Iris pigment epithelium

Iris pigment epithelium (IPE) is a single layer of cells located on the posterior surface of the iris in the eye. It is part of the uvea, which also includes the choroid and ciliary body. The IPE plays a crucial role in the eye's function and health, particularly in relation to light absorption and the regulation of intraocular pressure.

Structure

The IPE is composed of a single layer of densely pigmented, columnar cells. These cells are hexagonal in shape and are tightly packed together, forming a smooth and continuous layer. The pigmentation of the IPE is responsible for the eye color in humans.

Function

The primary function of the IPE is to absorb light, preventing it from reflecting back into the eye and causing a decrease in visual acuity. This is particularly important in preventing glare and halos around lights.

In addition to light absorption, the IPE also plays a role in the regulation of intraocular pressure. It does this by controlling the flow of aqueous humor, the clear fluid that fills the anterior chamber of the eye.

Clinical significance

Damage or abnormalities in the IPE can lead to a variety of eye conditions. For example, aniridia, a condition characterized by the absence of the iris, is often associated with abnormalities in the IPE. Similarly, pigment dispersion syndrome, a condition in which pigment granules from the IPE are dispersed throughout the eye, can lead to glaucoma.

See also

• Iris (anatomy)
• Uvea
• Choroid
• Ciliary body
• Aniridia
• Pigment dispersion syndrome