Trial to see if a gene therapy can stop or reverse one of the most common causes of vision loss

An Australian-first trial will see if gene therapy can stop or reverse one of the most common causes of vision loss.

An Australian-first trial is testing if a gene therapy can stop or even reverse one of the most common causes of vision loss.

Age-related macular degeneration is the main cause of sight impairment in people over 40. About 1.1 million adults nationwide have a form of the condition, which is untreatable and creates holes in the central vision.

A build-up of debris in the central retina in dry AMD progressively robs patients of the ability to see faces and print.

The research is aiming to stop or reverse one of the most common causes for loss of vision.

Melbourne’s Centre for Eye Research Australia has launched two clinical trials to test whether injecting a gene into the back of the eye to replace a defective one can kickstart a cell-regeneration process and preserve eyesight.

Centre principal investigator of retinal gene therapy research and vitreoretinal surgeon Tom Edwards said while gene therapy had been tested in rare eye diseases, the field was now moving on to more genetically complex and common conditions.

“We’re using the ability of a virus to deliver genetic material into a cell,” Dr Edwards said. “It’s a bit like hijacking a delivery van. You’re emptying out its DNA contents and you’re filling it up with some useful parcels the virus delivers to target cells. In this case it’s the retina and it’s delivering a gene that we hope will slow or even halt the progression of advanced dry AMD.”

The first two of 20 patients have undergone the procedure in the international phase II study at the Royal Victorian Eye and Ear Hospital.

Using a cannula the width of a human hair, the liquid gene therapy is injected under the retina. Dr Edwards said there was growing evidence the gene was involved in an immune response that was important for the onset and progression of AMD.

“What this gene does is dampen down that particular part of the immune system in those cells. The theory is by doing so it will slow down or halt the progression,” he said.

The trial gives hope to patients including Robert Kerr, 73, who was diagnosed with dry AMD 20 years ago.

“If there was a cure for it, or at least a way to prevent deterioration, that would be terrific,” Mr Kerr said. “I sometimes have trouble finding my wife in the supermarket … It does inhibit some of the things you enjoy.”