Month: August 2013

In the eyes of mammals, visual information is processed on a daily schedule set within the eyes themselves — not one dictated by the brain, according to a new report in the journal Cell, a publication of Cell Press. The researchers found in mice that the eyes’ normal rhythmic response to light requires only that a molecular “clock” inside the retina go on ticking. The retina is a layer of nerve tissue covering the back of the eyeball, which is often likened to the film in a camera; without it, images can’t be captured.

The results offer the first glimpse into the physiological importance of circadian clocks found in organs throughout the body, said Charles Weitz of Harvard Medical School. The retina’s apparent independence when it comes to keeping itself on time further challenges the notion that the circadian rhythms of the body–which drive regular patterns of physiology and behavior–strictly follow orders handed down from a “master clock” in the brain, the researchers said.

“We’re moving from a dictatorial model of the circadian system to a federal model,” Weitz said. He added, however, that the brain’s master clock isn’t “completely off its pedestal” yet as it might still play a lead role in synchronizing the clocks found in other organs.

It has long been known that the roughly 24 hour circadian clock controlling behavior in mammals is located in the brain’s suprachiasmatic nucleus (SCN), Weitz explained. Even when animals are placed under conditions of constant darkness, that daily rhythm marches on.

More recently, researchers have discovered that circadian clocks are also distributed in other mammalian tissues, including the retina, multiple brain regions, and many peripheral tissues such as the liver and kidneys. But while scientists had suspected physiological functions for those many timepieces, few studies had addressed the issue.

In the new study, the researchers found that retinas of mice that completely lack a critical component of the clock — a gene known as Bmal1 — showed abnormal gene activity in hundreds of retinal genes and defective electrical responses in inner retinal cells critical for image processing. The animals’ photoreceptors still sensed light normally and, upon close examination, their eyes appeared normal.

Mice deficient for the Bmal1clock gene only in their retinas had defects of vision essentially identical to those of mice lacking the gene in all tissues, evidence that the clock’s function in the eye itself is the key. By contrast, the retinas of mice with brain lesions that disabled the SCN maintained normal visual responses and the regular ebb and flow of retinal gene activity.

“Circadian clocks in mammals are widely distributed, but except for the SCN clock known to regulate behavior, their physiological functions in vivo have largely been mysterious,” Weitz concluded. “The studies described here indicate that an intrinsic retinal circadian clock regulates visual processing in vivo and that it does so autonomously, with no detectable contribution from the SCN or other clocks.”

Whether the retina’s ability to keep time on its own is the exception, “we don’t know,” Weitz said. Unlike other tissues, the eye’s role as a light sensor does provide its component structures a unique ability to track the environment on their own authority, he noted.

Nonetheless, he said, “our work provides evidence that circadian clocks outside the SCN contribute important physiological functions in mammals. Over evolutionary time, different cell types have likely recruited the circadian clock mechanism inherited from a single-celled ancestor for control of specialized tissue-specific processes,” he suggested.

The researchers include Kai-Florian Storch and Carlos Paz of the Department of Neurobiology, Harvard Medical School in Boston; James Signorovitch of the Department of Biostatistics, Harvard School of Public Health in Boston; Elio Raviola of the Department of Neurobiology, Harvard Medical School in Boston; Basil Pawlyk and Tiansen Li of Massachusetts Eye & Ear Infirmary, Berman-Gund Laboratory, Department of Ophthalmology, Harvard Medical School in Boston; and Charles J. Weitz of the Department of Neurobiology, Harvard Medical School in Boston. This work was supported by grants from the National Institutes of Health to C.J.W. (NS055831), E.R. (EY001344), and T.L. (EY10309).

Storch et al.: “Intrinsic Circadian Clock of the Mammalian Retina: Importance for Retinal Processing of Visual Information.” Publishing in Cell 130, 730-741, August 24, 2007. DOI 10.1016/j.cell.2007.06.045 cell/

Source: Nancy Wampler

Cell Press

Age-related macular degeneration (AMD) is a leading cause of severe vision loss among Americans ages 65 and over. Knowing your risk factors, being aware of your family history, and keeping regular appointments with your Eye M.D. can help reduce your risks for vision loss from macular degeneration. In its most severe form, known as wet AMD, the disease can lead to permanent loss of central vision which is essential for driving, reading, and recognizing faces.

