Susan Slobac asked about: Finding macular degeneration treatments.
Vision problems due to the onset of macular degeneration are quite prevalent, especially in the elderly. Macular degeneration occurs when the macula, located in the central portion of the retina in the eye, becomes weakened or damaged. The result is a loss of central vision. Central vision is used to read and drive, so it is crucial to save as much of a patient’s vision as possible as soon as possible. Although this medical condition has no cure at this time, there are some promising new macular degeneration treatments that have shown to alleviate and slow down some of the symptoms of age-related macular degeneration.
There is a range of vision loss that can occur depending on the severity and type of age-related macular degeneration a patient has. Because it affects the macula located in the center of the retina, a patient’s peripheral vision is usually not adversely affected by the condition. With the onset of the condition, a patient’s vision might still be quite good, but the situation can worsen over time. There are two different types of age-related macular degeneration that often result in the greatest loss of central vision, and they are called wet and dry. The dry form of advanced macular degeneration is caused by the reduction of the rods and cones located in the retina, while wet advanced macular degeneration occurs due to leakage of excessive blood vessels and the resulting scarring under the macula.
One thing that retinal specialists might tell their patients with macular degeneration is to take certain vitamins as part of a spectrum of macular degeneration treatment s. Patients in the initial onset stages of this condition sometimes benefit from taking vitamins C, E, zinc, lutein, zeaxanthin and eating foods that are high in beta-carotenes, such as dark green leafy vegetables, corn and peas.
Another macular degeneration treatment can be found in cholesterol reducing drugs. People in the early stages of this medical condition often develop drusen, or yellow deposits, in the macula. The development and increase in the number of drusen seems to be related to the patient’s cholesterol level, with drusen more prevalent in those with higher cholesterol. Medications, such as statins, which reduce cholesterol, and aspirin, which reduces inflammation, may have a significant impact on reducing the size and number of drusen in the macula and thus lessen the chances of someone developing age-related macular degeneration.
A couple of wet advanced macular degeneration treatments, Macugen and Lucentis, have been approved by the FDA. Macugen is useful because it helps to reduce the number of excessive blood vessels that can grow under the retina. These can become inflamed and eventually burst, causing vision problems. Lucentis also reduces the growth of too many blood vessels. Lucentis is administered as an injection under the eye, and offers a great new treatment option for some patients with these kinds of vision problems.
The future is looking brighter with these emerging new macular degeneration treatments.
Wednesday, January 28, 2009
Saturday, January 24, 2009
Seeing Machine Helps Blind See Pictures
A seeing machine developed at MIT helps people with visual impairments see pictures.
Nick Barber, IDG News Service
Friday, January 23, 2009 12:00 PM PST
Using her prototype "seeing machine," Elizabeth Goldring can take pictures and see them -- with her blind eye.
After more than 20 years of work, Goldring, a senior fellow at MIT's Center for Advanced Visual Studies and her colleagues have designed a portable device that allows people with visual impairments to watch videos, access the internet, view photographs, or just see the face of a friend.
Her work started when she lost the vision in both of her eyes and doctors at the Schepens Eye Research Institute in Boston used a scanning laser ophthalmoscope, or SLO, to determine if she had any healthy retina left. The machine, which costs over US$100,000, projected images directly onto the retina of the eye, bypassing the hemorrhages contributing to her blindness.
"Technicians projected stick figures onto my retinas and I could see some of those stick figures," she said of the experience. Goldring then asked them if they could write the word "sun," which she could also see. "I was amazed. It was the first word I'd seen for months."
After her visit, she contacted and worked with the inventor of the SLO, hoping to reduce the size and cost of the device. That research yielded a $4,000 desktop model that allowed the blind to see black-and-white images. Soon after, a desktop model was created that allowed for color images to be seen. Goldring admits that version doesn't work well, but it paved the way for the current prototype.
Once a video signal is plugged into the 5-inch square box, it is then fed to an LCD panel on the inside, according to Quinn Smithwick, a postdoctoral associate at the MIT Media who has been working with Goldring on the seeing machine. The connection to the box is for a standard RCA video jack so almost anything with a video output can be plugged in. The LCD panel inside is illuminated by a bright bank of LEDs behind it, which are collimated, or traveling in the same direction. As the light passes through the LCD screen, the image pattern is "imprinted" onto the light. A lens at the back of the box focuses the light into a single point, which then enters the pupil of the eye and passes onto the retina.
"It's not that we're taking the camera image and blowing it up so you can see something big," said Smithwick. "We're trying to bypass any bad optics you may have and then get enough light and enough contrast onto the back of your retina and then you can use what little bits of retina you may have left to view it."
Goldring thinks the seeing machine could help people with macular degeneration and proliferative retinal diseases, two of the main causes of blindness in the U.S., according to Goldring. Using the device, Goldring said she can see faces and general details of people such as the color of their hair and what they are wearing. Without it, she would only know that someone is standing close to her.
Brandon Taylor, a graduate student at the MIT Media Lab, said the next step for the seeing machine is to test it with a wider population.
"We've received positive results with Elizabeth and there have been a couple other people who have used it and its been very encouraging, but what we really want to do for this testing phase is figure out what types of eye conditions this is beneficial for ... and how much improvement this machine can achieve," said Taylor. Goldring noted that there does need to be some working retina for the machine to work.
"People aren't interested in what blind people see and we have a lot of pent-up desire to express ourselves visually and this is the first step to that," said Goldring.
She and her team already have plans under way to test the seeing machine at the Low Vision Clinic at the Joslin Diabetes Center's Beetham Eye Institute in Boston. After refining the device, they would also like to make it commercially available, though are not sure when it will be or for how much. Their prototype, not including the digital camera, cost under $500 because "everything in it is already mass-produced for other purposes," Taylor said.
"Keeping the visual sense alive is something good, even if you don't use it to cross the street," Goldring said.
Nick Barber, IDG News Service
Friday, January 23, 2009 12:00 PM PST
Using her prototype "seeing machine," Elizabeth Goldring can take pictures and see them -- with her blind eye.
After more than 20 years of work, Goldring, a senior fellow at MIT's Center for Advanced Visual Studies and her colleagues have designed a portable device that allows people with visual impairments to watch videos, access the internet, view photographs, or just see the face of a friend.
Her work started when she lost the vision in both of her eyes and doctors at the Schepens Eye Research Institute in Boston used a scanning laser ophthalmoscope, or SLO, to determine if she had any healthy retina left. The machine, which costs over US$100,000, projected images directly onto the retina of the eye, bypassing the hemorrhages contributing to her blindness.
"Technicians projected stick figures onto my retinas and I could see some of those stick figures," she said of the experience. Goldring then asked them if they could write the word "sun," which she could also see. "I was amazed. It was the first word I'd seen for months."
After her visit, she contacted and worked with the inventor of the SLO, hoping to reduce the size and cost of the device. That research yielded a $4,000 desktop model that allowed the blind to see black-and-white images. Soon after, a desktop model was created that allowed for color images to be seen. Goldring admits that version doesn't work well, but it paved the way for the current prototype.
Once a video signal is plugged into the 5-inch square box, it is then fed to an LCD panel on the inside, according to Quinn Smithwick, a postdoctoral associate at the MIT Media who has been working with Goldring on the seeing machine. The connection to the box is for a standard RCA video jack so almost anything with a video output can be plugged in. The LCD panel inside is illuminated by a bright bank of LEDs behind it, which are collimated, or traveling in the same direction. As the light passes through the LCD screen, the image pattern is "imprinted" onto the light. A lens at the back of the box focuses the light into a single point, which then enters the pupil of the eye and passes onto the retina.
