MedicalResearch.com Interview with:
Pradeep Ramulu MD MHS PhD
Associate Professor of Ophthalmology
Wilmer Eye Institute
Johns Hopkins University
MedicalResearch: What is the background for this...
MedicalResearch.com Interview with:
Julia E. Richards, Ph.D.
Harold F. Falls Professor of Ophthalmology and Visual Sciences
Professor of Epidemiology
Director, Glaucoma Research Center
The University of Michigan
Medical Research: What is the background for this study?
Response: We have a special interest in how the developmental processes of aging increase the risk of late onset diseases. We wondered whether drugs that target known aging pathways might be able to reduce risk of late onset disease. In the aging field, an emerging area of interest has been the category of drugs called caloric restriction mimetic (CRM) drugs, which have been found to extend life span and to reduce risk or delay onset of some late-onset diseases. These caloric restriction mimetic drugs target a set of pathways that have come to be seen as playing roles in longevity. One of these caloric restriction mimetic drugs, metformin, happens to also be one of the most common drugs used in the treatment of type 2 diabetes.
Glaucoma is a leading cause of blindness worldwide and classical open-angle glaucoma shows onset in late middle age or late age, so we hypothesized that a caloric restriction mimetic drug might be able to reduce the risk of open-angle glaucoma. We used data from a large health services database to compare the rate at which open-angle glaucoma developed in individuals with diabetes mellitus who used metformin versus those who did not use metformin. We predicted that metformin would be associated with reduced risk of open-angle glaucoma.
Medical Research: What are the main findings?
Response: We found that use of metformin was associated with reduced risk of open-angle glaucoma. A 2 gram per day dose of the CRM drug metformin for two years was associated with a 20.8% reduction in risk of developing open-angle glaucoma. When we looked at the highest quartile of drug prescribed (>1,100 grams over a two year period) we found a 25% reduction in risk relative to those taking no metformin. This risk reduction is seen even when we account for glycemic control in the form of glycated hemoglobin, and use of other diabetes drugs was not associated with reduced risk of open-angle glaucoma. A possible explanation for our findings might be that the mechanism of risk reduction is taking place by CRM drug mechanisms that target aging pathways rather than through glycemic control of diabetes.
In the long run, the approaches to late onset diseases in general will become much more powerful if we can use parallel approaches that simultaneously target both the aging processes going on and the disease-specific pathways going on. In the literature we see caloric restriction mimetic drugs metformin, rapamycin and resveratrol all being explored for their ability to target points in aging pathways in ways that can impact the risk of a variety of late-onset diseases, so it will be important for those interested in the risk factors affecting late onset diseases to pay attention to how caloric restriction mimetic drugs might be altering risk for those late onset diseases. (more…)
MedicalResearch.com Interview with:
Andrew Bastawrous, MRCOphth
International Centre for Eye Health, Clinical Research Department
London School of Hygiene and Tropical Medicine (LSHTM), London, England
Medical Research: What is the background for this study? What are the main findings?
Dr. Bastawrous: As part of my PhD with the International Centre for Eye Health at the London School of Hygiene & Tropical Medicine, I led the follow-up of a major cohort study of eye disease [http://www.biomedcentral.com/1471-2415/14/60] following up 5,000 people in 100 different locations across the Great Rift Valley in Kenya. It was really challenging, two-thirds of the locations had no road access or electricity and we were carrying over £100,000 worth of fragile eye equipment and a team of 15 people in two vans to be able to carry out high quality measures of eye disease and answer some important questions for planning eye services.
What we found was that in the most difficult to reach locations we would find lots of people waiting to see us who had been unnecessarily blind from preventable/treatable diseases. Despite the locations having no roads, electricity and often no water, nearly all the locations had good phone signal.
Together with a brilliant team of developers, engineers and ophthalmologists we developed a suite of smartphone based tests to see if we could replace some of the standard equipment being used, in the hope that we could make it more portable and easier for non-specialists to perform so that ultimately the most high-risk individuals could be reached and treated.
This paper describes one of those tests, the visual acuity test - Peek Acuity.