March is AMD Awareness Month, and the American Academy of Ophthalmology, through its EyeSmart™ Campaign, encourages Americans to know their risks for AMD.

“The past few years have been marked by significant improvement in understanding the causes and the treatment of AMD,” says George Williams, MD, an AMD expert and Academy clinical correspondent. “New research and clinical advances are helping us to better treat both the “dry” AMD and “wet” forms of AMD. One strong risk factor that people may not be aware of is family history. It’s important to find out whether your relatives have had AMD, and to tell your Eye M.D., if you have a history of AMD in your family. Knowing your risks can save your sight.”

Here are the top 5 risk factors for AMD:

– Being over the age of 60
– Having a family history of AMD
– Cigarette smoking
– Obesity
– Hypertension

If you have any two of these risk factors, you should schedule an appointment with your Eye M.D for a complete evaluation. Your Eye M.D. may recommend certain preventive measures which can reduce your risk of vision loss from this disorder.

People who are at risk should know the symptoms of wet AMD, the form most likely to cause rapid and serious vision loss. These include sudden, noticeable loss or distortion of vision, such as seeing “wavy” lines. See an Eye M.D. right away if these symptoms occur. Current treatments for wet AMD provide an excellent chance of stopping vision loss and may actually restore some vision when macular degeneration develops. Earlier diagnosis of wet AMD gives a better chance of successful treatment.

There are some AMD risk factors that a person can change such as smoking and diet to reduce the risk of vision loss from AMD. Other risk factors such as genetic factors cannot be changed. However, knowing your family medical history is one way to learn whether you may be genetically predisposed to a disease. One way to reduce AMD risk is to quit smoking or never start. For patients at high risk for developing late-stage AMD, taking a dietary supplement of vitamin C, vitamin E and beta carotene, along with zinc, has been shown to lower the risk of AMD advancing to advanced stages by 25 percent. Patients should check with their Eye M.D. before starting any dietary supplement.

About AMD

The disease takes two forms, termed “dry” and “wet.”

– Early-stage AMD: Yellow deposits called “drusen” develop under the retina, the light-sensitive tissue at the back of the eye that focuses images and relays them to the optic nerve. At this stage, most people would do not have reduced vision.

– Intermediate AMD: Patients have more and larger drusen and more pigment changes in the macula (the part of the retina responsible for central vision); they are at higher risk for both advanced dry and wet AMD. The majority of those with intermediate AMD do not progress to an advanced stage, but should be followed by an Eye M.D. so they can be treated if needed.

– Advanced “dry” AMD: Patients with more advance dry AMD may have a blind spot in their central vision. Currently there is no proven therapy to restore vision lost from advanced dry AMD. Low-vision technologies, including improved lighting and magnification, help maintain their quality of life.

– Advanced “wet” AMD: In this stage, abnormal blood vessel form under the retina. These blood vessels can leak fluid or bleed and cause sudden and drastic loss of central vision.

Although only about 10 percent of the 10 to 15 million Americans with AMD have the “wet” form, it is responsible for most severe vision loss. New, highly effective treatments such as the injectable medications ranibizumab and bevacizumab are dramatically reducing damage from “wet” AMD and can stabilize vision in more than 90 percent of patients and actually improve vision in up to 30 to 40 percent of patients.

For more information about AMD and other eye diseases, visit geteyesmart.

Source
American Academy of Ophthalmology

If you don’t suffer from dry eye syndrome (DES), chances are you’ve never heard of it. It is a condition characterized by an insufficiency in the amount or quality of tears. For the millions of Americans who do suffer from DES, it can get in the way of daily living.

