Choroid Choroid The choroid, also known as the choroidea or choroid coat, is the vascular layer of the eye, containing connective tissues, and lying between the retina and the sclera. The human choroid is thickest at the far extreme rear of the eye (at 0.2 mm), while in the outlying areas it narrows to 0.1 mm. The choroid provides oxygen and nourishment to the outer layers of the retina. Along with the ciliary body and iris, the choroid forms the uveal tract. The structure of the choroid is generally divided into four layers (classified in order of furthest away from the
Enucleation of the eye To avoid a sunken appearance to the eye socket, an implant approximating this volume can be placed into the space of the removed eye, secured, and covered with Tenon's capsule and conjunctiva (the mucous membrane covering the natural sclera). Implants can be made of many materials with the most common being plastic, hydroxylapatite, metal alloy or glass. Later, once the conjunctiva have healed and post-operative swelling has subsided, an ocular prosthesis can be placed to provide the appearance of a natural eye. The prosthesis is fabricated by an ocularist. Its form is that of a cupped disc so that it