Carolina Herrera Ortiz
University of Granada
Researchers from the University of Granada have provided an early diagnosis of certain ocular diseases that are very common today, such as age-related macular degeneration and keratitis, by applying an existing optical technique that had never before been used for this purpose.
Scientists from the UGR have studied the image quality in subjects affected by one of these two pathologies, finding a greater amount of ocular aberrations and a higher level of scattering (term associated with the dispersion that light suffers when passing through the various ocular media) in affected eyes compared with results in healthy eyes. This significantly affects visual performance.
This work has been performed by the researcher Carolina Herrera Ortiz, from the Optics Department at the University of Granada, and directed by professors José Ramón Jiménez Cuesta and Francisco Pérez Ocón.
Age-related macular degeneration (ARMD) is the leading cause of central vision loss in developed countries, and mainly affects people of over 50 years of age. As far as keratitis is concerned, this condition causes inflammation of the cornea and can cause blindness, due to the severe alterations that the corneal surface may suffer.
Optical instruments
To carry out this work, the scientists measured the image quality with two optical instruments and used a psychophysical test for assessing visual performance. Results from patients with ARMD were compared with those obtained from a control group of similar age without any ocular pathology. Thus, the researchers could verify that for individuals affected by this condition there is an increased level of ocular scattering that could be mainly due to the disruption suffered by the light reflected in the damaged retina of the ARMD eyes, because a priori optics are not expected to be altered, since it is a retinal pathology.
On the other hand, optical quality and visual performance have also been studied in patients affected by keratitis. Eyes affected by keratitis present a poorer optical quality and a reduced visual performance that improves significantly after the resolution of the pathology. Nevertheless, once medical treatment ends, eyes that suffered from keratitis still have a worse image quality compared to the contralateral healthy eye, a result that significantly influences visual performance even having reached the normal values of visual acuity.
Visual quality characterization
The results of this research carried out at the UGR will make a full and objective characterization of visual quality in patients affected by any of these ocular pathologies. So far, the use of new techniques for assessing objectively the optic quality of the eye has been limited to studies on refractive or cataract surgery. However, as Carolina Ortiz Herrera suggests, this work "may be of particular interest to establish an early diagnosis of certain ocular diseases such as age-related macular degeneration, the main cause of central vision loss in developed countries."
Furthermore, this technique allows researchers to carry out a monitoring of possible stages of both diseases. Ortiz Herrera stresses the importance of including "both in the clinical practice of optometry and ophthalmology" the use of new techniques that, objectively, could indicate deterioration in vision even when the visual acuity values are normal, since "vision is not only seeing well, but providing quality and comfort."
The results of this PhD research led to two publications in journals of international prestige such as Journal of Modern Optics, Cornea. and a future issue of Current Eye Research.
For more information go to www.maculardegenerationassociation.org
Friday, November 27, 2009
Monday, November 16, 2009
Survey Shows That Americans Lack Significant Knowledge of Age-Related Vision Problems
Macular degeneration and glaucoma among the top areas Americans have the most misunderstanding according to the American Optometric Association
It's a fact of life that eyes change with age, and baby boomers - Americans born between 1946 and 1964 - are at the stage when many are affected by vision problems. Despite the prevalence of Americans affected by these changes, a new survey from the American Optometric Association (AOA) shows a concerning lack of public knowledge and misunderstanding regarding age-related eye diseases and conditions.
According to the AOA's American Eye-Q® survey, which assesses public knowledge and understanding of issues related to eye and visual health, only 18 percent of Americans know that macular degeneration is the leading cause of blindness in adults 65 years of age and older, and less than a quarter of all Americans understand the effects of glaucoma. Even more concerning, 89 percent of Americans incorrectly believe that glaucoma is preventable, when in fact it is only treatable if caught early.
Americans who are 40 years of age or older have probably noticed changes in vision. Difficulties seeing clearly for reading and close work are among the most common problems adults develop between the ages of 41 to 60. According to the Eye-Q® survey, top concerns about the effects of vision problems include not being able to live independently, cited by 45 percent; not being able to see loved ones, 21 percent; being unable to read, 20 percent and losing the ability to drive, 11 percent.
"When left undetected and untreated, many age-related eye diseases can damage your vision permanently," said Mark Wilkinson, O.D., Chair of the AOA's Vision Rehabilitation Section. "The good news is that most people can preserve their vision with proper treatment, so the key is early detection."
Age-related vision disorders baby boomers and seniors should be aware of include:
•Age-related macular degeneration (AMD) - an eye disease that causes loss of central vision. Activities like reading, driving, watching TV and recognizing faces all require clear central vision.
•Diabetic retinopathy - a condition occurring in people with diabetes, which causes progressive damage to the retina, the light-sensitive lining at the back of the eye. If left untreated, it can cause blindness.
•Cataracts - a cloudy or opaque area in the clear lens of the eye. Usually cataracts develop in both eyes, but one may be worse than the other. Cataracts can cause a decrease in contrast sensitivity, a dulling of colors and increased sensitivity to glare.
•Glaucoma - a group of eye diseases characterized by damage to the optic nerve resulting in peripheral vision loss. People at higher risk of developing glaucoma include those with a family history of the disease, older adults, African-Americans and Hispanics.
•Dry eye - a condition where there is an insufficient amount of tears or a poor quality of tears to lubricate and nourish the eye. Tears contribute to clear vision and the health of the front surface of the eye.
•Retinal detachment - tearing or separation of the retina from the underlying tissue. This can be caused by trauma to the eye or head, health problems due to advanced diabetes, and inflammatory disorders of the eye.
