 |
|
New treatment for glaucoma shows promise in laboratory, say Iowa State researchers
August 02, 2007AMES, Iowa -- Iowa State University researchers have developed a new technique that successfully treated rats for blindness caused by glaucoma. Their experimental treatment will be used on canine patients in the next year. If successful, it is expected to move to human trials.
An estimated 3 million people in the U. S. are affected by glaucoma, the second leading cause of blindness in the developed world and the number one cause of vision loss among blacks. People with elevated intraocular pressure are at greatest risk for developing glaucoma.
Iowa State researchers leading the six-year project are Dr. Sinisa Grozdanic, a veterinary ophthalmologist and assistant professor of veterinary clinical sciences; Donald Sakaguchi, neuroscientist and associate professor of genetics, development and cell biology; and Matt Harper, doctoral student in neuroscience. The team also included researchers from the University of Iowa, Yale University, Tulane University and the University of Miami. The work was presented at a recent meeting of the Association for Research in Vision and Ophthalmology Conference.
The researchers previously determined that animals with glaucoma increase production of proteins with neuron-protective capabilities (neurotrophins) in an attempt to shield against blindness. So, they imitated that process in the laboratory, modifying bone marrow-derived stem cells. Then they transplanted the cells into the eyes.
"Once we realized the nature of these self-protective mechanisms, we just tried to mimic the same thing exactly," Grozdanic said. "We used bone-derived stem cells from the patient, modified them to produce the neurotrophin and injected these cells into glaucomatous eyes."
A sophisticated computerized analysis of noninvasive measurements of optic nerve function and the retina's electrical activity showed dramatic improvement in the rats' visual functions after the procedure.
Four years earlier, the researchers had conducted experiments in which biodegradable polymers coated with neuroprotective substances were inserted into the eyes of rats. As the polymer degrades, the neuroprotective substance is released into the eye. The approach worked well, and the same procedure was successful in dogs with optic nerve damage. However, because polymer-based drug delivery generally lasts for only months and glaucoma destroys vision in humans over a period of decades, the scientists shifted their strategy to a longer-lasting approach. They genetically modified the bone marrow stem cells for transplantation so the delivery of the neuroprotective protein can be achieved for years.
"One of the really unique aspects of this approach is that we can isolate these stem cells from the same individual being treated," Sakaguchi said. "It eliminates the ethical issues associated with embryonic stem cells, and the immunological problems of graft rejection."
Grozdanic said the "results were phenomenal." So, the Iowa State team intends to use the technique on dogs as soon as possible.
"Dogs suffer many of the same diseases people do and there's a lot of physiological similarity in their eyes and ours," Grozdanic said.
"Four years ago, I was very skeptical that this would work," he said. "Now I see positive results. Hopefully in a few years, we'll be able to say it's working in humans."
The cell biology work and the genetic modification were conducted by Sakaguchi and Harper, while Grozdanic developed techniques for evaluating the molecular changes in the animals. Researchers at the University of Miami provided genetic material for the modification while collaborators at Tulane assisted with culturing the bone marrow stem cells. A biodegradable polymer engineered with neuroprotective substances used in preliminary testing was developed by Erin Lavik at Yale University. Three faculty from the University of Iowa's Department of Ophthalmology and Visual Sciences - Dr. Randy Kardon, Dr. Young Kwon and Dr. Markus Kuehn - helped develop models of elevated eye pressure and assessing visual function. They also compared data from tissue from the rats and dogs to data from human donor tissue to help the team better understand molecular changes caused by glaucoma.
Iowa State University
The researchers previously determined that animals with glaucoma increase production of proteins with neuron-protective capabilities (neurotrophins) in an attempt to shield against blindness. So, they imitated that process in the laboratory, modifying bone marrow-derived stem cells. Then they transplanted the cells into the eyes.
"Once we realized the nature of these self-protective mechanisms, we just tried to mimic the same thing exactly," Grozdanic said. "We used bone-derived stem cells from the patient, modified them to produce the neurotrophin and injected these cells into glaucomatous eyes."
A sophisticated computerized analysis of noninvasive measurements of optic nerve function and the retina's electrical activity showed dramatic improvement in the rats' visual functions after the procedure.
