The significance of oxidative mechanisms in diseases of the retina

The eye is at high risk to be damaged by oxidative mechanisms. One major reason is the exposure to light throughout life. Anterior segment structures are mostly exposed to UV light. Visible blue light is believed to be a significant damaging mechanism for the retina. The biochemical composition of the posterior segment structures (unsaturated fatty acids) is an important factor making the eye more susceptible than other organs. Damaging mechanisms such as xanthin oxidase mechanisms are responsible for damage occurring in ischaemic diseases. These mechanisms are well known from diseases of other organs. Ischaemic processes are no longer believed to be the primary damaging mechanisms in diabetic retinopathy. Here, advanced glycation end products (AGE's) and related products may induce oxidative reactions and the expression of growth factors. In age-related macular degeneration photodynamic processes occurring. already in childhood are believed to be a major factor contributing to the pathogenesis of the disease process. In addition, the expression of growth factors and new vessel growth can be initiated via inflammatory reactions or oxidative metabolites. In this manuscript we give an overview on oxidative mechanisms involved in the pathogenesis of retinal diseases. Different therapeutical and preventive approaches such as the results of the ARED-Study and possible side effects are discussed.