Age-related macular degeneration (AMD) is the leading cause of irreversible central blindness in the world. The number of people with AMD is predicted to be 288 million by 2040, with an estimated 1 in 10 people over the age of 55 already showing early signs of the condition. If AMD were a country, it would be the 8th most populous country in the world. Unfortunately, the end stage of AMD, namely geographic atrophy (GA), currently has no form of therapy available to patients. Therefore, a diagnosis of GA will ultimately lead to complete loss of central vision, with patients unable to read, see faces or drive. In short, a complete loss of independence is the result of having no therapeutic available to treat the condition.
Over 224,000 Irish people and 40 million people worldwide are affected by severe vision loss where they would be considered legally blind. The number of people affected by blindness is increasing, largely due to our ageing population. The Economic Cost and Burden of Eye Diseases and Preventable Blindness in Ireland report was released in April 2014 by the National Vision Coalition, part of a pan-European study of 16 countries by Deloitte, an alliance of ophthalmology healthcare professionals, those working in the sight loss community, and service users (
http://www.ncbi.ie/aboutncbi/(opens in new window)). People should not have to suffer avoidable sight loss, the vision loss associated with retinal diseases as outlined here should be avoidable with partner diagnostic and personalized treatment using our innovative approaches. The burden of blindness/sight loss on healthcare services stretches beyond Ophthalmology care as people with vision loss are up to eight times more likely to fracture a hip, three times more likely to be depressed, and admission to nursing homes takes place up to three years earlier. There will be a significant financial benefit if sight loss can be avoided.
Here, we sought to develop a gene therapy based approach to treating AMD. Our concept was based on the idea of stabilising the blood vessels in the retina at the back of the eye. One issue with gene therapy however, is that the viral vectors used to deliver the medicine can have difficulty in targeting blood vessels. The purpose of this ERC PoC award was to develop a novel form of viral vector that was "encapsulated" in a fatty delivery agent known as an exosome. We had 3 major objectives. 1) We synthesised our new form of viral vector using a novel method of synthesis. 2) We sought to screen our new virus in cells in vitro. 3) We wished to screen the effect of our virus in the living mouse eye.
In all, the central aim of this project was to develop an advanced form of gene therapy for treating AMD and preventing vision loss.
