Gene Therapy To Restore And Improve Vision

Reduced vision, or even blindness my exist for an individual for a number of reasons. Treatment will depend on what the cause is, and how effective the treatment will be. Conventional, non invasive treatment has always been eye glasses, or contact lenses to correct visual problems. Over time, improved eye glass lenses and contacts have evolved that reduce glare, eliminate unwanted wavelengths of light, improve depth perception, and address many environmental issues.

More recently, there have been new developments in the medical treatment for visual impairments. For example, Avastin a drug that was originally intended to treat Colo-rectal cancer has been found to improve the vision in patients with Macular Degeneration, Diabetic Retinopathy and other vascular related retinal diseases. Non steroidal anti inflammatory drugs can reduce retinal inflammation, and cyst formations. New drugs have been developed to treat infections more affectively.

A major challenge has been therapeutic alte
atives for genetic and congenital disorders. These diseases arise from within the patient, and therefore pose limited treatment options. The future appears to be gene therapy. Recent clinical trials performed at the Scheie Eye Institute in Philadelphia using gene therapy have dramatically improved patient’s vision from detecting hand motion to reading letters on an eye chart. These tests were performed on individuals suffering from a congenital disease called Leber’s Congenital Amaurosis. The study was then published in the New England journal of Medicine. This particular eye disease results from a mutation in the RPE 65 gene. This mutation prevents the gene from producing a protein required in the manufacturing of the retinal pigment epithelium. This protein is required for the retinal tissue to absorb and process the light into vision.

The treatment included injecting a normal RPE 65 gene directly into the retina. Two weeks following the injection, all the patients demonstrated improved vision. In addition, all participants became more sensitive to light. As a result of the increase in acuity, there was a concomitant decrease in abnormal eye movements which further increased the eye’s ability to see.

While these clinical investigations were performed on individuals with a certain congenital disorder, it gives hope to other people with genetic conditions that help is on the way. With any luck, retinal disease will be a thing of the past as these treatment modalities improve.