Month: April 2013

Eye examinations every other year are more cost-effective than currently recommended annual eye exams for people with diabetes who are at low risk of diabetic retinopathy progression.

If adopted into standard practice, this finding could result in an estimated $200 million in health care savings annually at little to no additional risk to patients, according to a new study by researchers at RTI International, Centers for Disease Control & Prevention, National Center for Chronic Disease Prevention and Health Promotion, and the University of Wisconsin.

The study, released ahead of print on the online website of Health Services Research, used a simulation model to assess cost-effective eye screenings for the approximately 9 million Americans with diabetes but no or minimal damage to the retina from the visual complications of diabetic retinopathy.

The researchers looked at the costs and visual health impacts of annual eye exams, biennial (every other year) eye exams, telemedicine and self-referral to care, following visual symptoms. Telemedicine uses digital retinal photography to enable screening in non-eye care settings, such as primary care; images are transferred to a grading center for evaluation and, if necessary, referred to an eye care professional.

“We found that biennial eye evaluations offered virtually the same benefits to low-risk patients as annual eye exams, but at lower costs,” said David Rein, Ph.D., a senior research economist at RTI. “Telemedicine alone, or telemedicine combined with periodic dilated eye evaluations, may also be a promising alternative for this population. The cost-effectiveness of telemedicine depended on its ability to detect other eye conditions, especially uncorrected refractive errors such as those caused by presbyopia associated with aging.”

The researchers said that self-referral (simply allowing people to self-refer themselves to a doctor’s office) from a purely cost-effectiveness perspective was only cost-effective to a point.

“However, because many people would only seek care after losing vision in one or both eyes, such a recommendation is not medically ethical regardless of cost-effectiveness,” Rein said. “Rather, the self-referral option is used to understand the benefits of current recommendations and their alternatives against a world in which no routine evaluation occurred.”

When the study was conducted, telemedicine was the most cost-effective model when only diabetic retinopathy was considered. However, telemedicine was not as effective at identifying other eye conditions such as macular degeneration and refractive error.

“Changes in technology are quickly enhancing telemedicine’s ability to detect other eye conditions,” Rein said. “Thus, the benefits of telemedicine are likely to increase in the very near future, and it may soon become more cost-effective than biennial exams.”

Source:
RTI International

Neurotech Pharmaceuticals, Inc., today announced that, as reported in Investigative Ophthalmology & Visual Science (April, 2011, Vol. 52), the Company’s product candidate NT-501 demonstrated statistically significant cone photoreceptor preservation in patients with retinitis pigmentosa (RP)-a slowly developing condition that causes the progressive bilateral degeneration of photoreceptor cells in the retina, eventually resulting in blindness. NT-501 is an intraocular implant that consists of human cells genetically modified to secrete ciliary neurotrophic factor (CNTF)-a nerve growth factor capable of rescuing and protecting dying photoreceptors. The study utilized Adaptive Optics Scanning Laser Ophthalmoscopy (AOSLO), a breakthrough diagnostic technology, to image and measure the rate of the progressive degeneration of cone photoreceptors. AOSLO overcomes a major obstacle in the study of retinal degeneration-the non-invasive measurement of cone photoreceptor cells and their rate of degeneration in the eyes of living subjects.

“Given the slow progression of these diseases, measuring improvements in visual function appears to require extremely lengthy trials. We believe tools such as AOSLO that measure photoceptor preservation can play an important role in defining meaningful and measurable near-term benefits of treatment of such slow-progressing, debilitating diseases”

