A MacArthur Foundation “Genius” Award for Artificial Retina Research

a laboratory mouse

Sheila Nirenberg, Ph.D., is a neuroscientist whose research is focused on the development of alternative approaches to restoring sight after photoreceptor cell degeneration. She is an associate professor in the Department of Physiology and Biophysics at Weill Medical College of Cornell University, where she studies neural coding: how the brain takes information from the outside world and encodes it in patterns of electrical activity.

What her work could mean for people with retinal disease, from macular degeneration and retinitis pigmentosa for example, is significant. In the laboratory, Dr. Nirenberg has demonstrated the ability to restore nearly normal vision in laboratory mice, via a surgery-free prosthetic retina. Please note that this strategy is still in the earliest phases of laboratory/clinical testing.

More about the Prosthetic Retina

I first became aware of Dr. Nirenberg’s work in 2010, when she presented her research at the Society for Neuroscience with Chethan Pandarinath, Ph.D., a former Cornell graduate student in Dr. Nirenberg’s lab who is now conducting postdoctoral research at Stanford University School of Medicine.

As described at the time in Now I See You: A surgery-free prosthetic retina restores vision in blind mice in the Massachusetts Institute of Technology’s Technology Review,

Artificial retinas already exist. But they require surgery to implant an array of electrodes deep into the eye. The electrodes stimulate [retinal] cells that transmit information to the brain, and must be powered by an external battery. They are capable of restoring crude vision, allowing patients to pick up only major contrasts and edges, such as a light object against a dark background.

But [Dr.] Nirenberg’s research … enables still and moving images to be conveyed more cleanly and rapidly than ever before possible. And the method doesn’t require surgery.

In mammals’ eyes, a set of cells in the retina detects light [i.e., photoreceptor cells], and then a separate layer of cells, called ganglion cells, relays that information to the brain. Because macular degeneration and other retinal diseases cause the light-detecting cells to die but leave the ganglion cells intact, researchers have been trying for 50 years to decipher their code—the patterns by which the ganglion cells fire—so as to capitalize on the eye’s natural circuitry.

[Dr.] Nirenberg has now nailed that, or at least a close approximation. After ten years of work, she knows the relationship between what we see and how that translates into ganglion-cell firing patterns.

A MacArthur “Genius” Award for Dr. Nirenberg

And now, Dr. Nirenberg has been named a 2013 MacArthur Foundation Fellow. The MacArthur Fellows (“Genius Awards”) Program awards five-year unrestricted $625,000 fellowships to individuals who show “exceptional creativity in their work and the prospect for still more in the future.” The fellowship is designed to provide recipients with the flexibility to pursue their creative activities in the absence of specific obligations or reporting requirements.

You can view Dr. Nirenberg describing her research in this MacArthur Foundation video:

Neuroscientist Sheila Nirenberg, 2013 MacArthur Fellow at YouTube.

How the Prosthetic Retina Works

Dr. Nirenberg has developed a prosthetic system that consists of two parts: an encoder and a transducer [i.e., a device that converts input energy of one form into output energy of another].

The encoder converts visual input into the retina’s code [i.e., the code that the retina normally uses to communicate with the brain]. The transducer then drives the retina’s output cells – the ganglion cells – to fire in accordance with the code’s specifications.

Here is a further explanation of Dr. Nirenberg’s work from the MacArthur Foundation:

In the visual sensory system in mammals, the photoreceptor cells in the retina take in information from the outside world, such as an image or visual pattern. This information is then passed through the retinal circuitry to the ganglion cells, which transform it into a neural code that the brain can understand.

In the case of diseases such as macular degeneration and retinitis pigmentosa, which affect approximately 20–25 million people worldwide, vision is lost when deteriorating photoreceptor cells no longer take in visual signals.

Instead of trying to replace the lost photoreceptor cells—an approach that is usually quite invasive and that has shown limited benefit for advanced stage disease—Nirenberg has developed a method for bypassing the damaged photoreceptor cells entirely and interacting directly with the ganglion cells.

Nirenberg invented a computerized eyeglass prosthetic that transmits the codes to the ganglion cells, which then send the codes to the brain.

You can read more about the research, entitled Retinal prosthetic strategy with the capacity to restore normal vision, in the Proceedings of the National Academy of Sciences of the United States of America. VisionAware will continue to provide updates of this research as they become available.