Experimental Autoimmune Uveitis As Animal Model for Human Posterior Uveitis

Uveitis is an intraocular inflammatory disease that mostly affects children and young adults. It is one of the major causes of blindness in young individuals in India and the world. It is responsible for about 10 per cent of total visual impairment. Unfortunately, etiological diagnosis is not evident in a majority of these patients. It is generally felt that autoimmune mechanism may be involved in so called 'idiopathic' cases which has led to search for the putative autoantigens in experimental animal models. It has been demonstrated that experimental autoimmune uveitis (EAU) can be elicited against several retinal proteins in rats, mice and sub-human primates. These include the S-antigen, a major protein on retinal photoreceptor cell, interphotoreceptor retinoid binding protein (IRBP) and several others. There are many similarities between clinical entities and the EAU, but the EAU differs from the clinical conditions in being self-limited, and requiring complete Freund's adjuvant for induction of the disease. The disease can be induced only in susceptible strains. Nevertheless, use of the EAU model has allowed for identification of disease causing epitopes of antigens and evaluation of disease modifying strategies which could be applied in clinical situations. There has been significant progress in this field, but still a lot more is required to be learnt to translate it into clinical practice.