According to researchers, from two trials of gene therapy on an inherited form of blindness in children, it has been found that eyesight of some patients can be improved.

According to the researchers, the retina's light sensitivity has been increased by gene therapy injections. Researchers said children who have Leber's congenital amaurosis (LCA) lack night vision and lose daylight vision. The UK and the US scientists have published findings of the study in the New England Journal of Medicine.

The functioning of the retina gets affected by Leber's congenital amaurosis. The researchers said that about 10% of people with LCA carry a mutated form of the gene RPE65 that is usually vital for vision. In people with LCA, the light-detecting cells finally die and communication between the retina and the brain gets disrupted and it also leads to loss of vision.

The effects of injecting healthy genes into the retinas of 12 young patients more than six years have been studied by researchers at University College London's Institute of Ophthalmology and Moorfields Eye Hospital.

According to the researchers, it has been found that about 50% of patients had shown some improvements in their night vision and this peaked at six to 12 months after the treatment. The researchers said that day time vision did not appear to get better.

“Gene therapy improves night vision but there is no evidence that it slows progression of the disorder. We now need a more potent gene therapy vector”, said Prof Robin Ali, head of genetics at UCL's Institute of Ophthalmology.

According to Ali, a new and more powerful way of carrying and delivering the gene to its target cells has been developed by the research team. The team is planning to test the new vector shortly in a second clinical trial.