A new wireless eye prosthesis, PRIMA, has restored functional vision to people with advanced macular degeneration in a clinical trial.
A clinical trial of the prosthesis reveals that they regained enough vision to read books.
The tiny wireless chip implanted in the back of the eye and a pair of high-tech glasses partially restored vision.
The trial, led by Stanford Medicine researchers and international collaborators, showed that 27 out of 32 participants regained the ability to read a year after receiving the device.
With digital enhancements enabled by the device, such as zoom and higher contrast, some participants could read with acuity equivalent to 20/42 vision.
PRIMA, developed at Stanford Medicine, is the first eye prosthesis to restore functional sight to patients with incurable vision loss, giving them the ability to perceive shapes and patterns (form vision).
Daniel Palanker, a professor of ophthalmology and a co-senior author of the paper, said: ‘All previous attempts to provide vision with prosthetic devices resulted in basically light sensitivity, not really form vision. We are the first to provide form vision.’
The other senior author is José-Alain Sahel, MD, professor of ophthalmology at the University of Pittsburgh School of Medicine. The lead author is Frank Holz, MD, professor of ophthalmology at the University of Bonn in Germany.
The two-part device consists of a small camera, mounted on a pair of glasses, that captures images and projects them in real time via infrared light to a wireless chip in the eye.
The chip converts the images into electrical stimulation, effectively taking the place of natural photoreceptors that have been damaged by disease.
PRIMA is the culmination of decades of development, prototypes, animal trials and a small first-in-human trial.
Palanker first imagined such a device 20 years ago, when he was working with ophthalmic lasers used to treat eye conditions.
He said: ‘I realised we should use the fact that the eye is transparent and deliver information by light. The device we imagined in 2005 now works in patients remarkably well.’
Participants in the new trial had an advanced form of age-related macular degeneration – geographic atrophy – that gradually erodes central vision.
Over 5 million people globally are affected by the condition, and it is the most common cause of irreversible blindness among the elderly.
The trial’s results are in the New England Journal of Medicine