"It's not that we're taking the camera image and blowing it up so you can see something big," said Smithwick. "We're trying to bypass any bad optics you may have and then get enough light and enough contrast onto the back of your retina and then you can use what little bits of retina you may have left to view it."
Goldring thinks the seeing machine could help people with macular degeneration and proliferative retinal diseases, two of the main causes of blindness in the U.S., according to Goldring. Using the device, Goldring said she can see faces and general details of people such as the color of their hair and what they are wearing. Without it, she would only know that someone is standing close to her.
Brandon Taylor, a graduate student at the MIT Media Lab, said the next step for the seeing machine is to test it with a wider population.
"We've received positive results with Elizabeth and there have been a couple other people who have used it and its been very encouraging, but what we really want to do for this testing phase is figure out what types of eye conditions this is beneficial for ... and how much improvement this machine can achieve," said Taylor. Goldring noted that there does need to be some working retina for the machine to work.
"People aren't interested in what blind people see and we have a lot of pent-up desire to express ourselves visually and this is the first step to that," said Goldring.
She and her team already have plans under way to test the seeing machine at the Low Vision Clinic at the Joslin Diabetes Center's Beetham Eye Institute in Boston. After refining the device, they would also like to make it commercially available, though are not sure when it will be or for how much. Their prototype, not including the digital camera, cost under $500 because "everything in it is already mass-produced for other purposes," Taylor said.
"Keeping the visual sense alive is something good, even if you don't use it to cross the street," Goldring said.
Wednesday, January 14, 2009
Improve your peripherical circulation
Simon - one of my regular clients for massage - has a problem with his peripherical circulation: his feet are always cold, no matter if it is summer or winter. So, I decided to make a research in order to give him some advice on how to reduce the symptoms and I thought to share the results with you.
FOOD
Many herbal remedies such as ginkgo biloba can help improve blood circulation but so too can much of the food we eat. Five of the most effective circulation boosting foods are as follows:
1) Pumpkin seeds: they are a good source of vitamin E which research has shown can help reduce the stickiness of blood and therefore lower the likelihood of blood clots forming.
2) Oranges: the high levels of vitamin C and bioflavonoids in oranges help the flow of blood through your body by strengthening the capillary walls.
3) Nuts: they contain niacin, or vitamin B3 as it is sometimes referred to, which essentially gives your blood a boost and therefore can prevent circulation problems.
4) Watermelon and tomatoes: they are rich in lycopene which can help prevent a buildup of plaque (a substance that can interfere with blood flow) in the arteries and therefore ensure healthy blood circulation.
5) Garlic: blood circulation is another of the many strings to garlic’s bow. It can help prevent the accumulation of plaque and in some cases actively reduce it.
6) Bilberry: it has been used for centuries, both medicinally and as a food in jams and pies. It is related to the blueberry and is native to Northern Europe. Bilberry fruit contains some chemicals that have excellent antioxidant properties. They scavenge damaging particles in the body known as free radicals, helping to prevent or reverse damage to cells. Antioxidants have been shown to help prevent a number of long-term illnesses such as heart disease, cancer, and an eye disorder called macular degeneration.
EXERCISE
Regular exercise can help to reduce the symptoms of reduced peripherical circulation.
SMOKING
Stop smoking, if you smoke.
LOWER YOUR BLOOD PRESSURE
If it is too high.
REGULAR MASSAGE
Can help increase the blood flow going into the muscles.
Roberto Bocchetti is an experienced and qualified Personal Trainer and Massage Terapist in London, UK. To contact Roberto, please call +44 7508 250 126.
FOOD
Many herbal remedies such as ginkgo biloba can help improve blood circulation but so too can much of the food we eat. Five of the most effective circulation boosting foods are as follows:
1) Pumpkin seeds: they are a good source of vitamin E which research has shown can help reduce the stickiness of blood and therefore lower the likelihood of blood clots forming.
2) Oranges: the high levels of vitamin C and bioflavonoids in oranges help the flow of blood through your body by strengthening the capillary walls.
3) Nuts: they contain niacin, or vitamin B3 as it is sometimes referred to, which essentially gives your blood a boost and therefore can prevent circulation problems.
4) Watermelon and tomatoes: they are rich in lycopene which can help prevent a buildup of plaque (a substance that can interfere with blood flow) in the arteries and therefore ensure healthy blood circulation.
5) Garlic: blood circulation is another of the many strings to garlic’s bow. It can help prevent the accumulation of plaque and in some cases actively reduce it.
6) Bilberry: it has been used for centuries, both medicinally and as a food in jams and pies. It is related to the blueberry and is native to Northern Europe. Bilberry fruit contains some chemicals that have excellent antioxidant properties. They scavenge damaging particles in the body known as free radicals, helping to prevent or reverse damage to cells. Antioxidants have been shown to help prevent a number of long-term illnesses such as heart disease, cancer, and an eye disorder called macular degeneration.
EXERCISE
Regular exercise can help to reduce the symptoms of reduced peripherical circulation.
SMOKING
Stop smoking, if you smoke.
LOWER YOUR BLOOD PRESSURE
If it is too high.
REGULAR MASSAGE
Can help increase the blood flow going into the muscles.
Roberto Bocchetti is an experienced and qualified Personal Trainer and Massage Terapist in London, UK. To contact Roberto, please call +44 7508 250 126.
Friday, January 9, 2009
Dry macular degeneration
Definition
Age-related macular degeneration is a chronic eye disease marked by deterioration of tissue in the part of your eye that's responsible for central vision. The deterioration occurs in the macula (MAK-u-luh), which is in the center of the retina — the layer of tissue on the inside back wall of your eyeball.
Macular degeneration doesn't cause total blindness, but it worsens your quality of life by blurring or causing a blind spot in your central vision. Clear central vision is necessary for reading, driving, recognizing faces and doing detail work.
Macular degeneration tends to affect adults age 50 and older. Dry macular degeneration, in which tissue deterioration is not accompanied by bleeding, is the most common form of the disease.
Symptoms
Dry macular degeneration usually develops gradually and painlessly. You may notice these vision changes:
* The need for increasingly bright light when reading or doing close work
* Increasing difficulty adapting to low light levels, such as when entering a
dimly lit restaurant
* Increasing blurriness of printed words
* A decrease in the intensity or brightness of colors
* Difficulty recognizing faces
* Gradual increase in the haziness of your overall vision
* Blurred or blind spot in the center of your visual field combined with a
profound drop in the sharpness (acuity) of your central vision
Your vision may falter in one eye while the other eye remains fine for years. You may not notice any or much change because your good eye compensates for the weak one. Your vision and lifestyle begin to be dramatically affected when this condition develops in both eyes.
Hallucinations
Additionally, some people with macular degeneration may experience visual hallucinations as their vision loss becomes more severe. These hallucinations may include unusual patterns, geometric figures, animals or even faces. You might be afraid to discuss these symptoms with your doctors or friends and family for fear you'll be considered crazy. However, such hallucinations aren't a sign of mental illness. In fact, they're so common that there's a name for this phenomenon — Charles Bonnet syndrome.
