iblog

Thomas King: An 18-year-old British man has had his failing eyesight improved by cutting edge gene therapy.

Steven Howard from Bolton, near Manchester, suffers from a rare form of blindness called Leber’s congenital amaurosis. The condition is the result of a faulty gene which prevents sufferers from manufacturing rhodopsin, a light-absorbing pigment which is a vital component of the human eye.

Lack of this pigment has left Howarth with extremely poor night-vision since birth but his vision was progressively worsening and would have left him totally blind by his mid-to-late twenties.

The treatment, pioneered by doctors at London’s Moorfields Eye Hospital, works by replacing the damaged gene. This rejuvenates the dying cells on the retina and restores vision as they recover.

A healthy copy of the gene is inserted into the cells by injecting a fluid containing a modified virus which carries the healthy gene. When the virus ‘infects’ the retinal cells and copies its own genetic material across, it also copies the healthy gene and repairs the cells’ nuclei.

The treatment has improved Howarth’s low-light vision 100-fold and has also improved his peripheral vision, allowing him to see out of the corner of his eye for the first time. Where once he could barely walk across a dimly lit room, Howarth now says he would ‘feel comfortable’ walking home at night.

The study’s leader, Professor Robin Ali said that the result was “a major boost for the whole field”. Professor Ali, who is the brother of Brick Lane author Monica Ali, admitted that he was surprised to see such a significant improvement but now felt that gene therapies for other vision-reducing conditions, such as macular degeneration, could soon be possible.

He said “I find it difficult to remember being as excited as I am today about our science and what it might achieve.”

The success is the second breakthrough by Moorfield’s Eye Hospital in just over a week. On the 21st of April, researchers at the hospital announced the trialling of a ‘bionic eye’ which could help sufferers of a degenerative eye disease, retinitis pigmentosa, to regain a basic level of vision.

The ‘eye’ is actually a camera mounted on a pair of glasses. The camera picks up images and transmits them wirelessly to a receiver which is connected to the patient’s retina. The receiver sends a sequence of electrical impulses which the retina passes onto the brain. Here they are decoded as patterns of light and darkness to give subjects a vague outline of their surroundings.

Researchers warned that it was ‘early days’ but said that they were hopeful for the trial’s success.