Scientists are now designing a variety of medical devices to counter the effects of retinal disorders by sending visual signals to the brain.
Israeli and British scientists have developed a new, light-sensitive film that could eventually form the basis of a prosthetic retina to help people suffering from retinal damage or degeneration. Hebrew University and Tel Aviv University researchers with colleagues from Newcastle University produced the research, which was recently published in the journal Nano Letters.
The retina – a the thin layer of tissue on the inner surface of the eye that is composed of light-sensitive nerve cells – converts images to electrical impulses and sends them to the brain. Damage to the retina from macular degeneration, retinitis pigmentosa and other eye diseases can reduce vision or cause total blindness. In the US alone, age-related macular degeneration (AMD) affects more than 15 million Americans, and over 200,000 new cases are diagnosed every year.
Scientists are now designing a variety of medical devices to counter the effects of retinal disorders by sending visual signals to the brain. But these silicon-chip based solutions are typically hampered by their size, use of rigid parts or requirement of external wiring such as to energy sources.
In the new study, HU researchers headed by Prof. Uri Banin and his graduate student Nir Waiskopf of the chemistry institute and the Center for Nanoscience and Nanotechnology worked with TAU and Newcastle University colleagues to develop a novel approach for retina stimulation. Their device absorbs light and stimulates neurons without using wires or external power sources.
The researchers combined semiconductor nanorods and carbon nanotubes to create a wireless, light-sensitive, flexible implantable film. The film transforms visual cues to electric signals, mimicking the function of the photo-sensitive cells in the retina. Thus it could potentially form part of a future prosthetic device that will replace the damaged cells in the retina. The researchers tested the new device on light-insensitive retinas from embryonic chicks and observed a neuronal response triggered by light.
The new device is compact, capable of higher resolution than previous designs and more effective at stimulating neurons. While much work remains until this can provide a practical solution, with additional research the researchers hope their carbon nanotube-semiconductor nanocrystal film will one day effectively replace damaged retinas in humans.
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Source: The Jerusalem Post