One implant, three components

One implant, three components


The implant

There are a number of indications that cause the loss of retinal photoreceptors (rods and cones). The inner retina and optic nerve, however, still form an intact connection with the brain and do not lose their functionality. This is also the case in retinitis pigmentosa. Due to this lack of photoreceptors, the retina can no longer convert light into electric signals [via the photoreceptors], and thus no visual information can be sent to the optic nerve. The subretinal implant RETINA IMPLANT Alpha AMS is able to replace the functionality of the degenerated photoreceptors to a limited degree by way of electrical stimulation of the outer retinal tissue. As a result, information can be transmitted to the visual cortex of the brain through the optic nerve, thus generating visual images.  The chip is only 3.2 x 4 mm in size with a height of 70 µm. It is equipped with 1600 photodiodes, which convert the incident light into an electrical signal. This signal is amplified and relayed via electrodes to the retinal signal processing layers which are still functional. From there, the signal follows the natural optical path through the optic nerve into the area of the brain (visual cortex), where the incoming information is interpreted and visual images are produced. By placing the implant under the retina, the patient is able to make use of their natural eye movements to see. A special camera for taking pictures outside the eye is not required.

RETINA IMPLANT Alpha AMS Receiver and Control Unit

The receiver and the control unit

The components of the RETINA IMPLANT Alpha AMS implanted in the eye rely on an external power supply.  The compact handheld device (15 cm x 9.2 cm x 2.8 cm) contains batteries and an electronic circuit that generates a magnetic alternating field in the transmitting coil (transponder D). It can easily be carried in a pocket. Consequently, energy is transmitted via induction through the skin to the receptor implanted behind the ear in the cranial bone, as long as the transmitting coil is magnetically coupled to the receiver coil. The current generated in the receiver coil is fed to the eyeball via a cable running under the skin to the temple. The current is passed through a thin conductor strip through the eye wall (sclera) to the microchip under the retina. The microchip can then be switched on and operated.


Adjusting brightness and contrast

Via the handheld device, the patient can adjust the brightness and contrast of the signal to the surrounding brightness using two controllers.