Our eyes need tears to keep them healthy. In most people, a constant tear film lubricates and protects the eyes. In people with DES, a decreased production of fluid can weaken the tear film, causing the eye to become dry, irritated and uncomfortable.

In a recent study published in the American Journal of Ophthalmology, researchers discovered that DES can have a considerable and detrimental effect on everyday life for people who suffer from the condition. The study of about 700 people found that sufferers of DES were more likely to report problems with daily activities, including reading, using a computer, driving and watching television, than people without DES. The researchers concluded that DES may be more of a public health problem than previously realized.

Dry eye symptoms usually first appear in adults over the age of 40, but they can appear in individuals between the ages of 20 and 30.

Women are approximately two to three times more likely to get DES than men. “We do not know all of the reasons why,” said Dr. Debra Schaumberg, author of the study and director of ophthalmic epidemiology at Brigham and Women’s Hospital in Boston, Mass. “However, there is speculation that one of the chief reasons might be that sex steroid hormones are involved in the pathogenesis of the disease.”

Other reasons women may be disproportionately affected by DES include the balance of female and male sex hormones. “There are data to support the hypothesis that androgens (male sex hormones) are protective whereas estrogens (female sex hormones) appear to play a more detrimental role,” Schaumberg said.

Despite the fact that DES is one of the most common reasons people seek care from eye doctors, it may be clinically disregarded. “DES is relatively overlooked because it is not on the short list of major causes of blindness and visual impairment,” Schaumberg said.

DES is not a common cause of vision loss, but it is still a serious issue for people who have it. People with DES often complain that their eyes are burning and feel itchy and painful. Many also complain of a constant feeling of sandiness or grittiness in their eyes. The symptoms tend to get worse as the day progresses.

If the symptoms persist, they can present other problems for sufferers. According to Schaumberg, “people with DES are bothered by irritative ocular symptoms which can be likened to other chronic pain syndromes wherein such ongoing problems may also lead to a general sense of ill health or psychological comorbidities.” In other words, persistent DES symptoms can be as debilitating as other chronic illnesses and lead to larger physical and emotional health problems.

There is no cure for DES, “but its irritations can most certainly be alleviated and its effects most certainly treated,” writes Dr. Robert Latkany, founder and director of the Dry Eye Clinic at the New York Eye and Ear Infirmary, in his new book, “The Dry Eye Remedy.”

Current treatments include eye drops, artificial tear solutions, anti-inflammatory agents, topical steroids, procedures to plug the tear ducts and surgery. Research into new treatments is on the horizon. According to Latkany, “at least a dozen new drugs are in development and testing, ready for release in the near future.”

You can obtain a free copy of “The Dry Eye Remedy” through the Society for Women’s Health Research Web site at womenshealthresearch. Click on the “The Dry Eye Remedy” icon for more information.

Society for Women’s Health Research (SWHR)
1025 Connecticut Ave. NW, Ste. 701
Washington, DC 20036
United States
womenshealthresearch

Two experimental treatments, a retinal prosthesis and fetal tissue transplant, restored some vision to people with blinding eye diseases. The findings, presented at Neuroscience 2009, the annual meeting of the Society for Neuroscience and the world’s largest source of emerging news on brain science and health, may lead to new treatments for the blind. Researchers also reported that an engineered protein restored vision in an animal model and identified ways to improve stem cell treatments.

The new studies tested both people and animals with two degenerative eye diseases: retinitis pigmentosa and age-related macular degeneration. These diseases destroy the light-sensitive nerve cells in the retina, leading to blindness. In all, vision loss and eye disease affect 3.6 million Americans and cost the United States $68 billion each year.

Research released today shows that:
A retinal prosthesis restores partial vision to people who are totally blind. The prosthesis, made of an array of electrodes, transmits visual information captured by a video camera (Jessy Dorn, PhD, abstract 216.6, see attached summary).

Transplanted “sheets” of fetal retinal cells improve visual acuity in several people with retinitis pigmentosa and age-related macular degeneration (Robert B. Aramant, PhD, abstract 837.12, see attached summary).

