Overview of Coloboma

1752 Words8 Pages
Coloboma is a congenital eye defect, which is represented by missing pieces of tissue (gaps or notches) in eye structures. The eye consist of several protective layers and cavities. The outer layer consists of the sclera and the cornea. The front part of the sclera is covered by a transparent membrane called conjunctiva, involved in protecting the eyes and lining the inside of the eyelids. The cornea is a dome-shaped structure in the front of the eye that encloses the anterior chamber of the eye. It is transparent, allowing light to enter the eye, and along with the lens helps focus and direct light onto the retina. The middle layer of the eye includes the iris, the ciliary body, the lens and the choroid. The iris gives a person’s distinct eye colour, controls the size of the pupil and hence the amount of light entering the eye. It separates the anterior and posterior chambers in the front part of the eye. These chambers contain the aqueous humour, which is important in nourishing the lens and cornea. The lens is a shear, flexible structure, which changes its shape and hence participate in focusing one’s vision on close or distant objects. The vitreous humor is a jelly-like substance that fills the back portion of the eye. It has a structural function and is involved in maintaining the eye’s shape, but also helps transmitting the light to the retina. The choroid is a membrane found between the sclera and the retina. It lines the back of the eye and is rich in blood vessels. It is highly pigmented in order to absorb light and prevent scattering. The inner layer- the retina lines the inside of the back part of the eye and is the light-sensitive part. It is rich in photoreceptor cells and each photoreceptor is linked to... ... middle of paper ... ...Willer, G.B., Smith, K., Gregg, R.G., and Gross, J.M.(2008) Zebrafish blowout provides genetic evidence for Patched1-mediated negative regulation of Hedgehog signaling within the proximal optic vesicle of the vertebrate eye, Developmental Biology 319(1):10-22 Sanyanusin P., A.McNoe L., J.Sullivan M., Weaver R.Grey. Eccles M.R. (1995) Mutation of PAX2 in two siblings with renal-coloboma syndrome, Human Molecular Genetics Vol. 4, No. 11 2183-2184 Torres M, Gómez-Pardo E., Gruss p. (1996) Pax2 contributes to inner ear patterning and optic nerve trajectory , Development 122, 3381-3391 Viringipurampeer I. A., Ferreira T., DeMaria S., Yoon J. J., Shan X., Moosajee M., Gregory-Evans K., Ngai J., Gregory-Evans C. Y., (2012) Pax2 regulates a fadd-dependent molecular switch that drives tissue fusion during eye development, Human Molecular Genetics, Vol. 21, No. 10 2357–2369

More about Overview of Coloboma

Open Document