Researchers in Oxford have performed the world’s first gene therapy operation to tackle a common cause of blindness due to age related macular degeneration (AMD). The surgery was performed on an 80-year-old woman from Oxford who was the first to undergo this treatment.
The procedure was carried out at the John Radcliffe Hospital by Prof Robert MacLaren, Professor of Ophthalmology at the University of Oxford in a clinical trial.
Dry AMD is a slow deterioration of the macular cells affecting the central part of a patient’s vision with gaps or smudges, making everyday activities like reading and recognizing faces difficult.
A solution containing a harmless virus is injected underneath the retina of the eye during surgery.
The virus carries a modified DNA sequence which is released on to the pigmented cell layer of retinal pigment epithelial cells (RPE). The gene then helps correct a genetic defect that causes AMD.
In AMD the macular degeneration is brought about by the proteins of the hosts’ natural immune complement system. The proteins become over-active and attack the persons own retinal cells leading to an impaired vision. The gene therapy deactivates the complement system at the site and could help slow down the progression of the disorder.
“The idea of this gene therapy is to deactivate the complement system, but at a very specific point at the back of the eye, so the patient would otherwise be unaffected by it, and we hope that in future it will slow down the progression of macular degeneration,” said Prof. MacLaren.
He also mentions that a genetic treatment administered early could preserve the vision in patients who would otherwise lose their sight. If successful, the treatment could have a beneficial impact on patients’ quality of life and their ability to remain independent.