When to see a doctor
See your eye doctor — particularly after age 50 — if:
* You notice changes in your central vision
* Your ability to see colors and fine detail becomes impaired
One way to monitor your eyes to determine if you may need to visit your eye doctor is to check your vision regularly using an Amsler grid. This simple test may help you detect changes in your sight that you otherwise may not notice.
Here's how to perform the test:
* Hold the grid 14 inches (about 36 centimeters) in front of you in good light.
Use your corrective glasses or reading glasses if you normally wear them.
* Cover one eye.
* Look directly at the center dot with your uncovered eye.
* While looking at this dot, determine whether all of the lines of the grid appear
straight, uninterrupted and have the same contrast.
* Repeat the above steps with your other eye.
* If any part of the grid is missing or looks wavy, blurred or dark, contact your
eye doctor immediately.
Causes
The exact cause of dry macular degeneration is unknown, but the condition develops as the eye ages. The initial site of change is not in the light-sensitive cells of the macula, but in the retinal pigment epithelium (RPE), a single layer of cells located just behind the retina close to the back wall of your eye.
Your macula is an area about two-tenths of an inch (5 millimeters) in diameter at the center of your retina. This small part of your eye is responsible for clear vision, particularly in your direct line of sight.
The macula consists of millions of densely packed light-sensitive cells called cones and rods. Cones and rods have two segments: An inner segment controls cell functions and produces proteins responsive to light, and an outer segment stores and makes use of these proteins.
As they absorb light, outer segment proteins become degraded and eventually are shed as waste. Meanwhile, the inner segments continuously provide replacements for the outer segments. One function of the cells of the RPE is to remove the outer segments that are shed.
As the eye ages, cells in the RPE begin to deteriorate (atrophy) and lose their pigment. As a consequence, the RPE becomes less efficient in removing outer segment waste. When that happens, the normally uniform reddish color of the macula (as seen with an ophthalmoscope) takes on a mottled appearance. Drusen — yellow, fat-like deposits — begin to appear under the cones and rods. As the drusen and mottled pigmentation continue to develop, your vision gradually deteriorates.
Based on this progression, dry macular degeneration is categorized in three stages:
* Early stage. Several small drusen or a few medium-sized drusen are detected on
the macula in one or both eyes. Generally, there's no vision loss in the
earliest stage.
* Intermediate stage. Many medium-sized drusen or one or more large drusen are
detected in one or both eyes. At this stage, your central vision may start to
blur and you may need extra light for reading or doing detail work.
* Advanced stage. Several large drusen, as well as extensive breakdown of light-
sensitive cells in the macula, are detected. These features cause a well-defined
spot of blurring in your central vision. The blurred area may become larger and
more opaque over time.
Macular degeneration almost always starts out as the dry form. Dry macular degeneration may initially affect only one eye but, in most cases, both eyes eventually become involved.
Risk factors
Contributing factors for development of macular degeneration include:
* Age. In the United States, macular degeneration is the leading cause of severe
vision loss in people age 60 and older.
* Family history of macular degeneration. If someone in your family had macular
degeneration, your odds of developing macular degeneration are higher. In recent
years, researchers have identified some of the genes associated with macular
degeneration. In the future, genetic screening tests may be helpful for
assessing early risk of the disease.
* Race. Macular degeneration is more common in whites than it is in other groups,
especially after age 75.
* Sex. Women are more likely than men to develop macular degeneration, and because
they tend to live longer, women are more likely to experience the effects of
severe vision loss from the disease.
* Cigarette smoking. Exposure to cigarette smoke doubles your risk of macular
degeneration. Cigarette smoking is the single most preventable cause of macular
degeneration.
* Obesity. Being severely overweight increases the chance that early or
intermediate macular degeneration will progress to the more severe form of the
disease.
* Light-colored eyes. People with light-colored eyes appear to be at greater risk
than do those with darker eyes.
* Exposure to sunlight. Although the retina is more sensitive to shorter
wavelengths of light, including ultraviolet (UV) light, only a small percentage
of ultraviolet light actually reaches the retina. Most ultraviolet light is
filtered by the transparent outer surface of your eye (cornea) and the natural
crystalline lens in your eye. Some experts believe that long-term exposure to
ultraviolet light may increase your risk of developing macular degeneration, but
this risk has not been proved and remains controversial.
* Low levels of nutrients. This includes low blood levels of minerals, such as
zinc, and of antioxidant vitamins, such as A, C and E. Antioxidants may protect
your cells from oxygen damage (oxidation), which may partially be responsible
for the effects of aging and for the development of certain diseases such as
macular degeneration.
* Cardiovascular diseases. These include high blood pressure, stroke, heart attack
and coronary artery disease with chest pain (angina).
Preparing for your appointment
To check for macular degeneration, a dilated eye exam is necessary. Make an appointment with a doctor who specializes in eye care — an optometrist or an ophthalmologist — who can evaluate your condition and perform a complete eye exam.
What you can do
Appointments can be brief. Make the best use of that limited time by preparing beforehand.
* Be aware of any pre-appointment restrictions. When you make the appointment, ask
if there's anything you need to do in advance.
* Write down any symptoms you're experiencing, including any that may seem
unrelated to your vision problem.
* Make a list of all medications, as well as any vitamins or supplements, that
you're taking.
* Ask a family member or friend to accompany you, if possible. Having your pupils
dilated for the eye exam may compromise your vision for a time afterward. You
may need someone else to drive or accompany you from your appointment.
Questions to ask your eye doctor
* What kind of macular degeneration do I have?
* What is the visual acuity in my central vision?
* How advanced is my macular degeneration?
* Will I experience further vision loss?
* Will taking a vitamin or mineral supplement help prevent further vision loss?
* What's the best way to monitor my vision for any changes?
* What low-vision aids or adaptive devices might be helpful to me?
Questions your eye doctor may ask
* When did you first notice your vision problem?
* Does the condition affect one or both eyes?
* Do you have trouble seeing things near you, at a distance or both?
Tests and diagnosis
Diagnostic tests for macular degeneration may include:
* An eye examination. One of the things your eye doctor looks for while examining
the inside of your eye is the presence of drusen and mottled pigmentation in the
macula. The eye examination includes a simple test of your central vision and
may include testing with an Amsler grid. If you have macular degeneration, when
you look at the grid some of the straight lines may seem faded, broken or
distorted. By noting where the break or distortion occurs — usually on or near
the center of the grid — your eye doctor can better determine the location and
extent of your macular damage.
Regular screening examinations can detect early signs of macular degeneration
before the disease leads to vision loss.
* Angiography. To evaluate the extent of the damage from macular degeneration,
your eye doctor may use fluorescein angiography. In this procedure, fluorescein
dye is injected into a vein in your arm and photographs are taken of the back of
the eye as the dye passes through blood vessels in your retina and choroid. Your
doctor then uses these photographs to detect changes in macular pigmentation or
to identify small macular blood vessels.
Your doctor may also suggest a similar procedure called indocyanine green
angiography. Instead of fluorescein, a dye called indocyanine green is used.
This test provides information that complements the findings obtained through
fluorescein angiography.
* Optical coherence tomography. This noninvasive imaging test helps identify and
display areas of retinal thickening or thinning. Such changes are associated
with macular degeneration. This test can also reveal the presence of abnormal
fluid in and under the retina or the RPE. It's often used to help monitor the
response of the retina to macular degeneration treatments.
