Othera's Eye Drop to Cure ARMD Seems Promising But Too Early to Tell
April 16, 2009
Implications
An eye drop that stabilizes the most common form of AMD is encouraging. The ability for an eye drop to be effective is curious. Historically it has been difficult to get any medication effectively delivered to the retina via topical medications. The development of geographic atrophy is very, very slow and it is surprising that a positive trend can be noted in such a short time.
Analysis
Macular degeneration is on the rise. It is estimated that the prevalence of the disease will double in the next 40 years. Macular degeneration is often broken down into "wet" and "dry." The exudative, or wet form, involves choroidal neovascularization and is treated with anti-VEGF treatments such as Avastin, Macugen or Lucentis.
The dry form is the more common form affecting about 90% of all those afflicted with macular degeneration. The most severe of these is geographic atrophy (GA). It is a slowly progressive disease causing damage and loss of the vital underlying RPE cells. It usually takes years for patients to notice a change to their vision.
The news release describes a treatment that may be potentially helpful to most patients that are afflicted with macular degeneration. A simple eye drop to treat this disease is very intriguing. Presently, most treatments for wet macular degeneration involve direct intraocular injection of a substance as topical therapy has traditionally yielded poor drug levels reaching the retinal surface.
Clinically, it has been my experience that the disease progresses very slowly and to notice a change, for better or worse, in such a short time of two years is surprising.
Randall V. Wong, M.D.
Sunday, April 26, 2009
Sunday, April 19, 2009
Vigorous Exercise May Help Prevent Vision Loss
Vigorous exercise may help prevent vision loss, according to a pair of studies from the U.S. Department of Energy's Lawrence Berkeley National Laboratory. The studies tracked approximately 31,000 runners for more than seven years, and found that running reduced the risk of both cataracts and age-related macular degeneration.
The research, which is among the first to suggest that vigorous exercise may help prevent vision loss, offers hope for people seeking to fend off the onset of eye disease.
"In addition to obtaining regular eye exams, people can take a more active role in preserving their vision," says Paul Williams, an epidemiologist in Berkeley Lab's Life Sciences Division who conducted the research. "The studies suggest that people can perhaps lessen their risk for cataracts and macular degeneration by taking part in a fitness regimen that includes vigorous exercise."
A cataract, which is a cloudy opacity of the eye lens, is the leading cause of blindness. More than one-half of people in the U.S. over the age of 65 suffer from some form of cataracts. Macular degeneration, which is damage to the retina, is the leading cause of irreversible vision loss in older white Americans, affecting 28 percent of people aged 75 and older.
Macular degeneration gradually destroys sharp, central vision. Macular degeneration affects the macula, the part of the eye that allows you to see fine detail. The macula is located in the center of the retina, the light-sensitive tissue at the back of the eye. The retina instantly converts light, or an image, into electrical impulses. The retina then sends these impulses, or nerve signals, to the brain. Macular degeneration causes no pain.
The diseases have several known risk factors, such as sunlight exposure and diabetes in the case of cataracts, but few interventions. Now, it appears that vigorous cardiovascular exercise may be one way to derail the diseases.
To conduct the research, Williams analyzed data collected in the National Runners' Health Study, which he established in 1991 to determine the health benefits of running.
In this case, he followed approximately 29,000 male runners and 12,000 female runners for more than seven years. Of these people, 733 men reported being diagnosed with cataracts on a questionnaire filled out at the end of the study. Too few women reported cataracts to track.
Men who ran more than 5.7 miles per day had a 35 percent lower risk of developing cataracts than men who ran less than 1.4 miles per day. The study also analyzed men's 10-kilometer race performances, which is a good indicator of overall fitness. The fittest men boasted one-half the risk of developing cataracts compared to the least-fit men.
A second study found that running appeared to reduce the risk of macular degeneration. In the study, 152 men and women reported being diagnosed with the disease. Compared to people who ran less than 1.2 miles per day, people who averaged between 1.2 and 2.4 miles per day had a 19 percent lower risk for the disease, and people who ran more than 2.4 miles per day had between 42 percent and 54 percent lower risk of macular degeneration.
