A stem cell patch has successfully restored sight to two blind patients in the UK. The Phase I trial is the first of its kind to use a whole engineered piece of tissue to treat vision impairment. The patients both suffered from a sudden and severe loss of vision due to age-related macular degeneration (AMD).
As we grow older, there are many parts of our body begin to deteriorate. One of the most basic functions that often fails in old age is our eyesight. Out of the many conditions that lead to loss of vision in the elderly, age-related macular degeneration (AMD) is one of the most common. It affects over six million people worldwide, and often impairs vision to the point where everyday tasks, such as driving, reading, or even recognizing the faces of loved ones, become impossible.
By effectively removing all the finer details of a person’s vision, the condition severely compromises the patient’s quality of life and ability to remain independent.
AMD is usually a slow and gradual process caused by deterioration of the macula. The macula is an oval shaped area in the retina, and is responsible for central, high resolution and color vision. Therefore as the macula degrades, so does your central field of vision, with patients subject to ever increasing blurriness, loss of visual acuity and even visual hallucinations (caused by Charles Bonnet Syndrome). AMD does not lead to total blindness, as the peripheral vision of the patient remains intact, but by effectively removing all the finer details of a person’s vision, the condition severely compromises the patient’s quality of life and ability to remain independent.
There is now hope for people suffering from AMD related vision impairment that they might regain what they've lost. A stem cell patch, generated by researchers at the University College London and Moorfields Eye Hospital, has managed to reverse the effects of AMD in two patients by allowing their eyes to self-heal. The treatment, part of a Phase I clinical trial, took place over the course of a year, during which both patient's’ vision was nearly fully restored. The patients, who had both been considered effectively blind, had their vision so improved by the patch that they were both even able to read again.
The stem cell patch restored sight by promoting the regeneration of the retinal cells in the damaged macula.
Stem cells have actually been used in previous experimental treatments for AMD, but what sets this trial apart is that it’s the first time that severe and sudden loss of vision has been treated with an entire engineered piece of tissue. The patch was created using human embryonic stem cells grown on a thin plastic membrane, and then inserted into the eyes of the patients with a microsurgical tool. The patch then restored sight by promoting the regeneration of the retinal cells in the damaged macula.
Although this treatment is still at an early stage as far as clinical trials go, the researchers are confident that the technology will continue to show good results. They hope to make the stem cell patch available to AMD sufferers within the next five years.
Image 'Macular Degeneration' by Bruce Blaus from Wikimedia Commons