Treatments and drugs
There's no treatment available to reverse dry macular degeneration. But this doesn't mean you'll eventually lose all of your sight. Dry macular degeneration usually progresses slowly, and many people with the condition are able to live relatively normal, productive lives, especially if only one eye is affected. Dry macular degeneration can, however, develop into the more rapidly progressive wet type of macular degeneration at any time.
Taking a high-dose formulation of antioxidants and zinc may reduce progression of dry macular degeneration to advanced macular degeneration. The National Eye Institute-sponsored Age-Related Eye Disease Study (AREDS) showed that a daily supplement of 500 milligrams (mg) of vitamin C, 400 international units (IU) of vitamin E, 15 mg of beta carotene (often as vitamin A — up to 25,000 IU), 80 mg of zinc (as zinc oxide) and 2 mg of copper (as cupric oxide) reduced the risk of progressing to moderate or severe vision loss by up to 25 percent.
Lifestyle and home remedies
Macular degeneration doesn't affect your side (peripheral) vision and usually doesn't cause total blindness. But it can rob you of your central vision — which is important for driving, reading and recognizing people's faces. A low-vision center may be able to assess your visual capabilities and suggest certain optical and household devices that can be helpful for some near-vision tasks. Ask your eye doctor if there are any low-vision centers in your area.
There are ways to cope with impaired vision. Below are a few suggestions:
* Use caution when driving. First, check with your doctor to see if driving is
still safe based on your current visual acuity. When you do drive, there are
certain situations to avoid. For example, don't drive at night, in heavy traffic
or in bad weather.
* Seek help traveling. Use public transportation or ask family members to help,
especially with night driving.
* Travel with others. Contact your local area agency on aging for a list of vans
and shuttles, volunteer driving networks or ride shares.
* Get good glasses. Optimize the vision you have with the right glasses, and keep
an extra pair in the car.
* Use magnifiers. Large-print books and magazines can help you read more easily.
* View with large type on the Internet. Look for Web sites that use large-sized
type fonts, or change the font size on your display.
* Obtain specialized appliances. Some clocks, radios, telephones and other
appliances have extra-large numbers.
* Have proper light in your home. This will help with reading and other activities.
* Remove home hazards. Eliminate throw rugs and other possible tripping hazards in
your home.
* Ask friends and family members for help. Tell them about your vision problems so
that they can help you perform certain tasks and help you recognize people.
* Don't become socially isolated. A common frustration of people with macular
degeneration is the inability to recognize other people and greet them by name.
If this happens to you, try asking people you know to say hi and tell you their
names when you meet them on the street or in other situations so that you can
greet them back.
* Take advantage of online networks. The Internet is a good source for support
groups and resources for people with macular degeneration.
Alternative medicine
Some people have turned to complementary or alternative therapies, such as bilberry, ginkgo and shark cartilage, in the belief that they can help prevent the progression of macular degeneration.
However, there's no conclusive evidence that any of these products are effective for macular degeneration, and some may interact with other medications you're taking. Check with your doctor before taking any dietary or herbal supplement.
Prevention
The following measures may help you avoid macular degeneration:
* Eat foods containing antioxidants. Foods with antioxidants are those rich in
vitamins A, C and E. People who eat diets rich in vegetables, particularly leafy
green vegetables, may have a lower risk of macular degeneration. The National
Eye Institute is currently sponsoring a clinical trial to assess the efficacy of
three specific antioxidants — lutein, zeaxanthin and omega-3 fatty acids — in
lowering the risk of macular degeneration. Lutein and zeaxanthin are found in
high concentrations in egg yolks, corn, and spinach and other green leafy
vegetables. Omega-3 fatty acids are found in fish as well as other foods such as
almonds.
* Take antioxidant and zinc supplements. For people with moderate to advanced
macular degeneration, findings from the National Eye Institute-sponsored
Age-Related Eye Disease Study (AREDS) indicate that taking high doses of zinc,
beta carotene, and vitamins C and E is effective in reducing the risk of further
vision loss. However, beta carotene has been linked to increased risk of lung
cancer in smokers. Too much vitamin E can be toxic. Ask your doctor about these
supplements before trying anything on your own.
* Eat fish. A diet rich in the omega-3 fatty acids found in fish can result in a
reduced risk of macular degeneration.
* Stop smoking. Smokers are more likely to develop macular degeneration than are
nonsmokers. Ask your doctor for help to stop smoking.
* Manage your other diseases. For example, if you have cardiovascular disease or
high blood pressure, take your medication and follow your doctor's instructions
for controlling the condition.
* Get regular eye exams. Early detection of macular degeneration increases your
chances of preventing serious vision loss. If you're older than 40, get an exam
every two to four years, and older than 65, every year or two. If you have a
family history of macular degeneration, have your eyes examined more frequently.
* Screen your vision regularly. If you've received a diagnosis of early-stage
macular degeneration, your doctor may suggest that you regularly monitor your
vision at home with an Amsler grid. Doing so may help you to detect subtle
changes in your vision at the earliest possible time and seek help promptly.
If you have some vision loss because of macular degeneration, your eye doctor can prescribe optical devices called low-vision aids that will help you see better for close-up work. Or your doctor may refer you to a low-vision specialist. In addition, a wide variety of support services and rehabilitation programs are available that may help you adjust your lifestyle.
By Mayo Clinic Staff
Aug. 26, 2008
Age-related macular degeneration is a chronic eye disease marked by deterioration of tissue in the part of your eye that's responsible for central vision. The deterioration occurs in the macula (MAK-u-luh), which is in the center of the retina — the layer of tissue on the inside back wall of your eyeball.
Macular degeneration doesn't cause total blindness, but it worsens your quality of life by blurring or causing a blind spot in your central vision. Clear central vision is necessary for reading, driving, recognizing faces and doing detail work.
Macular degeneration tends to affect adults age 50 and older. Dry macular degeneration, in which tissue deterioration is not accompanied by bleeding, is the most common form of the disease.
Symptoms
Dry macular degeneration usually develops gradually and painlessly. You may notice these vision changes:
* The need for increasingly bright light when reading or doing close work
* Increasing difficulty adapting to low light levels, such as when entering a
dimly lit restaurant
* Increasing blurriness of printed words
* A decrease in the intensity or brightness of colors
* Difficulty recognizing faces
* Gradual increase in the haziness of your overall vision
* Blurred or blind spot in the center of your visual field combined with a
profound drop in the sharpness (acuity) of your central vision
Your vision may falter in one eye while the other eye remains fine for years. You may not notice any or much change because your good eye compensates for the weak one. Your vision and lifestyle begin to be dramatically affected when this condition develops in both eyes.
Hallucinations
Additionally, some people with macular degeneration may experience visual hallucinations as their vision loss becomes more severe. These hallucinations may include unusual patterns, geometric figures, animals or even faces. You might be afraid to discuss these symptoms with your doctors or friends and family for fear you'll be considered crazy. However, such hallucinations aren't a sign of mental illness. In fact, they're so common that there's a name for this phenomenon — Charles Bonnet syndrome.
When to see a doctor
See your eye doctor — particularly after age 50 — if:
* You notice changes in your central vision
* Your ability to see colors and fine detail becomes impaired
One way to monitor your eyes to determine if you may need to visit your eye doctor is to check your vision regularly using an Amsler grid. This simple test may help you detect changes in your sight that you otherwise may not notice.
Here's how to perform the test:
* Hold the grid 14 inches (about 36 centimeters) in front of you in good light.
