Ciliary Body


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ciliary body

[¦sil·ē‚er·ē ¦bäd·ē]
(anatomy)
A ring of tissue lying just anterior to the retinal margin of the eye.

Ciliary Body

 

in terrestrial vertebrates, including humans, the part of the eye that converts blood serum into the intraocular fluid that is secreted into the posterior chamber of the eye. The ciliary body forms a circle of numerous radial folds (70 to 80 in humans) on the internal surface of the eye between the iris and the retina. It consists of mesodermal stroma and two neuroepithelia. The external pigmented neuroepithelium is a continuation of the pigmented epithelium of the retina, whereas the nonpigmented internal layer, which plays a major role in the secretion of intraocular fluid, is a continuation of the retina proper.

Fibers of the zonule of Zinn are attached to the basal membrane of the ciliary folds. The amount of tension of the ligament is determined by contraction of the circular ciliary muscle situated in the stroma of the ciliary body near the place of contact with the sclera. The tension of the ciliary muscle determines the shape of the crystalline lens. The ciliary body is the most vascularized part of the eye; it is supplied by blood vessels from the systemic circulation of the iris.

Inflammation of the ciliary body is called cyclitis; inflammation of both the ciliary body and the iris is called iridocyclitis.

REFERENCES

Stroeva, O. G. Morfogenez i vrozhdennye anomalii glaza mlekopitaiushchikh. Moscow, 1971.
Davson, H. The Physiology of the Eye, 3rd ed. Edinburgh-London, 1972.

O. G. STROEVA

References in periodicals archive ?
Grade 4 (35-45 degrees): the widest angle (characteristic of myopia and aphakia) in which the ciliary body can still be visualised with ease.
One study investigating the survival in cats that underwent enucleation owing to diffuse melanoma showed that tumor invasion to the ciliary body or iris stroma, or with secondary glaucoma due to tumor ingrowth, decrease lifetime in comparison with age-matched healthy cats (KALISHMAN et al.
Given the observed blood flow improvement measured in the retinal capillary vessels, it is likely that more blood reaches the ciliary body and provides nourishment to the ciliary muscles.
Topical adrenaline and the adrenaline precursor dipivefrin lower IOP They probably act on pre-synaptic [Alpha]-2 adrenoceptors on the ciliary body [21].
It is, of course, moved by muscles in the socket, and a cluster of tiny muscles known as the ciliary body focuses the lens.
The middle group (vascular tunic, also called the uvea), consists of the choroid, the ciliary body, and the iris.
Intermediate uveitis affects the middle portion of the eye, such as the ciliary body and vitreous.
1) Iris melanoma, the most common malignancy of the iris, originates from the melanocytes of the iris stroma and its prognosis is better than that of choroid and ciliary body melanomas.
Iritis" refers to an inflammation of the iris only, while "iridocyclitis" involves both the iris and the ciliary body.
More than 90% of uveal melanomas involve the choroid with the remainder affecting the iris and ciliary body.
frequently culminate in loss of eye vision as a result of endophthalmitis, anterior chamber collapse and glaucoma or chronic leakage of aqueous humour, leading to atrophy of ciliary body and phthisis bulbi (Felberg, 2003).
4 mm (apical thickness) [Figure 1]b; ultrasound biomicroscopy demonstrated a moderately irregular acoustically solid in 10:30–13:30 o'clock meridians in the ciliary body, measuring 9.