Our field workers tested patients in their own homes using a standard card based Snellen chart (the type of vision test most non-ophthalmic healthcare workers are familiar with and has been the most commonly used acuity test for several decades now) and Peek Acuity. The same tests were repeated by the same healthcare worker in the clinic the following day as well as a reference standard vision test (LogMAR ETDRS) performed by an eye trained clinical officer.
This allowed us to perform "test re-test", a measure of a tests repeatability. i.e. if you have the same test at two separate time points we would expect the the measures to be very close. We found that for both Peek Acuity and Snellen they were highly repeatable. An advantage of Snellen is the speed of the test, Peek Acuity came out slightly quicker overall. We also found when compared to the reference standard test, Peek Acuity was highly comparable and within a clinically acceptable limit of difference.
(more…)
MedicalResearch.com Interview with:
Akrit Sodhi, M.D., Ph.D.
Assistant Professor of Ophthalmology
Retina Division
Wilmer Eye Institute
Johns Hopkins Medical Institutions
Medical Research: What is the background for this study? What are the main findings?Dr. Sodhi: Diabetic eye disease is the most common cause of severe vision loss in the working age population in the developed world, and proliferative diabetic retinopathy (PDR) is its most vision-threatening sequela. In proliferative diabetic retinopathy, retinal ischemia leads to the upregulation of angiogenic factors that promote neovascularization. Therapies targeting vascular endothelial growth factor (VEGF) delay the development of neovascularization, in some, but not all diabetic patients, implicating additional factor(s) in proliferative diabetic retinopathy pathogenesis. In our study, we demonstrate that the angiogenic potential of aqueous fluid from PDR patients is independent of VEGF concentration, providing an opportunity to evaluate the contribution of other angiogenic factor(s) to PDR development. We identified angiopoietin-like 4 (ANGPTL4) as a potent angiogenic factor whose expression is upregulated in hypoxic retinal Müller cells in vitro and the ischemic retina in vivo. Expression of ANGPTL4 was increased in the aqueous and vitreous of PDR patients, independent of VEGF levels, correlated with the presence of diabetic eye disease, and localized to areas of retinal neovascularization. Inhibition of ANGPTL4 expression reduced the angiogenic potential of hypoxic Müller cells; this effect was additive with inhibition of VEGF expression. An ANGPTL4 neutralizing antibody inhibited the angiogenic effect of aqueous fluid from proliferative diabetic retinopathy patients, including samples from patients with low VEGF levels or receiving anti-VEGF therapy. Collectively, our results suggest that targeting both ANGPTL4 and VEGF may be necessary for effective treatment or prevention of proliferative diabetic retinopathy and provide the foundation for studies evaluating aqueous ANGPTL4 as a biomarker to help guide individualized therapy for diabetic eye disease.
(more…)
MedicalResearch.com Interview with:
Professor James Bainbridge, MA, PhD, FRCOphth
Professor of Retinal Studies, UCL Institute of Ophthalmology
NIHR Research Professor, NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of OphthalmologyConsultant Ophthalmologist, Moorfields Eye Hospital NHS Foundation Trust
Medical Research: What is the background for this study? What are the main findings?Prof. Bainbridge : Leber Congenital Amaurosis (LCA) is one of the most common causes of inherited, untreatable blindness in children. There are at least 14 different types of Leber Congenital Amaurosis of which LCA Type 2 (LCA2), caused by defects in the gene RPE65, affects around one in 100,000 people worldwide. Evidence from animal studies support that LCA2 may be amenable to treatment with RPE65 gene replacement therapy.
The main findings of this phase I/II clinical trial confirm our preliminary findings (published in NEJM, 2008) that gene therapy can improve night vision. Improvements peak within the first 12 months after treatment but then decline during the three-year follow-up period which is consistent with the published results and interim findings from other studies of RPE65 gene therapy.
(more…)
MedicalResearch.com Interview with:
Dr. Raj Kapoor
National Hospital for Neurology and Neurosurgery
University College London Hospitals NHS Foundation Trust
Medical Research: What is the...
MedicalResearch.com Interview with:
Dan Gong BA
Yale University School of Medicine
------------
James C. Tsai, M.D., M.B.A.
