin every four weeks or on a variable schedule depending on the patient’s response to treatment;

3.    Injection of Lucentis on a variable schedule;
 
4.    Injection of Avastin on a variable schedule.

Have you been advised by your eye or retinal specialist to treat your macular degeneration symptoms with eye injections?

If so please read on….

In 2006 the U.S Food and Drug Administration (FDA) approved the drug Lucentis for the treatment of wet amd or macular degeneration wet as it also known.

Clinical trials showed that Lucentis, administered via injection approximately every four weeks, slowed the progression of vision loss. Some people even reported improved vision. Great news for those with this essentially incurable condition.

Before the approval of Lucentis another drug, Avastin, was approved by the FDA specifically for the treatment of colon cancer. Retinal specialists were also allowed to use the drug Avastin for "off-label" use to treat wet AMD.

Lucentis and Avastin both work in a similar way against the blood vessel growth which is a factor in macular degeneration wet.

Despite the more recent approval of Lucentis many retinal specialists have continued to use Avastin because it costs a lot less than Lucentis. Lucentis costs about $2,000 per injection which is about 40 times more expensive than Avastin!

In December 2008 Genentech, the drug company which distributes Avastin and Lucentis in the US, revealed to doctors that a number of patients had suffered eye inflammation after being injected with Avastin. Eye inflammation is also a risk factor with Lucentis but the number of inflammations from the Avastin injections was unusually high. According to Genentech most of the eye inflammation cases were eventually traced to a single batch of the Avastin drug.

If you are considering the use of Avastin macular injections it might be wise to discuss your options with your retinal specialist in light of these recent findings.

Another type of treatment is photodynamic therapy where a dye which is sensitive to light is injected into the patient’s bloodstream. This then eventually works its way to the retina and the blood vessels that are causing the problem are highlighted. A special cold laser is then shone into the eye which causes a chemical in the dye to kill off the vessels.
(more…)

Technorati Tags: Macular Degeneration Eye, Macular Degeneration Treatments