Researchers at the University of Rochester Medical Center have developed a new imaging technique that could revolutionize how eye health and disease are assessed. The group is first to be able to make out individual cells at the back of the eye that are implicated in vision loss in diseases like glaucoma. They hope their new technique could prevent vision loss via earlier diagnosis and treatment for these diseases.
In a study Ethan A. Rossi, Ph.D., assistant professor of Ophthalmology at the University of Pittsburgh School of Medicine, describes a new method to non-invasively image the human retina. The group, led by David Williams, Ph.D., Dean for Research in Arts, Sciences, and Engineering and the William G. Allyn Chair for Medical Optics at the University of Rochester, was able to distinguish individual retinal ganglion cells (RGCs), which bear most of the responsibility of relaying visual information to the brain.
There has been a longstanding interest in imaging RGCs because their death causes vision loss in glaucoma, the second leading cause of acquired blindness worldwide. Despite great efforts, no one has successfully captured images of individual human RGCs, in part because they are nearly perfectly transparent.
This new approach might eventually allow us to detect the loss of single ganglion cells. The sooner we can catch the loss, the better our chances of halting disease and preventing vision loss.
Instead of imaging RGCs directly, glaucoma is currently diagnosed by assessing the thickness of the nerve fibres projecting from the RGCs to the brain. However, by the time a change is typically detected in the retinal nerve fibre thickness, a patient may have lost tens of thousands of RGCs or more.
“In principle, this new approach might eventually allow us to detect the loss of single ganglion cells,” said Williams. “The sooner we can catch the loss, the better our chances of halting disease and preventing vision loss.”
Rossi and his colleagues were able to see RGCs by modifying an existing technology – confocal adaptive optics scanning light ophthalmoscopy (AOSLO). They collected multiple images, varying the size and location of the detector they used to gather light scattered out of the retina for each image, and then combined those images. The technique, called multi-offset detection, was performed at the University of Rochester Medical Center in animals as well as volunteers with normal vision and patients with age-related macular degeneration.
The University of Rochester Medical Centerhttp://tinyurl.com/yc78dk4v