In the prospective study, two patients with RP and one patient with Usher syndrome type 2, a rare genetic disorder characterized by vision loss due to RP and bilateral hearing loss, were evaluated by AOSLO at baseline and at 3, 6, 12, 18 and 24 months following implantation. Patients studied were selected from Neurotech’s Phase 2 NT-501 study in patients with early-stage RP. For each patient, one eye received an NT-501 implant while the fellow eye received sham-treatment. AOSLO quantitatively assessed photoreceptor loss by measuring cone density and average cone spacing at several prospectively identified locations in the retina of each patient, aggregating repeated measures for all data points, and comparing results for the active- and sham-treated eyes. No increase in cone spacing or decrease in cone density was observed in any of the eyes treated with NT-501. An increase in cone spacing and a decrease in cone density are both indicative of photoreceptor loss. In addition, the results demonstrated a statistically significant preservation of cone photoreceptors in the eyes of all three subjects treated with the NT-501 implant versus sham-treated eyes. Cone spacing increased by 2.9% more per year in sham-treated eyes than in NT-501-treated eyes (p < 0.001), and cone density decreased by 9.1% more per year in sham-treated eyes than in NT-501-treated eyes (p = 0.002). The study was led by Jacque Duncan, MD, Professor of Clinical Ophthalmology, University of California, San Francisco, and Austin Roorda, PhD, Professor of Optometry and Vision Science, Chair and Head Graduate Advisor in the Vision Science Program, University of California, Berkeley. Dr. Duncan commented, “We are extremely encouraged by the photoreceptor preserving effect of NT-501 seen in this study as well as the usefulness of AOSLO as a diagnostic tool for retinitis pigmentosa progression. Larger studies using AOSLO are urgently needed to confirm the photoreceptor protective effect of NT-501 treatment in patients with retinal degeneration.” Paul Sieving, MD, PhD, Director of the National Eye Institute and Principal Investigator of Neurotech’s Phase 1 study of NT-501 in RP commented, “These results suggest that AOSLO may play a meaningful role in the early assessment of photoreceptor loss due to retinitis pigmentosa well before serious functional loss is detected by standard measures of visual function, and that NT-501 may play an important neuroprotective role.” “These exciting results add to the growing body of evidence that NT-501 will benefit individuals who suffer from retinitis pigmentosa and other retinal degenerative diseases,” stated Ted Danse, Chief Executive Officer of Neurotech. “Given the slow progression of these diseases, measuring improvements in visual function appears to require extremely lengthy trials. We believe tools such as AOSLO that measure photoceptor preservation can play an important role in defining meaningful and measurable near-term benefits of treatment of such slow-progressing, debilitating diseases,” added Danse. About RP and Usher Syndrome Retinitis Pigmentosa (RP) is an inherited disease that causes the retina’s rod and cone photoreceptors to gradually degenerate leading to loss of vision and blindness. The symptoms of RP predominately appear in young adults and affect approximately 100,000 people in the United States and over 1 million people worldwide. Currently there are no approved treatments for RP. Usher syndrome is a rare genetic disorder that is a leading cause of deafblindness and is characterized by vision loss due to RP and bilateral congential hearing loss. Hearing loss in Usher Type 2 generally involves people who are not born deaf, but gradually lose their hearing. About NT-501 NT-501 is one of Neurotech’s lead product candidates under development and consists of encapsulated human cells genetically modified to secrete ciliary neurotrophic factor (CNTF). CNTF is a nerve growth factor capable of rescuing dying photoreceptors and protecting them from degeneration. NT-501 is designed to continually deliver a therapeutic dose of CNTF directly to the back of the eye in a controlled, continuous manner by means of the Company’s proprietary Encapsulated Cell Therapy (ECT) platform. Delivery via ECT bypasses the blood-retinal barrier and overcomes a major obstacle in the long-term treatment of retinal disease. NT-501 has received orphan and fast-track designations for the treatment of visual loss in RP from the United States Food and Drug Administration (FDA). About AOSLO AOSLO technology is able to image cone photoreceptors, those cells of the retina responsible for fine central and color vision, and quantitatively measure the changes in those cones over time. Standard clinical imaging techniques cannot visualize individual photoreceptors due to optical imperfections in living eyes. Scanning laser ophthalmoscopy (SLO) is a method of diagnostic imaging of the eye that uses confocal imaging to obtain high-resolution optical images at varying depths within the eye. The use of adaptive optics (AO) improves SLO by removing aberrations in retinal images caused by imperfections in the eye’s optics. The improved image makes it possible to see individual cone photoreceptor cells non-invasively in the eyes of living subjects. About Encapsulated Cell Therapy Neurotech’s core technology platform is Encapsulated Cell Therapy (ECT), a unique technology that allows for the long-term, sustained delivery of therapeutic factors to the back of the eye. ECT implants consist of cells that have been genetically modified to produce a specific therapeutic protein and are encapsulated in a semi-permeable hollow fiber membrane. The diffusive characteristics of the hollow fiber membrane are designed to promote long-term cell survival by allowing the influx of oxygen and nutrients while simultaneously preventing direct contact of the encapsulated cells with the cellular and molecular elements of the immune system. The cells continuously produce the therapeutic protein which diffuses out of the implant at the target site. ECT enables the controlled, continuous delivery of therapeutic factors directly to the retina, thereby bypassing the blood-retina barrier. Source:
Neurotech Pharmaceuticals, Inc.

