The eye proteome
Eyes are responsible for the detection of light and its subsequent conversion of visual stimuli to neuronal signals that are transported to the visual centers of the brain. Protein expression of selected genes with literature indicating function related to different structures in the eye, excluding retina, were analyzed by using the whole section of the eye. Table 1 includes the full list of genes that have been analyzed so far. For information about gene and protein expression in the retina, please visit the The retina proteome.
Table 1. Following 29 genes have been analyzed in eye.
Figure 1. Immunohistochemical staining of human eye using an antibody toward CRYBB2 shows strong positivity in lens.
Figure 2. Immunohistochemical staining of human eye using an antibody toward OPTC shows strong positivity in the vitreous of the eye.
Figure 3. Immunohistochemical staining of human eye using an antibody toward KRT12 shows strong positivity in corneal epithelium.
Eye anatomy, function and histology
The eyes are responsible for the detection of light and its transformation to neuronal signals which are then sent to the visual centers of the brain. The eye globe is enveloped in a fibrous corneoscleral layer. The anterior portion includes a translucent surface called the cornea, while the rest is made up of sclera, a white-colored fibrous layer to which the outer eye muscles are attached. The front of the cornea is covered with a non-keratinized stratified corneal epithelium. Underneath the corneoscleral coat lies the choroid, a layer containing blood and lymphatic vessels. Its main function is to provide nutrients to the cells of the eye. Light enters the eye via the pupil, which is an opening surrounded by the iris. The iris consists of a pigmented fibrovascular layer that allows for the contraction or dilation of the pupil, as well as a layer of pigmented epithelial cells. The size of the pupil affects the amount of light that enters the eye. Light is refracted by the lens, a transparent disc suspended by ciliary muscle fibers. Elongated fiber cells are the predominant component of the lens while the anterior side is lined with epithelial cells. The refracted light is focused onto the retina, the innermost layer of the eye, which transforms light into nerve signals that are then transmitted by the optical nerve to the brain. The space between the retina and lens is filled up by a transparent gelatinous mass called the vitreous humor. The vitreous humor consists of 99 percent water and is contained in a thin hyaloid membrane.