Using a high-tech imaging process to measure the thickness of the eye’s retina may one day predict the progression of multiple sclerosis, a new study suggests.

The finding might lead to better ways to judge the effectiveness of treatments because different parts of the retina seem to indicate different aspects of the disease and the toll it takes on different parts of the brain, the researchers said.

The report was published online Oct. 1 in the Archives of Neurology.

Surgeons at UC Davis Medical Center have successfully implanted a new telescope implant in the eye of a patient with end-stage age-related macular degeneration (AMD), the most advanced form of the disease and a leading cause of blindness in older Americans.

The device, approved by the Food and Drug Administration in 2010, is the only medical/surgical option available that restores a portion of vision lost to the disease. UC Davis Health System’s Eye Center, in collaboration with the Society for the Blind, is one of the few in California and the nation to offer the innovative procedure.

With his knack for knowing what stem cells want, Yoshiki Sasai has grown an eye and parts of a brain in a dish.

All it took to grow a retina, it turned out, were a few tweaks, such as a reduction in the concentration of growth factors and the addition of a standard cell-culture ingredient called Matrigel. The result closely mimics eye development in the embryo. By the sixth day in culture, the brain balls start sprouting balloon-like growths of retinal cells, which then collapse in on themselves to make the double-walled optic cups. Sasai’s team snip them off — “like taking an apple from a tree”, says Sasai — transfer them to a different culture and let them be. Two weeks later, the cups have formed all six layers of the retina, an architecture that resembles the eye of an 8-day-old mouse (which, at that age, is still blind). That the cells could drive themselves through this dramatic biomechanical process without surrounding tissues to support them stunned Sasai as much as anyone else. “When I saw it, I thought, ‘Oh my god.’ Shape, topology and size are all recapitulated,” he says. Carefully explaining the pun to come, he adds: “In English, when you are surprised, you say ‘eye-popping’ — so we really thought this was eye-popping.”

(Source: nature.com)

To find out how mice use their high-resolution ganglion, a team from Harvard attached a tiny camera to a rat volunteer and then watched to see what sorts of things it focused on. Next, they played the video back directly onto the retinas of several test mice while simultaneously monitoring neural cell activity. In so doing, they found that the high-resolution cells sat mostly quiet, doing nothing.

When silhouettes of birds were projected overhead, the waiting ended as the ganglia sprang into action, interpreting every movement. This shows, the researchers say, that the high-resolution neuron groups in mice retinas serve not as interpreters of everyday life, but as highly specific predator detectors. More specifically they found the nerves reacted when the birds were in their center of view, meaning close and ready to snatch them up. Sadly, they also found that the nerves quit firing once the birds came close enough, indicating the mice were doomed.

An Artificial Retina with the Capacity to Restore Normal Vision

Two researchers at Weill Cornell Medical College have deciphered a mouse’s retina’s neural code and coupled this information to a novel prosthetic device to restore sight to blind mice. The researchers say they have also cracked the code for a monkey retina — which is essentially identical to that of a human — and hope to quickly design and test a device that blind humans can use.

The breakthrough, reported in the Proceedings of the National Academy of Sciences (PNAS), signals a remarkable advance in longstanding efforts to restore vision. Current prosthetics provide blind users with spots and edges of light to help them navigate. This novel device provides the code to restore normal vision. The code is so accurate that it can allow facial features to be discerned and allow animals to track moving images.

(Image credit: Frank Müller, Institute of Complex Systems)