Letting your imagination run away with you may actually influence how you see the world. New research from Vanderbilt University has found that mental imagery–what we see with the “mind’s eye”–directly impacts our visual perception.

The research was published online June 26 by the journal Current Biology.

“We found that imagery leads to a short-term memory trace that can bias future perception,” Joel Pearson, research associate in the Vanderbilt Department of Psychology. and lead author of the study, said. “This is the first research to definitively show that imagining something changes vision both while you are imagining it and later on.”

“These findings are important because they suggest a potential mechanism by which top-down expectations or recollections of previous experiences might shape perception itself,” Pearson and his co-authors wrote.

It is well known that a powerful perceptual experience can change the way a person sees things later. Just think of what can happen if you discover an unwanted pest in your kitchen, such as a mouse. Suddenly you see mice in every dust ball and dark corner–or think you do. Is it possible that imagining something, just once, might also change how you perceive things?

“You might think you need to imagine something 10 times or 100 times before it has an impact,” Frank Tong, associate professor of psychology and co-author of the study, said. “Our results show that even a single instance of imagery can tilt how you see the world one way or another, dramatically, if the conditions are right.”

To test how imagery affects perception, Pearson, Tong and co-author Colin Clifford of the University of Sydney had subjects imagine simple patterns of vertical or horizontal stripes, which are strongly represented in the primary visual areas of the brain. They then presented a green horizontal grated pattern to one eye and a red vertical grated pattern to the other to induce what is called binocular rivalry. During binocular rivalry, an individual will often alternately perceive each stimulus, with the images appearing to switch back and forth before their eyes. The subjects generally reported they had seen the image they had been imagining, proving the researcher’s hypothesis that imagery would influence the binocular rivalry battle.

Additional experiments found that the effect of imagery on perception was approximately the same as showing the research subject a faint representation of one of the patterns between trials. Stronger shifts in perception were found if subjects either viewed or imagined a particular pattern for longer periods of time. They found that both imagery and perception can lead to a build-up of a “perceptual trace” that influences subsequent perception.

Pearson, Clifford and Tong also discovered that changing the orientation of the image from what had been imagined greatly reduced the impact of imagery on perception. Because orientation is processed in early visual areas, this suggests that imagery’s interaction with perception may occur at early stages of visual processing.

The new findings offer an objective tool to assess the often-slippery concept of imagination.

“It has been very hard to pin down in the laboratory what exactly someone is experiencing when it comes to imagery, because it is so subjective,” Tong said. “We found that the imagery effect, while found in all of our subjects, could differ a lot in strength across subjects. So this might give us a metric to measure the strength of mental imagery in individuals and how that imagery may influence perception.”

The findings may also help settle a longstanding debate in the research community over whether mental imagery is visual – that one imagines something just as one sees it – or more abstract.

“More recently, with advances in human brain imaging, we now know that when you imagine something parts of the visual brain do light up and you see activity there,” Pearson said. “So there’s more and more evidence suggesting that there is a huge overlap between mental imagery and seeing the same thing. Our work shows that not only are imagery and vision related, but imagery directly influences what we see.”