The good news is the majority of the American Eye-Q® survey respondents (92 percent) understand that visiting an eye doctor on a regular basis for comprehensive eye exams can help reduce the risk of developing age-related vision problems. The bad news is that respondents were less aware that avoiding smoking (40 percent) and eating a low-fat, low-salt diet (30 percent) can also reduce age-related vision problems.
"Some common warning signs of age-related vision problems include fluctuating vision, seeing floaters or flashes of light, loss of side vision and seeing distorted images," said Dr. Wilkinson. "However, often patients with eye diseases do not have recognizable symptoms until the conditions are quite advanced, so regular comprehensive eye exams are essential for baby boomers and seniors."
Addressing Age-Related Vision Problems
The American Eye-Q® survey also revealed that respondents age 55 and older are taking steps to address their age-related vision problems. Thirty three percent said they limit their night driving; 27 percent use brighter lights; 24 percent use wetting eye drops or artificial tears and 18 percent purchase or request items in large print.
Adding certain nutrients to one's diet every day - either through foods or supplements - can help preserve vision and prevent age-related eye diseases.
The AOA recommends the following eye-healthy nutrients and foods:
•Lutein and zeaxanthin: Colorful fruits and vegetables such as broccoli, spinach, kale, corn, green beans, peas, oranges and tangerines
•Essential fatty acids: Fatty fish like tuna, salmon, or herring; whole-grain foods; chicken and eggs
•Vitamin C: Fruits and vegetables, including oranges, grapefruit, strawberries, papaya, green peppers and tomatoes
•Vitamin E: Vegetable oils, such as safflower or corn oil; almonds and pecans; sweet potatoes and sunflower seeds
•Zinc: Extra-lean red meat, poultry, liver, shellfish, milk, baked beans and whole grains
Dealing with Vision Loss
Comprehensive eye exams are important for Americans of all ages, but become especially important later in life when more Americans develop age-related conditions and begin taking medications more frequently. The AOA recommends that adults over age 60 have a comprehensive eye examination by an optometrist once a year or more frequently if a doctor recommends it.
For patients with age-related vision loss, a specialized examination by an optometrist who treats vision impairment is a critical first step in the care process that focuses on maintaining and/or regaining independence and maximizing useful remaining vision. Prescribed treatment options commonly include specialized reading spectacles, spectacle-mounted telescopes, hand-held magnifiers and telescopes, therapeutic filters, specialized contact lenses, field enhancement treatments, and video magnification technology that both enlarge and enhance the contrast of reading materials.
There also are numerous other assistive products that can help with daily activities for people who have vision impairment, such as large-type books, magazines, and newspapers, books-on-tape, talking wristwatches, self-threading needles, and more. To learn more about vision rehabilitation and available treatment options, talk to an optometrist.
For additional information about aging eyes or to find a doctor of optometry in your area, please visit www.aoa.org.
About the survey:
The fourth annual American Eye-Q® survey was created and commissioned in conjunction with Penn, Schoen & Berland Associates (PSB). From May 21 - 24, 2009, using an online methodology, PSB interviewed 1,000 Americans 18 years and older who embodied a nationally representative sample of U.S. general population. (Margin of error at 95 percent confidence level.)
About the American Optometric Association (AOA):
The American Optometric Association represents approximately 36,000 doctors of optometry, optometry students and paraoptometric assistants and technicians. Optometrists serve patients in nearly 6,500 communities across the country, and in 3,500 of those communities are the only eye doctors. Doctors of optometry provide two-thirds of all primary eye care in the United States.
American Optometric Association doctors of optometry are highly qualified, trained doctors on the frontline of eye and vision care who examine, diagnose, treat and manage diseases and disorders of the eye. In addition to providing eye and vision care, optometrists play a major role in a patient's overall health and well-being by detecting systemic diseases such as diabetes and hypertension.
Prior to optometry school, optometrists typically complete four years of undergraduate study, culminating in a bachelor's degree. Required undergraduate coursework for pre-optometry students is extensive and covers a wide variety of advanced health, science and mathematics. Optometry school consists of four years of post-graduate, doctoral study concentrating on both the eye and systemic health. In addition to their formal training, doctors of optometry must undergo annual continuing education to stay current on the latest standards of care.
For more information go to www.maculardegenerationassociation.org
It's a fact of life that eyes change with age, and baby boomers - Americans born between 1946 and 1964 - are at the stage when many are affected by vision problems. Despite the prevalence of Americans affected by these changes, a new survey from the American Optometric Association (AOA) shows a concerning lack of public knowledge and misunderstanding regarding age-related eye diseases and conditions.
According to the AOA's American Eye-Q® survey, which assesses public knowledge and understanding of issues related to eye and visual health, only 18 percent of Americans know that macular degeneration is the leading cause of blindness in adults 65 years of age and older, and less than a quarter of all Americans understand the effects of glaucoma. Even more concerning, 89 percent of Americans incorrectly believe that glaucoma is preventable, when in fact it is only treatable if caught early.
Americans who are 40 years of age or older have probably noticed changes in vision. Difficulties seeing clearly for reading and close work are among the most common problems adults develop between the ages of 41 to 60. According to the Eye-Q® survey, top concerns about the effects of vision problems include not being able to live independently, cited by 45 percent; not being able to see loved ones, 21 percent; being unable to read, 20 percent and losing the ability to drive, 11 percent.
"When left undetected and untreated, many age-related eye diseases can damage your vision permanently," said Mark Wilkinson, O.D., Chair of the AOA's Vision Rehabilitation Section. "The good news is that most people can preserve their vision with proper treatment, so the key is early detection."
