Ocular Cell System

Here you can find tissue from most parts of the human eye. You can also find medium to grow the cells as well as RNA, DNA and protein derived from these cells.

The cornea is a unique tissue for two reasons: the transparency function and the synthesis of most of its proteins due to the cornea being an avascular tissue. The cornea consists of three distinct cell layers, the outer epithelium, the inner endothelium and the central stroma (the keratocytes).

The corneal epithelium plays a role in the innate immune response by sensing the presence of pathogens and providing signals that activate the corneal defense system. It also protects against UV- and 4-hydroxynonenal-induced cellular damage.

The conjunctival epithelium is a stratified, non-keratinized epithelium. It can be distinguished from the corneal epithelium by the expression of different cytokeratins, mucins and by the presence of glycocalix. Decrease or loss of mucin/glycocalix production generates squamous metaplasia, which may lead to dry eye and ocular surface diseases.

The ciliary epithelium rests upon the folds of the ciliary processes. It consists of two layers of cells which appear structurally and functionally distinct [1]. The basal membranes of the pigmented ciliary epithelial cells face the stroma, and the basal membranes of the non-pigmented ciliary epithelial cells (NPCEC) abut the aqueous humor. The NPCEC is largely responsible for the formation of aqueous humor in the mammalian eye.

The keratocyte of the cornea, or corneal fibroblast, is a highly specialized cell that is sandwiched between orthogonally arranged layers of collagen lamellae in the corneal stroma. They play a key role in maintaining the structure and transparency of the cornea as they are the source of stromal collagen and proglycans. They also play important roles in corneal wound healing and tissue repair.

The retina is a multi-layered structure lining the rear of the eye. It consists of photoreceptor cells and retinal pigment epithelial cells (RPE). RPE situated between the neurosensory retina and the choroid, form the outer blood-retina barrier that controls the chemical composition of the subretinal space.

The retinal astrocytes are very variable in type, most intimately associated with all parts of neurons, and thus most functionally interesting in their relationships with neurons. They provide structural, trophic, and metabolic support to neurons connected to the retina and modulate synaptic activity.

The iris is a pigmented disk with a variable aperture which forms the pupil of the eye. It is covered by squamous epithelium on anterior surface and 2 layers of pigmented epithelium on posterior. The iris pigment epithelial cells (IPE) share functional properties with retinal pigment epithelial cells (RPE) such as phagocytosis, degradation of rod outer segments and synthesis of trophic factors. In recent years, IPE have been transplanted into the subretinal space of eye to treat RPE defects.

The lens is built up by types of cells: lens fiber cells, which form the bulk of the lens, and a monolayer of epithelial cells cover the anterior surface of the fibers. The normal development of the lens of the eye involves the progressive differentiation and maturation of the lens epithelial cells.

The fibroblast is the cellular element responsible for fibrosis. Conjunctival fibroblasts, as other fibroblasts, act not only as structural cells in the production of the matrix components, but are also actively involved as effectors in allergic conjunctivitis.

Trabecular meshwork cells (TMC) play an active role in the aqueous outflow mechanism. Specific receptors for neurotransmitters and neuropeptides, including epinephrine, acetylcholine, and neuropeptide Y, have been identified in TMC.