The research was funded by the National Institutes of Health, an Australian Research Council Discovery Grant and an Australia National Health and Mental Research Council Martin Fellowship. Pearson is a member of the Vanderbilt Vision Research Center. Tong is a member of the Vanderbilt Vision Research Center and the Vanderbilt Center for Integrative and Cognitive Neuroscience.

A multimedia version of this story is available on Exploration, Vanderbilt’s online research magazine, at vanderbilt.edu/exploration/stories/mindseye.html.

Source: Melanie Moran

Vanderbilt University

The U.S. Food and Drug Administration is alerting health care professionals and their patients who wear soft contact lenses about a voluntary recall of Complete MoisturePlus Multi Purpose Solution manufactured by Advanced Medical Optics of Santa Ana, Ca.

The company is taking this action as a precaution because of reports of a rare, but serious, eye infection, Acanthamoeba keratitis, caused by a parasite. The link between the solution and the infection was identified as a result of an investigation by the Centers for Disease Control and Prevention (CDC).

Consumers who wear soft contact lenses should stop using the solution, discard all partially-used or unopened bottles and replace their lenses and storage container.

“We believe the company acted responsibly in taking this voluntary action and support their decision to be proactive in the interest of public health,” said Daniel Schultz, M.D., director of FDA’s Center for Devices and Radiological Health. “FDA and CDC are working closely with the company to collect additional information and we will continue to alert consumers and advise them as more information becomes available.”

Acanthamoeba keratitis may lead to vision loss with some patients requiring a corneal transplant. The infection primarily affects otherwise healthy people who wear contact lenses.

Consumers should ask their doctor about choosing an appropriate alternative cleaning/disinfecting product and seek immediate treatment if they have symptoms of eye infection as early diagnosis is important for effective treatment. The symptoms of Acanthamoeba keratitis can be very similar to those of other more common eye infections and may include eye pain or redness, blurred vision, light sensitivity, sensation of something in the eye or excessive tearing but Acanthamoeba is more difficult to treat.

It is estimated that Acanthamoeba keratitis infections occur in approximately 2 out of every 1 million contact lens users in the United States each year. However, in a multi-state investigation to evaluate a recent increase in Acanthamoeba keratitis cases, CDC determined that the risk of developing AK was at least seven times greater for those consumers who used Complete MoisturePlus solution versus those who did not. Additional information regarding the CDC results is available at the CDC website, link here.

“The ongoing CDC investigation is a collaborative effort,” said Michael Beach, M.D., a Division of Parasitic Diseases team leader with CDC. “We are working with FDA, state, territory, university, and clinical partners in an effort to further understand whether usage or contamination of this solution led to these Acanthamoeba infections.”

All contact lens users should closely adhere to the following measures to help prevent eye infections:

— Remove contact lenses before any activity involving contact with water, including showering, using a hot tub, or swimming.

— Wash hands with soap and water and dry them before handling contact lenses.

— Clean contact lenses according to manufacturer guidelines and instructions from an eye care professional.

– Use fresh cleaning or disinfecting solution each time lenses are cleaned and stored. Never reuse or top off old solution.
– Never use saline solution and rewetting drops to disinfect lenses. Neither solution is an effective or approved disinfectant.

— Schedule regular eye exams with your eye care professional

— Wear and replace contact lenses according to the schedule prescribed by your eye care professional.

— Store lenses in a proper storage case.

– Storage cases should be irrigated with sterile contact lens solution (never use tap water) and left open to dry after each use.
– Replace storage cases at least once every three months.

FDA and CDC want to gather information related to Acanthamoeba keratitis in contact lens users. Report adverse events related to these products to MedWatch, the FDA’s voluntary reporting program: www.fda/medwatch/report.htm; Phone: (800) 332-1088; Fax: (800) 332-0178; Mail: MedWatch, Food and Drug Administration, 5600 Fishers Lane, Rockville, MD, 20852-9787.

Consumers who believe they are in possession of the recalled product may call the company at 1-888-899-9183.