Age-related vision disorders baby boomers and seniors should be aware of include:
•Age-related macular degeneration (AMD) - an eye disease that causes loss of central vision. Activities like reading, driving, watching TV and recognizing faces all require clear central vision.
•Diabetic retinopathy - a condition occurring in people with diabetes, which causes progressive damage to the retina, the light-sensitive lining at the back of the eye. If left untreated, it can cause blindness.
•Cataracts - a cloudy or opaque area in the clear lens of the eye. Usually cataracts develop in both eyes, but one may be worse than the other. Cataracts can cause a decrease in contrast sensitivity, a dulling of colors and increased sensitivity to glare.
•Glaucoma - a group of eye diseases characterized by damage to the optic nerve resulting in peripheral vision loss. People at higher risk of developing glaucoma include those with a family history of the disease, older adults, African-Americans and Hispanics.
•Dry eye - a condition where there is an insufficient amount of tears or a poor quality of tears to lubricate and nourish the eye. Tears contribute to clear vision and the health of the front surface of the eye.
•Retinal detachment - tearing or separation of the retina from the underlying tissue. This can be caused by trauma to the eye or head, health problems due to advanced diabetes, and inflammatory disorders of the eye.
The good news is the majority of the American Eye-Q® survey respondents (92 percent) understand that visiting an eye doctor on a regular basis for comprehensive eye exams can help reduce the risk of developing age-related vision problems. The bad news is that respondents were less aware that avoiding smoking (40 percent) and eating a low-fat, low-salt diet (30 percent) can also reduce age-related vision problems.
"Some common warning signs of age-related vision problems include fluctuating vision, seeing floaters or flashes of light, loss of side vision and seeing distorted images," said Dr. Wilkinson. "However, often patients with eye diseases do not have recognizable symptoms until the conditions are quite advanced, so regular comprehensive eye exams are essential for baby boomers and seniors."
Addressing Age-Related Vision Problems
The American Eye-Q® survey also revealed that respondents age 55 and older are taking steps to address their age-related vision problems. Thirty three percent said they limit their night driving; 27 percent use brighter lights; 24 percent use wetting eye drops or artificial tears and 18 percent purchase or request items in large print.
Adding certain nutrients to one's diet every day - either through foods or supplements - can help preserve vision and prevent age-related eye diseases.
The AOA recommends the following eye-healthy nutrients and foods:
•Lutein and zeaxanthin: Colorful fruits and vegetables such as broccoli, spinach, kale, corn, green beans, peas, oranges and tangerines
•Essential fatty acids: Fatty fish like tuna, salmon, or herring; whole-grain foods; chicken and eggs
•Vitamin C: Fruits and vegetables, including oranges, grapefruit, strawberries, papaya, green peppers and tomatoes
•Vitamin E: Vegetable oils, such as safflower or corn oil; almonds and pecans; sweet potatoes and sunflower seeds
•Zinc: Extra-lean red meat, poultry, liver, shellfish, milk, baked beans and whole grains
Dealing with Vision Loss
Comprehensive eye exams are important for Americans of all ages, but become especially important later in life when more Americans develop age-related conditions and begin taking medications more frequently. The AOA recommends that adults over age 60 have a comprehensive eye examination by an optometrist once a year or more frequently if a doctor recommends it.
For patients with age-related vision loss, a specialized examination by an optometrist who treats vision impairment is a critical first step in the care process that focuses on maintaining and/or regaining independence and maximizing useful remaining vision. Prescribed treatment options commonly include specialized reading spectacles, spectacle-mounted telescopes, hand-held magnifiers and telescopes, therapeutic filters, specialized contact lenses, field enhancement treatments, and video magnification technology that both enlarge and enhance the contrast of reading materials.
There also are numerous other assistive products that can help with daily activities for people who have vision impairment, such as large-type books, magazines, and newspapers, books-on-tape, talking wristwatches, self-threading needles, and more. To learn more about vision rehabilitation and available treatment options, talk to an optometrist.
For additional information about aging eyes or to find a doctor of optometry in your area, please visit www.aoa.org.
About the survey:
The fourth annual American Eye-Q® survey was created and commissioned in conjunction with Penn, Schoen & Berland Associates (PSB). From May 21 - 24, 2009, using an online methodology, PSB interviewed 1,000 Americans 18 years and older who embodied a nationally representative sample of U.S. general population. (Margin of error at 95 percent confidence level.)
About the American Optometric Association (AOA):
The American Optometric Association represents approximately 36,000 doctors of optometry, optometry students and paraoptometric assistants and technicians. Optometrists serve patients in nearly 6,500 communities across the country, and in 3,500 of those communities are the only eye doctors. Doctors of optometry provide two-thirds of all primary eye care in the United States.
American Optometric Association doctors of optometry are highly qualified, trained doctors on the frontline of eye and vision care who examine, diagnose, treat and manage diseases and disorders of the eye. In addition to providing eye and vision care, optometrists play a major role in a patient's overall health and well-being by detecting systemic diseases such as diabetes and hypertension.
Prior to optometry school, optometrists typically complete four years of undergraduate study, culminating in a bachelor's degree. Required undergraduate coursework for pre-optometry students is extensive and covers a wide variety of advanced health, science and mathematics. Optometry school consists of four years of post-graduate, doctoral study concentrating on both the eye and systemic health. In addition to their formal training, doctors of optometry must undergo annual continuing education to stay current on the latest standards of care.
