Opportunistic Chorioretinitis

Abstract

The choroid is the posterior part of the uvea, the middle tunic of the eye; the choroid is composed of blood vessels, melanocytes, fibroblasts, resident immunocompetent cells and supporting collagenous and elastic connective tissue, its main function is to supply oxygen and nutrients to the outer retina and, in species with avascular retinas, to the inner retina as well. Retina is the light-sensitive structure of the eye; vision begins at the retina, where light is converted into neurochemical and electrical signals. The neural retina is made up of multiple layers, the retina has two main components: a sensory layer and a pigmented layer, derived from the inner and outer layers of the optic vesicle, respectively. The immune system is a system of biological structures and processes within an organism that protects against disease. To function properly, an immune system must detect a wide variety of agents, known as pathogens, from viruses to parasitic worms, and distinguish them from the organism's own healthy tissue.