Additional information about Acanthamoeba infection is available from the CDC website at here.

fda

A unique nanoparticle made in a laboratory at
the University of Central Florida is proving promising as a drug
delivery device for treating glaucoma, an eye disease that can cause
blindness and affects millions of people worldwide.

“The nanoparticle can safely get past the blood-brain barrier making
it an effective non-toxic tool for drug delivery,” said Sudipta Seal,
an engineering professor with appointments in UCF’s Advanced Materials
Processing and Analysis Center and the Nanoscience Technology Center.

The findings will be published in an article appearing in the June 28
issue of the Journal of Physical Chemistry C.

Seal and his colleagues from North Dakota State University note in the
article that while barely 1-3 percent of existing glaucoma medicines
penetrate into the eye, earlier experiments with nanoparticles have
shown not only high penetration rates but also little patient
discomfort. The miniscule size of the nanoparticles makes them less
abrasive than some of the complex polymers now used in most eye drops.

Seal and his team created a specialized cerium oxide nanoparticle and
bound it with a compound that has been shown to block the activity of an
enzyme (hCAII) believed to play a central role in causing glaucoma.

The disease involves abnormally high pressure of the fluid inside the
eye, which, if left untreated, can result in damage to the optic nerve
and vision loss. High pressure occurs, in part, because of a buildup of
carbon dioxide inside the eye, and the compound blocks the enzyme that
produces carbon dioxide.

Seal and a team of collaborators including Sanku Mallik, of North
Dakota State University, developed the research on using nanoparticles
as a delivery mechanism for the compound after supervising a student
summer project at UCF. Duke University undergraduate Serge Reshetnikov
spent a summer studying nanoscience on UCF’s Orlando campus as part of
a Research Experience for Undergraduates (REU) project funded by the
National Science Foundation. Reshetnikov started looking into the
possibilities of using nanoparticles as drug delivery tools. Subsequent
research with his advisors led to the specific application for glaucoma.

In their paper on the research, which was also supported by the
National Science Foundation, Seal and Mallik note the results are
“very promising” and that their nanoparticle configuration offers
seemingly limitless possibilities as a non-toxic drug delivery tool.

University of Central Florida
ecf.edu

Many healthcare professionals are failing to advise people with medical conditions that could affect their ability to drive whether they should get behind the wheel, according to research from the University of Warwick.

Researchers from the University’s Warwick Medical School have found many healthcare professionals are failing to tell patients with certain conditions such as diabetes or visual impairment if they are not fit to drive.

In a study undertaken for the Department for Transport, the research team explored the knowledge and attitudes of healthcare professionals towards advising patients about their fitness to drive. The researchers recruited 1519 health professionals, 358 patients and 55 medical school personnel to the study.

The research team, led by Dr Carol Hawley, Principal Research Fellow at Warwick Medical School, found doctors in training received little tuition on medical aspects of fitness to drive.

They also found that although most healthcare professionals were aware of the Driving and Vehicle Licensing Agency (DVLA) guidelines stipulating fitness to drive, many were unable to reliably distinguish between medically unfit drivers, borderline drivers and fit drivers. When presented with paper case studies of patients only 7.5% scored all of them correctly.

When presented with an acted scenario of a patient who was unfit to drive, 75% of healthcare professionals failed to offer advice on driving. The results also showed 40% of healthcare professionals agreed they did not have sufficient knowledge of the DVLA Fitness to Drive guidelines.

As part of the current DVLA licensing system there is a legal obligation on individuals to declare the onset or worsening of any medical condition that may affect their fitness to drive. This requirement is publicised on driving licence application forms and in accompanying information leaflets.

Advice for the public on the medical standards of fitness to drive is published by DVLA in a booklet and made available on Direct.

For medical professionals, the DVLA helped to develop the General Medical Council’s new guidance on patient confidentiality and reporting medical conditions to the DVLA. There are also various projects in development such as E learning for junior doctors and the DVLA is working with the Department of Health to develop a learning module on medical conditions and driver licensing awareness.

Dr Hawley’s research has been published as a main report, along with nine sub-reports, by the Department for Transport.