For more information go to www.maculardegenerationassociation.org
Monday, November 9, 2009
Medicare to Pay More to Doctors for Avastin
In a recent decision, it was announced that Medicare would now pay more to doctors for administering Avastin to patients. Earlier, Medicare had cut payments for Avastin by 80% and had agreed to pay doctors only $7 per dose which is much lower than the $50 per dose costs incurred by them. In turn, the doctors decided to prescribe the more expensive Lucentis which costs $2000 per dose and is not subject to reimbursement limits!! So, in effect the Medicare policy was costing both the taxpayers and the patients (who now had big copays for the $2000 drug). The only entity benefiting from this was Genentech. Genentech says Lucentis is specially formulated with smaller molecules than Avastin to better penetrate the eye. However, many eye doctors say there is no detectable difference in outcomes for patients. The American Academy of Ophthalmologists estimates about 60 percent of all injections for macular degeneration use Avastin. Now, after this policy reversal, it could cost Genentech money due to decrease in sales of Lucentis. Just shows how short sighted senate policies which do not take the full ramifications into account end up having the counter effect!
For more information go to www.maculardegenerationassociation.org
For more information go to www.maculardegenerationassociation.org
Tuesday, October 27, 2009
1 shot of gene therapy and children with congenital blindness can now see
Born with a retinal disease that made him legally blind, and would eventually leave him totally sightless, the nine-year-old boy used to sit in the back of the classroom, relying on the large print on an electronic screen and assisted by teacher aides. Now, after a single injection of genes that produce light-sensitive pigments in the back of his eye, he sits in front with classmates and participates in class without extra help. In the playground, he joins his classmates in playing his first game of softball.
His treatment represents the next step toward medical science's goal of using gene therapy to cure disease. Extending a preliminary study published last year on three young adults, the full study reports successful, sustained results that showed notable improvement in children with congenital blindness.
The study, conducted by researchers from the University of Pennsylvania School of Medicine and the Center for Cellular and Molecular Therapeutics at The Children's Hospital of Philadelphia, used gene therapy to safely improve vision in five children and seven adults with Leber's congenital amaurosis (LCA). The greatest improvements occurred in the children, all of whom are now able to navigate a low-light obstacle course—one result that the researchers call "spectacular."
"This result is an exciting one for the entire field of gene therapy," said Katherine A. High, M.D., co-first author of the study and the director of the Center for Cellular and Molecular Therapeutics, the facility that sponsored the clinical trial at The Children's Hospital of Philadelphia. High, an investigator of the Howard Hughes Medical Institute and a past president of the American Society of Gene Therapy, has been a pioneer in translational and clinical studies of gene therapy for genetic disease. "This study reports dramatic results in restoring vision to patients who previously had no options for treatment," said High. "These findings may expedite development of gene therapy for more common retinal diseases, such as age-related macular degeneration."
Although the patients did not attain normal eyesight, half of them (six of 12) improved enough that they may no longer be classified as legally blind. "The clinical benefits have persisted for nearly two years since the first subjects were treated with injections of therapeutic genes into their retinas," said senior author Jean Bennett, M.D., Ph.D., F.M. Kirby professor of Ophthalmology at the University of Pennsylvania School of Medicine. For Bennett, the results build on nearly 20 years of gene studies on hereditary blindness, starting with pioneering work in mice and dogs. "These remarkable results," she added, "have laid a foundation for applying gene therapy not only to other forms of childhood-onset retinal disease, but also to more common retinal degenerations."
The study team reported their findings today in an online article in The Lancet.
"Children who were treated with gene therapy are now able to walk and play just like any normally sighted child," said co-first author Albert M. Maguire, M.D., an associate professor of Ophthalmology at Penn and a physician at Children's Hospital. "They can also carry out classroom activities without visual aids."
Maguire and Bennett have been researching inherited retinal degenerations for nearly 20 years. Leber's congenital amaurosis, the target of this current study, is a group of inherited blinding diseases that damages light receptors in the retina. It usually begins stealing sight in early childhood and causes total blindness during a patient's twenties or thirties. Currently, there is no treatment for LCA.
Walking along a dimly lit, simulated street route, the children were able to negotiate barriers they bumped into before the surgery. Another child, who since birth, could only see light and shadows, stared into his father's face and said he could see the color of his eyes. Later they played soccer together.
For children and adults in the study, functional improvements in vision followed single injections of genes that produced proteins to make light receptors work in their retinas.
The 12 subjects ranged in age from 8 to 44 years old at the time of treatment. Four of the children, aged 8 to 11, are the world's youngest individuals to receive gene therapy for a non-lethal disease (A fifth subject was 17 years old). On the other end of the age scale, the 35-year-old man and 44-year-old woman are the oldest patients to ever receive gene therapy for retinal degeneration.
For the current human trial, the research team used a vector, a genetically engineered adeno-associated virus, to carry a normal version of the gene, called RPE65, that is mutated in one form of LCA, called LCA2, that accounts for 8 to 16 percent of all LCA cases. Jeannette Bennicelli, Ph.D., in Bennett's laboratory, cloned the gene. The clinical vector production facility at Children's Hospital's Center for Cellular and Molecular Therapeutics (CCMT), directed by Fraser Wright, Ph.D., manufactured the vector.
The clinical trial brought together subjects and scientists from two continents. Five patients enrolled in the study were identified at the Department of Ophthalmology at the Second University of Naples, an institution with a long-standing program in researching inherited retinal diseases, under the supervision of Francesca Simonelli, M.D. Two children from Belgium were recruited through Ghent University Hospital, under the supervision of Bart Leroy, M.D., Ph.D. Jennifer Wellman, of the CCMT, directed all local and federal regulatory interactions for the study.
