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The highly vascular layer of the vertebrate eye, lying between the sclera and the retina.



the connective-tissue coat of the eye located between the retina and the sciera. It is through the choroid that metabolites and oxygen pass from the blood to the pigmentary epithelium and photoreceptors of the retina.

The choroid includes a suprachoroid layer facing the sciera, a layer of large veins, a layer of arteries and veins, the choriocapil-laris, and Bruch’s membrane. The suprachoroid layer consists of compact reticulin and collagenous fibers. It is rich in fibroblasts and melanocytes, whose processes run through the entire choroid. The arteries and veins of the choroid have a double endothelial lining and basal and adventitial layers. Bruch’s membrane is made up of an amorphous substance containing elastic reticulin and collagenous fibers. It is bounded on the inside by a cell membrane of pigmentary epithelium and on the outside by a porous membrane of capillary endothelium.

The choroid of some fishes and mammals, for example, ungulates, has a reflecting layer, or a mirror, that intensifies the light stimulation of the photoreceptors and increases the sensitivity of the eye to light.


Stebaeva, L. F., and O. V. Volkova. “Ul’trastruktura sosudistoi obo-lochki glaza krolika v norme i pri allergicheskom uveite.” Arkhiv anatomii, gistologii i embriologii, 1974, vol. 66, no. 2.
System of Ophthalmology, vol. 2. Edited by S. Duke-Elder. London, 1961.
Structure of the Eye: Proceedings of the Symposium at the Seventh International Congress of Anatomists. New York-London, 1961.


References in periodicals archive ?
Occasionally, CSF overproduction may occur as the result of choroid plexus tumors.
Vinit Mahajan, assistant professor in ophthalmology at the UI, said that this molecular map now gives them clues why certain areas of the choroid are more sensitive to certain diseases, as well as where to target therapies and why.
This molecular map now gives us clues why certain areas of the choroid are more sensitive to certain diseases, as well as where to target therapies and why," says Vinit Mahajan, assistant professor in ophthalmology at the UI and corresponding author on the paper, published in the journal JAMA Ophthalmology.
Combined endoscopic third ventriculostomy and choroid plexus cauterization as primary treatment of hydrocephalus for infants with myelomeningocele: Long-term results of a prospective intent-to-treat study in 115 East African infants.
In this form, the choroid, a matrix of blood vessels that feed the pigment epithelium at the back of the eye, grows new blood vessels that push the retina away from the choroid.
LCT's NTCELL implant is injected directly into areas of the brain where the neurons have died off, introducing new choroid plexus cells, the same 'support' cell that exist naturally in the brain.
The organoid grew structures similar to a human brain's hippocampus, retina and choroid plexus, which produces cerebrospinal fluid in the brain.
Yan was diagnosed with a brain tumor called choroid plexus carcinoma in August 2008 when he was 6 months old.
Approximately two-thirds of the total CSF volume is generated by the choroid plexus, with the remainder produced by extra-choroidal tissue.
The second is devoted to medical issues, and the third to surgery and to tumors of the retina, choroid, and vitreous.
A choroid plexus papilloma is usually midline without temporal bone destruction.
Clearside treats the pathological changes to the blood retinal barrier that lead to retinal blindness by delivering therapeutics through the suprachoroidal space to the retina and choroid using a proprietary microinjection dosage form.