Four years earlier, the researchers had conducted experiments in which biodegradable polymers coated with neuroprotective substances were inserted into the eyes of rats. As the polymer degrades, the neuroprotective substance is released into the eye. The approach worked well, and the same procedure was successful in dogs with optic nerve damage. However, because polymer-based drug delivery generally lasts for only months and glaucoma destroys vision in humans over a period of decades, the scientists shifted their strategy to a longer-lasting approach. They genetically modified the bone marrow stem cells for transplantation so the delivery of the neuroprotective protein can be achieved for years.
"One of the really unique aspects of this approach is that we can isolate these stem cells from the same individual being treated," Sakaguchi said. "It eliminates the ethical issues associated with embryonic stem cells, and the immunological problems of graft rejection."
Grozdanic said the "results were phenomenal." So, the Iowa State team intends to use the technique on dogs as soon as possible.
"Dogs suffer many of the same diseases people do and there's a lot of physiological similarity in their eyes and ours," Grozdanic said.
"Four years ago, I was very skeptical that this would work," he said. "Now I see positive results. Hopefully in a few years, we'll be able to say it's working in humans."
The cell biology work and the genetic modification were conducted by Sakaguchi and Harper, while Grozdanic developed techniques for evaluating the molecular changes in the animals. Researchers at the University of Miami provided genetic material for the modification while collaborators at Tulane assisted with culturing the bone marrow stem cells. A biodegradable polymer engineered with neuroprotective substances used in preliminary testing was developed by Erin Lavik at Yale University. Three faculty from the University of Iowa's Department of Ophthalmology and Visual Sciences - Dr. Randy Kardon, Dr. Young Kwon and Dr. Markus Kuehn - helped develop models of elevated eye pressure and assessing visual function. They also compared data from tissue from the rats and dogs to data from human donor tissue to help the team better understand molecular changes caused by glaucoma.
Iowa State University
Glaucoma Current Events and Glaucoma News RSSEye conditions linked with obstructive sleep apnea
If a good night's sleep helps the brain and body perform better, it's a good guess that sleep problems can cause more than just fatigue. Numerous studies have shown a connection between sleep disorders and medical conditions such as cardiovascular disease, cerebrovascular disease, and metabolic disorders, including the risk of obesity and diabetes mellitus. In the November issue of Mayo Clinic Proceedings, Mayo Clinic researchers outline several interesting associations between sleep disorders and eye disease.
Vision loss more common in people with diabetes
Visual impairment appears to be more common in people with diabetes than in those without the disease, according to a report in the October issue of Archives of Ophthalmology, one of the JAMA/Archives journals.
Medication slows progression of myopia in children
Daily treatment with a medication called pirenzepine can slow the rate of progressive myopia, or nearsightedness, in children, reports a study in the August issue of the Journal of AAPOS (American Association for Pediatric Ophthalmology and Strabismus).
Glaucoma procedure now available at Mayo Clinic aims to prevent further eye damage
For the first time in Florida, patients with glaucoma have a new treatment option known as the Trabectome.
Case Western Reserve and Penn State investigators inhibit corneal inflammation
Researchers from the Case Western Reserve University School of Medicine and Penn State Hershey College of Medicine identified a novel therapeutic that reduces sterile inflammation within the cornea.
Glaucoma report points to increased costs
A new Centre for Eye Research Australia/ Access Economics report shows the cost of glaucoma will more than double in the next two decades.
'Fluorescent' cells give early warning for eye disease
Scientists at the University of Michigan have shown that their new metabolic imaging instrument can accurately detect eye disease at a very early stage.
Role identified for glaucoma gene and related signaling pathway
Researchers have found that a gene and a related signaling pathway play a role in the development of glaucoma, which is a common cause of visual impairment and blindness worldwide.
Cost of glaucoma medications may impact treatment
In the United States, the management of glaucoma costs about $2.5 billion per year. Of the $1.9 billion in direct costs, glaucoma medications account for an estimated 38% to 52% of the total.
Using fMRI to study brain development
Functional magnetic resonance imaging (fMRI) is a powerful noninvasive tool for studying brain activity in both humans and experimental animals.