President - New York Eye and Ear Infirmary of Mount Sinai
Delafield-Rodgers Professor and Chair Department of Ophthalmology Icahn School of Medicine at Mount Sinai
Medical Research: What is the background for this study? What are the main findings?
Congress first introduced the Medicare Physician Fee Schedule built on the resource-based relative value scale (RBRVS) in the Omnibus Budget Reconciliation Act of 1989. Until recently, Medicare payments to physicians were adjusted annually based on the sustainable growth rate (SGR) formula.
When adjusting physician payments, one controversial belief by policymakers was the assumption that in response to fee reductions, physicians would recuperate one-half of lost revenue by increasing the volume and complexity of services.
This study questioned this assumption that this inverse relationship between Medicare payment and procedural volume is uniform across all procedures. In particular, glaucoma procedures have not been studied in the past.
Using a fixed effects regression model, we found that for six commonly performed glaucoma procedures, four did not have any significant Medicare payment and procedural volume relationship (laser trabeculoplasty, trabeculectomy with and without previous surgery, aqueous shunt to reservoir). Two procedures, laser iridotomy and scleral reinforcement with graft, did have significant and inverse associations between Medicare payment and procedural volume. (more…)
MedicalResearch.com Interview with:
Catherine L. Chen M.D., M.P.H.
UCSF Dept of Anesthesia
Medical Research: What is the background for this study? What are the main findings?
Dr. Chen: Cataract surgery is a very common and safe surgery that most older adults have in their 70's or 80's. It usually happens as a same-day surgery and most patients only need eye drops to numb the eye with little or no intravenous sedation for a procedure that on average is only 18 minutes long. Given their age, these patients typically have other concurrent medical problems, so even though multiple research studies and professional societies have concluded that routine preoperative testing is not necessary before cataract surgery, we found that this testing still frequently occurs in these patients. More than half of the patients in our study had at least one preoperative test performed in the month before their surgery.
We hypothesized prior to undertaking this study that the older and sicker patients were the ones who were most likely to get preoperative testing. Instead, what we found was that the most important factor that determined whether or not a patient got tested was the ophthalmologist who operated on the patient. This is an important finding because it shows that most patients are not getting extra testing, but the few that do are getting testing because that's the way their ophthalmologist typically prepares his patients for surgery. Most of the time, this testing is not needed and will not affect how well the patient does during and after surgery. (more…)
MedicalResearch.com Interview with:
Carolina P B Gracitelli, M.D.
Ophthalmology - PhD Candidate/ Research Fellow
University of California San Diego - Hamilton Glaucoma Center
Medical Research: What is the background for this study? What are the main findings?
Dr. Gracitelli: Of all the diseases that can lead to blindness, glaucoma is one of the most important diseases; it affects more than 70 million people worldwide, of whom approximately 10 % are bilaterally blind. Different studies have reported that the damage caused by glaucomatous disease lead to retinal ganglion cell (RGC) loss and consequently loss of intrinsically photosensitive retinal ganglion cells (ipRGCs), which is a subtype of retinal ganglion cell. This subpopulation of RGC is clearly related with non-image-forming visual function such as photic synchronization of circadian rhythms and the pupillary light reflex. However, the true impact of glaucoma on sleep quality, sleep disturbance or circadian rhythm was until nowadays controversial.
The main clinical finding of our study was that glaucoma leads to retinal ganglion cell death, including ipRGC death. These cells are connected to several non-image-forming functions, including circadian photoentrainment and pupillary reflexes. Therefore, the image-forming and non-image-forming visual systems are associated with glaucoma. Circadian function has not been well investigated in clinical daily practice, but it can interfere with the quality of life of these patients. Concerns about sleep disturbances in glaucoma patients should be incorporated into clinical evaluations.
(more…)
Alison Ng PhD, BSc(Hons), MCOptom
Post-Doctoral Fellow
Centre for Contact Lens Research
School of Optometry & Vision Science
University of Waterloo
Waterloo, Ontario Canada
Medical Research: What is the background for this study? What are the main findings?