"These findings are compelling because of the large size of the study, and the fact that we are looking at something that is fairly well defined: vigorous exercise, as opposed to more moderate exercise," says Williams.
Most of the runners in the study exceeded the current public health recommendations for physical activity, which is at least 30 minutes of moderate-intensity activities such as brisk walking five days a week, or smaller doses of more vigorous exercise such as running. It is unclear whether people might also lower their risk for cataracts and age-related macular degeneration by walking.
"We know there are important health benefits to walking, including lowering heart disease risk," says Williams. "It is quite likely that the studies' results might apply to a lesser extent to smaller doses of more moderate exercise."
Williams also adds that further research is needed to explore why there is a link between vigorous exercise and a decreased risk for eye disease.
"We know some of the physiological benefits of exercise, and we know about the physiological background of these diseases, so we need to better understand where there's an overlap," says Williams.
The research, which is among the first to suggest that vigorous exercise may help prevent vision loss, offers hope for people seeking to fend off the onset of eye disease.
"In addition to obtaining regular eye exams, people can take a more active role in preserving their vision," says Paul Williams, an epidemiologist in Berkeley Lab's Life Sciences Division who conducted the research. "The studies suggest that people can perhaps lessen their risk for cataracts and macular degeneration by taking part in a fitness regimen that includes vigorous exercise."
A cataract, which is a cloudy opacity of the eye lens, is the leading cause of blindness. More than one-half of people in the U.S. over the age of 65 suffer from some form of cataracts. Macular degeneration, which is damage to the retina, is the leading cause of irreversible vision loss in older white Americans, affecting 28 percent of people aged 75 and older.
Macular degeneration gradually destroys sharp, central vision. Macular degeneration affects the macula, the part of the eye that allows you to see fine detail. The macula is located in the center of the retina, the light-sensitive tissue at the back of the eye. The retina instantly converts light, or an image, into electrical impulses. The retina then sends these impulses, or nerve signals, to the brain. Macular degeneration causes no pain.
The diseases have several known risk factors, such as sunlight exposure and diabetes in the case of cataracts, but few interventions. Now, it appears that vigorous cardiovascular exercise may be one way to derail the diseases.
To conduct the research, Williams analyzed data collected in the National Runners' Health Study, which he established in 1991 to determine the health benefits of running.
In this case, he followed approximately 29,000 male runners and 12,000 female runners for more than seven years. Of these people, 733 men reported being diagnosed with cataracts on a questionnaire filled out at the end of the study. Too few women reported cataracts to track.
Men who ran more than 5.7 miles per day had a 35 percent lower risk of developing cataracts than men who ran less than 1.4 miles per day. The study also analyzed men's 10-kilometer race performances, which is a good indicator of overall fitness. The fittest men boasted one-half the risk of developing cataracts compared to the least-fit men.
A second study found that running appeared to reduce the risk of macular degeneration. In the study, 152 men and women reported being diagnosed with the disease. Compared to people who ran less than 1.2 miles per day, people who averaged between 1.2 and 2.4 miles per day had a 19 percent lower risk for the disease, and people who ran more than 2.4 miles per day had between 42 percent and 54 percent lower risk of macular degeneration.
"These findings are compelling because of the large size of the study, and the fact that we are looking at something that is fairly well defined: vigorous exercise, as opposed to more moderate exercise," says Williams.
Most of the runners in the study exceeded the current public health recommendations for physical activity, which is at least 30 minutes of moderate-intensity activities such as brisk walking five days a week, or smaller doses of more vigorous exercise such as running. It is unclear whether people might also lower their risk for cataracts and age-related macular degeneration by walking.
"We know there are important health benefits to walking, including lowering heart disease risk," says Williams. "It is quite likely that the studies' results might apply to a lesser extent to smaller doses of more moderate exercise."
Williams also adds that further research is needed to explore why there is a link between vigorous exercise and a decreased risk for eye disease.
