High-Resolution Imaging of Superficial Retinal Vascular Changes in Experimental Glaucoma
Glaucoma is the leading cause of irreversible blindness worldwide (estimated to affect over 60 million people) and is generally considered to be caused by the damage of retinal ganglion cell (RGC) axons and the death of RGCs. Previous studies support the idea that the loss of radial peripapillary capillaries may play an important role in axonal degeneration in glaucoma. This project will use high-resolution in vivo imaging to better clarify changes in the radial peripapillary capillaries and optic nerve head in relation to neuronal damage in living eyes with experimental glaucoma. The results of the proposed work may aid in earlier diagnosis and management of this disease by providing an earlier structural marker for detecting glaucomatous damage compared with current clinical measures.
The overall goal of our lab’s research is to learn more about the causes of different types of eye diseases. The work supported by this BrightFocus grant focuses on the group of blinding diseases called glaucoma. Glaucoma is a leading cause of blindness in the world and likely affects more than 60 million people. Eye doctors and scientists know that glaucoma (1) causes certain cells in the light sensitive retina of the eye (called ganglion cells) to die; and (2) damages the fibers that leave the eye and carry signals from these ganglion cells through the optic nerve to the brain. However, doctors and scientists are less certain about how these fibers and cells are damaged when glaucoma first starts. Previous research studies have suggested that the loss of a particular type of blood vessel in the retina, called radial peripapillary capillaries, may play an important role in damaging fibers in glaucoma. Therefore, our study will explore whether changes in these capillaries occur before other changes in the eye that are known to happen at the earliest stages of glaucoma.
Because glaucoma is a disease that can take a long time to develop in patients, we choose to look at changes in the eyes of animals with glaucoma, where the disease occurs much faster, but still causes the same types of vision loss that we see in human patients. We will take high magnification pictures of the retina and optic nerve in these animals before and after they develop glaucoma to better understand how the eye changes in glaucoma. In particular, we will use a special imaging technique, called adaptive optics imaging, to overcome the eye’s optical imperfections (that exist even when wearing glasses or contact lenses) in order to take pictures with the detail needed to see these small, fine capillaries in the living eye. We will investigate whether any changes we see in our pictures of these retinal capillaries are related to other retinal and optic nerve changes that have been shown scientifically and/or clinically to happen early in glaucoma.
We believe our study will help us learn more about how glaucoma happens and develop ways to detect the disease faster and earlier than doctors are able to do right now. Should the results of this work be applied successfully to human patients (through future studies), they could potentially allow doctors to make earlier decisions about treatment and save the vision of human patients with glaucoma.
About the Researcher
While I have been conducting research in glaucoma for the past 14 years, my career as a vision scientist actually began by studying the front of the eye. I completed my graduate work in optics at the University of Rochester's Institute of Optics under the advisement of Dr. David Williams. My graduate research focused on better understanding the optical quality of normal eyes and the changes in vision and optical quality that occurred in the eye following conventional and customized LASIK (laser in-situ keratomileusis) procedures. As a graduate student, I also had the opportunity to work on other lab-related projects, such as contributing to the design of an adaptive optics ophthalmoscope, an instrument that is capable of imaging individual cells in living human eyes. It was during this time that I developed my interests in high-resolution imaging of the eye. As a postdoctoral fellow with Dr. Williams, I began to study glaucoma and gained further experience in optical instrumentation and the design and use of adaptive optics ophthalmoscopes for high-resolution imaging in living eyes. I was fortunate to lead and contribute to projects that visualized ganglion cells, dendrites and axons in living animal eyes. Now, as an associate professor, my laboratory seeks to improve our ability to detect, track and examine the development and progression of glaucoma using highly sensitive optical imaging tools in animal models and human patients. Through our previous NIH grant, I collaborated with Dr. Laura Frishman (an expert in retinal function), Drs. Ronald Harweth and Nimesh Patel (experts in structure/function relationships in glaucoma), and Dr. Danica Marelli (an optometric glaucoma specialist) to better understand the relationship between changes in lamina cribrosa and optic nerve head structure, axonal damage and vision loss in normal, older human eyes and in animal and human eyes with glaucoma. I am excited to continue my collaboration with Dr. Patel in this study to determine whether we can detect damage to the eye in glaucoma in its earliest stages.
My laboratory, collaborators and I are very appreciative of the BrightFocus Foundation donors for helping to provide the opportunity to apply for and receive support to sponsor our research in glaucoma. As the competition to obtain federally supported awards continues to increase, it is important for researchers to be able to explore additional avenues to support their labs and continue their important research efforts. This BrightFocus award came at a very critical junction for my laboratory and its personnel (including a graduate student who is central to the project). We are very thankful for this support and are very excited for the opportunity to make an important contribution with the potential to influence the way that clinicians think about and make decisions regarding glaucoma treatment.
First published on: November 14, 2018
Last modified on: March 31, 2020