Another co-author, Edwin Stone, M.D., Ph.D., Howard Hughes Medical Institute Investigator and director of the Carver Center, a genetic testing laboratory at the University of Iowa, identified and verified several of the disease-causing mutations in the study subjects.
In April 2008, the current study team published encouraging preliminary results in the New England Journal of Medicine regarding three young adults, the first to receive gene therapy in this current clinical trial. Those subjects showed improvements in their visual function in both objective vision tests and subjective reports by the patients themselves. Patients who could only detect hand movements gained the ability to read lines on an eye chart.
After the first group of three young adults was treated safely, the study team extended gene therapy to five children from the United States, Italy and Belgium, in addition to four other adults. Because animal studies conducted by Bennett and colleagues had shown that visual improvement was age-dependent, the researchers tested the hypothesis that younger human subjects would receive greater benefits from the treatment. "LCA is a progressive disease, so if a treatment was possible, it was plausible to intervene before damage to the retina was severe," said Bennett.
In all, 12 patients received the gene therapy via a surgical procedure performed by Maguire starting in October 2007 at The Children's Hospital of Philadelphia. For each subject, Maguire injected the therapeutic genes into the eye with poorer function. There were three patient cohorts, receiving low, middle and high doses. No serious adverse events occurred in any of the test subjects.
Starting two weeks after the injections, all 12 subjects reported improved vision in dimly lit environments in the injected eye. An objective measurement, which measures how the eye's pupil constricts, showed that all the subjects were able to detect significantly more light after treatment and also showed greater light sensitivity in each patient's treated eye compared to the untreated eye. In addition, before treatment, nine patients had nystagmus, an involuntary movement of the eyes that is common in LCA. After treatment, seven of them had significant improvements in nystagmus.
Some of the most dramatic results, captured on video by the researchers, are apparent as subjects traverse a standardized obstacle course. Before the treatment, the patients had great difficulty avoiding barriers, especially in dim light. After treatment, the children navigated the course more quickly, with fewer errors than before, even at the lowest light levels. Not all the adults performed better on the mobility course, and for those who did, the improvements were more modest compared to the children's.
"In follow-up studies, we will continue to monitor these patients to determine whether this treatment stops the progression of this retinal degeneration," said Maguire. "In the future, we hope to investigate whether other
retinal disease will be amenable to this gene therapy approach."
Thanks to University of Pennsylvania School of Medicine for this article.
For more information go to www.maculardegenerationassociation.org
His treatment represents the next step toward medical science's goal of using gene therapy to cure disease. Extending a preliminary study published last year on three young adults, the full study reports successful, sustained results that showed notable improvement in children with congenital blindness.
The study, conducted by researchers from the University of Pennsylvania School of Medicine and the Center for Cellular and Molecular Therapeutics at The Children's Hospital of Philadelphia, used gene therapy to safely improve vision in five children and seven adults with Leber's congenital amaurosis (LCA). The greatest improvements occurred in the children, all of whom are now able to navigate a low-light obstacle course—one result that the researchers call "spectacular."
"This result is an exciting one for the entire field of gene therapy," said Katherine A. High, M.D., co-first author of the study and the director of the Center for Cellular and Molecular Therapeutics, the facility that sponsored the clinical trial at The Children's Hospital of Philadelphia. High, an investigator of the Howard Hughes Medical Institute and a past president of the American Society of Gene Therapy, has been a pioneer in translational and clinical studies of gene therapy for genetic disease. "This study reports dramatic results in restoring vision to patients who previously had no options for treatment," said High. "These findings may expedite development of gene therapy for more common retinal diseases, such as age-related macular degeneration."
Although the patients did not attain normal eyesight, half of them (six of 12) improved enough that they may no longer be classified as legally blind. "The clinical benefits have persisted for nearly two years since the first subjects were treated with injections of therapeutic genes into their retinas," said senior author Jean Bennett, M.D., Ph.D., F.M. Kirby professor of Ophthalmology at the University of Pennsylvania School of Medicine. For Bennett, the results build on nearly 20 years of gene studies on hereditary blindness, starting with pioneering work in mice and dogs. "These remarkable results," she added, "have laid a foundation for applying gene therapy not only to other forms of childhood-onset retinal disease, but also to more common retinal degenerations."
The study team reported their findings today in an online article in The Lancet.
"Children who were treated with gene therapy are now able to walk and play just like any normally sighted child," said co-first author Albert M. Maguire, M.D., an associate professor of Ophthalmology at Penn and a physician at Children's Hospital. "They can also carry out classroom activities without visual aids."
Maguire and Bennett have been researching inherited retinal degenerations for nearly 20 years. Leber's congenital amaurosis, the target of this current study, is a group of inherited blinding diseases that damages light receptors in the retina. It usually begins stealing sight in early childhood and causes total blindness during a patient's twenties or thirties. Currently, there is no treatment for LCA.
Walking along a dimly lit, simulated street route, the children were able to negotiate barriers they bumped into before the surgery. Another child, who since birth, could only see light and shadows, stared into his father's face and said he could see the color of his eyes. Later they played soccer together.
For children and adults in the study, functional improvements in vision followed single injections of genes that produced proteins to make light receptors work in their retinas.
The 12 subjects ranged in age from 8 to 44 years old at the time of treatment. Four of the children, aged 8 to 11, are the world's youngest individuals to receive gene therapy for a non-lethal disease (A fifth subject was 17 years old). On the other end of the age scale, the 35-year-old man and 44-year-old woman are the oldest patients to ever receive gene therapy for retinal degeneration.