Engineered, light-sensitive proteins restore vision in a mouse study of retinitis pigmentosa. The findings could lead to new treatments for people with degenerative retinal diseases (Natalia Caporale, PhD, abstract 806.10, see attached summary).

As researchers strive to develop stem cell therapies for eye disease, a new method increases the yield of retinal cells from human stem cells derived from both embryonic and adult tissue (Jason S. Meyer, PhD, abstract 113.1, see attached summary).

“Basic neuroscience research has formed the basis for significant progress in treating eye disease,” said press conference moderator Rachel O. L. Wong, PhD, of the University of Washington, an expert on visual system development. “These studies would not be possible without technological advances and basic science research that continues to explain the normal function and development of the visual system,” Wong said.

Access the full release and study information here.

This research was supported by national funding agencies, such as the National Institutes of Health, and by private and philanthropic organizations.

Source:
Kat Snodgrass

Society for Neuroscience

Laser surgery to correct vision problems has been in use since the early 1990s. Photorefractive Keratotomy (PRK) is typically used to correct low to moderate myopia, while laser in-situ keratomileusis (LASIK) is preferred for high myopia corrections. Although over 18 million LASIK procedures have been performed worldwide, there is still some controversy regarding the maximum correction possible and efficacy with this technique. In an article published in the January 2008 issue of the American Journal of Ophthalmology, researchers from Miguel Hernandez University, Medical School, Alicante, Spain; and Ankara University School of Medicine, Ankara, Turkey; report on a study of high myopia patients ten years after LASIK surgery. The findings show that LASIK for myopia over -10 D is a safe and effective procedure in the long-term.

196 high myopic eyes of 118 patients, preoperatively needing at least 10 diopter (10 D) corrections to achieve 20/20 vision, were evaluated ten years following surgery. Uncorrected vision was 77% of best-corrected vision (BSCVA) before surgery. BSCVA improved 1 line. Only 5% of eyes lost more than 2 lines of BSCVA and 40% avoided the use of glasses. 119 (61 %) of eyes were within ?� 2.00 Diopters at 10 years. Only 2 eyes (1%) developed corneal ectasia. The retreatment rate was 27%.

According to lead investigator Jorge L. Ali??, “These results are extremely encouraging considering that this refractive correction implies the maximum limit of application of this technique. This study has allowed us to demonstrate that, in spite of the prejudices about the limits of LASIK technique, the results regarding predictability, efficacy and safety for high myopic patients are very good in the long term. The optimum limit of predictability for this technique is around 10 D of myopia. This reference study, with a long time perspective, allows us to know the safety, precision and limits of LASIK in highly myopic eyes.”

The article is “Ten-year Follow-up of Laser In Situ Keratomileusis for High Myopia” by Jorge l. Ali??, Orkun Muftuoglu, Dolores Ortiz, Juan Jose P?�rez-Santonja, Alberto Artola, Maria-Jose Ayala, Maria Jose Garcia, and Gracia Castro De Luna. It appears in the American Journal of Ophthalmology, Volume 145, Issue 1, (January 2008), and is published by Elsevier.

About The American Journal Of Ophthalmology

The American Journal of Ophthalmology is a peer-reviewed, scientific publication that welcomes the submission of original, previously unpublished manuscripts directed to ophthalmologists and visual science specialists describing clinical investigations, clinical observations and clinically relevant laboratory investigations. Published monthly since 1884, the full text of the American Journal of Ophthalmology and supplementary material are also presented on the Internet at AJO.

The American Journal of Ophthalmology publishes Original Articles, Brief Reports, Perspectives, Editorials, Abstracts, Correspondence, Book Reports and Announcements. Perspectives, Editorials and Abstracts (from other journals) are published by invitation.

About Elsevier

Elsevier is a world-leading publisher of scientific, technical and medical information products and services. Working in partnership with the global science and health communities, Elsevier’s 7,000 employees in over 70 offices worldwide publish more than 2,000 journals and 1,900 new books per year, in addition to offering a suite of innovative electronic products, such as ScienceDirect, MD Consult, Scopus, bibliographic databases, and online reference works.

