Southampton eye experts trial 'buzzing belt' to help patients with sight loss

The technology, known as the Low-vision Enhancement Optoelectronic (LEO) Belt, has already been used to help people with retinitis pigmentosa (RP) successfully navigate a maze.

RP, which is the most common inherited eye condition, affects around one in 4,000 people in the UK. It causes a loss of peripheral sight - ‘tunnel vision’ - and can make it difficult to see in low light.

The belt consists of a 3D depth-sensing camera and a portable computer stick connected via Wi-Fi to vibration patches hidden on a vest and ankle straps.

It scans the area in front of the person using the 3D camera and warns the user about nearby objects through vibrations – the faster the buzzing, the nearer the object – with the position indicated by the left, centre or right patch.

It was developed by Professor Steve Russell of the University of Iowa with the support of Professor Andrew Lotery, a consultant ophthalmologist at University Hospital Southampton, who has trialled it.

Prof Lotery and Ffion Brown, a medical student at the University of Southampton, assessed six patients with advanced RP and 20 healthy people wearing goggles that restricted their vision.

The results, published in the journal PLOS One, showed all participants were able to use the belt to guide them around four mazes made from obstacles arranged in different ways.

Those with RP found the belt particularly useful when finding their way around the mazes in low lighting when their vision is worse.

“In this small pilot study we have shown the belt has great promise and, based on what we have learned, intend to develop it further to hopefully help patients retain their independence despite sight loss,” explained Prof Lotery (pictured), who is a professor of ophthalmology at the University of Southampton.

“The belt has the advantage over alternative aids for people with sight loss, such as a white stick or guide dog, in that it can be worn under their clothes and be relatively discreet. This could help those who are reluctant to use a visual aid for fear of discrimination.”