Use your corrective glasses or reading glasses if you normally wear them.
* Cover one eye.
* Look directly at the center dot with your uncovered eye.
* While looking at this dot, determine whether all of the lines of the grid appear
straight, uninterrupted and have the same contrast.
* Repeat the above steps with your other eye.
* If any part of the grid is missing or looks wavy, blurred or dark, contact your
eye doctor immediately.
Causes
The exact cause of dry macular degeneration is unknown, but the condition develops as the eye ages. The initial site of change is not in the light-sensitive cells of the macula, but in the retinal pigment epithelium (RPE), a single layer of cells located just behind the retina close to the back wall of your eye.
Your macula is an area about two-tenths of an inch (5 millimeters) in diameter at the center of your retina. This small part of your eye is responsible for clear vision, particularly in your direct line of sight.
The macula consists of millions of densely packed light-sensitive cells called cones and rods. Cones and rods have two segments: An inner segment controls cell functions and produces proteins responsive to light, and an outer segment stores and makes use of these proteins.
As they absorb light, outer segment proteins become degraded and eventually are shed as waste. Meanwhile, the inner segments continuously provide replacements for the outer segments. One function of the cells of the RPE is to remove the outer segments that are shed.
As the eye ages, cells in the RPE begin to deteriorate (atrophy) and lose their pigment. As a consequence, the RPE becomes less efficient in removing outer segment waste. When that happens, the normally uniform reddish color of the macula (as seen with an ophthalmoscope) takes on a mottled appearance. Drusen — yellow, fat-like deposits — begin to appear under the cones and rods. As the drusen and mottled pigmentation continue to develop, your vision gradually deteriorates.
Based on this progression, dry macular degeneration is categorized in three stages:
* Early stage. Several small drusen or a few medium-sized drusen are detected on
the macula in one or both eyes. Generally, there's no vision loss in the
earliest stage.
* Intermediate stage. Many medium-sized drusen or one or more large drusen are
detected in one or both eyes. At this stage, your central vision may start to
blur and you may need extra light for reading or doing detail work.
* Advanced stage. Several large drusen, as well as extensive breakdown of light-
sensitive cells in the macula, are detected. These features cause a well-defined
spot of blurring in your central vision. The blurred area may become larger and
more opaque over time.
Macular degeneration almost always starts out as the dry form. Dry macular degeneration may initially affect only one eye but, in most cases, both eyes eventually become involved.
Risk factors
Contributing factors for development of macular degeneration include:
* Age. In the United States, macular degeneration is the leading cause of severe
vision loss in people age 60 and older.
* Family history of macular degeneration. If someone in your family had macular
degeneration, your odds of developing macular degeneration are higher. In recent
years, researchers have identified some of the genes associated with macular
degeneration. In the future, genetic screening tests may be helpful for
assessing early risk of the disease.
* Race. Macular degeneration is more common in whites than it is in other groups,
especially after age 75.
* Sex. Women are more likely than men to develop macular degeneration, and because
they tend to live longer, women are more likely to experience the effects of
severe vision loss from the disease.
* Cigarette smoking. Exposure to cigarette smoke doubles your risk of macular
degeneration. Cigarette smoking is the single most preventable cause of macular
degeneration.
* Obesity. Being severely overweight increases the chance that early or
intermediate macular degeneration will progress to the more severe form of the
disease.
* Light-colored eyes. People with light-colored eyes appear to be at greater risk
than do those with darker eyes.
* Exposure to sunlight. Although the retina is more sensitive to shorter
wavelengths of light, including ultraviolet (UV) light, only a small percentage
of ultraviolet light actually reaches the retina. Most ultraviolet light is
filtered by the transparent outer surface of your eye (cornea) and the natural
crystalline lens in your eye. Some experts believe that long-term exposure to
ultraviolet light may increase your risk of developing macular degeneration, but
this risk has not been proved and remains controversial.
* Low levels of nutrients. This includes low blood levels of minerals, such as
zinc, and of antioxidant vitamins, such as A, C and E. Antioxidants may protect
your cells from oxygen damage (oxidation), which may partially be responsible
for the effects of aging and for the development of certain diseases such as
macular degeneration.
* Cardiovascular diseases. These include high blood pressure, stroke, heart attack
and coronary artery disease with chest pain (angina).
Preparing for your appointment
To check for macular degeneration, a dilated eye exam is necessary. Make an appointment with a doctor who specializes in eye care — an optometrist or an ophthalmologist — who can evaluate your condition and perform a complete eye exam.
What you can do
Appointments can be brief. Make the best use of that limited time by preparing beforehand.
* Be aware of any pre-appointment restrictions. When you make the appointment, ask
if there's anything you need to do in advance.
* Write down any symptoms you're experiencing, including any that may seem
unrelated to your vision problem.
* Make a list of all medications, as well as any vitamins or supplements, that
you're taking.
* Ask a family member or friend to accompany you, if possible. Having your pupils
dilated for the eye exam may compromise your vision for a time afterward. You
may need someone else to drive or accompany you from your appointment.
Questions to ask your eye doctor
* What kind of macular degeneration do I have?
* What is the visual acuity in my central vision?
* How advanced is my macular degeneration?
* Will I experience further vision loss?
* Will taking a vitamin or mineral supplement help prevent further vision loss?
* What's the best way to monitor my vision for any changes?
* What low-vision aids or adaptive devices might be helpful to me?
Questions your eye doctor may ask
* When did you first notice your vision problem?
* Does the condition affect one or both eyes?
* Do you have trouble seeing things near you, at a distance or both?
Tests and diagnosis
Diagnostic tests for macular degeneration may include:
* An eye examination. One of the things your eye doctor looks for while examining
the inside of your eye is the presence of drusen and mottled pigmentation in the
macula. The eye examination includes a simple test of your central vision and
may include testing with an Amsler grid. If you have macular degeneration, when
you look at the grid some of the straight lines may seem faded, broken or
distorted. By noting where the break or distortion occurs — usually on or near
the center of the grid — your eye doctor can better determine the location and
extent of your macular damage.
Regular screening examinations can detect early signs of macular degeneration
before the disease leads to vision loss.
* Angiography. To evaluate the extent of the damage from macular degeneration,
your eye doctor may use fluorescein angiography. In this procedure, fluorescein
dye is injected into a vein in your arm and photographs are taken of the back of
the eye as the dye passes through blood vessels in your retina and choroid. Your
doctor then uses these photographs to detect changes in macular pigmentation or
to identify small macular blood vessels.
Your doctor may also suggest a similar procedure called indocyanine green
angiography. Instead of fluorescein, a dye called indocyanine green is used.
This test provides information that complements the findings obtained through
fluorescein angiography.
* Optical coherence tomography. This noninvasive imaging test helps identify and
display areas of retinal thickening or thinning. Such changes are associated
with macular degeneration. This test can also reveal the presence of abnormal
fluid in and under the retina or the RPE. It's often used to help monitor the
response of the retina to macular degeneration treatments.
Treatments and drugs
There's no treatment available to reverse dry macular degeneration. But this doesn't mean you'll eventually lose all of your sight. Dry macular degeneration usually progresses slowly, and many people with the condition are able to live relatively normal, productive lives, especially if only one eye is affected. Dry macular degeneration can, however, develop into the more rapidly progressive wet type of macular degeneration at any time.