For the current human trial, the research team used a vector, a genetically engineered adeno-associated virus, to carry a normal version of the gene, called RPE65, that is mutated in one form of LCA, called LCA2, that accounts for 8 to 16 percent of all LCA cases. Jeannette Bennicelli, Ph.D., in Bennett's laboratory, cloned the gene. The clinical vector production facility at Children's Hospital's Center for Cellular and Molecular Therapeutics (CCMT), directed by Fraser Wright, Ph.D., manufactured the vector.
The clinical trial brought together subjects and scientists from two continents. Five patients enrolled in the study were identified at the Department of Ophthalmology at the Second University of Naples, an institution with a long-standing program in researching inherited retinal diseases, under the supervision of Francesca Simonelli, M.D. Two children from Belgium were recruited through Ghent University Hospital, under the supervision of Bart Leroy, M.D., Ph.D. Jennifer Wellman, of the CCMT, directed all local and federal regulatory interactions for the study.
Another co-author, Edwin Stone, M.D., Ph.D., Howard Hughes Medical Institute Investigator and director of the Carver Center, a genetic testing laboratory at the University of Iowa, identified and verified several of the disease-causing mutations in the study subjects.
In April 2008, the current study team published encouraging preliminary results in the New England Journal of Medicine regarding three young adults, the first to receive gene therapy in this current clinical trial. Those subjects showed improvements in their visual function in both objective vision tests and subjective reports by the patients themselves. Patients who could only detect hand movements gained the ability to read lines on an eye chart.
After the first group of three young adults was treated safely, the study team extended gene therapy to five children from the United States, Italy and Belgium, in addition to four other adults. Because animal studies conducted by Bennett and colleagues had shown that visual improvement was age-dependent, the researchers tested the hypothesis that younger human subjects would receive greater benefits from the treatment. "LCA is a progressive disease, so if a treatment was possible, it was plausible to intervene before damage to the retina was severe," said Bennett.
In all, 12 patients received the gene therapy via a surgical procedure performed by Maguire starting in October 2007 at The Children's Hospital of Philadelphia. For each subject, Maguire injected the therapeutic genes into the eye with poorer function. There were three patient cohorts, receiving low, middle and high doses. No serious adverse events occurred in any of the test subjects.
Starting two weeks after the injections, all 12 subjects reported improved vision in dimly lit environments in the injected eye. An objective measurement, which measures how the eye's pupil constricts, showed that all the subjects were able to detect significantly more light after treatment and also showed greater light sensitivity in each patient's treated eye compared to the untreated eye. In addition, before treatment, nine patients had nystagmus, an involuntary movement of the eyes that is common in LCA. After treatment, seven of them had significant improvements in nystagmus.
Some of the most dramatic results, captured on video by the researchers, are apparent as subjects traverse a standardized obstacle course. Before the treatment, the patients had great difficulty avoiding barriers, especially in dim light. After treatment, the children navigated the course more quickly, with fewer errors than before, even at the lowest light levels. Not all the adults performed better on the mobility course, and for those who did, the improvements were more modest compared to the children's.
"In follow-up studies, we will continue to monitor these patients to determine whether this treatment stops the progression of this retinal degeneration," said Maguire. "In the future, we hope to investigate whether other
retinal disease will be amenable to this gene therapy approach."
Thanks to University of Pennsylvania School of Medicine for this article.
For more information go to www.maculardegenerationassociation.org
Thursday, October 22, 2009
Fish intake can help prevent macular degeneration
The addition of omega-3 fatty acids to the diet, particularly in the form of fish, can help prevent the development of age-related macular degeneration vision loss by more than 30 per cent, according to a new study.
Macular degeneration is the leading cause of blindness in people older than 50, and is an eye disease that attacks the central part of the retina called the macula, which controls fine, detailed vision. The condition results in progressive loss of central vision, leaving only peripheral sight, making it difficult to drive a car, read a book or recognize faces.
With an aging population in Canada, the incidence of age-related macular degeneration (AMD) expected to increase by 50 per cent over the next two decades.
Previous research has shown that a high intake of omega-3 fatty acids and fish may slow the progression of macular degeneration in those in the advanced stages of the disease.
The current study, published online in the American Journal of Clinical Nutrition, looked at 1,837 people in the Age-Related Eye Disease Study (AREDS) who had a moderate to high risk of developing advanced macular degeneration.
They found that those with the highest omega-3 fat intake - mainly from fish and seafood - were 30 per cent less likely to progress to advanced AMD over 12 years than their peers who consumed the least.
Those with the highest intake ate the equivalent of about 3 ounces of Atlantic salmon or 5 ounces of rainbow trout per week.
It's thought that an omega-3 fatty acid found in fish called DHA (docosahexaenoic acid) may work to prevent damage to the retina through its anti-inflammatory and antioxidant properties.
Since omega-3 fatty acids cannot be manufactured by the body, it is essential that people get them through their diet., says Canada AM nutrition expert Leslie Beck.
"I would recommend eating oily fish like salmon, trout or sardines twice per week," she says. "If you don't like fish, consider taking a fish oil capsule once or twice daily. If you're a vegetarian, DHA supplements made from algae are available."
Other sources of omega-3 fatty acids include nuts, which also have anti-inflammatory and antioxidant effects and may also reduce the risk of heart disease and type 2 diabetes -- diseases that are linked to AMD.
