Intermediate and posterior uveitis.

Sight-threatening intraocular inflammation affecting the posterior segment of the eye may be predominantly located in the peripheral retina and vitreous (intermediate uveitis) or postequatorially where it manifests as inflammation of the retina, retinal vessels and/or optic nerve with cellular infiltration of the choroid and retina and edema particularly at the macula. Involvement of the macula is the main cause for visual loss. Experimental models of posterior uveitis have revealed much concerning the mechanisms of inflammatory cell damage to the retina, implicating CD4 T cells, effector macrophages and pro-inflammatory cytokines. In particular, transgenic and gene deletion models of inflammation have allowed an understanding of how immune privilege in the posterior segment of the eye is disrupted. Importantly, this has led to the development of new treatments with novel immunosuppressants and 'biologics' and the promise of cell-based therapies which may allow customized therapies tailored to the individual's inflammatory profile.