Scientists transplant photoreceptors from retina grown ‘in a dish’

University College of London scientists have carried out the first successful transplant of light-sensitive photoreceptor cells extracted from a synthetic retina, grown 'in a dish' from embryonic stem cells.

Professor Robin Ali of the University's Institute of Ophthalmology

When transplanted into night-blind mice these cells appeared to develop normally, integrating into the existing retina and forming the nerve connections needed to transmit visual information to the brain.

The study, funded by the Medical Research Council (MRC) and published today in Nature Biotechnology, suggests that embryonic stem cells could in future provide a potentially unlimited supply of healthy photoreceptors for retinal cell transplantations to treat blindness in humans.

The loss of photoreceptors – light sensitive nerve cells that line the back of the eye – is a leading cause of sight loss in degenerative eye diseases such as age-related macular degeneration, retinitis pigmentosa and diabetes-related blindness.

There are two types of photoreceptor in the eye – rods and cones. Rod cells are especially important for seeing in the dark as they are extremely sensitive to even low levels of light.

Previous work by Professor Robin Ali and his team at the UCL Institute of Ophthalmology and Moorfields Eye Hospital has shown that transplanting immature rod cells from the retinas of healthy mice into blind mice can restore their sight. However, in humans this type of therapy would not be practical for the thousands of patients in need of treatment.