Benefits and risks

Information for the public

When NICE looked at the evidence, it decided that there was not enough evidence to know how well this procedure works or how safe it is. The 7 studies that NICE looked at involved a total of 73 patients but some patients may have taken part in more than 1 study.

Generally, the studies showed small improvements in vision. Some people were better able to perceive light, or direction of movement, or recognise shapes.

The studies showed that the risks of the procedure included:

problems with the retina during or after the procedure, that did not get better with time for some people
the microchip or cable stopping working properly. Some people chose to have their prosthesis system taken out
problems with the conjunctiva (a thin membrane that covers the white part of the eye) after the procedure, that were successfully treated
high pressure in the eye, that was successfully treated.

If you want to know more about the studies, see the guidance. Ask your health professional to explain anything you don't understand.