Elsevier is a global business headquartered in Amsterdam, The Netherlands and has offices worldwide. Elsevier is part of Reed Elsevier Group plc , a world-leading publisher and information provider. Operating in the science and medical, legal, education and business-to-business sectors, Reed Elsevier provides high-quality and flexible information solutions to users, with increasing emphasis on the Internet as a means of delivery. Reed Elsevier’s ticker symbols are REN (Euronext Amsterdam), REL (London Stock Exchange), RUK and ENL (New York Stock Exchange).

Jason S. Meyer, Ph.D., assistant professor of biology in the School of Science at Indiana University-Purdue University Indianapolis, will be honored by the largest eye and vision research organization in the world for work which one day may lead to reversal of blindness caused by macular degeneration, retinitis pigmentosa and other diseases of the retina.

The Association for Research in Vision and Ophthalmology (ARVO) will present Meyer with a 2011 ARVO-AFER/Merck Innovative Ophthalmology Research Award at the organization’s annual meeting in Fort Lauderdale, Fla., on May 1.

Meyer is being recognized for a study he published in the Proceedings of the National Academy of Sciences (PNAS) in 2009. The paper, “Modeling Early Retinal Development with Human Embryonic and Induced Pluripotent Stem Cells” provides an important step toward the potential repair of damaged retinas by cells grown from a patient’s own skin.

“In the PNAS study, we were able to produce significant numbers of photoreceptor cells and other retinal cell types which are lost in many blinding disorders. Our work could serve as a foundation for unlocking the mechanisms that produce human retinal cells,” said Meyer, who co-directed the study when he previously worked at the University of Wisconsin.

A developmental biologist, he continues this promising line of research in his laboratory at the School of Science at IUPUI utilizing the recently (2007) developed and not yet common technology of induced pluripotent stem (iPS) cells.

“Since iPS cells can be derived from patients with a specific known disease, these cells could help us study neurological disorders like those of the retina, the auditory system and other parts of the body, in novel ways at both the cellular and subcellular levels, bringing us closer to therapeutic approaches,” said Meyer.

Now that he and colleagues have reprogrammed skin cells into stem cells that can become any cell type of the body, and then triggered the development of retinal cell types, Meyer believes that clinical trials and eventually treatment of retinal diseases with iPS cells is only a matter of time. Since they can be derived from the specific patient who needs them, use of iPS cells avoids the problem of transplant rejection.

Human iPS cells can be obtained from a single paper punch-hole size slice of easily accessible skin requiring only one or two stitches following the removal procedure.

Meyer will receive a $10,000 grant as the second prize recipient in the stem cell applications to eye disease category. The awards, open to researchers aged 45 years or younger who hold a doctoral degree, are presented biennially. This is only the second year in which an American has received the award.

Meyer joined the School of Science at IUPUI faculty in 2010, the second year consecutive year the School of Science recruited a record number of new faculty.

Source:
Cindy Fox Aisen
Indiana University-Purdue University Indianapolis School of Science

It’s hard to miss the huge eye of a squid. But now it appears that certain squids can detect light through an organ other than their eyes as well.

That’s what researchers at the University of Wisconsin-Madison report in the current issue (June 2) of the Proceedings of the National Academy of Sciences.

The study shows that the light-emitting organ some squids use to camouflage themselves to avoid being seen by predators – usually fish sitting on the ocean floor – also detects light.

The findings may lead to future studies that provide insight into the mechanisms of controlling and perceiving light.

“Evolution has a ‘toolkit’ and when it needs to do a particular job, such as see light, it uses the same toolkit again and again,” explains lead author Margaret McFall-Ngai, a professor of medical microbiology and immunology at the UW-Madison School of Medicine and Public Health (SMPH). “In this case, the light organ, which comes from different tissues than the eye during development, uses the same proteins as the eye to see light.”

In studying the squid for the past 20 years, McFall-Ngai and her colleagues have been drawn to the fact that the squid-light organ is a natural model of symbiosis – an interdependent relationship between two different species in which each benefits from the other.