Dr. Ng: Eye care practitioners often see patients coming into our clinics with eyeliner “floating” in the tears or adhered to the surface of contact lenses during our routine examinations. When products such as eyeliner enters and contaminates the tear film, some patients complain of temporary discomfort, and if they wear contact lenses, they may report blurred vision if the lenses become spoiled. Specifically in this pilot study, we wanted to look at how differently eyeliner migrated into the tear film when applied in two different ways: inside the lash line and outside of the lash line.
(more…)
MedicalResearch.com Interview with:
Eric Crouch, MD, FAAO, FAAP, FACS
Vice Chair, PEDIGAssociate Professor
Department of Ophthalmology
Eastern Virginia Medical School Assistant Professor
Department of Pediatrics Eastern Virginia Medical School
Chief of Ophthalmology, Children's Hospital of the King's Daughters Norfolk, Virginia
MedicalResearch: What is the background for this study? Dr. Crouch: In this letter PEDIG is reporting on the improvement in vision during the run-in phase of a study in children 3 years of age to less than 8 years old. During the run-in phase, the children were followed at 6 weeks intervals and served as the baseline for entering into a randomized trial for increasing the amount of patching. The patients were randomized to either 2 hours of prescribed patching or 6 hours of prescribed patching once they completed the run-in phase.
MedicalResearch: What are the main findings?Dr. Crouch: For amblyopic children, even those who have moderate or severe amblyopia in the 20/100 - 20/400 range, clinicians can start treatment with patching two hours a day.
(more…)
MedicalResearch.com Interview with:
Rohit Varma, MD, MPH
Professor and Chair, Department of OphthalmologyUSC Eye Institute, Keck School of Medicine
University of Southern California, Los Angeles, California
Medical Research: What is the background for this study? What are the main findings?
Dr. Varma: The Centers for Disease Control and Prevention estimates that 4.4% of adults with diabetes aged 40 and older have advanced diabetic retinopathy that may result in severe vision loss. Clinical trials have shown that intravitreal injections of anti-VEGFs, such as ranibizumab, can reduce visual impairment and even in some cases improve visual acuity outcomes in patients with diabetic macular edema. We developed a model, based on data from the RIDE and RISE clinical trials, to estimate the impact of ranibizumab treatment on the number of cases of vision loss and blindness avoided in non-Hispanic white and Hispanic persons with diabetic macular edema in the United States.Results from the model suggest that, compared with no treatment, every-4-week ranibizumab 0.3 mg reduces legal blindness between 58%-88% and reduces vision impairment between 36%-53% over 2 years in this population. (more…)
MedicalResearch.com Interview with:
Adam Glassman, M.S.
Director, DRCRnet Coordinating Center
Jaeb Center for Health Research
Tampa, FL 33647
Medical Research: What is the background for...
MedicalResearch.com Interview with:
Ren-Long JanDepartment of Pediatrics, Chi Mei Medical Center, Liouying, Tainan, Taiwan Graduate Institute of Clinical Medicine, National Cheng Kung University, Tainan, Taiwan.
Medical Research: What is the background for this study? What are the main findings?
Response: The pathologenic factors underlying retinal artery occlusion (RAO) are also associated with acute coronary syndrome (ACS). Previous studies showed the relation but was limited by sample sizes. We used Taiwan Longitudinal Health Insurance Database and found the increased risk of ACS following Retinal artery occlusion. (more…)
MedicalResearch.com Interview with:
Simone L. Li, PhD
Retina Foundation of the Southwest
Dallas, Texas
Medical Research: What is the background for this study? What are the main findings?
Dr. Li: In a previous study, we found that binocular iPad game play significantly improved visual acuity in the amblyopic eye. The purpose of the current study was to determine the longevity of these effects and we found that the visual acuity improvements obtained with binocular iPad game play had been retained for at least 12 months after the treatment ended.
(more…)
MedicalResearch.com Interview with:
Pravin U. Dugel MD
Managing Partner, Retinal Consultants of Arizona Phoenix AZ
Clinical Professor USC Eye Institute
Keck School of Medicine ...
