Author Interviews, Macular Degeneration, Ophthalmology / 08.08.2019

MedicalResearch.com Interview with: Matthew Campbell, PhD Smurfit Institute of Genetics Trinity College Dublin Dublin MedicalResearch.com: What is the background for this study? What are the main findings? Response: Age related macular degeneration (AMD) is the most common form of central retinal blindness in the world. However the underlying causes and initiating factors for disease progression are still not clear. It is classically a disease of the outer retina, where cells called retinal pigment epithelial (RPE) cells degenerate. However, our findings suggest that some of the early initiating events that promote AMD progression are actually coming from the inner retina and more specifically the microvasculature of the inner retina. We discovered that a gene called claudin-5 appears to be regulated by a circadian rhythm that in turn can regulate what gets into and out of the retina on a daily basis. Dysregulating the levels of this component made the inner retinal blood vessels marginally leaky and promoted a pathology that was AMD-like in animal models.  We also showed that the blood vessels of the retina appear to be highly dynamic in human subjects and can appear leakier at different times of the day, likely a mechanism that allows for clearance and replenishment of material into and out of the retina.  It is this process we believe breaks down in early AMD.  (more…)
Author Interviews, Neurological Disorders, Ophthalmology, Pediatrics / 23.11.2016

MedicalResearch.com Interview with: Marius George Linguraru, DPhil, MA, MB Principal Investigator Associate Professor of Pediatrics and Radiology George Washington University School of Medicine and Health Sciences Children’s National Health System Washington, DC MedicalResearch.com: What is the background for this study? What are the main findings? Response: Neurofibromatosis type 1 (NF1) is the most common cancer predisposition syndrome affecting the central nervous with an incidence of one in 3,000 births. Nearly one in five children with NF1 develops an optic pathway glioma (OPG), a low-grade tumor of the anterior visual pathway (i.e., optic nerves, chiasm and tracts). These tumors are not amenable to surgical resection and can cause permanent vision loss ranging from a mild decline in visual acuity to complete blindness. Only half of children with NF1-OPGs will experience vision loss, typically between 1 to 6 years of age. The other half will never lose vision or require treatment. All previous studies have consistently demonstrated that the change in NF1-OPG size is not related to the clinical outcome. For example, the optic pathway glioma size may be stable or even decrease, yet the vision will decline. Alternatively, the OPG size may increase, yet the clinical outcome remains stable or even improves. As no imaging or clinical features can identify which children with NF1-OPGs will ultimately lose vision, clinicians struggle to follow these children and decide when to intervene. We used quantitative imaging technology to accurately assess in magnetic resonance imaging (MRI) the total volume of OPGs in NF1. We also determined the retinal nerve fiber layer thickness in these children, a measure of axonal degeneration and an established biomarker of visual impairment. The results were outstanding, as we showed for the first time that the volume of an optic pathway glioma is indeed correlated with the likelihood of vision loss in children with Neurofibromatosis type 1. (more…)