In this case, the light organ is filled with luminous bacteria that emit light and provide the squid protection against predators. In turn, the squid provides housing and nourishment for the bacteria.

The UW-Madison researchers have been intrigued by the light organ’s “counterillumination” ability – this capacity to give off light to make squids as bright as the ocean surface above them, so that predators below can’t see them.

“Until now, scientists thought that illuminating tissues in the light organ functioned exclusively for the control of the intensity and direction of light output from the organ, with no role in light perception,” says McFall-Ngai. “Now we show that the E. scolopes squid has additional light-detecting tissue that is an integral component of the light organ.”

The researchers demonstrated that the squid light organ has the molecular machinery to respond to light cues. Molecular analysis showed that genes that produce key visual proteins are expressed in light-organ tissues, including genes similar to those that occur in the retina. They also showed that, as in the retina, these visual proteins respond to light, producing a physiological response.

“We found that the light organ in the squid is capable of sensing light as well as emitting and controlling the intensity of luminescence,” says co-author Nansi Jo Colley, SMPH professor of ophthalmology and visual sciences and of genetics.

Adds McFall-Ngai, “The tissues may perceive environmental light, providing the animal with a mechanism to compare this light with its own light emission.”

McFall-Ngai’s large research program into the relatively simple squid-light organ symbiosis aims to shed light on symbiosis affecting humans.

“We know that humans house trillions of bacteria associated with components of eight of their 10 organ systems,” she says. “These communities of bacteria are stable partners that make us healthy.”

Both Colley and McFall-Ngai are members of the UW-Madison Eye Research Institute.

Source:
Dian Land

University of Wisconsin-Madison

The American Academy of Ophthalmology (Academy) has collaborated with Cloud Nine Development, LLC, to enhance its free iPhone application, the Eye Handbook. The application, created for ophthalmologists by ophthalmologists, offers ophthalmic calculators, clinical videos, study tools and more. Through the partnership, the Eye Handbook now features select Academy Summary Benchmarks for Preferred Practice Pattern® Guidelines, patient education videos and a link to the Academy’s latest online clinical offering, the EyeWiki.

The Eye Handbook is currently the most comprehensive and popular mobile application for eye physicians and has been included amongst the top 100 free iPhone medical applications. With the addition of the Academy’s clinical and patient education content, the latest version of the Eye Handbook application will help to enhance physician education and improve the quality of patient care.

“The Eye Handbook application comes at an exciting time when mobile applications are increasingly popular and necessary,” said David W. Parke, II, MD, CEO of the Academy. “This partnership between the Academy and Cloud Nine Development, LLC allows ophthalmologists and physicians-in-training easy, mobile access to patient care information.”

“It’s an honor to work with an organization that shares our mission of educating eye care professionals,” said Rohit Krishna, MD, Cloud Nine Development, LLC. “The Academy-selected content will allow us to broaden our reach and impact the people who educate and serve our patients on a daily basis.”

Download the Eye Handbook for free on iTunes, and learn more by visiting: here.

Source:

American Academy of Ophthalmology

Indiana University School of Medicine research and a federal small business grant have set an Indianapolis startup company on a path to develop potential new treatments for age-related macular degeneration.

The National Institutes of Health has awarded a $225,000 Small Business Technology Transfer (STTR) grant to ApeX Therapeutics and its co-founder Mark R. Kelley, Ph.D., Betty and Earl Herr Professor in Pediatric Oncology Research and professor of biochemistry and molecular biology and of pharmacology and toxicology at the IU School of Medicine.

The age-related macular degeneration project represents a new direction for Dr. Kelley’s research, which has focused on the mechanisms cells use to repair damaged DNA and how those mechanisms can be manipulated when developing cancer treatments. In particular, Dr. Kelley’s work has examined a protein called APE1 and its activities in tumor development.

A new drug to treat age-related macular degeneration would be welcome – it is the leading cause of severe vision loss in people over age 60 and more than 7 million older Americans have or are at high risk to develop advanced macular degeneration.

