High-Resolution Imaging of Superficial Retinal Vascular Changes in Experimental Glaucoma

Jason Porter, PhD University of Houston


Nimesh Patel, OD, PhD University of Houston
Hope Queener, MS University of Houston


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.

Project Details

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.