"We know some of the physiological benefits of exercise, and we know about the physiological background of these diseases, so we need to better understand where there's an overlap," says Williams.
Saturday, April 11, 2009
Implantable Eye Telescope Brings Sight Back To The Blind
Implantable Eye Telescope Brings Sight Back To The Blind
Written on April 10, 2009 – 10:45 am | by Drew Halley |
imt_photoFor the millions of people who suffer from age-related eye degeneration, restoring sight to the blind might sound less like reality and more like a miracle. But thanks to an incredible miniature eye implant that works to restore central vision, the future’s looking bright.
The macula is a part of the retina responsible for highly detailed central vision. It contains a high density of cone cells, which allow us to perceive fine detail and quick movement in our environment - for healthy individuals, that is. Patients suffering from age-related macular degeneration (AMD) partially or totally lose this functionality, resulting in a “blind spot” where their focal point normally rests. This can make it difficult to read, recognize faces, or even watch television… until now.
The Implantable Miniature Telescope, or IMT, is a tiny prosthetic implanted into the patient’s eye. Rather than directing light to the damaged macula, the telescope projects the image onto a broader surface of the retina that surrounds the macula. In this way, visual information is redirected to healthy rods and cones, and can be processed in the brain as central vision.
Both central and peripheral vision are important functions of the visual system. Because of this, the IMT is only implanted into one eye of patients with macular degeneration. One eye continues to process peripheral vision normally (which is better suited for low-light vision, for example), while the implanted eye restores the central vision that was previously impaired. This allows individuals to again experience the full range of visual stimuli so necessary to everyday life. And because the implant is embedded in the iris, it goes unnoticed to others.
A simulation of impaired vision caused by AMD
Macular degeneration primarily effects older adults, and is the leading cause of blindness in the elderly. Nearly 15 million people suffer from AMD in the United States alone. Approximately 10% of adults between the ages of 66 and 74 suffer from AMD, a figure that jumps to 30% between the ages of 75 and 85, according to The Eye Digest.
“In an end-stage AMD population, the indicated improvements in this study are substantial compared to risks of surgery,” said study coauthor R. Doyle Stulting, M.D., Ph.D. “For patients with this level of visual impairment, the ability to be less dependent on others and to reclaim even a few of the activities they once enjoyed could make a real difference in their lives.”
The IMT was developed by VisionCare Ophthalmic Technologies, and the implant has recently completed Phase II/III clinical trials. The tests showed that the IMT doubled the vision of 2/3 of participants’ eyes (3 lines on a visual acuity chart) after one year with the implant. Some patients experienced side effects like intraocular pressure and inflammation, though these may have been related to the surgury. On March 27, an advisory panel for the Food and Drug Administration (FDA) unanimously recommended the prosthetic for approval. Barring any unforeseen events, the IMT will soon gain FDA approval and hit the market soon thereafter.
While the IMT is certainly an amazing breakthrough, it is just one of many technologies we’ve reported on that are overcoming blindness (such as bionic eyes and gene therapy). Besides the direct clinical application of such amazing technology, eye implants beg the question of how far these kinds of advances will go. Who knows? Maybe your grandkids will sport bionic eyes capable of zooming, night vision, and infrared perception. Regardless, anatomical prosthetics like the IMT promise to improve individuals’ lives today, and lay the theoretical foundation for exciting technology to come.
Written on April 10, 2009 – 10:45 am | by Drew Halley |
imt_photoFor the millions of people who suffer from age-related eye degeneration, restoring sight to the blind might sound less like reality and more like a miracle. But thanks to an incredible miniature eye implant that works to restore central vision, the future’s looking bright.
The macula is a part of the retina responsible for highly detailed central vision. It contains a high density of cone cells, which allow us to perceive fine detail and quick movement in our environment - for healthy individuals, that is. Patients suffering from age-related macular degeneration (AMD) partially or totally lose this functionality, resulting in a “blind spot” where their focal point normally rests. This can make it difficult to read, recognize faces, or even watch television… until now.
