Wide-field Volumetric Fluorescence Angiography for Sensitive Detection of RPE Permeability in AMD
Macular degeneration is a disease that damages the center of the eyesight and can cause blindness. The disease takes a long time to develop and gradually progresses to blinding conditions. The problem is that we don’t have the proper tools to predict when a patient’s eyesight will be damaged and when to treat the patient before the vision gets really bad. This project plans to address this problem by developing new techniques to detect disease progression.
Our retina sits on a single layer of cells called retinal pigment epithelium (RPE) that protects the retina. RPE is extremely important in several roles, such as digesting the debris from the photoreceptors, absorbing excessive light, and in particular, maintaining a blood-retina barrier from choroid. The compromised RPE barrier function is a critical step in development of age-related macular degeneration (AMD), and our goal is to image and measure the RPE permeability. We will develop novel three-dimensional imaging techniques to image the leakage through the RPE into retina, and use it to indicate AMD progression. We will use an animal model of AMD to test our technique and see whether the RPE permeability can be quantified by simply shining a light into the eye. This study is innovative in that it proposes a non-invasive imaging technique that can uniquely measure the barrier function of RPE, and can be translated into patient care. If successful, the imaging technique can be readily applied in clinics, and directly impact the diagnosis and treatment of AMD patients, to stall the disease progress and prevent blindness.
About the Researcher
Dr. Ji Yi is currently an assistant professor in the Boston University School of Medicine. His research is to develop novel optical imaging methods for biomedical applications, in particular, for early detection of chronic diseases such as age-related macular degeneration. He obtained his BS degree from Tsinghua University (Beijing, China), and trained in biomedical engineering at Northwestern University (Chicago, IL). After his PhD, he continued his postdoctoral training at Northwestern University before joining Boston University in 2015. He is an expert in the field of biomedical optics. He has pioneered and patented several novel imaging techniques, including visible light optical coherence tomography (vis-OCT), and oblique scanning laser ophthalmoscopy (oSLO). The major body of his work has resulted in more than 40 peer-reviewed publications in high-quality journals, five approved/pending U.S. patents, and numerous international oral conference presentations.
I have been in the field of biomedical optics for a number of years before I entered the ophthalmic imaging field. Because the retina is the only internal organ that can be directly accessed by light, I immediately fell in love with optical imaging the retina. Even today, I am still fascinated by the elegance, efficiency and complexity of the eye and the retina. I have previously worked with cortex imaging, and just as the blood vessel wall forms a blood-brain barrier in the cortex, the same type of barrier exists in the retina, called the blood-retina barrier. What is interesting about the retina is that the blood-retina barrier is maintained by a single layer of retina pigment epithelium (RPE) cells at the back side of the retina, while the choroidal vessels are actually fairly leaky. This seemingly straight design makes the integrity of the RPE barrier important, because the compromise of the barrier function can lead to the fluid buildup in the retina, causing vision damage in AMD. My unique optics background now provides a unique perspective into RPE barrier function, and I propose to design a novel imaging method to direct visualize the RPE leakage as an indicator of AMD progression. That is a very rewarding study that can potentially benefit patients directly. I greatly appreciate the support from BrightFocus Foundation, as now I am allowed to pursue this interesting and yet important study which hopefully will lead to the prediction of AMD progression and prevention of blindness.
First published on: November 14, 2018
Last modified on: March 5, 2020