More Glaucoma Current Events and Glaucoma News Articles
 | What Your Doctor May Not Tell You About(TM) Glaucoma: The Essential Treatments and Advances That Could Save Your Sight (What Your Doctor May Not Tell You About...) by Gregory K. Harmon, Nancy Intrator Most people can recite the warning signs of cancer and just about everybody knows the risk factors for heart disease. But how many people know the facts about glaucoma? Well, what you don't know might save your sight. Glaucoma is an insidious and painful disease that is often misunderstood, and ultimately can rob patients of their sight completely. Between three and four million Americans are... |
 | A Patient's Guide to Glaucoma by Young H Kwon, John H Fingert, Emily C Greenlee The Patient's Guide to Glaucoma is a very useful educational resource. The authors have done an excellent job of covering the pertinent aspects of glaucoma from the patient's perspective. It provides more complete explanations of aspects of glaucoma care than any other presently available resource. It will be very helpful to patients who want more information about medications, laser,... |
 | Heal Yourself of Anything: Example Glaucoma by Nancy Lynne Harris Nancy Lynne Harris, spiritual counselor and healer, tells how her nine-year-old son was healed of congenital glaucoma when she reversed her attitude toward a domineering (pressuring) person in her life. Nancy explains the spiritual healing process, which can be used to heal any illness. Your problems can become mental harmony disturbers because they bring negative words to your mind. By... |
 | Glaucoma Medical Therapy: Principles and Management (Ophthalmology Monographs) In recent years, a large number of drugs have been developed for the treatment of glaucoma. The clinical use of drugs for glaucoma therapy has evolved, adapting with the advent of each new drug. Clinicians need to understand, synthesize, and use data about medications that have specific benefits and risks for their glaucoma patients. The focus of this book is the current art and science of... |
 | Shields' Textbook of Glaucoma This popular reference on glaucoma management now offers a more practical and clinically focused textbook for ophthalmologists and residents. Readers find new or extensively updated information on cellular and molecular biology of the eye, molecular genetics and classification of glaucomas, epidemiology and public health, screening and risk assessment, congenital and developmental glaucomas with... |
| Becker-Shaffer's Diagnosis and Therapy of the Glaucomas by Robert L. Stamper, Marc F. Lieberman, Michael V. Drake For the first time in full-color, the seventh edition of BECKER-SHAFFER'S DIAGNOSIS AND THERAPY OF THE GLAUCOMAS provides comprehensive coverage of diagnostic and treatment modalities for the glaucomas. The new editors have heavily revised this classic text, bringing it up to date with the very latest in clinical examination, medical treatment, laser therapy, and surgical procedures. The addition... | |
 | Glaucoma: Color Atlas & Synopsis of Clinical Ophtalmology (Wills Eye Series) by Douglas J. Rhee, Christopher J. Rapuano Quick reference and color atlases covering 5 sub-specialties in ophthalmology. Each book will cover the following areas: Epidemiology and Etiology; History Physical Examination; Differential Diagnosis;Laboratory and Special Examinations; Diagnosis; Prognosis;... |
 | Surgical Techniques in Ophthalmology Series: Glaucoma Surgery: Text with DVD (Surgical Techniques in Ophthalmology) by Teresa C. Chen Whether you're in training or an established practitioner, the brand-new Surgical Techniques in Ophthalmology Series features the essential information you need on a variety of surgical maneuvers in six subspecialty areas. Every author has been carefully selected for each title based on their experience and wealth of clinical expertise. And, each book is presented in a concise, templated format... |
 | The Pediatric Glaucomas by Anil Mandal, Peter Netland Here is a comprehensive and up-to-date source on the origins, diagnosis, and management of glaucomas in children. The authors balance evidence-based management guidelines with perspectives from their abundant direct clinical experience. Coverage includes the most recent advances in genetics, medical therapy, and surgical treatment...long-term management...treatment of intractable glaucomas...and... |
 | Bilberry & Lutein: The Vision Enhancers! Protect Against Cataracts, MacUlar Degeneration, Glaucoma, Retinopathy & Other Health Problems (Health lear (Health Learning Handbook) by Beth M. Ley Our eyes are perhaps our most delicate and sensitive organs. They are at high risk for damage, especially from UV rays and other causes of free radical damage. Cataracts afflict approximately 29% of Americans between 65 and 74 years of age. Age-related macular degeneration is the most common cause of severe visual impairment in older Americans. Approximately 1.7 million have decreased vision and... |
| © 2008 BrightSurf.com |