Newest Therapies for Macular Degeneration are Reducing Vision Loss and Admissions to Long-Term Care
by Maureen Duffy
Here is some good news during National Age-Related Macular Degeneration Awareness Month. Two economists from Duke University have presented evidence that within the past ten years, since the introduction of anti-VEGF therapies (Lucentis, Avastin, and Eylea), older Americans with "wet" or exudative macular degeneration are less likely to experience vision loss and less likely to move into long-term care settings.
The research, entitled The Effects of Technological Advances on Outcomes for Elderly Persons with Exudative Age-related Macular Degeneration, has been published online ahead-of-print in the January 23, 2014 edition of JAMA Ophthalmology (formerly Archives of Ophthalmology). JAMA Ophthalmology is an international peer-reviewed journal published monthly by the American Medical Association.
The authors are Frank A. Sloan, PhD and Brian W. Hanrahan, MA, from the Department of Economics, Duke University, Durham, North Carolina.
About the Research
From Anti-VEGF drugs making a difference in vision, long-term care, via Reuters Health:
Two Duke University economists looked at Medicare beneficiaries with so-called "wet" age-related macular degeneration (AMD) and found those diagnosed after the introduction of anti-VEGF drugs were less likely to go blind and less likely to move into long-term care.
Previous clinical research has indicated that anti-VEGF treatments are effective for wet AMD, but [lead study author] Sloan said those types of studies don't let you see longer-term outcomes or how well the therapy works in a real-world setting.
The researchers used Medicare claims information from 1994 to 2011 to examine the vision outcomes and long-term care facility admissions of wet AMD patients who were treated with older methods [i.e., photodynamic therapy] or with the new anti-VEGF drugs.
The researchers discovered that the use of anti-VEGF therapy reduced vision loss by 41 percent and the onset of severe vision loss and blindness by 46 percent, compared to earlier forms of treatment.
They also found that patients who received anti-VEGF therapy were 19 percent less likely to be admitted to long-term care facilities during a two-year follow-up period compared to those treated before the drugs came into use.
About Age-Related Macular Degeneration (AMD)
In wet, or exudative, macular degeneration (AMD), the choroid (a part of the eye containing blood vessels that nourish the retina) begins to sprout abnormal blood vessels that develop into a cluster under the macula (called choroidal neovascularization).
The macula is the part of the retina that provides the clearest central vision. Because these new blood vessels are abnormal, they tend to break, bleed, and leak fluid under the macula, causing it to lift up and pull away from its base. This damages the fragile photoreceptor cells, which sense and receive light, resulting in a rapid and severe loss of central vision.
Anti-Angiogenic Drugs and Anti-VEGF Treatments
Angiogenesis is a term used to describe the growth of new blood vessels and plays a crucial role in the normal development of body organs and tissue. Sometimes, however, excessive and abnormal blood vessel development can occur in diseases such as cancer (tumor growth) and AMD (retinal and macular bleeding).
Substances that stop the growth of these excessive blood vessels are called anti-angiogenic (anti=against; angio=vessel; genic=development), and anti-neovascular (anti=against; neo=new; vascular=blood vessels).
The focus of current anti-angiogenic drug treatments for wet AMD is to reduce the level of a particular protein (vascular endothelial growth factor, or VEGF) that stimulates abnormal blood vessel growth in the retina and macula; thus, these drugs are classified as anti-VEGF treatments. At present, these drugs are administered by injection directly into the eye after the surface has been numbed.
Avastin is an anti-VEGF drug that is FDA-approved since 2004 for intravenous use in colorectal cancer. It is currently used on an "off-label" basis (i.e., via eye injection) to treat wet AMD.
Lucentis was derived from a protein similar to Avastin, specifically for injection in the eye to block blood vessel growth in AMD. In 2005, clinical trials established Lucentis as highly effective for the treatment of wet AMD. The FDA approved Lucentis in 2006.
Eylea was approved by the FDA in late 2011 as an effective treatment for wet AMD. It is administered once every two months after three initial once-a-month injections.
A Prior AMD Treatment: Photodynamic Therapy
Photodynamic therapy (PDT) has been approved by the FDA for AMD since April 2000. PDT works as follows: A 10-minute intravenous administration of Visudyne (a photosensitive drug) is followed by the application of a low-dose, non-thermal (light only) laser to the affected area of the retina. The drug circulates throughout the body's blood vessels, and is particularly attracted to new blood vessels, including the abnormal vessels under the macula.
More about the Study from JAMA Ophthalmology
From the article abstract:
Objectives: To assess the effects of introducing new therapies for treating exudative AMD on vision of the affected population and other outcomes among Medicare beneficiaries newly diagnosed as having AMD.
Setting and Participants: The analysis was based on longitudinal data for the United States, January 1, 1994, to December 31, 2011, for Medicare beneficiaries with fee-for-service coverage. [Note: A longitudinal study follows, and gathers information about, the same group of people over an extended period of time.] The sample was limited to beneficiaries 68 years or older newly diagnosed as having exudative AMD as indicated by beneficiaries having no claims with this diagnosis in a 3-year look-back period.
Results: Among beneficiaries newly diagnosed as having exudative AMD, the introduction of anti-VEGF therapy reduced vision loss by 41% and onset of severe vision loss and blindness by 46%. Beneficiaries who received anti-VEGF therapy and were not admitted to a long-term care facility during the look-back period were 19% less likely on average to be admitted to a long-term care facility during the follow-up period.
Additional Information about AMD
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