She said: “Although the information is there and results suggest healthcare professionals are aware of the DVLA fitness to drive guidelines, they had a poor knowledge of how the guidelines applied to specific conditions.

“There is also uncertainty about which groups of healthcare professionals are responsible for informing a patient about how their condition can affect their ability to drive. Interviews with patients revealed that only one third of them had been advised about their fitness to drive without having to ask for advice.”

Dr Hawley said the DVLA had already taken steps to ensure more widespread knowledge and implication of the current guidelines for the public and healthcare professionals. However, she added they may need to be simplified to make them more user-friendly and more training was needed for healthcare professionals and medical students.

Source: Kelly Parkes-Harrison

University of Warwick

The artificial intelligence group at Freie Universit?�t Berlin, under the direction of the computer science professor Ra??l Rojas, has developed a new type of information system for blind and visually impaired individuals. Field trials are being carried out to optimize the device for future users. During the next six months it will be tested by 25 persons. The artificial intelligence group at Freie Universit?�t is collaborating with a research group at the Telekom Laboratories headed by Dr. Pablo Vidales and the Berlin Association for the Education of the Blind and Visually Impaired e.V. The joint project is called InformA. After completion of the field trials, it will receive funding from the German Federal Ministry of Education and Research through its EXIST seed funding program for university-based business start-ups. In addition, IBM Germany is providing funding for further development of the device at Freie Universitat.

“InformA” is a small computer that is connected wirelessly to the Internet. The device is operated like a radio. The user can choose between different information channels. By pressing a button, the time or the weather will be announced, but there are also current newspapers available as audio files (currently Tagesspiegel and taz).

In addition, e-mails can be read aloud by the device. The user can answer e-mails by dictating a message. An integrated camera makes it possible to have printed documents such as letters or package information leaflets read aloud fully automatically. In more complicated cases – such as a statement of account for a heating bill – the user of the device can take a photo of the document and send it to a call center. Persons doing community service instead of military service who work for the Berlin Association for the Education of the Blind and Visually Impaired e.V. then provide further assistance. “Through the wealth of information provided by InformA, the device can also be of interest for older people without previous experience with computers, who until now have not had access to information offered through the Internet,” according to the project leader, Ra??l Rojas.

Twenty-five individuals have already volunteered for the field trials. In a second phase, another 25 will be added. In order to optimize the device, the participants will be interviewed during the course of the trials, about how they cope with the device. There is no charge for participating in the field trials.

Dr. Armgard von Reden, who is the director of governmental programs at IBM and who signed the cooperation agreement between Freie Universit?�t and IBM, stated, “The integration of persons with disabilities has a long history at IBM. That applies to our products, where we are constantly working to provide barrier-free access to the information society. But it also applies to the nearly century-old tradition of employing people with disabilities at IBM.”

InformA is an example of an information appliance. Even in the age of the Internet, it is not always necessary to use a fully equipped computer for online communications. Specialized equipment, such as internet radios, can cover specific needs, if the equipment is small, portable, and easy to use.

German Telecom is providing 50 DSL lines and just as many InformA information devices for the participants in the field trials. After the field trials IBM Germany will be supporting the project at Freie Universit?�t Berlin as part of its diversity program. IBM will provide funding for student asistants and computers.

Source: Freie Universitaet Berlin

Researchers in Boston studied elderly male twins and found that those who smoke or have a history of smoking had an increased risk of developing age-related macular degeneration as compared to those who never smoked. At the same time, those who ate more fish and had diets with higher levels of omega-3 fatty acids reduced their risk of this blinding disease. Their findings are published in the July 2006 issue of the Archives of Ophthalmology.

Researchers at the Massachusetts Eye and Ear Infirmary and Department of Biostatistics at Harvard Medical School studied 681 male twins from the National Academy of Sciences-National Research Council World War II Veteran Twin Registry. To determine genetic and environmental risk factors for Age-related Macular Degeneration (AMD), twins were surveyed for a prior diagnosis of AMD and underwent an eye examination, fundus photography, and food frequency and risk factor questionnaires. The study included 222 twins with intermediate and late-stage AMD and 459 twins with no signs of the disease.