The Implantable Miniature Telescope, or IMT, is a tiny prosthetic implanted into the patient’s eye. Rather than directing light to the damaged macula, the telescope projects the image onto a broader surface of the retina that surrounds the macula. In this way, visual information is redirected to healthy rods and cones, and can be processed in the brain as central vision.
Both central and peripheral vision are important functions of the visual system. Because of this, the IMT is only implanted into one eye of patients with macular degeneration. One eye continues to process peripheral vision normally (which is better suited for low-light vision, for example), while the implanted eye restores the central vision that was previously impaired. This allows individuals to again experience the full range of visual stimuli so necessary to everyday life. And because the implant is embedded in the iris, it goes unnoticed to others.
A simulation of impaired vision caused by AMD
Macular degeneration primarily effects older adults, and is the leading cause of blindness in the elderly. Nearly 15 million people suffer from AMD in the United States alone. Approximately 10% of adults between the ages of 66 and 74 suffer from AMD, a figure that jumps to 30% between the ages of 75 and 85, according to The Eye Digest.
“In an end-stage AMD population, the indicated improvements in this study are substantial compared to risks of surgery,” said study coauthor R. Doyle Stulting, M.D., Ph.D. “For patients with this level of visual impairment, the ability to be less dependent on others and to reclaim even a few of the activities they once enjoyed could make a real difference in their lives.”
The IMT was developed by VisionCare Ophthalmic Technologies, and the implant has recently completed Phase II/III clinical trials. The tests showed that the IMT doubled the vision of 2/3 of participants’ eyes (3 lines on a visual acuity chart) after one year with the implant. Some patients experienced side effects like intraocular pressure and inflammation, though these may have been related to the surgury. On March 27, an advisory panel for the Food and Drug Administration (FDA) unanimously recommended the prosthetic for approval. Barring any unforeseen events, the IMT will soon gain FDA approval and hit the market soon thereafter.
While the IMT is certainly an amazing breakthrough, it is just one of many technologies we’ve reported on that are overcoming blindness (such as bionic eyes and gene therapy). Besides the direct clinical application of such amazing technology, eye implants beg the question of how far these kinds of advances will go. Who knows? Maybe your grandkids will sport bionic eyes capable of zooming, night vision, and infrared perception. Regardless, anatomical prosthetics like the IMT promise to improve individuals’ lives today, and lay the theoretical foundation for exciting technology to come.
Sunday, April 5, 2009
Purdue Professor's Insight Leads to Better Understanding of Vision Loss
Purdue Professor's Insight Leads to Better Understanding of Vision Loss
WEST LAFAYETTE, Ind., April 3 (AScribe Newswire) -- A Purdue University researcher's work could shed light on new targets for treating retinal degenerative diseases that cause blindness.
According to the National Eye Institute, blindness or low vision affects 3.3 million Americans age 40 and older, and retinal degenerative diseases, such as age-related macular degeneration and diabetic retinopathy, are some of the leading causes.
Yuk Fai Leung, an assistant professor of biological sciences, co-led a team that developed a new analysis method and identified key genes involved in retinal development. A paper detailing the work was published in the Proceedings of the National Academy of Sciences last fall.
"Once we know the genetic network that influences retinal development, we can begin to understand the changes in specific genes that lead to vision loss," Leung said. "With this information, treatments could be developed that would prevent or reverse the physical affects."
Leung also recently received a $25,000 award from Hope for Vision, a nonprofit foundation that raises money to develop treatments and cures for diseases that cause blindness.
Leung led the research with John E. Dowling of the Department of Molecular and Cellular Biology at Harvard University. The research team used the analysis method to identify genes that control cellular differentiation in the retina of zebrafish.
Zebrafish are closer to humans in eye development than mice or other animal models, Leung said.
The analysis method, called factorial microarray analysis, can examine thousands of genes at once and analyze several experimental changes at the same time. Examining several changes at once is critical for understanding how one change can lead to several others, Leung said.
