Eye Implant Offers Life-Changing Results to Blind Patients

The PRIMA system. Credit: Science Corp.

A new implant device is helping people with an advanced form of dry age-related macular degeneration (AMD), called geographic atrophy (GA), be able to read again.

A 2mm-square photovoltaic microchip is surgically inserted under the patient’s retina. The patient then puts on glasses with a video camera that can send an infrared beam of video images to the implant, which is about the size of a human hair. The device then sends the images to a small pocket processor to be enhanced before arriving back at the brain via the implant and the optic nerve.

The research was published in the New England Journal of Medicine and involved inserting the PRIMA (Photovoltaic Retinal Implant for Age-Related Macular Degeneration) implant into 38 patients.

Credit: Pixabay

The clinical trial conducted by Stanford Medicine in five European countries showed that of 32 patients with geographic atrophy given the PRIMA implant, 27 were able to read again using their central vision. After 12 months, the patients had improved to reading 25 letters, or five lines on an eye chart.

The patients spent months learning how to interpret the information as the use of the device takes extreme concentration. The device can only focus on one or two letters at a time while the individual holds their head very still to steady the camera feed.

The implant is the first of its kind offering patients with incurable vision loss to restore their functional sight like perceiving shapes and patterns. In some cases, the digital enhancements enabled the patient to read with 20/42 vision. As geographic atrophy affects five million worldwide, this pioneering technology is expected to offer life-changing results to many individuals.

The condition is more common in older adults as the cells in a tiny area of the retina in the back of the eye gradually become damaged and die. This leads to blurred or distorted central vision and the potential loss of color and fine details.

The device is not yet licensed so it can not be used outside of clinical trials. While it is possible the device could help with other eye conditions in the future, the implant is not expected to help individuals whose optic nerve is not functioning as this is how signals are sent from the retina to the brain.

It is not clear how much the PRIMA implant will cost once it is put on the market, or if the research reported in the New England Journal of Medicine by the research team will help with other vision-enhancing advances.