The choroid is the layer of blood vessels and connective tissue between the sclera (white of the eye) and retina. It is part of the uvea and supplies nutrients to the inner parts of the eye. Inflammation of the choroid is called choroiditis.
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Fay A. Diseases of the visual system. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 449.