A team at Moorfields Eye Hospital and the Institute of Ophthalmology have made the world's first attempt to treat a sight disorder using gene therapy. The research team lead by Professor Robin Ali, included Professor Tony Moore, Consultant Ophthalmologist and James Bainbridge, Consultant Ophthalmologist.

Below is some more information about the trial.

What is the condition?

The trial involves patients with a condition known as Leber’s congenital amaurosis (LCA), which is an inherited degeneration of the retina. It is not a single specific disorder and is the term used for a group of conditions that have in common abnormality of retinal receptors that result in severe vision impairment from a very young age.

The retina is made up of a layer of cells called photoreceptors which can detect light. The cells then convert the light into electrical impulses and transfer these to the brain via the optic nerve.

What causes LCA?

LCA is caused by mutations in the RPE65 gene that controls production of an enzyme responsible for the recycling of retinol, a chemical necessary for capturing light. This recycling takes place in the retinal pigment epithelium (RPE), a supportive tissue underlying the layer of photoreceptor cells in the retina. If used retinol cannot be recycled, the photoreceptor cells run out of supplies and can no longer function.

Is this treatment available now?

At the moment it is only at the clinical trial stage, therefore it’s not available to patients. As it is the first trial of its kind in the world, the researchers will need to establish that the procedure is safe. The subjects will need to be followed up to assess the long term effect of the treatment, and the overall results may not be available for months.

Can I take part in the clinical trial?

All of the people involved in the trial have been carefully selected and unfortunately we cannot accept anyone else at this stage.

What do the researchers hope to achieve?

In this form of retinal degeneration the photoreceptor cells are present, but not functioning. Their aim is to restore the activity in these cells and therefore restore vision. It is anticipated the best results will be achieved in younger patients, as they will be treated when the disease is in its earlier stages of development.

Are there plans for future trials for other forms of retinal conditions?

For each form of retinal degeneration, the use of gene therapy will need to be developed independently and the treatment will need to be tested in a separate clinical trial for that disease. Nevertheless, results from this first trial are likely to provide an important basis for many more gene therapy protocols in the future.

Further Information

More information about gene therapy and other trials can be found on the Molecular Therapy site, part of the UCL Institute of Ophthalmology