Taking a high-dose formulation of antioxidants and zinc may reduce progression of dry macular degeneration to advanced macular degeneration. The National Eye Institute-sponsored Age-Related Eye Disease Study (AREDS) showed that a daily supplement of 500 milligrams (mg) of vitamin C, 400 international units (IU) of vitamin E, 15 mg of beta carotene (often as vitamin A — up to 25,000 IU), 80 mg of zinc (as zinc oxide) and 2 mg of copper (as cupric oxide) reduced the risk of progressing to moderate or severe vision loss by up to 25 percent.
Lifestyle and home remedies
Macular degeneration doesn't affect your side (peripheral) vision and usually doesn't cause total blindness. But it can rob you of your central vision — which is important for driving, reading and recognizing people's faces. A low-vision center may be able to assess your visual capabilities and suggest certain optical and household devices that can be helpful for some near-vision tasks. Ask your eye doctor if there are any low-vision centers in your area.
There are ways to cope with impaired vision. Below are a few suggestions:
* Use caution when driving. First, check with your doctor to see if driving is
still safe based on your current visual acuity. When you do drive, there are
certain situations to avoid. For example, don't drive at night, in heavy traffic
or in bad weather.
* Seek help traveling. Use public transportation or ask family members to help,
especially with night driving.
* Travel with others. Contact your local area agency on aging for a list of vans
and shuttles, volunteer driving networks or ride shares.
* Get good glasses. Optimize the vision you have with the right glasses, and keep
an extra pair in the car.
* Use magnifiers. Large-print books and magazines can help you read more easily.
* View with large type on the Internet. Look for Web sites that use large-sized
type fonts, or change the font size on your display.
* Obtain specialized appliances. Some clocks, radios, telephones and other
appliances have extra-large numbers.
* Have proper light in your home. This will help with reading and other activities.
* Remove home hazards. Eliminate throw rugs and other possible tripping hazards in
your home.
* Ask friends and family members for help. Tell them about your vision problems so
that they can help you perform certain tasks and help you recognize people.
* Don't become socially isolated. A common frustration of people with macular
degeneration is the inability to recognize other people and greet them by name.
If this happens to you, try asking people you know to say hi and tell you their
names when you meet them on the street or in other situations so that you can
greet them back.
* Take advantage of online networks. The Internet is a good source for support
groups and resources for people with macular degeneration.
Alternative medicine
Some people have turned to complementary or alternative therapies, such as bilberry, ginkgo and shark cartilage, in the belief that they can help prevent the progression of macular degeneration.
However, there's no conclusive evidence that any of these products are effective for macular degeneration, and some may interact with other medications you're taking. Check with your doctor before taking any dietary or herbal supplement.
Prevention
The following measures may help you avoid macular degeneration:
* Eat foods containing antioxidants. Foods with antioxidants are those rich in
vitamins A, C and E. People who eat diets rich in vegetables, particularly leafy
green vegetables, may have a lower risk of macular degeneration. The National
Eye Institute is currently sponsoring a clinical trial to assess the efficacy of
three specific antioxidants — lutein, zeaxanthin and omega-3 fatty acids — in
lowering the risk of macular degeneration. Lutein and zeaxanthin are found in
high concentrations in egg yolks, corn, and spinach and other green leafy
vegetables. Omega-3 fatty acids are found in fish as well as other foods such as
almonds.
* Take antioxidant and zinc supplements. For people with moderate to advanced
macular degeneration, findings from the National Eye Institute-sponsored
Age-Related Eye Disease Study (AREDS) indicate that taking high doses of zinc,
beta carotene, and vitamins C and E is effective in reducing the risk of further
vision loss. However, beta carotene has been linked to increased risk of lung
cancer in smokers. Too much vitamin E can be toxic. Ask your doctor about these
supplements before trying anything on your own.
* Eat fish. A diet rich in the omega-3 fatty acids found in fish can result in a
reduced risk of macular degeneration.
* Stop smoking. Smokers are more likely to develop macular degeneration than are
nonsmokers. Ask your doctor for help to stop smoking.
* Manage your other diseases. For example, if you have cardiovascular disease or
high blood pressure, take your medication and follow your doctor's instructions
for controlling the condition.
* Get regular eye exams. Early detection of macular degeneration increases your
chances of preventing serious vision loss. If you're older than 40, get an exam
every two to four years, and older than 65, every year or two. If you have a
family history of macular degeneration, have your eyes examined more frequently.
* Screen your vision regularly. If you've received a diagnosis of early-stage
macular degeneration, your doctor may suggest that you regularly monitor your
vision at home with an Amsler grid. Doing so may help you to detect subtle
changes in your vision at the earliest possible time and seek help promptly.
If you have some vision loss because of macular degeneration, your eye doctor can prescribe optical devices called low-vision aids that will help you see better for close-up work. Or your doctor may refer you to a low-vision specialist. In addition, a wide variety of support services and rehabilitation programs are available that may help you adjust your lifestyle.
By Mayo Clinic Staff
Aug. 26, 2008
Saturday, January 3, 2009
Common Treatments for Macular Degeneration
In this section, you will find information on:
* Angiogenesis Inhibitors
* Laser Photocoagulation
* Photodynamic Therapy
* Vitamin and Mineral Supplements
Angiogenesis Inhibitors
Angiogenesis Inhibitors are used to treat the wet form of macular degeneration. The two most commonly used are Lucentis® (ranibizumab injection) and Macugen® (pegaptanib sodium injection).
Lucentis®
Generic name: ranibizumab injection
Year approved by the FDA: 2006
Effective for: Wet age-related macular degeneration (AMD)
How it works: Vision loss in wet AMD is caused by the growth of abnormal leaky blood vessels that eventually damage the macula (area of the eye responsible for central vision). Lucentis is an antibody fragment that binds to and inhibits the activity of human vascular endothelial growth factor (VEGF), a protein believed to play a critical role in the formation of these new blood vessels. Lucentis is injected into the vitreous portion of the eye (the clear jelly-like substance that fills the eye from the lens back to the retina). In AMD, VEGF is continually produced, so routine administration of Lucentis over a period of time is required.
Most common side effects: The most commonly reported adverse events included hemorrhage of the conjunctiva (the membrane that covers the white part of the eye), floaters, eye pain, increased eye pressure and inflammation of the eye. Serious adverse events such as endophthalmitis (severe inflammation of the interior of the eye), retinal detachment, retinal tear, increased eye pressure and traumatic cataract are rare.
Status: Avastin®, a drug manufactured by the same company that makes Lucentis (Genentech, Inc.), has been used by physicians as an “off-label” treatment for AMD, but is actually an FDA-approved cancer therapy. Both drugs are similarly administered. However, Avastin costs much less, and many physicians believe these drugs are equally effective. The National Eye Institute of the National Institutes of Health is planning to conduct clinical trials in 2008 (Comparison of Treatments Trials or CATT) to study the relative efficacy and safety of Avastin and Lucentis.
Macugen®
Generic name: pegaptanib sodium injection
Year approved by the FDA: 2004
Effective for: Wet age-related macular degeneration (AMD)
How it works: Vision loss in wet AMD is caused by the growth of abnormal leaky blood vessels that eventually damage the macula (area of the eye responsible for central vision). Macugen blocks vascular endothelial growth factor (VEGF), a protein that promotes this blood vessel growth.
Macugen is injected into the vitreous portion of the eye (the clear jelly-like substance that fills the eye from the lens back to the retina). In AMD, VEGF is continually produced, so ongoing, routine administration of Macugen is required.