MedicalResearch.com Interview with:
Prof. David Mackey
Centre for Ophthalmology and Vision Science/Lions Eye Institute Perth
Managing Director/Chair of University of Western Australia,
Perth, Australia
Centre for Eye Research Australia, Melbourne University
MedicalResearch: What is the background for this study? What are the main findings?Prof. Mackey: Too much or too little sun? Excessive sun exposure is associated with the eye disease pterygium, while lack of outdoor activity in childhood increases the risk of myopia (short sightedness).
Measuring the amount of early sun damage to a person’s eyes would be of great use to researchers and potential use in clinical practice.
Over the last few years we have developed a biomarker for sun exposure to the eye by photographing Conjunctival UV Auto-Fluorescence (CUVAF).
The study published in JAMA Ophthalmology looked at the genetic and environmental factors that contribute to CUVAF levels in three Australian studies from Tasmania, Perth and Brisbane.
People who live in sunnier environments closer to the equator have more evidence of sun damage using CUVAF. However, genetic factors also play a role.
(more…)
MedicalResearch.com Interview with:
Zheng He and Bang V. Bui
Department of Optometry & Vision Sciences
University of Melbourne, Parkville, Australia
Medical Research: What is the background for this study? What are the main findings?
Response: Glaucoma, the second leading cause of blindness in the world, is a condition that occurs when too much pressure builds up inside the eye. This excess pressure injures the optic nerve (the wire that transmits visual information to the brain) resulting in vision loss. Many risk factors for glaucoma are not well understood.
High blood pressure (> 140/90 mmHg) is probably the most common comorbidity in patients presenting to optometry clinics. The overall prevalence of hypertension worldwide is over 26%, and increases dramatically with advancing age. Long-term hypertension leads to remodeling of the heart and blood vessels, promoting the risk of multiple end organ damage.
Whilst chronic hypertension is a well-documented risk factor for stroke, the link between hypertension and glaucoma remains unclear. Previously, it was thought that high blood pressure could counteract high intraocular pressure, which is a clear risk factor for glaucoma. However, this issue may be more complicated than first thought.
The Baltimore Eye Survey compared the prevalence of glaucoma in young and older patients with hypertension. They found that young patients with high blood pressure were at lower risk of glaucoma compared to the entire cohort. This outcome is consistent with the idea that higher blood pressure provides better perfusion pressure to the eye. Paradoxically systemic hypertension in older subjects actually increased the risk of glaucoma. Its seems that longer durations of systemic hypertension impact glaucoma risk negatively. One explanation for this is that any benefit from high blood pressure counteracting high eye pressure is lost as damage to blood vessels — a consequence of hypertension — becomes more dominant.
This hypothesis was tested by comparing the effect of acute (one hour) and chronic (four weeks) hypertension in lab rats with elevated eye pressure. When blood pressure was raised for four weeks, there was less functional protection against eye pressure elevation compared with the one-hour case. This shows that having high blood pressure for a longer time compromises the eye's capacity to cope with high eye pressure. This impairment was associated with thicker and narrower blood vessels and a reduced capacity for the eye to maintain blood flow at normal levels in response to eye pressure elevation (this process is known as autoregulation). Thus in chronic hypertension, smaller reduction in ocular perfusion pressure can result in blood flow deficiency.
(more…)
MedicalResearch.com Interview with:
Shi Lili
Department of Medical informatics and Nantong University Library
Nantong University, Nantong, China
Medical Research: What is the background for this study? What are the main findings?
Response: Diabetic retinopathy (DR) is the most frequently occurring complication of diabetes and one of the major causes of acquired blindness in the working-age population around the world. DR can be detected using various methods. Telemedicine based on digital photographs of the fundus is being used with increasing frequency to detect DR, and especially for Diabetic retinopathy screening. The purpose of our study was to assess the diagnostic accuracy of telemedicine in the full range of DR and DME severity compared with the current gold standard.
We found that the diagnostic accuracy of telemedicine using digital imaging in DR was overall high. It can be used widely for Diabetic retinopathy screening.
