New clinical trial aims to cure the wet form of age-related macular degeneration
Surgeons at Moorfields Eye Hospital (UK) have carried out an operation using human embryonic stem cells to cure age-related macular degeneration
Surgeons in London have carried out a pioneering human embryonic stem cell operation in an ongoing trial to find a cure for blindness for patients that suffer from age-related macular degeneration (AMD). The procedure was performed on a woman aged 60 at Moorfields Eye Hospital (London, UK) last month. In total, ten patients with the wet form of AMD will undergo the procedure.
AMD affects more than 600,000 people in the UK and is the leading cause of sight loss in the developed world. It is estimated that one in every ten people over 65 has some degree of AMD. The London Project to Cure Blindness was established a decade ago to try to reverse vision loss in patients with AMD.
All patients involved in the trial will have suffered a sudden loss of vision as a result of defective blood vessels in the eye. They will be followed and monitored for a year to assess the safety and effectiveness of the treatment. "We won't know until at least Christmas how good her vision is and how long that may be maintained, but we can see the cells are there under the retina where they should be and they appear to be healthy," explained Peter Coffey, of the UCL Institute of Ophthalmology (London, UK) and co-leader in the London Project.
The operation involved 'seeding' and implanting a tiny patch of specialized eye cells at the back of the retina. Specifically, the cells being utilized are those that form the retinal pigment epithelium (RPE) – the layer of cells that nourish and support the photoreceptors in the macula (the part of the eye that enables vision).
In macular degeneration, the RPE cells die, and as a result the eye loses function. Sufferers of AMD lose their central vision, which becomes distorted and blurred. If the treatment is successful, it could also help patients in the early stages of dry AMD, and could potentially halt their vision loss. “This is truly a regenerative project. In the past it's been impossible to replace lost neural cells,” commented Lyndon Da Cruz, who carried out the surgery at Moorfields Eye Hospital. "If we can deliver the very layer of cells that is missing and give them their function back this would be of enormous benefit to people with the sight-threatening condition".
The team at Moorfields is working in partnership with the pharmaceutical company Pfizer, which is funding the trial. It is not known how much the one-off surgical treatment might cost, although the scientists involved point out that treating and dealing with sight loss is a huge burden on the NHS.
Currently, 40 AMD patients have already been treated at Moorfields, with cells taken from their own eyes. "We saw extraordinary recovery, with some people being able to read again and drive, and that recovery being sustained for years," stated Lyndon Da Cruz. Utilizing patient’s own cells is complex and carries risks, which is why the London Project opted for the embryonic stem cell line, which can produce a limitless supply of specialist cells.
It is far too early to make any judgment on the efficacy and safety of the treatment, but if successful, it would be a great medical development with important implications for this prevailing eye condition.