“Current smokers had a 1.9-fold increased risk of developing AMD, while past smokers had about a 1.7-fold increased risk,” said Johanna M. Seddon, M.D., director of the Epidemiology Unit at the Massachusetts Eye and Ear Infirmary and an associate professor of ophthalmology at Harvard Medical School. “We also found that increased intake of fish reduced the risk of AMD, particularly if they ate two more servings per week. Dietary omega-3 fatty intake was also inversely associated with AMD. This study of twins provides further evidence that cigarette smoking increases risk while fish consumption and omega-3 fatty acid intake reduce risk of AMD.”

AMD is the leading cause of irreversible visual impairment and blindness among persons aged 60 and older. With the elderly population steadily growing, the burden related to this loss of visual function will increase. Limited treatment options exist and prevention remains the best approach for addressing this public health concern.

Lead author Dr. Seddon and her colleagues previously reported that the heritability of AMD is high (46% to 71%) in this same cohort of twins (Arch Ophthalmol 2005). They also found that systemic markers of inflammation, including serum levels of high sensitivity C-reactive protein, as well as plasma homocysteine are associated with AMD (JAMA 2004, Am J Ophthalmol 2006). A decade ago they reported the increased risk of AMD with cigarette smoking (JAMA 1996), and the decreased risk of this disease related to dietary intake of carotenoids and foods rich in lutein and zeaxanthin (JAMA 1994). They also found in several of their study cohorts that fish intake appears beneficial and reduces risk of AMD (Arch Ophthalmol 2001, 2003, and current article), and high body mass index or obesity is also a risk factor for progression of the disease. (Arch Ophthalmol 2003).

This most recent research was funded by grants from the National Institute of Health, the Foundation Fighting Blindness Inc., the Retirement Research Foundation, DSM Inc, the Massachusetts Lions Eye Research Fund, and the Epidemiology Research Fund.

MASSACHUSETTS EYE AND EAR INFIRMARY
meei.harvard.edu/

The Massachusetts Eye and Ear Infirmary, an independent specialty hospital, is an international center for treatment and research and a teaching hospital of Harvard Medical School.

HARVARD MEDICAL SCHOOL

hms.harvard.edu/

Harvard Medical School has more than 7,000 full-time faculty working in eight academic departments based at the School’s Boston quadrangle or in one of 47 academic departments at 18 Harvard teaching hospitals and research institutes. Those Harvard hospitals and research institutions include Beth Israel Deaconess Medical Center, Brigham and Women’s Hospital, Cambridge Health Alliance, the CBR Institute for Biomedical Research, Children’s Hospital Boston, Dana-Farber Cancer Institute, Forsyth Institute, Harvard Pilgrim Health Care, Joslin Diabetes Center, Judge Baker Children’s Center, Massachusetts Eye and Ear Infirmary, Massachusetts General Hospital, Massachusetts Mental Health Center, McLean Hospital, Mount Auburn Hospital, Schepens Eye Research Institute, Spaulding Rehabilitation Hospital, and VA Boston Healthcare System.

Contact: Mary E. Leach

Harvard Medical School

Cedars-Sinai Medical Center’s Keratoconus Research Program has recently been awarded a $3.4 million grant by the National Eye Institute of Health to study the genetic basis of keratoconus, a degenerative corneal disorder that causes distortion and reduced vision, affecting more than 20,000 people in the United States.

While the cause of the disease is unknown, previous studies have identified genetic factors associated with keratoconus. The goal of this five-year study is to identify the genes and possible mutations that may contribute to susceptibility to the disease.

“Special contact lenses can help those with keratoconus, but many will need corneal transplants during their lifetime to keep their vision,” says Yaron Rabinowitz, M.D., director of the Cornea-Genetic Eye Institute at Cedars-Sinai in Los Angeles and principal investigator of the study. “Analyzing a large database of corneal genes from people who have the disease will help us understand more about its genesis, and, we hope, ultimately lead to ways to slow the progression of the disease and to the development of new treatments.”

