Ciliary Zonule

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Related to zonule: Zonular fibres

Ciliary Zonule

 

(also zonule of Zinn), in terrestrial vertebrates, including humans, a round ligament supporting the crystalline lens. The ciliary zonule was first described in 1755 by the German scientist J. Zinn. It consists of dense glycoprotein fibers attached to the basal membrane of the ciliary folds and to the equator of the lens capsule. The fibers of the ciliary zonule are covered by a mucopolysaccharide gel. The gel fills the spaces between the fibers and protects the fibers from the proteolytic enzymes of the anterior chamber of the eye. The gel imparts a membranous appearance to the anterior and posterior surfaces of the ciliary zonule. Tightening or loosening the ciliary zonule by contraction of the ciliary muscle alters the curvature of the lens and thereby effects accommodation.

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Steven, "Development, composition, and structural arrangements of the ciliary zonule of the mouse," Investigative Opthalmology and Visual Science, vol.
Weak lens zonules are associated with which of the following conditions?
UBM performed in our patient did not reveal any significant echogenicity belonging to zonules at the defective site.
All outpatients presenting for care at the glaucoma specialty clinic at Beijing Tongren Eye Center, Beijing from May 2006 to April 2007 were evaluated for signs of PDS: corneal endothelial pigmentation, anterior iris stromal pigment dusting, ITDs, posterior iris bowing, increased TM pigmentation, and pigment granule dusting on lens zonules or peripheral posterior surface.
They are located within the anterior sclera and provide both protection for the globe and an attachment site for the lens zonules, which function to change the shape of the lens during focusing.
Without adequate B6 at the right lime, remodeling the pigmentary layer of the iris is accomplished with surrogate proteins, which are vulnerable to flaking off with athletic bouncing and with unfortunate engagement with the zonules. Using the supplemental protein cannot be recommended without simultaneous availability of B complex and especially B6.
Ectopia lentis, a common manifestation of homocystinuria and Marfan syndrome, can be due to subluxation (lens zonules are still in place) or dislocation (no zonules in place).
With pigment dispersion glaucoma, the lens zonules rub against the posterior surface of the iris and release pigment that may clog the trabecular meshwork and increase intraocular pressure.
a) Iris pigment is released due to friction between lens zonules and peripheral iris
In pseudoexfoliation syndrome, the lens zonules are more fragile and have diminished elasticity, and spontaneous intraocular lens dislocation may occur due to capsular fibrosis.
The actual dislocation event typically occurs later in life as zonules weaken [2].