What is zonular weakness?
Zonular weakness can be caused by disease or trauma, and its presence can make cataract surgery more challenging. Fortunately, there are adjunctive devices to effectively manage it and achieve successful outcomes. Causes. Certain diseases of the eye are associated with zonular weakness or insufficiency.
What is zonular dehiscence?
Definition. Rupture of the fibrous strands connecting the ciliary body and the crystalline lens of the eye. [ from NCI]
What is Zonular cataract?
This type of cataract is bilateral. It can be congenital or it can be acquired during the first years of life due to tetany or rickets. The cataract is always large enough to occlude the pupil. Its effect on vision depends primarily on the density of its components – especially the nucleus.
What is zonular?
The zonules are the tiny thread-like fibers that hold the eye’s lens firmly in place. The zonules also work with the ciliary muscles to help the lens accommodate (change focus). The zonule fibers tighten and pull the lens for near vision. They relax as the lens flattens for distance vision.
What do zonular fibers do?
Description. The zonular fibers anchor the the equator of the lens and adjacent anterior and posterior surface of the lens to the ciliary body and and ciliary part of the retina. The ciliary epithelial cells of the eye probably synthesize portions of the zonules.
What causes oil drop cataract?
Bilateral lens changes. Zonular or nuclear opacity with increased refractive power of the nuclear portion causes an “oil droplet” appearance on retroillumination. Lenticular myopia.
Where do zonules attach?
the lens capsule
The zonules attach to the lens capsule 2 mm anterior and 1 mm posterior to the equator, and arise of the ciliary epithelium from the pars plana region as well as from the valleys between the ciliary processes in the pars plicata.
What is the use of crystalline lens?
The crystalline lens of the eye is a natural lens which produces one third of the eye’s total optical power and focuses light into an image on the retina (the light-sensitive tissue at the back of the eye). The crystalline lens is elastic which allows it to flex in order to change its shape.