More studies are underway to investigate the role of the diet and AMD. AREDS2, a five-year randomized trial involving 4,000 people will test the effectiveness of supplementing with certain antioxidants and/or omega-3 fatty acids on the progression to advanced AMD.
For more information go to www.maculardegenerationassociation.org
Macular degeneration is the leading cause of blindness in people older than 50, and is an eye disease that attacks the central part of the retina called the macula, which controls fine, detailed vision. The condition results in progressive loss of central vision, leaving only peripheral sight, making it difficult to drive a car, read a book or recognize faces.
With an aging population in Canada, the incidence of age-related macular degeneration (AMD) expected to increase by 50 per cent over the next two decades.
Previous research has shown that a high intake of omega-3 fatty acids and fish may slow the progression of macular degeneration in those in the advanced stages of the disease.
The current study, published online in the American Journal of Clinical Nutrition, looked at 1,837 people in the Age-Related Eye Disease Study (AREDS) who had a moderate to high risk of developing advanced macular degeneration.
They found that those with the highest omega-3 fat intake - mainly from fish and seafood - were 30 per cent less likely to progress to advanced AMD over 12 years than their peers who consumed the least.
Those with the highest intake ate the equivalent of about 3 ounces of Atlantic salmon or 5 ounces of rainbow trout per week.
It's thought that an omega-3 fatty acid found in fish called DHA (docosahexaenoic acid) may work to prevent damage to the retina through its anti-inflammatory and antioxidant properties.
Since omega-3 fatty acids cannot be manufactured by the body, it is essential that people get them through their diet., says Canada AM nutrition expert Leslie Beck.
"I would recommend eating oily fish like salmon, trout or sardines twice per week," she says. "If you don't like fish, consider taking a fish oil capsule once or twice daily. If you're a vegetarian, DHA supplements made from algae are available."
Other sources of omega-3 fatty acids include nuts, which also have anti-inflammatory and antioxidant effects and may also reduce the risk of heart disease and type 2 diabetes -- diseases that are linked to AMD.
More studies are underway to investigate the role of the diet and AMD. AREDS2, a five-year randomized trial involving 4,000 people will test the effectiveness of supplementing with certain antioxidants and/or omega-3 fatty acids on the progression to advanced AMD.
For more information go to www.maculardegenerationassociation.org
Tuesday, October 13, 2009
MIT’s Retinal Implant is Moving Forward, But Hasn’t Caught Up with Argus II
By Aaron Saenz
Way back at the beginning of the year we told you about the Argus II, an artificial retina that was helping some blind people to see. MIT researchers from the Retinal Implant Research Group led by John Wyatt are developing their own retinal implant that works along much the same principles. As reported in IEEE’s Transactions on Biodmedical Engineering, Wyatt and his team are currently testing the implants for viability in the eyes of pigs. He hopes in the next three years to move to a new prototype and human testing. However, the Argus II is already there with 20 human patients currently testing those devices.
Diseases like macular degeneration and retinitis pigmentosa are responsible for around 25 million cases of blindness worldwide. Retinal implants have the unique ability to bypass the damaged retinal tissue and stimulate the optical nerves that still function. In this way, the blindness is replaced with a very simplified vision that many users define as hazy and limited. Still, tests for the Argus II have allowed some patients to cook, make out shapes at sporting events, and move more easily through their homes. Current artificial retinas are clearly in their infancy, but as these devices are improved in the next few decades, they may serve as a means to restore near-perfect vision.
Distinguishing between the MIT artificial retina and the Argus II isn’t easy. They both use cameras or sensors embedded on glasses to record visual information that is sent to a processing pack. That pack then wirelessly relays the information to an electrode array implanted directly on the eye. As the electrodes stimulate the optic nerve, patients should see a limited series of light and dark spots that correspond to the original visual information from the glasses. The MIT artificial retina may have a superior casing structure, made of titanium.
The biggest difference between the two implants is where the electrodes attach. While the Argus array is placed on the retina, the MIT implant will be connected subretinally. This will reduce the risk of tearing during implantation. This difference may have important implications as complications during operation could affect long term viability (the MIT team wants the implant to last more than 10 years). In most other ways, the two devices are remarkably similar.
Except of course that Argus II seems to be years ahead in terms of producing a marketable product. Besides the fact that the MIT implant is still being tested for safety while the Argus II is in human trials, there’s also the issue of image resolution. The next version of the device, Argus III, is slated to have many more electrodes in the array (1000 vs. the current 60) which will greatly increase the level of detail available to users. The MIT implant, with 15 channels, has a ways to go to catch up.
Yet, even if the MIT device seems to be lagging behind the Argus, it’s good that there is more than one team in the race. Teams, which we should emphasize, are both making good progress even if they are at different stages. The Argus II, as we’ve said before is being tested in 20 patients with remarkable results. The MIT implant has been proven to be safe in pig eyes for at least 10 months, and the programming algorithms have been thoroughly tested. Both teams are well funded and have the potential to create a viable product at some point in the future. For the millions of blind people who suffer from retinal problems, who makes a retinal implant isn’t so important as long as it gets done.
For more information go to www.maculardegenerationassociation.org
Way back at the beginning of the year we told you about the Argus II, an artificial retina that was helping some blind people to see. MIT researchers from the Retinal Implant Research Group led by John Wyatt are developing their own retinal implant that works along much the same principles. As reported in IEEE’s Transactions on Biodmedical Engineering, Wyatt and his team are currently testing the implants for viability in the eyes of pigs. He hopes in the next three years to move to a new prototype and human testing. However, the Argus II is already there with 20 human patients currently testing those devices.
