Photonics for a Better World

Researchers in the USA, Australia, Sweden, the UK, and elsewhere are working on implants, neurostimulators, and bionic devices to restore vision to those who have significant vision loss.

Biosynthetic corneas have dramatically improved the sight of 10 Swedes, according to a study published in Science Translational Medicine earlier this year, and the Boston Retinal Implant Project in the United States has developed a microelectronic retinal implant that they hope will restore functional vision to patients with certain forms of retinal blindness. The Boston's group prototype receives visual information from a microchip in eyeglasses worn by the patient. The microchip then activates electrodes that stimulate nerve cells that carry signals to the brain.

In California, VisionCare Ophthalmic Technologies, a privately held developer of advanced visual prosthetic devices, announced in July that it received FDA approval for its implantable miniature telescope that can improve vision in patients with end-stage, age-related macular degeneration (AMD).

"Our device is the first of its kind. It is the first FDA-approved implantable medical device demonstrated to improve visual acuity and quality of life in individuals with end-stage AMD," Chet Kumar, VisionCare's VP of business and market development, told optics.org. "There is truly an un-met need for these patients as no drugs or surgical procedures are available to reverse the effects of macular degeneration."

The 3.6 mm-diameter telescope projects an image that would normally be destined for the damaged macula onto healthy retinal cells instead. However, as cells in this peripheral retinal location generate images at a lower resolution, it is essential to magnify the image.

"Unfortunately, if you take any image and magnify it, the field of view decreases," says Eli Aharoni, head of the company's research and manufacturing activities in Israel, where the company was founded in 1997.

"When we magnify the image on to the retina, instead of having the naturally wide field of view of a normal eye, people have a limited and smaller field of view. A normal eye has a detection field of view of anywhere between 90 to 130 degrees, not necessarily all at high resolution. Our two telescope platforms are wide-angle, offering a magnification of 2.2x and 3x with a relatively large field of view of 24 degrees and 20 degrees, respectively."

To enable patients to compensate for the peripheral retina being used for central vision, VisionCare only implants its telescope technology into one eye. The implanted eye restores the patient's central vision, while the untreated eye retains peripheral vision for mobility and orientation. Although this sounds disconcerting, patients are reported to adapt within a few weeks.

The telescope is implanted in an outpatient procedure and involves removing the eye's natural lens. The implantable telescope is essentially a telephoto device that, in combination with the cornea, creates a telescopic effect that magnifies objects in view. The device is composed of a sealed glass capsule which contains all of the bi-convex and bi-concave convergent and divergent micro-lenses confined within air pockets to create a magnified image on the retina.

And in Toronto, a filmmaker who was blinded in one eye in a childhood accident has opted to bypass a device that would restore some of his vision. Instead, Rob Spence now wears a built-in camera in his eye socket.

"I am a filmmaker, so naturally I decided to modify my prosthetic eye into a video camera," Spence says about his so-called Eyeborg project. The first-of-its-kind device is the size of a dime and contains a tiny camera, circuit board, wireless transmitter, and rechargeable battery. It can transmit live images of everything he sees. It was named one of the 50 best inventions of the year by TIME magazine last year.

Satellite data from around the world are being used to generate essential maps of flood-stricken Pakistan where up to 20 million people were affected this year.

Among the important imagery from optical instruments were maps of the saturated soils created by the European Space Agency's new Soil Moisture and Ocean Salinity (SMOS) satellite. SMOS, launched in November 2009, carries an 8m-wide interferometric radiometer that senses the natural emission of microwaves coming off the surface of the Earth and then helps to create images of brightness temperature. Variations in the sogginess of the soil modify the signal, providing data for maps of soil moisture and ocean salinity.

The International Charter on Space and Disasters was activated in August to respond to the disaster in Pakistan. Maps generated via the Charter are essential because they use the very latest satellite imagery to show exactly how far the flood waters have spread, enabling rescue teams on the ground to identify the best way to access those stranded and in need. This is especially important because this year's flood has affected such a vast area, estimated at a third of the country.

For more, see the SPIE Newsroom article.

Scientists in Buffalo (USA) have developed an imaging approach capable of monitoring in real-time apoptosis, the transformations that cellular macromolecules undergo during programmed cell death. The work could help realize the potential of customized molecular medicine, in which chemotherapy, for example, can be precisely targeted to cellular changes exhibited by individual patients. It can also be a valuable drug development tool.

Apoptosis is essential to normal development, healthy immune system function, and cancer prevention. The limitations of conventional microscopy methods have kept much about this structural reorganization a mystery. The University at Buffalo research was reported in the Proceedings of the National Academy of Sciences.

Building on an enzyme found in nature, researchers at Rensselaer Polytechnic Institute (USA) have created a nanoscale coating for surgical equipment, hospital walls, and other surfaces which safely eradicates methicillin resistant staphylococcus aureus (MRSA), the bacteria responsible for antibiotic resistant infections.

"We're building on nature," says Jonathan S. Dordick, director of Rensselaer's Center for Biotechnology & Interdisciplinary Studies. "Here we have a system where the surface contains an enzyme that is safe to handle, doesn't appear to lead to resistance, doesn't leach into the environment, and doesn't clog up with cell debris. The MRSA bacteria come in contact with the surface, and they're killed."

The new coating marries carbon nanotubes with lysostaphin, a naturally occurring enzyme used by non-pathogenic strains of Staph bacteria to defend against staphylococcus aureus, including MRSA.

The research, led by Dordick and Ravi Kane, an RPI professor in the Department of Chemical and Biological Engineering, along with collaboration from Dennis W. Metzger at Albany Medical College, and Ravi Pangule, a Chemical Engineering graduate student on the project, was published in the July 2010 edition of the journal ACS Nano, published by the American Chemical Society.

Lighting engineers are working to create less harmful light and reduce the need for artificial light. Bringing more natural light into homes and offices is one solution.

Several companies now make a type of rooftop skylight that maximizes the amount of natural light funneled inside buildings and homes during daylight hours. These solar light pipes, tubes, and domes collect, focus, and reflect natural sunlight indoors without any electricity.

Not only do they provide environmental and cost-saving benefits, but natural light from these skylights have been correlated with reduced worker illness and injury, enhanced worker productivity, improved visual acuity, reduced eyestrain, fewer headaches, and overall improved moral in the workplace.

The Apollo solar light pipe, made by Orion Energy Systems, received the Product of the Year award from the National Society of Professional Engineers (USA) in July.

Articles in our Photonics for a Better World series highlight optics and photonics technologies that bring tangible gains to humanity.

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