(more…)
MedicalResearch.com Interview with:
Rui Azevedo Guerreiro
Centro Hospitalar de Lisboa Central
PortugalMedical Research: What is the background for this study? What are the main findings?
Response: This article aims to summarise the current state of understanding on the possible ophthalmic complications that can occur after a bariatric surgery. The main finding of this review article is that ophthalmic complications after bariatric surgeries are more frequent that we could thought initially, especially in patients not adherent to their vitamin supplements. In one study, the percentage of patients with vitamin A deficiency 4 years after the surgery reached up to 69%.
(more…)
MedicalResearch.com Interview with: Lilach Bareket
School of Electrical Engineering, ‡Tel Aviv University Center for Nanoscience and Nanotechnology, and ⊥School of Chemistry,
Tel Aviv University, Tel Aviv 69978, Israel
Medical Research: What is the background for this study?Response: Neuro-prosthetic devices aim to restore impaired function through
artificial stimulation of the nervous system. Visual prosthetic
devices, operating by light activation of neurons, are presently
developed as an approach to treat blindness. In particular, in the
case of patients suffering from age-related macular degeneration in
which the photoreceptors in the retina degenerate.
(more…)
MedicalResearch.com Interview with:
B. John Mancini, MD, FRCPC, FACP, FACC
Professor of Medicine; University of British Columbia;
Department of Medicine, Division of Cardiology;
Research Director, Division of Cardiology;
Director, Cardiovascular Imaging Research Core Laboratory (CIRCL);
President, Vancouver Hospital Medical, Dental and Allied Staff;
Staff Cardiologist, VH Cardiology Clinics and Cardiac Computed Tomographic Angiography Program; Staff Cardiologist, St. Paul's Hospital Healthy Heart/Prevention Clinic.
MedicalResearch: What are the main findings of this study?Dr. Mancini: The main findings are that we found evidence of a relationship between statin use and the need for cataract surgery. The unique nature of the study is that it looked for the association in two distinctly different populations (a Canadian database and a separate, American database) and found a consistent association in both populations.
(more…)
MedicalResearch.com Interview with:
Dr. Andrea Russo
Medico Chirurgo - Specialista in Oculistica
Università degli Studi di Brescia Brescia Italy
Medical Research: What is the background for this study? What are the main findings?Dr. Russo: When I finished my residency program in Ophthalmology two years ago I realized that many patients were referred to me to assess and classify diabetic and hypertensive retinopathy. Therefore, I started wondering if there was an ophthalmoscopy method to make General Practitioners and Internist Physicians independent for these screening retinal assessments. I thought that we all own a personal computer connected with a (high quality) camera in our pocket and therefore smartphone ophthalmoscopy was feasible. Both the indirect and direct ophthalmoscopy techniques were suitable, however the latter was much easier to obtain. Furthermore, direct ophthalmoscopy can exploit smartphones’ autofocus and flash LED light making the required optics very simple and inexpensive. I purchased my 3D printer and started realizing very first working prototypes. A few months were required to improve the light path to eliminate internal and corneal reflections. Finally, I patented the optical solution and joined my partner Si14 S.p.A. (Padova, Italy) for the industrialization process.
The main findings are that that smartphone ophthalmoscopy with the D-Eye system can accurately detect retinal lesions for grading diabetic retinopathy. Furthermore, we noticed an amazing convenience in the assessment of babies, since they seem to be spontaneously attracted by the non-disturbing light emitted by the device, making the fundus acquisition straightforward. The advantages of smartphone-based retinal image acquisition for remote, non-hospital settings include portability and immediate upload/analysis. Indeed, telemedicine has the potential to reach patients and communities that currently receive negligible or suboptimal eye care as a result of geographic or sociocultural barriers, or both.
