Every six minutes, at least one person living in the UK will begin to lose their vision, according to the Royal National Institute of Blind People (RNIB). Most cases of vision loss are attributable to factors such as glaucoma, diabetes, or cataract. These risk factors are especially common in older individuals and, in general, population ageing foreshadows an exponential increase in those living with impaired sight in the coming years.
With skyrocketing vision-related issues all over the globe, already, more than 2.2 billion people are living with visual impairment, translating to more than one in four individuals worldwide, and making it imperative that new solutions for this widespread complication are developed. Luckily, researchers have recently accomplished exactly this with a life-changing implantable electronic device, called PRIMA, which enables patients with a condition called age-related macular degeneration (AMD) to see again.
However, before delving deeper into how the device works, it is essential to have an understanding of the ophthalmological condition that it addresses.
AMD is the predominant cause of sight loss in the UK. It is incurable and is caused by damage to a part of the eye called the macula, which is a minuscule region of the retina responsible for central vision, facial recognition, and colour perception. Both lifestyle and genetic factors are believed to contribute to the condition’s aetiology, with hypertension, smoking, and obesity being just a few. Despite the condition being painless and not causing complete blindness, those with AMD gradually lose the ability to engage in daily activities such as reading, writing, or driving due to substantial visual blurring or distortion. AMD is not the only culprit, and other conditions affecting the macula include cone dystrophy and Stargardt disease, which are inherited recessively.
AMD can be divided into two forms: dry and wet. Although both forms are profoundly impactful, the dry form, characterised by the build-up of macula-damaging deposits called drusen, is the most common and negatively impacts the quality of life of millions globally. This is where PRIMA takes charge.
Initially designed by Daniel Palanker, PhD, of Stanford University while working for Pixium Vision, the abbreviation of the device stands for photovoltaic retinal implant microarray and has since been acquired by Science Corporation. It became the first documented eye prosthesis to restore vision in individuals with irreversible sight loss as tested in an international clinical trial on patients with advanced dry AMD, also known as geographic atrophy. This trial, published by the New England Journal of Medicine around mid-October, was authored by more than 20 researchers, including the ophthalmologists Frank Holz, José-Alain Sahel, and Palanker himself. The device’s miraculous effects were demonstrated in the trial, where roughly 84% of the 32 participants assessed after a year were able to read again, despite having lacked central vision prior to receiving the implant.
The technology consists of a 2×2 mm electronic chip, which is inserted beneath the retina via a surgical procedure called a vitrectomy. While this procedure, like any surgery, carries potential risks such as infection, bleeding, or retinal detachment, the implant operates alongside light-converting glasses that allow visual perception by the brain. These glasses permit patients to magnify desired text and have a camera attached to a portable computer. Upon capturing an image, the camera transmits it to the computer, which, in turn, directs the glasses to focus on the focal point of the image. The image is then sent to the implanted chip using infrared rays, and the captured visual information is deciphered by the chip into electrical impulses that are sent to the brain through the retina and optic nerve.
Currently, Palanker is working on creating improved versions of his original device, which are intended to be smaller but higher-resolution, with the capacity to allow greyscale vision for facial recognition. He is also keen on exploring the device’s potential for other retinal ciliopathies besides AMD.
Yet, the cost of the treatment, from surgery to computer equipment to ongoing maintenance, could make the technology inaccessible to many, regardless of how safe or effective it becomes. Despite this, the positive impacts of the device cannot be ignored. Patients involved in the trial have reported significant improvements in quality of life, and its creation represents a cornerstone in technological advancement for ophthalmological conditions. This innovation, although new, offers hope for the millions, if not billions, of people around the globe who are impacted by sight loss, and will undoubtedly pave the way for other revolutionary medical technologies.