Macular Diseases
What is the macula?
 The macula is an oval area in the retina on the back of the eye where the
photoreceptors are most dense and where the light is focused. The center of
the macula is called the fovea. The macula is responsible for the central
(or reading) vision. The macula has the greatest concentration of
photoreceptor cells, and when the eye is directed at an object, the part of
the image that is focused on the fovea is the image most accurately seen.
What is macular degeneration?
Age-related macular degeneration (AMD) is the leading cause of irreversible blindness among people 50 years of age and older in most industrialized countries.
* Dry AMD is the most common form of macular degeneration and can progress to cause severe central vision loss. AMD always starts as dry AMD. This disease progresses slowly and most people usually maintain some vision in at least one eye. Dry AMD refers to the slow degenerative process that occurs without any formation of abnormal blood vessels. When the abnormal blood vessels form, the disease is called wet AMD. The Age-Related Eye Disease Study (AREDS) demonstrated that vitamin supplementation slowed the progression of dry AMD. This study demonstrated the benefits of taking Vitamin C, Vitamin E, beta-carotene, and zinc along with copper. Several preparations containing the appropriate amounts of these vitamins and micronutrients are currently available and we encourage patients with AMD to discuss these various vitamin preparations with their eye care specialist. Smoking may be detrimental to patients with AMD (as well as a great number of other diseases such as stroke, myocardial infarction and lung cancer). All smokers should avoid beta-carotene, and these individuals should take a vitamin formulation that contains lutein rather than beta-carotene. There are no treatments at this time that can preserve or improve vision.
* "Wet" macular degeneration (exudative or neovascular AMD) is caused by blood vessels growing under the retina in the macula. "Wet" AMD always arises from pre-existing "dry" AMD. These blood vessels leak fluid, protein, lipid, and blood. Eventually, a scar forms under the macula and central vision is destroyed. There are several treatments for "wet" macular degeneration that can prevent scar formation and preserve or improve vision; however, these treatments convert the wet AMD back to dry AMD, so over time, vision loss will still occur.
Click here more information about macular degeneration at Bascom Palmer Eye Institute
What are the symptoms of macular degeneration?
There is no pain associated with dry or wet AMD. The most common symptom of dry AMD is slightly blurred or fuzzy vision and the need for brighter lights for reading. Also, many patients with AMD report an inability to recognize faces at a distance.
As dry AMD progresses, a blurred spot develops in the center of the vision. With time, the spot may get bigger and darker, reducing central vision. Often, when dry AMD is limited to one eye, patients do not complain of visual changes because of the ability of the other healthy eye to see clearly. The better eye permits driving, reading, recognizing faces, and seeing fine details.
Symptoms of wet AMD may be that straight lines, such as sentences on a
page, appear wavy; rapid loss of central vision; and a blurred or blind
spot in the center of vision.
How is macular degeneration diagnosed?
If an ophthalmologist suspects AMD, he or she may:
* Perform a visual acuity test to measure vision at a distance
* Ask the patient to look at an Amsler grid with a pattern of straight horizontal and vertical lines. To the person with AMD, the lines appear wavy, distorted or missing or a black spot may appear in the center of the grid
* Perform a dilated pupil examination to look inside the eye and check for drusen (tiny yellow deposits on the retina which are the most common early signs of AMD), geographic atrophy, and neovascularization (abnormal blood vessels)
* Perform optical coherence tomography (OCT) and fluorescein angiography to determine the extent of AMD.
What are the current treatment options for dry AMD?
There is no therapy that can stop the vision loss from dry AMD. At the Bascom Palmer Eye Institute, we are testing new drugs that could stop the disease from progressing and these drugs may even improve vision.
Patients with dry macular degeneration should check the vision in each eye, one at a time, at least once a day. By staring at the central point on an Amsler grid, patients can help monitor their vision regularly and can detect distortions in vision. These distortions represent the earliest stages of wet macular degeneration, the ideal time to start anti-VEGF treatment, see below.
What are the current treatment options for wet AMD?
The Bascom Palmer Eye Institute’s faculty led the way to develop and study treatments for wet AMD. Treatments are currently available and offer promise for wet AMD, the more devastating form of AMD. Vision improvement is possible if the wet form of AMD is treated at an early stage. If vision loss has been long standing and if there is no evidence of blood vessels growing and leaking in the eye, then these treatments are unlikely to result in any vision improvement.