Most common side effects: Common side effects of Macugen include inflammation of the eye, blurred vision or changes in vision, cataracts, bleeding in the eye, swelling of the eye, eye discharge, irritation or discomfort of the eye and "spots" in vision.
Laser Photocoagulation
Year approved by the FDA: 1991
Effective for: Wet age-related macular degeneration (AMD)
How it works: Photocoagulation was the first treatment that was used for wet AMD. During this outpatient procedure, the eye is numbed, and a high-energy laser heats, seals and destroys abnormal leaky blood vessels. This can help prevent or slow further damage, but it results in a permanent blind spot. When successful, laser photocoagulation is a one-time treatment. However, if new blood vessels grow, surgery may have to be repeated.
Most common side effects: Some patients experience mild pain during and shortly after the procedure. This is usually relieved by taking non-prescription pain medication. Reduced vision and scarring of the retina may also occur.
Status: It is not possible to treat those with “subfoveal” AMD in which the abnormal blood vessels are located under the fovea, in the center of the macula. Almost 90% of AMD is subfoveal, so only a small percentage of patients are candidates for this procedure.
Photodynamic Therapy
Visudyne® Generic name: verteporfin
Year approved by the FDA: 2000
Effective for: Wet age-related macular degeneration (AMD)
How it works: Photodynamic therapy (PDT) using Visudyne ® (verteporfin) is widely used to treat the new growth of fragile and abnormal blood vessels or neovascularization that is characteristic of wet AMD. PDT is most effective for a subtype of AMD called predominantly classic subfoveal, in which areas of abnormal blood vessel growth and bleeding in the fovea, at the center of the macula, are well-defined. The great majority of AMD cases are subfoveal, but only 25% of these cases are the predominantly classic subtype.
During the PDT procedure, Visudyne, a light-sensitive drug, is injected into a vein in the arm. The drug enters the bloodstream and is absorbed by the abnormal blood vessels growing underneath the macula. A low-intensity, non-thermal (“cold”) laser is then directed at the retina for a little over a minute. This activates the Visudyne allowing it to destroy the abnormal vessels and inhibit the neovascularization. The cold laser does not damage the retina or other cell layers that overlie the abnormal vessels. PDT may help to stabilize vision, but it will not restore lost vision and is not likely to improve vision. Treatments are typically administered every 3 months and as many times as needed to prevent re-growth of the abnormal vessels (potentially 6-7 treatments over 2-3 years). One treatment normally takes about 20 minutes and is relatively painless.
Most common side effects: The most common side effects of PDT include headache, injection site reaction, and possibly blurred or reduced vision. Because the drug is activated by light, patients must avoid exposing their eyes or any part of their skin to sunlight or bright indoor light for up to five days after treatment.
Status: To date, the FDA has only approved Visudyne for PDT. Other light-sensitive drugs are being evaluated, and researchers are also studying the use of verteporfin in combination with other types of therapies.
Vitamin and Mineral Supplements
Year approved by the FDA: The Food and Drug Administration (FDA) regulates dietary supplements under a different set of regulations than those covering conventional foods and drugs (prescription and over-the-counter). Dietary supplement manufacturers are responsible for ensuring that a dietary supplement is safe before it is marketed; the FDA may take action against any unsafe supplement after it reaches the market. Generally, however, manufacturers do not need to register their products with FDA nor get FDA approval.
Effective for: Intermediate dry age-related macular degeneration (AMD)
How it works: Currently, there is no treatment or cure for dry macular degeneration. However, in 2001, the National Eye Institute’s (NEI’s) Age-Related Eye Disease Study (AREDS) found that taking a specific high dose formula of vitamins and mineral supplements (AREDS formula) significantly reduced the risk of progressing from intermediate macular degeneration to advanced or wet macular degeneration. The study showed no benefit for those with early stage macular degeneration.
When macular degeneration progresses to the advanced stage, toxic substances build up that may damage the retina. The vitamins and minerals of the AREDS formula act as antioxidants to help maintain healthy cells and tissues and may prevent this damage. In the study, the effective formula contained 500 milligrams of vitamin C, 400 International Units of vitamin E, 15 milligrams of beta-carotene, 80 milligrams of zinc as zinc oxide and two milligrams of copper as cupric oxide.
Many of the antioxidants in the AREDS formula can be found in over-the-counter vitamin and mineral supplements, but the dosages required to achieve maximum efficacy are far greater. AREDS formula supplements may be contra-indicated with medications and patients should consult a physician before taking any vitamins or minerals. Patients with intermediate macular degeneration in one or both eyes or advanced macular degeneration in one eye but not the other eye might consider taking the formula.
Most common side effects: Some participants in the AREDS clinical trials reported minor side effects. A small percentage of those given zinc treatments developed urinary tract problems that required hospitalization. Yellowing of the skin, a well-known side effect of large doses of beta-carotene, was reported slightly more often by participants taking antioxidants.
Status: NEI is currently recruiting 4,000 volunteers to participate in AREDS-2 trials. The study will focus on the effect of adding two supplements, lutein and zeaxanthin, as well as two omega-3 long chain fatty acids (DHA and EPA) to the original AREDS formula. Researchers are interested in the effect of these supplements on the progression to advanced macular degeneration and/or moderate vision loss in those at risk of progression. Participants will also be offered variations on levels of beta-carotene and zinc to the original AREDS formula. Scientists will follow up for at least five years.
Disclaimer: The information provided in this section is a public service of the American Health Assistance Foundation, and should not in any way substitute for the advice of a qualified healthcare professional and is not intended to constitute medical advice. Although we take efforts to keep the medical information on our website updated, we cannot guarantee that the information on our website reflects the most up-to-date research. Please consult your physician for personalized medical advice; all medications and supplements should only be taken under medical supervision. The American Health Assistance Foundation does not endorse any medical product or therapy.
Source: The information provided in this section of our website was obtained from the National Eye Institute of the National Institutes of Health and ClinicalTrials.gov. The American Health Assistance Foundation is grateful to Jeffrey H. Stern, M.D., Ph.D. at the Regenerative Research Foundation in Rensselaer, New York for reviewing aspects of the above content.
Last Reviewed On: 11/21/08
* Angiogenesis Inhibitors
* Laser Photocoagulation
* Photodynamic Therapy
* Vitamin and Mineral Supplements
Angiogenesis Inhibitors
Angiogenesis Inhibitors are used to treat the wet form of macular degeneration. The two most commonly used are Lucentis® (ranibizumab injection) and Macugen® (pegaptanib sodium injection).
Lucentis®
Generic name: ranibizumab injection
Year approved by the FDA: 2006
Effective for: Wet age-related macular degeneration (AMD)
How it works: Vision loss in wet AMD is caused by the growth of abnormal leaky blood vessels that eventually damage the macula (area of the eye responsible for central vision). Lucentis is an antibody fragment that binds to and inhibits the activity of human vascular endothelial growth factor (VEGF), a protein believed to play a critical role in the formation of these new blood vessels. Lucentis is injected into the vitreous portion of the eye (the clear jelly-like substance that fills the eye from the lens back to the retina). In AMD, VEGF is continually produced, so routine administration of Lucentis over a period of time is required.
Most common side effects: The most commonly reported adverse events included hemorrhage of the conjunctiva (the membrane that covers the white part of the eye), floaters, eye pain, increased eye pressure and inflammation of the eye. Serious adverse events such as endophthalmitis (severe inflammation of the interior of the eye), retinal detachment, retinal tear, increased eye pressure and traumatic cataract are rare.