Any person with keratoconus with no other associated diseases is eligible for the study. Participants will receive an eye exam and high resolution computerized topography maps of their corneas. They will also complete a questionnaire regarding their medical and surgical history, and will have blood drawn so that researchers can study and analyze their genetic material. Participants must be over the age of 10. There is no cost to any patient who participates in the study.

Source
Cedars-Sinai Medical Center

University of Florida scientists conducting experiments with mice have found evidence that the body naturally replenishes small amounts of cells in the eye essential for healthy vision.
The finding may shatter the belief that a cell layer vital for eyesight called the retinal pigment epithelium, or RPE, is a nonrenewable resource, say researchers writing in a recent issue of Investigative Ophthalmology & Visual Science.

RPE plays a vital role in our visual health by forming the outer barrier of the retina and supporting the function of cells that receive light. Damage to RPE is present in many diseases of the retina, including age-related macular degeneration, which affects more than 1.75 million people in the United States.

With evidence that the body does indeed regenerate these cells in small amounts, scientists can focus on ways to accelerate natural healing processes to treat sight-robbing injuries or diseases.

“What this tells us is for problems such as age-related macular degeneration, we should be able to harvest stem cells to help repair the damage,” said senior author Edward Scott, Ph.D., a professor of molecular genetics at the UF Shands Cancer Center and director of the Program in Stem Cell Biology and Regenerative Medicine at UF’s College of Medicine. “The question is whether we can do it in a patient.”

Scientists widely believe that RPE is a finite resource. The same belief used to be held about brain cells – people who suffered from trauma, stroke or disease formerly faced no hope of growing new cells to replace dead ones.

Then, in the late 1990s, when scientists began to report findings of brain cell growth in humans and monkeys later in life, focus turned toward understanding the mechanisms to regenerate cells in the brain.

Now, UF researchers believe it may be possible to also grow new cells in the retina to replace cells lost to injury or disease.

“In people, retinal pigment epithelium can become damaged with age,” said Jeffrey Harris, a graduate student in the department of molecular cell biology in UF’s College of Medicine and first author of the paper. “Factors like smoking and diet also come into play. The problem is without these cells, the rods and cones – our primary cells for vision – die. If we can regenerate the retinal pigment epithelium, it could make a big difference in our visual health.”

Scientists were able to detect that RPE cells indeed appear to be naturally replenished in the test animals by transplanting bone marrow cells from normal male mice into albino females with two different types of acute RPE injury.

Bone marrow contains stem cells, which have the extraordinary abilities to home in on injuries and possibly regenerate other cell types in the body. In this case, the cells were transplanted to confirm that bone marrow does regenerate the injured RPE. It was easier to track male, pigment-producing cells in female, albino recipients, Harris said.

Chemical and microscopic analysis showed the cells that traveled to the injury site and transformed into RPE indeed had male genetic characteristics. Furthermore, these cells were capable of producing pigment – a colorful indication that the RPE could only have arisen from the donor bone marrow stem cells.

“We did not use a direct model of age-related macular degeneration,” Scott said. “But we now know that when RPE is injured, it can be replaced in certain situations. It gives us growth factors, cell pathways and other different places to look at to find reasons why the disease is occurring.”

Researchers want to discover ways to mobilize an elderly patient’s own cells to travel to the injury site to make repairs.

“The dogma has been that we’re born with a fixed amount of RPE, but there is growing evidence retinal progenitor cells exist in the adult,” said Lawrence Rizzolo, Ph.D., a Yale University associate professor of anatomy and experimental surgery and of ophthalmology and visual science who was not involved in the research. “To derive cells of neuronal lineage from cells of bone-marrow lineage is significant, if the finding stands up to the test of time. Compared to RPE transplantation, there are a lot of advantages if someone’s own bone marrow could supply the cells, because it’s a ready source and the cells would not be rejected by the patient. Further, if bone-marrow progenitors circulating in the blood could be attracted to sites of disease, surgery could be avoided.”

Contact: John D. Pastor
University of Florida