The type of age-related macular degeneration that causes most of the vision loss is caused by abnormal blood vessel growth in the eye, which has led to treatments using drugs designed to block blood vessel growth in cancer – known as anti-angiogenesis drugs. No more than a third of patients get significant benefits from those drugs, however.

The pursuit of a treatment for macular degeneration came about because “we were studying the effects of an APE1 inhibitor in cancer and we saw that it had anti-angiogenesis effects,” said Dr. Kelley, who is associate director of the Herman B Wells Center for Pediatric Research and associate director of basic science research at the Indiana University Melvin and Bren Simon Cancer Center on the campus of Indiana University, Purdue University – Indianapolis.

Dr. Kelley has been working with Xiaoxi Qiao, M.D., Ph.D., associate professor of ophthalmology, and their experiments have reduced blood vessel growth in the laboratory. They also are able to apply the compound via eye drops rather than injections, Dr. Kelley said.

“The grant and research will provide a new dimension to the work of ApeX Therapeutics, which was founded to develop oncology related products,” said chief executive officer Martin F. Haslinger, Ph.D.

“We’re not changing the direction of the company, we’re adding on,” he said.

Haslinger said the company, which has offices and laboratory space in the IU Emerging Technology Center in Indianapolis, hopes to have a compound worthy of taking to clinical testing in about six months.

Kelley and Qiao’s research received support from the Indiana Clinical and Translational Sciences Institute, the IU Medical Group and ITRAC, a cancer center program to help researchers move their laboratory discoveries to the next steps toward development of new treatments for patient care.

“This STTR grant is a culmination of how the translational research process can work – laboratory research developments progress with CTSI assistance and are developed commercially by a local company built on school of medicine research,” said Dr. Kelley.

Source
Indiana University School of Medicine

Forget what you know about how diseases are diagnosed – new research published in the May 2010 print issue of The FASEB Journal details a noninvasive ground-breaking tool that detects signs of disease at early molecular stages before symptoms can be seen using traditional methods. Even better, this tool promises to detect some eye diseases so early that they may be reversed before any permanent damage can occur. Its use may well extend to other areas of the body in the future, and this tool may also give physicians a more precise way of evaluating the effectiveness of therapies.

“Quantitative knowledge of the dynamic molecular changes in health and disease will not only advance our understanding, but also change the way medicine will be practiced in the future,” said Ali Hafezi-Moghadam, M.D., Ph.D., co-author of the study from the Massachusetts Eye and Ear Infirmary, Department of Ophthalmology at Harvard Medical School in Boston.

To make this discovery, Hafezi-Moghadam and colleagues combined fluorescent microspheres with molecules found on the surface of immune cells. These molecules are up-regulated early in inflammation. The scientists took this compound and combined it once more with custom-designed imaging probes. Then they used both single- and double-combined probes targeting endothelial markers in the eyes of test animals because of the eye’s unique accessibility to light-based imaging. Results showed a strikingly superior sensitivity of the double-conjugated probes that allowed detection of molecules that may be expressed at very low levels, which occurs in many diseases. The imaging probes also detected activated immune cells, leading to unprecedented quantitative knowledge about immune response to disease.

“This tool is a total game-changer: it detects inflammatory eye disease at the molecular level before damage occurs,” said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal, “Once you have symptoms, it may be too late. By then, doctors are often limited to damage control. Now in the eye, and later in other areas of the body, early detection of molecular changes by fluorescent microspheres will save lives. It should certainly change people’s expectations of when treatment is indicated.”

Details:
Dawei Sun, Shintaro Nakao, Fang Xie, Souska Zandi, Alexander Schering, and Ali Hafezi-Moghadam. Superior sensitivity of novel molecular imaging probe: simultaneously targeting two types of endothelial injury markers. FASEB J. 2010 24: 1532-1540 ; doi: 10.1096/fj.09-148981.

Source:
Cody Mooneyhan
Federation of American Societies for Experimental Biology