Vascular Endothelial Growth Factor (VEGF) is a protein that causes the abnormal blood vessels to grow, leak, bleed and damage a part of the retina known as the macula resulting in loss of central vision that prevents driving, reading, recognizing people, and other important tasks that contribute to a high quality of life. Patients with wet AMD have high levels of VEGF in their affected eyes. Two different drugs with anti-VEGF properties are available for direct injection into the eye.
Bevacizumab (Avastin). Bascom Palmer Eye Institute’s retina specialist Philip Rosenfeld, M.D., Ph.D. pioneered the off-label use of Avastin to treat the wet form of AMD. Now used by retina specialists throughout the world for its effectiveness and low cost compared with other treatments, Avastin was the first effective treatment in clinical practice that had the potential not only to stop further deterioration in vision from wet AMD, but bring about significant improvement in vision for these patients.Avastin is currently approved by the U.S. Food and Drug Administration (FDA) for the treatment of metastatic colorectal cancer, metastatic non-small cell lung cancer and metastatic breast cancer. In Bascom Palmer’s clinical experience, our published results show similarity with the results published using another drug known as ranibizumab (Lucentis).
Ranibizumab (Lucentis). Bascom Palmer Eye Institute’s retina specialist Philip Rosenfeld, M.D., Ph.D. pioneered the use of Lucentis as well. In June 2006, the FDA approved Lucentis for the treatment of the wet form of AMD. Lucentis and Avastin are both manufactured by Genentech, Inc. and both drugs are derived from the same monoclonal antibody against VEGF and virtually perform the same function. Lucentis was engineered specifically for the eye and tested in rigorous Phase III trials. Like Avastin, Lucentis can improve visual acuity with over 35% of patients experiencing significant improvement. Bascom Palmer Eye Institute was involved in every clinical phase of Lucentis development. Dr. Rosenfeld was principal investigator and first author on publications from the Phase I, Phase II, and Phase III trails that resulted in FDA approval for Lucentis. Lucentis is now commercially available for the treatment of wet AMD, but a single dose of the drug costs more than $2000 compared with about $50 for Avastin. Medicare covers the cost of both treatments.
The proper treatment for the wet form of age-related macular degeneration is best determined by a retina specialist after thorough examination.
Despite all these advances to treat the wet form of AMD and the ongoing research for dry AMD, people with this disease may still end up with very poor vision. For this reason, the best option for many of our patients is to receive low vision training. Whether it is vision loss for conditions such as AMD, glaucoma, or diabetes, low vision aids help patients perform normal activities of daily living and lead independent lives. To help facilitate this training, Bascom Palmer Eye Institute has a Low Vision Center to assess patients' remaining vision and prescribe appropriate low vision aids.
Do vitamins have an impact on the development of macular degeneration?
The National Eye Institute, a branch of the National Institutes of Health, sponsored a major clinical trial called the Age-Related Eye Disease Study (AREDS). The results were published in the October 2001 issue of Archives of Ophthalmology. Scientists found that high levels of antioxidants and zinc may reduce the risk of losing vision in patients with obvious AMD. Patients with a very early stage of AMD showed no benefit from the AREDS supplement, and this supplement was never tested in people without clear evidence of AMD
Even though the AREDS trial showed that vitamin supplementation slowed the progression of AMD, questions were raised about whether the best dosing regimen was used in the study and if other anti-oxidants could improve the outcomes. For these reasons, a new trial known as AREDS2 is underway. AREDS2 will test different doses of the supplements as well as lutein, zeaxanthin, and omega-3-fatty acids.
Click here for greater details, including the dosage formulation and information for smokers.
Click here more information about macular degeneration at Bascom Palmer Eye Institute
What about macular degeneration research?
Much work needs to be done to slow the progression of both dry and wet AMD, and even restore vision in patients with this disease.
All of our treatments, so far, are designed to treat the vision loss associated with wet AMD and slow the progression of the disease. None of the therapies really treat the underlying cause of AMD. While we do not yet know the cause, we do know this is a disease with a strong genetic basis. We are years away from developing a successful therapy based on genetic information, but the basis for this therapy begins with the genetic research currently underway. Bascom Palmer is also dedicated to discovering new drugs that can help treat dry AMD and improve the treatment results of wet AMD. Many of our patients participate in clinical trials and get access to new, potentially vision saving treatments that are not available in the market.
The study of disease mechanisms that lead to dry AMD has shown that the Complement System plays an important part in this disease. As a result, drugs that inhibit the Complement system are being used in clinical trials. These trials are underway.