(more…)
MedicalResearch.com Interview with:Daniel L. Rubin, MD, MS
Assistant Professor of Radiology and Medicine (Biomedical Informatics)
Department of Radiology | Stanford University
Stanford, CA 94305-5488
Medical Research: What is the background for this study? What are the main findings?Dr. Rubin: Age-Related Macular Degeneration is the leading cause of blindness and central vision loss among adults older than 65. An estimated 10-15 million people in the United States suffer from the disease, in which the macula — the area of the retina responsible for vision — shows signs of degeneration. While about one of every five people with AMD develop the so-called “wet” form of the disease that can cause devastating blindness. In wet AMD, abnormal blood vessels accumulate underneath the macula and leak blood and fluid. When that happens, irreversible damage to the macula can quickly ensue if not treated quickly. Until now, there has been no effective way to tell which individuals with AMD are likely to convert to the wet stage. Current treatments are costly and invasive — they typically involve injections of medicines directly into the eyeball — making the notion of treating people with early or intermediate stages of Age-Related Macular Degeneration a non-starter. In our study, we report on a computerized method that analyzes images of the retina obtained with a test called spectral domain optical coherence tomography (SD-OCT), and our method can predict, with high accuracy, whether a patient with mild or intermediate Age-Related Macular Degeneration will progress to the wet stage. Our method generates a risk score, a value that predicts a patient’s likelihood of progressing to the wet stage within one year, three years or five years. The likelihood of progression within one year is most relevant, because it can be used to guide a recommendation as to how soon to schedule the patient’s next office visit. In our study, we analyzed data from 2,146 scans of 330 eyes in 244 patients seen at Stanford Health Care over a five-year period. Patients were followed for as long as four years, and predictions of the model were compared with actual instances of conversion to wet AMD. The model accurately predicted every occurrence of conversion to the wet stage of AMD within a year. In approximately 40% of the cases when the model predicted conversion to wet AMD within a year, the prediction was not borne out, however. We are currently refining the model to reduce the frequency of these false positives.
(more…)
MedicalResearch.com Interview with:Theodore Leng, MD, MS , one of the article’s senior authors
Byers Eye Institute at Stanford
Stanford University School of Medicine
Palo Alto, CA 94303
Dr. Leng: What is the background for this study? What are the main findings?Medical Research: Age-related macular degeneration (AMD) is the leading cause of blindness and central vision loss among adults older than 65 years. 80-85% of patients have the dry, non-exudative, form of the disease, but the wet, exudative, form of advanced AMD is of primary concern as it accounts for a majority of severe vision loss in Age-related macular degeneration. In wet AMD, abnormal blood vessels grow under the retina and can leak blood and fluid.
Until now, there has been no effective way to tell which patients with dry AMD are likely to progress to the wet stage. In our recent Investigative Ophthalmology & Visual Science article, we describe a new mathematical model that can predict which patients are likely to progress.
The predictive model identifies likely progressors by analyzing 3D spectral domain optical coherence tomography (SD-OCT) retinal imaging data that’s routinely obtained during retinal encounters.
We analyzed data from 2,146 SD-OCT scans of 330 eyes in 244 patients seen at The Byers Eye Institute at Stanford over a five-year period. We found that the area and height of drusen, the amount of reflectivity at the macular surface and the degree of change in these features over time, could be weighted to generate a patient’s risk score. Predictions from the model were compared with cases where patients actually progressed to wet Age-related macular degeneration. Our model accurately predicted every occurrence of progression within a year. There was a false positive rate of around 40%, but we thought this was a good tradeoff because we would not miss any potential progressors by using this sensitivity threshold.
(more…)
MedicalResearch.com Interview with: Takashi Ueta, M.D., Ph.D.
Assistant Professor, Department of Ophthalmology
Graduate School and Faculty of Medicine
The University of Tokyo
Medical Research: What is the background for this study? What are the main findings?Dr. Ueta: In 2009 we had reported an initial systematic review and meta-analysis which include pivotal RCTs but the number of the included studies were only 3 (MARINA, ANCHOR, FOCUS). During the following several years, more trials comparing different dosages and frequencies of ranibizumab treatment were conducted, which made us to update our meta-analysis.
