The Straits Times
By Liaw Wy-Cin
SCIENTISTS from the University College London (UCL) have succeeded in coaxing 'master' cells to become specialised eye cells which can be used to replace a diseased portion of the eye. They have done this in pigs and rats, and are hoping for the go-ahead from the British authorities to try out the method in humans in 18 months.
One in four people above the age of 60 is struck by this condition, known as age-related macular degeneration (AMD), said the project's lead scientist, Professor Pete Coffey, 47, from UCL's Institute of Ophthalmology. For 90 per cent of AMD patients, there is no treatment. A drug called Lucentis, recently approved for use here, can treat a less common form of AMD, affecting about 10 per cent of patients.
He said that for every patient diagnosed with AMD, an estimated 154 cases go undiagnosed.
By Liaw Wy-Cin
SCIENTISTS from the University College London (UCL) have succeeded in coaxing 'master' cells to become specialised eye cells which can be used to replace a diseased portion of the eye. They have done this in pigs and rats, and are hoping for the go-ahead from the British authorities to try out the method in humans in 18 months.
The special eye cells they created are retinal pigment epithelial (RPE) cells, which protect and supply nutrients to the retina. If the retina, which lies at the back of the eye, is starved of nutrients, or clouded by debris, it cannot perform its role of passing visual images from the front of the eye to the brain. The result is blurred vision and eventual blindness.
One in four people above the age of 60 is struck by this condition, known as age-related macular degeneration (AMD), said the project's lead scientist, Professor Pete Coffey, 47, from UCL's Institute of Ophthalmology. For 90 per cent of AMD patients, there is no treatment. A drug called Lucentis, recently approved for use here, can treat a less common form of AMD, affecting about 10 per cent of patients.
Prof Coffey's team has used embryonic stem cells, taken from a stem cell bank, and grown them to form a 6mm-by-3mm oval patch of RPE support cells. Embryonic stem cells are seen as having a lot of potential in medicine because they could one day be used to replace diseased or damaged body parts. In trials on animal eyes, Prof Coffey's team injected a fluid to separate the retina from the RPE cells, and through a small incision, inserted the patch on top of the diseased area of RPE cells.
'The cells then took over the function of the diseased cells in providing nutrients and clearing debris,' he said. In an experiment five years ago, his team found that this newly grown layer of cells restored the sight of about 80 per cent of blind rats.
One eye expert here is excited about the potential of this work, because he expects AMD to become a major cause of blindness in Singapore as the population ages. Said Associate Professor Au Eong Kah Guan, 42, head and senior consultant at the department of ophthalmology and visual sciences at Alexandra Hospital and Jurong Medical Centre: 'If this therapy works, it could be the most ground-breaking work on AMD treatment to date.
'Its impact would be enormous because it could potentially treat people who have already lost vision due to death of light-sensitive cells in the retina, something which all current therapies are unable to do.'
He said that for every patient diagnosed with AMD, an estimated 154 cases go undiagnosed.
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