Bascom Palmer has started a novel clinical trial with a new anti-complement drug that will be administered intravenously. This trial is known as the COMPLETE Study. Patients participating in this trial must have a confirmed diagnosis of dry AMD as defined by the presence of drusen or geographic atrophy. The trial will last for one year.
The results of these trials are eagerly awaited by ophthalmologists all over the world. Positive results from these trials will help millions of people over the world avoid blindness.
What is a macular hole?
 As people age, the vitreous gel in the eye shrinks and pulls away from
the retina. Usually this occurs without consequence, however, in some
cases where the vitreous is attached to the macula, it can result in the
formation of a macular hole. Fluid may leak under the edges of the hole,
causing a microscopic retinal detachment, which results in blurring and
distortion of vision.
What are the symptoms of a macular hole?
A macular hole can cause blurred or distorted vision. A hole that goes
all the way through the macula can result in significant loss of central
vision.
How is a macular hole diagnosed?
An ophthalmologists who suspects a macular hole may:
- perform a visual acuity test to measure vision at a distance
- perform a dilated pupil examination to see the inside of the eye with
an ophthalmoscope
- perform a fluorescein angiography. During this test, a dye is
injected into the arm and quickly travels throughout the blood system.
Once the dye reaches the blood vessels under the retina, a color
photograph is taken of the eye. The dye allows the ophthalmologist to
detect blood vessels that are leaking dye.
What are the treatment options for a patient with a macular hole?
Current treatment options for macular holes are limited to vitrectomy
with an internal tamponade. The most commonly used procedure involves
using a long-acting gas. During the surgery, the ophthalmologist will
remove the vitreous gel from the eye so that it is no longer pulling on
and distorting the macula. The vitreous gel is replaced with a bubble
containing a mixture of air and gas or even silicone oil can be used. The
long-acting gas acts as an internal, temporary bandage that holds the edge
of the macular hole in place as it heals, though it prohibits the patient
from traveling by air for at least six weeks. Under extenuating
circumstances a shorter acting gas or the silicone can be used to possibly
reduce or eliminate the prohibition of air travel. They physicians at
Bascom Palmer believe the shorter acting gas and silicone oil do not offer
quite as high success rates, but they are substantially successful. In
order to maximize the effect of the repair, the patient is usually
required to remain in a face down position for one week postoperatively to
allow the bubble to press against the macula and seal the hole. While
Bascom Palmer physicians believe that strict, continuous positioning
enhances success rates, substantially high rates are obtained even in
patients who are unable to maintain this position. The bubble will
gradually be reabsorbed by the eye within a few weeks following surgery.
As the bubble is reabsorbed, the vitreous cavity refills with a naturally
produced fluid.
Currently, it is customary to peel the internal limiting membrane during
surgery, as this may remove an impediment to healing the hole, and
possibly even stimulate healing. This issue is controversial and studies
of its efficacy are ongoing.
What advantage does Bascom Palmer offer for patients with a macular hole?
Bascom Palmer Eye Institute surgeons were among the first to perform
macular hole surgery, dating back to 1991. Much of the framework of
knowledge of pathogenesis, diagnostic methodology, and classification was
laid at this institute. Because of this early experience, we continue to
perform treatment on a high volume of patients. This allows us to make
observations and conclusions regarding the most effective treatment
modifications relatively rapidly.
What research in being conducted in the United States and at Bascom
Palmer Eye Institute on macular holes?
Research is currently aimed at efforts to improve the 90+% success rate
even more, and in a more convenient way to the patient. This is through
ongoing surveillance of success in clinical series. Bascom Palmer Eye
Institute conducts such series similarly to many other study centers in
the country.
Who are the Macular
Specialists at Bascom Palmer Eye Institute?
Thomas Albini, M.D.
John G. Clarkson, M.D.
Janet L. Davis, M.D.
Sander Dubovy, M.D.
Yale L. Fisher, M.D.
Harry W. Flynn, Jr., M.D.
Jaclyn L. Kovach, M.D.
Geeta Lalwani, M.D.
Wen-Hsiang Lee, M.D.
Andrew A. Moshfeghi, M.D.
Timothy G. Murray, M.D., M.B.A., F.A.C.S.
Philip J. Rosenfeld, M.D., Ph.D.
Stephen Schwartz, M.D., M.B.A.
William E. Smiddy, M.D.
Other Macular Disease Resources
AMD Alliance International
American Academy of Ophthalmology
Eye Resources on the Internet
Foundation Fighting Blindness
Macular Degeneration Partnership
National Eye Institute
Prevent Blindness America
Research to Prevent Blindness
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