"Some important changes could seem insignificant if examined in isolation," he said. "For example, both eating nutritious food and swimming for an hour are good for your health. However, if you eat right before swimming, you will probably get sick. Only by doing both at the same time is the issue identified."
Additional members of the research team and paper co-authors include Ping Ma from the Department of Statistics and Institute for Genomic Biology at the University of Illinois and Brian A. Link from the Department of Cell Biology, Neurobiology and Anatomy at the Medical College of Wisconsin.
The team compared the genetic makeup of normal fish with fish that were blind due to improper development of retinal cells. The cells begin on the same track as those in the normal fish but do not complete the final stage of development known as terminal differentiation.
Leung and his team were able to identify the genetic network that controls the terminal differentiation process and to examine the effects of different combinations of genetic changes at different stages within the developmental process.
"We still don't know a lot about eye development, so we need to gather knowledge to figure out what goes wrong in a disease situation," he said. "We know the genes involved, but don't know much about the downstream changes a mutation causes. This work sets up the framework and model that can be used to examine such cause-and-effect relationships."
Leung plans to study other developments to obtain a more complete picture of eye development.
This research was funded by the Croucher Foundation, Knights Templar Foundation, Merck Award for Genomics Research, National Eye Institute and National Science Foundation.
WEST LAFAYETTE, Ind., April 3 (AScribe Newswire) -- A Purdue University researcher's work could shed light on new targets for treating retinal degenerative diseases that cause blindness.
According to the National Eye Institute, blindness or low vision affects 3.3 million Americans age 40 and older, and retinal degenerative diseases, such as age-related macular degeneration and diabetic retinopathy, are some of the leading causes.
Yuk Fai Leung, an assistant professor of biological sciences, co-led a team that developed a new analysis method and identified key genes involved in retinal development. A paper detailing the work was published in the Proceedings of the National Academy of Sciences last fall.
"Once we know the genetic network that influences retinal development, we can begin to understand the changes in specific genes that lead to vision loss," Leung said. "With this information, treatments could be developed that would prevent or reverse the physical affects."
Leung also recently received a $25,000 award from Hope for Vision, a nonprofit foundation that raises money to develop treatments and cures for diseases that cause blindness.
Leung led the research with John E. Dowling of the Department of Molecular and Cellular Biology at Harvard University. The research team used the analysis method to identify genes that control cellular differentiation in the retina of zebrafish.
Zebrafish are closer to humans in eye development than mice or other animal models, Leung said.
The analysis method, called factorial microarray analysis, can examine thousands of genes at once and analyze several experimental changes at the same time. Examining several changes at once is critical for understanding how one change can lead to several others, Leung said.
"Some important changes could seem insignificant if examined in isolation," he said. "For example, both eating nutritious food and swimming for an hour are good for your health. However, if you eat right before swimming, you will probably get sick. Only by doing both at the same time is the issue identified."
Additional members of the research team and paper co-authors include Ping Ma from the Department of Statistics and Institute for Genomic Biology at the University of Illinois and Brian A. Link from the Department of Cell Biology, Neurobiology and Anatomy at the Medical College of Wisconsin.
The team compared the genetic makeup of normal fish with fish that were blind due to improper development of retinal cells. The cells begin on the same track as those in the normal fish but do not complete the final stage of development known as terminal differentiation.
Leung and his team were able to identify the genetic network that controls the terminal differentiation process and to examine the effects of different combinations of genetic changes at different stages within the developmental process.
"We still don't know a lot about eye development, so we need to gather knowledge to figure out what goes wrong in a disease situation," he said. "We know the genes involved, but don't know much about the downstream changes a mutation causes. This work sets up the framework and model that can be used to examine such cause-and-effect relationships."
Leung plans to study other developments to obtain a more complete picture of eye development.
This research was funded by the Croucher Foundation, Knights Templar Foundation, Merck Award for Genomics Research, National Eye Institute and National Science Foundation.
Subscribe to:
Posts (Atom)