Status: Avastin®, a drug manufactured by the same company that makes Lucentis (Genentech, Inc.), has been used by physicians as an “off-label” treatment for AMD, but is actually an FDA-approved cancer therapy. Both drugs are similarly administered. However, Avastin costs much less, and many physicians believe these drugs are equally effective. The National Eye Institute of the National Institutes of Health is planning to conduct clinical trials in 2008 (Comparison of Treatments Trials or CATT) to study the relative efficacy and safety of Avastin and Lucentis.
Macugen®
Generic name: pegaptanib sodium injection
Year approved by the FDA: 2004
Effective for: Wet age-related macular degeneration (AMD)
How it works: Vision loss in wet AMD is caused by the growth of abnormal leaky blood vessels that eventually damage the macula (area of the eye responsible for central vision). Macugen blocks vascular endothelial growth factor (VEGF), a protein that promotes this blood vessel growth.
Macugen is injected into the vitreous portion of the eye (the clear jelly-like substance that fills the eye from the lens back to the retina). In AMD, VEGF is continually produced, so ongoing, routine administration of Macugen is required.
Most common side effects: Common side effects of Macugen include inflammation of the eye, blurred vision or changes in vision, cataracts, bleeding in the eye, swelling of the eye, eye discharge, irritation or discomfort of the eye and "spots" in vision.
Laser Photocoagulation
Year approved by the FDA: 1991
Effective for: Wet age-related macular degeneration (AMD)
How it works: Photocoagulation was the first treatment that was used for wet AMD. During this outpatient procedure, the eye is numbed, and a high-energy laser heats, seals and destroys abnormal leaky blood vessels. This can help prevent or slow further damage, but it results in a permanent blind spot. When successful, laser photocoagulation is a one-time treatment. However, if new blood vessels grow, surgery may have to be repeated.
Most common side effects: Some patients experience mild pain during and shortly after the procedure. This is usually relieved by taking non-prescription pain medication. Reduced vision and scarring of the retina may also occur.
Status: It is not possible to treat those with “subfoveal” AMD in which the abnormal blood vessels are located under the fovea, in the center of the macula. Almost 90% of AMD is subfoveal, so only a small percentage of patients are candidates for this procedure.
Photodynamic Therapy
Visudyne® Generic name: verteporfin
Year approved by the FDA: 2000
Effective for: Wet age-related macular degeneration (AMD)
How it works: Photodynamic therapy (PDT) using Visudyne ® (verteporfin) is widely used to treat the new growth of fragile and abnormal blood vessels or neovascularization that is characteristic of wet AMD. PDT is most effective for a subtype of AMD called predominantly classic subfoveal, in which areas of abnormal blood vessel growth and bleeding in the fovea, at the center of the macula, are well-defined. The great majority of AMD cases are subfoveal, but only 25% of these cases are the predominantly classic subtype.
During the PDT procedure, Visudyne, a light-sensitive drug, is injected into a vein in the arm. The drug enters the bloodstream and is absorbed by the abnormal blood vessels growing underneath the macula. A low-intensity, non-thermal (“cold”) laser is then directed at the retina for a little over a minute. This activates the Visudyne allowing it to destroy the abnormal vessels and inhibit the neovascularization. The cold laser does not damage the retina or other cell layers that overlie the abnormal vessels. PDT may help to stabilize vision, but it will not restore lost vision and is not likely to improve vision. Treatments are typically administered every 3 months and as many times as needed to prevent re-growth of the abnormal vessels (potentially 6-7 treatments over 2-3 years). One treatment normally takes about 20 minutes and is relatively painless.
Most common side effects: The most common side effects of PDT include headache, injection site reaction, and possibly blurred or reduced vision. Because the drug is activated by light, patients must avoid exposing their eyes or any part of their skin to sunlight or bright indoor light for up to five days after treatment.
Status: To date, the FDA has only approved Visudyne for PDT. Other light-sensitive drugs are being evaluated, and researchers are also studying the use of verteporfin in combination with other types of therapies.
Vitamin and Mineral Supplements
Year approved by the FDA: The Food and Drug Administration (FDA) regulates dietary supplements under a different set of regulations than those covering conventional foods and drugs (prescription and over-the-counter). Dietary supplement manufacturers are responsible for ensuring that a dietary supplement is safe before it is marketed; the FDA may take action against any unsafe supplement after it reaches the market. Generally, however, manufacturers do not need to register their products with FDA nor get FDA approval.
Effective for: Intermediate dry age-related macular degeneration (AMD)
How it works: Currently, there is no treatment or cure for dry macular degeneration. However, in 2001, the National Eye Institute’s (NEI’s) Age-Related Eye Disease Study (AREDS) found that taking a specific high dose formula of vitamins and mineral supplements (AREDS formula) significantly reduced the risk of progressing from intermediate macular degeneration to advanced or wet macular degeneration. The study showed no benefit for those with early stage macular degeneration.
When macular degeneration progresses to the advanced stage, toxic substances build up that may damage the retina. The vitamins and minerals of the AREDS formula act as antioxidants to help maintain healthy cells and tissues and may prevent this damage. In the study, the effective formula contained 500 milligrams of vitamin C, 400 International Units of vitamin E, 15 milligrams of beta-carotene, 80 milligrams of zinc as zinc oxide and two milligrams of copper as cupric oxide.
Many of the antioxidants in the AREDS formula can be found in over-the-counter vitamin and mineral supplements, but the dosages required to achieve maximum efficacy are far greater. AREDS formula supplements may be contra-indicated with medications and patients should consult a physician before taking any vitamins or minerals. Patients with intermediate macular degeneration in one or both eyes or advanced macular degeneration in one eye but not the other eye might consider taking the formula.
Most common side effects: Some participants in the AREDS clinical trials reported minor side effects. A small percentage of those given zinc treatments developed urinary tract problems that required hospitalization. Yellowing of the skin, a well-known side effect of large doses of beta-carotene, was reported slightly more often by participants taking antioxidants.
Status: NEI is currently recruiting 4,000 volunteers to participate in AREDS-2 trials. The study will focus on the effect of adding two supplements, lutein and zeaxanthin, as well as two omega-3 long chain fatty acids (DHA and EPA) to the original AREDS formula. Researchers are interested in the effect of these supplements on the progression to advanced macular degeneration and/or moderate vision loss in those at risk of progression. Participants will also be offered variations on levels of beta-carotene and zinc to the original AREDS formula. Scientists will follow up for at least five years.
Disclaimer: The information provided in this section is a public service of the American Health Assistance Foundation, and should not in any way substitute for the advice of a qualified healthcare professional and is not intended to constitute medical advice. Although we take efforts to keep the medical information on our website updated, we cannot guarantee that the information on our website reflects the most up-to-date research. Please consult your physician for personalized medical advice; all medications and supplements should only be taken under medical supervision. The American Health Assistance Foundation does not endorse any medical product or therapy.
Source: The information provided in this section of our website was obtained from the National Eye Institute of the National Institutes of Health and ClinicalTrials.gov. The American Health Assistance Foundation is grateful to Jeffrey H. Stern, M.D., Ph.D. at the Regenerative Research Foundation in Rensselaer, New York for reviewing aspects of the above content.
Last Reviewed On: 11/21/08
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