Restore vision with new implant techniques

Diagram of implant equipment.( Photo: NewScientist )

US scientists are proposing a solution to transplant a solar-powered chip into the bottom of the blind eye. The chip will activate retinal cells by spraying them with neurotransmitters that can restore vision.

Unlike other implant techniques that use electric current directly on retinal cells, the new device does not heat up the cells. It also consumes very little energy, so there is no need to add an extra battery.

The retina (the part that connects the bottom and side of the eyeball) contains photosensitive receptors that release signaling chemicals - also called neurotransmitters - in response to light. These substances enter nerve cells located at the top of the photosensitive region, where the signal is relayed to the brain through a series of chemical and electronic reactions. In people with retinopathy, such as macular degeneration due to old age and retinitis, optical senses are damaged, do not release neurotransmitters, gradually causing blindness.

Last year, engineer Laxman Saggere from the University of Illinois at Chicago launched a transplant technique to replace these photosensors with a set of neurotransmitters that respond to light. Now he has built a major component of the device: a solar-powered piezoelectric motor responds to very weak light that hits the retina. Many such engines mounted on a single chip will collect details about the image focused on the retina, allowing some "pixels" to be transmitted to the brain.

Its principle is as follows: The light that shines on the solar cell on the implant chip creates a voltage. This voltage starts the piezoelectric motor, producing a pulse of nerve conduction to the retina.

T. An