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
The University of Illinois Eye and Ear Infirmary as the Claes Dohlman Chair in Ophthalmology, Professor of Ophthalmology at Harvard Medical School, and Senior Scientist & W. Clement Stone Scholar at The Schepens Eye Research Institute, as well as the Director, Cornea & Refractive Surgery, Massachusetts Eye & Ear Infirmary, Vice Chairman of Harvard Department of Ophthalmology, and Director of the Harvard Medical School Cornea Center for Excellence. Jennifer I. Lim: A leading authority on retina and vitreoretinal diseases, having performed more than 6,000 vitreoretinal surgeries and directed more than 50 clinical research studies and trials on age-related macular degeneration, diabetic retinopathy, macular edema and retinal vein occlusion