Smoking and Age Related Macular Degeneration

New York, NY – A new Japanese and American study, published in the journal Ophthalmology, shows a strong link between smoking cigarettes and age related macular degeneration (AMD). Previous studies on the link reportedly met with mixed results. AMD occurs when the light sensing cells in the retina begin to die off.

Scientists found that Japanese smokers were four times more likely to develop AMD than non-smokers. In addition to AMD, smokers also were five times more likely to develop a vision disorder called polypoidal choroidal vasculopathy. This disorder leads to bleeding in the retina.

AMD is more common in Japanese men than in women, but researchers say this is probably because more Japanese men smoke than do Japanese women. The study included 279 people with AMD and 143 without the disease.

There are several drugs that are used to keep AMD from rapid progression, although there is no cure for this leading cause of blindness in people over the age of 65. Lucentis, a drug made by Roche, prevents the formation of abnormal blood vessels.  Avastin, a drug with more side effects than Lucentis, is not approved for treating AMD, but is commonly used to treat it. Surgery is also a treatment to slow the progression of the disease.

There are two forms of AMD: Wet AMD is when blood vessels leak into the retina. Blindness occurs rapidly in wet AMD. Dry AMD is more common and progresses more slowly.

Some scientists currently have a theory that smoking may cause AMD. An eye surgeon at Royal Bolton Hospital in England, and author of two previous reviews on the link between smoking and AMD, says this latest study also supports that connection.  He believes that there needs to be a public health message that highlights the link between smoking and AMD in every country in the world. “In Europe we are calling on governments to put the message ‘smoking causes blindness’ on tobacco products.”

If you would like more information on age related macular degeneration, please contact an experienced eye doctor in your area to schedule an appointment.

Physicists Asks Whether Eye Implants Will Restore Beauty

A physicist considers the successful implementation of eye implants to restore the vision of blind people in an editorial in the upcoming May issue of Physics World. The professor of physics, psychology, and art at the University of Oregon warns that, although eye implants are becoming sufficiently sophisticated to restore rudimentary vision, they will have to adapt to reflect the way that humans see if they are ever to be a sufficient cure for blindness.

The human retina typically contains nearly 130 million photoreceptors in an area of only 1100 mm2 while state-of-the-art computer sensors contain less than 17 million receptors in 1600 mm2. The gap continues to close, but there are a number of important structural differences between computer sensors and the human eye.

One of the most important differences is that in the human eye the majority of receptors are concentrated in the center of the eye, the macula, and the even smaller sub-region, the fovea. In a computer sensor, however, the photoreceptors are evenly distributed throughout the sensor area.

This difference relates significantly to the way the human eye works. Even when you are looking fixedly at an object, your eye is not remaining completely stationary. Instead, it is constantly making numerous small movements to scan the visual field and keep the entire area of interest covered by the pin-point sized area at the center of the retina known as the fovea. The fovea is composed primarily of cone photoreceptors and is responsible for very fine detailed vision. It is crucial to many tasks that humans perform, such as reading and driving, but also potentially to our appreciation of beauty.

The professor notes that the human visual system utilizes fractal patterns in nature as a shortcut for visualizing the world, and that a completely uniform distribution of photoreceptors might overwhelm the visual cortex with visual data. In addition, the uniform visual data might short-circuit the eye’s natural scanning mechanism, which could diminish its appreciation for natural fractal patterns. Many types of natural fractal patters are considered beautiful and relaxing, such as clouds and trees. With a completely uniform visual system, it might be harder for the eye to appreciate these natural patterns.

Currently, vision implants are only a theoretical possibility, but in the future they may be able to restore vision to the blind. At that time we will be able to determine the extent to which their vision is fully restored or whether it remains only an artificial construct not fully capable of appreciating what it sees.

In the meantime, ophthalmologists continue to work to prevent blindness. To protect your vision, contact a local ophthalmologist today.

UC San Diego Awarded $4.6 Million Grant for “Severe Blindness” Research

San Diego, California – The University of California San Diego (UCSD) has received a five-year grant worth $4.66 million to research treatments that can potentially restore sight to people suffering from “severe blindness.” The university received the funding as part of the National Institute of Health Transformation Award.

Dr. Kang Zhang, a professor of ophthalmology at UCSD, will lead the research team. They plan to examine the regenerative potential of retinal cells in an attempt to repair vision lost as a result of eye conditions such as macular degeneration and retinitis pigmentosa.

