UPDATE ON ARTIFICIAL VISION

This article gives an overview of the methods that are being assessed to restore vision in patients with severe sight loss. Loss of vision occurs due to degeneration of the retina as in age related macular degeneration and retinitis pigmentosa. Age related macular degeneration is a major cause of visual impairment among people over 65 in Western countries (Van Newkirk et al., 2000); in the United Kingdom its incidence has increased by 30-40% over the past 40 years (Evans and Wormald, 1996). Retinitis pigmentosa generally occurs in a younger age group (incidence 1 per 4000 live births) and affects 1.5 million people worldwide (Parwez et al., 2005).In both conditions patients are visually impaired due to loss of photoreceptors. At present few treatments can remedy this and lead to recovery of vision (Klein & Francis, 2003 and Hunt & Margaron, 2003). Photodynamic laser therapy has been beneficial in some patients with age related macular degeneration, but this therapy does not address photoreceptor loss. Different gene and drug therapies have been tried, but their ability to replace lost photosensitive tissue is limited. Researchers are therefore investigating the possibility of using prostheses to restore vision (Parwez et al., 2005).