Three patients with retinitis pigmentosa, an inherited disease that causes blindness, can now see shapes and objects after undergoing groundbreaking retinal implant surgery.
The patients had previously had a limited ability to perceive bright light, but they were completely unable to recognise shapes. However, just days after having the device fitted, all three could locate objects on a table, including a cup, a saucer and different geometric shapes, while one patient could walk around a room, read the time off a clock face and read his own name.
The pilot study was testing the device developed by Retina Implant AG, a medical technology company based in Reutlingen, Germany. It involved two men and one woman aged 40, 44 and 38.
All three had become affected by the condition, which gradually destroys the light sensitive retina at the back of the eye, in early childhood and had lost the ability to read at least five years before having the operation.
Patients in the UK are due to receive the implant for the first time in a follow-up trial starting next year.
The implant is fitted beneath the retina and consists of a 3mm-square array of 1,500 light sensors.
Each “photodiode” delivers a pulsed electrical signal to adjoining groups of nerve cells, sending a message to the brain.
A power supply unit is connected to the device by means of a cable passed through the skin.
Details of the trial are published in the journal Proceedings B.