Based on our updated meta-analysis, increase in several systemic vascular adverse events was observed: 86% increase in odds ratio (OR) for the risk of cerebrovascular accident (CVA) when 0,5 mg ranibizumab used. 89% increase in OR for the risk of CVA when monthly ranibizumab of any dosage is used. 57% increase in OR for the risk of non-ocular hemorrhage when ranibizumab of any dosage with any frequency is used.(more…)
MedicalResearch.com Interview with:Ronald Klein, MD, MPH, Professor
Department of Ophthalmology and Visual Sciences
University of Wisconsin School of Medicine and Public Health
Madison WI
Medical Research: What are the main findings of the study? Dr. Klein: We found that more severe age-related macular degeneration (AMD) in 1 eye was associated with increased incidence of age-related macular degeneration [levels 1-2: hazard ratio [HR], 4.90 [95%CI, 4.26-5.63] and accelerated progression [levels 2-3: HR, 2.09 [95%CI, 1.42-3.06]; levels 3-4: HR, 2.38 [95%CI, 1.74-3.25] and incidence of late age-related macular degeneration [levels 4-5: HR, 2.46 [95%CI, 1.65-3.66] in its fellow eye. Less severe AMD in 1 eye was associated with less progression of AMD in its fellow eye. We estimated that 51% of participants who develop any age-related macular degeneration maintained age-related macular degeneration severity states within 1 step of each other between eyes and 90% of participants stay within 2 steps.
(more…)
MedicalResearch.com Interview with: Prof I. Jolanda M. de Vries
Professor, Dept of Tumor Immunology
Radboud University Nijmegen
Medical Research: What are the main findings of the study?Prof. de Vries:Dendritic cells are antigen-presenting cells with the unique capacity to activate naive antigen-specific T cells, and by this means are very suitable to induce immunologic antitumor responses. Dendritic cells cultured from monocytes can be matured and loaded with tumor antigen ex vivo and administered back into the patient. Within the lymph node, dendritic cells present antigens to T cells to initiate an immune response.
Metastatic uveal melanoma patients were vaccinated with autologous DCs loaded with tumor antigens (gp100 and tyrosinase), obtained by leukapheresis, according to a schedule of 3 biweekly vaccinations. One to 2 weeks after the last vaccination, a skin test was performed to analyse the induction of immunologic responses.
We can conclude that dendritic cell vaccination is feasible and safe in metastatic uveal melanoma. Dendritic cell-based immunotherapy is potent to enhance the host’s antitumor immunity against uveal melanoma in approximately one third of patients.
(more…)
MedicalResearch.com Interview with: Jinjin Zheng Selin, MSc
Unit of Nutritional Epidemiology
Institute of Environmental Medicine
Karolinska Institutet Stockholm Sweden
Medical Research: What are the main findings of the study?Response: Our results suggest that higher levels of total physical activity, especially in the long-term, as well as specific types of physical activity including walking/bicycling and work/occupational activity, may be associated with decreased risk of age-related cataract among middle-aged and elderly women and men. On the other side, high levels of leisure time inactivity may be associated with increased risk of cataract.
(more…)
MedicalResearch.com Interview with: Dr. Michael Kalloniatis
School of Optometry and Vision Science, UNSW Australia, Sydney, New South Wales, Australia; Centre for Eye Health, Sydney, New South Wales, Australia;
Medical Research: What are the main findings of the study? What was most surprising about the results?Dr. Kalloniatis: Normal mice given a single sildenafil treatment had a transient loss of visual function which recovered in two days. Carrier mice (mice which carry a single copy of a mutation that commonly causes recessive Retintis Pigmentosa) showed a supernormal visual response (a response much larger than the norm) to sildenafil which took two weeks to recover to normal. Carrier mice also showed an increase in an early marker for apoptosis (a protein which suggest cells may be preparing to die) suggesting sildenafil may cause retinal degeneration in these mice.
(more…)
This website uses cookies to improve your experience. We'll assume you're ok with this, but you can opt-out if you wish.AcceptRejectRead More
Privacy & Cookies Policy
Privacy Overview
This website uses cookies to improve your experience while you navigate through the website. Out of these cookies, the cookies that are categorized as necessary are stored on your browser as they are as essential for the working of basic functionalit...
Necessary cookies are absolutely essential for the website to function properly. This category only includes cookies that ensures basic functionalities and security features of the website. These cookies do not store any personal information.