The research team will focus on Muller cells, which have demonstrated the ability to successfully regenerate nerve cells in fish that have suffered a retinal injury. Muller cells contribute to the functioning of central nervous system neurons in humans as well, particularly those found in the eye or brain. Dr. Zhang and his team plan to examine the possibility of using chemicals to transform these cells into photoreceptors in the eye.

If successful, this study may be able to identify particular chemical tools which can improve cell-based therapy as a treatment for patients suffering from severe blindness caused by the degenerative eye conditions mentioned above.

Macular degeneration is one of the leading causes of blindness among people age 65 and older. It is caused by a deterioration of the macula, the region of the retina that achieves sharp vision. Currently, approximately 1.75 million Americans suffer from the condition. This figure is expected to rise dramatically in up-coming years.

Retinitis pigmentosa is an eye condition that results in blindness. It is generally genetically-based. Symptoms develop gradually over a period of years or sometimes even decades. The progression of the disorder varies from person to person; some people lose their vision completely during their childhood, while others may not become blind until their 40s or 50s.

Caffeine May Help Prevent Cataracts

Dr. Shambhu D. Varma of the University of Maryland School of Medicine has found that caffeine can prevent cataracts in rats. Dr. Varma treated rat pups with sodium seramide, a chemical that causes cataracts in the pups. While the control group all developed cataracts, the rat pups that were also given caffeine did not.

Cataracts are responsible for about half of all cases of blindness and while they can be treated with cataract surgery, no strategy for cataract prevention has yet been proven safe and effective. Caffeine, a bioflavonoid present in coffee and tea, prevents cataracts by inhibiting oxidative stress caused by oxygen radicals and by inhibiting the cataract-causing enzyme aldose reductase.

However, caffeine treatment for cataract prevention is not yet viable for humans as the dosage administered to Dr. Varma’s rat pups was quite high. Dr. Varma estimates that a human would need to consume about half a gram of pure caffeine (equivalent to 6.25 cups of coffee) daily to achieve the same effect. Dr. Varma is currently working on a more direct delivery system that works with a smaller dosage for use in humans. Caffeinated eye drops seem to be the most likely to work in people.

For more information on cataracts, find a qualified ophthalmologist in your area.

Glaucoma Treatment: A New Hope

Southampton, England – Professor of ophthalmology at Southampton General Hospital, Andrew Lotery, and a team of international eye specialists, have discovered a gene mutation they say leads to glaucoma. This breakthrough will help hundreds of thousands of people across the globe suffering from this eye disease and the leading cause for blindness worldwide.

It is hoped that with the discovery of this gene, those who are most likely to get glaucoma will have the condition detected earlier and be treated earlier. Today glaucoma is treated by lowering pressure within the eye through taking drops or through surgery. However, glaucoma treatment is not effective for everyone and nearly all glaucoma patients are not diagnosed until their eyesight begins deteriorating.

Glaucoma often has no symptoms and vision loss can happen suddenly, especially to people who live in places without access to regular eye care. Treatment can stem blindness, but it must be caught in time. Otherwise, the optic nerve is damaged beyond repair.

Professor Lotery says that making progress against glaucoma means better understanding the basic biological process leading to the disease. Better treatments can then be developed in order to slow or halt it. Professor Lotery likens the finding of the gene and biological pathway to that of the genes found that cause macular degeneration and leading to better clinical treatments. It is expected that better treatments for glaucoma will eventually have the same result.

The Southampton Gift of Sight appeal supported Professor Lotery’s research in finding the genetic reasons for glaucoma.

If you would like to learn more about treatment for glaucoma, please visit our Eye Doctor Directory to find an experienced eye surgeon in your area.

Cancer Drug Can Prevent Blindness

The cancer drug, Avastin, manufactured by Roche Holding AG, though not licensed for treatment of age-related macular degeneration (ARMD) is used widely for preventing blindness. The generic name for Avastin is bevacizumab and is a monoclonal antibody, a protein created to bind to a molecule in a specific way. The drug can be injected into the eyes and it slows leakage by blocking the receptor for a hormone called vascular endothelial growth factor.

According to researchers for the British Medical Journal, “Avastin is now probably the most widely used agent to treat neovascular AMD, despite subsequent licensing of ranibizumab (brand name Lucentis) over bevacizumab because of the low cost of treatment when it is used as an intraocular agent.” This particularly applies in third world counties, where Lucentis is much too expensive.

The findings come after a study of 131 patients with a mean age of 81 who participated in a clinical trial in the UK.

If you suffer from age-related macular degeneration or some other eye disease, please contact an experienced eye doctor in your area today.