Diseases like macular degeneration and retinitis pigmentosa are responsible for around 25 million cases of blindness worldwide. Retinal implants have the unique ability to bypass the damaged retinal tissue and stimulate the optical nerves that still function. In this way, the blindness is replaced with a very simplified vision that many users define as hazy and limited. Still, tests for the Argus II have allowed some patients to cook, make out shapes at sporting events, and move more easily through their homes. Current artificial retinas are clearly in their infancy, but as these devices are improved in the next few decades, they may serve as a means to restore near-perfect vision.
Distinguishing between the MIT artificial retina and the Argus II isn’t easy. They both use cameras or sensors embedded on glasses to record visual information that is sent to a processing pack. That pack then wirelessly relays the information to an electrode array implanted directly on the eye. As the electrodes stimulate the optic nerve, patients should see a limited series of light and dark spots that correspond to the original visual information from the glasses. The MIT artificial retina may have a superior casing structure, made of titanium.
The biggest difference between the two implants is where the electrodes attach. While the Argus array is placed on the retina, the MIT implant will be connected subretinally. This will reduce the risk of tearing during implantation. This difference may have important implications as complications during operation could affect long term viability (the MIT team wants the implant to last more than 10 years). In most other ways, the two devices are remarkably similar.
Except of course that Argus II seems to be years ahead in terms of producing a marketable product. Besides the fact that the MIT implant is still being tested for safety while the Argus II is in human trials, there’s also the issue of image resolution. The next version of the device, Argus III, is slated to have many more electrodes in the array (1000 vs. the current 60) which will greatly increase the level of detail available to users. The MIT implant, with 15 channels, has a ways to go to catch up.
Yet, even if the MIT device seems to be lagging behind the Argus, it’s good that there is more than one team in the race. Teams, which we should emphasize, are both making good progress even if they are at different stages. The Argus II, as we’ve said before is being tested in 20 patients with remarkable results. The MIT implant has been proven to be safe in pig eyes for at least 10 months, and the programming algorithms have been thoroughly tested. Both teams are well funded and have the potential to create a viable product at some point in the future. For the millions of blind people who suffer from retinal problems, who makes a retinal implant isn’t so important as long as it gets done.
For more information go to www.maculardegenerationassociation.org
Monday, October 5, 2009
Scientists Develop Antidote For New Class Of Drugs
A new antidote has been developed by scientists which appears to work against a whole new class of drugs called aptamers.The new compound can quickly counteract the action of the drugs, offering a way to reverse the drugs' actions if a patient develops serious side effects.
The compound was designed to work with a new blood-thinner being developed for heart patients undergoing angioplasty to clear out blocked arteries. Such patients need to take blood thinners to prevent blood clots during surgery, but bleeding is a common side effect.
Bruce Sullenger of Duke University Medical Center said that having an antidote on hand would make the treatments safer. His study was published in the journal Nature Medicine.
The antidote agent appears to work against a whole new class of drugs called aptamers.
Sullenger said,"Most drugs target proteins. The type of drugs we're talking about are ribonucleic acids (RNAs) that target proteins.”
"Normally in our body we don't have these types of molecules outside of cells," Sullenger said.
"What we are doing is using agents that will sop up any nucleic acid. It's basically acting like a sponge. We put the sponge in the one compartment where the drug is," he said.
These antidote molecules controlled the activity of eight different aptamer compounds that was tested by the team.
They also tried it in a pig that had been given an aptamer blood thinner compound. "We showed you could rapidly reverse that blood-thinning effect," he said.
Pfizer's Macugen, a treatment for age-related macular degeneration, is the only aptamer drug that has been currently approved for sale by the U.S. Food and Drug Administration. Sullenger confirmed that several others were undergoing test.
Regado Biosciences in Durham, North Carolina is the company that is testing his blood thinner, called REG1.
Sullenger thinks that an antidote to this emerging class of drugs will make them safe."We predict that this advance will significantly expand the number of diseases that can be more safely treated using antidote-controllable agents," he said.
For more information go to www.maculardegenerationassociation.org
The compound was designed to work with a new blood-thinner being developed for heart patients undergoing angioplasty to clear out blocked arteries. Such patients need to take blood thinners to prevent blood clots during surgery, but bleeding is a common side effect.
Bruce Sullenger of Duke University Medical Center said that having an antidote on hand would make the treatments safer. His study was published in the journal Nature Medicine.
The antidote agent appears to work against a whole new class of drugs called aptamers.
Sullenger said,"Most drugs target proteins. The type of drugs we're talking about are ribonucleic acids (RNAs) that target proteins.”
"Normally in our body we don't have these types of molecules outside of cells," Sullenger said.
"What we are doing is using agents that will sop up any nucleic acid. It's basically acting like a sponge. We put the sponge in the one compartment where the drug is," he said.
These antidote molecules controlled the activity of eight different aptamer compounds that was tested by the team.
They also tried it in a pig that had been given an aptamer blood thinner compound. "We showed you could rapidly reverse that blood-thinning effect," he said.
Pfizer's Macugen, a treatment for age-related macular degeneration, is the only aptamer drug that has been currently approved for sale by the U.S. Food and Drug Administration. Sullenger confirmed that several others were undergoing test.
Regado Biosciences in Durham, North Carolina is the company that is testing his blood thinner, called REG1.
Sullenger thinks that an antidote to this emerging class of drugs will make them safe."We predict that this advance will significantly expand the number of diseases that can be more safely treated using antidote-controllable agents," he said.
For more information go to www.maculardegenerationassociation.org
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