Blepharitis : Overview, Causes, & Risk Factors

Alternate Names : Eyelid inflammation

Definition

Blepharitis is an inflammation of the eyelash follicles, along the edge of the eyelid. The cause is overgrowth of the bacteria that is normally found on the skin.

Overview, Causes, & Risk Factors

Blepharitis is usually caused by seborrheic dermatitis or a bacterial infection, and sometimes it is a combination of both. Allergies and eyelash infestation with lice may also cause blepharitis, although these causes are less common.

This condition is characterized by excess oil production in the glands near the eyelid. Too much oil creates an environment where the normal bacteria found on the skin can overgrow. The eyelids appear red and irritated, with scales that cling to the base of the eyelashes.

Blepharitis may be connected to repeated styes and chalazia. Risk factors are seborrheic dermatitis of the face or scalp, rosacea, lice, and allergies.

Pictures & Images

Eye

The eye is the organ of sight, a nearly spherical hollow globe filled with fluids (humors). The outer layer or tunic (sclera, or white, and cornea) is fibrous and protective. The middle tunic layer (choroid, ciliary body and the iris) is vascular. The innermost layer (the retina) is nervous or sensory. The fluids in the eye are divided by the lens into the vitreous humor (behind the lens) and the aqueous humor (in front of the lens). The lens itself is flexible and suspended by ligaments which allow it to change shape to focus light on the retina, which is composed of sensory neurons.

Blepharitis

Blepharitis is an inflammation of the lash follicles at the eyelid margins due to excess growth in lash follicles of bacteria normally present on the skin.

• Blepharitis : Overview, Causes, & Risk Factors

• Blepharitis : Symptoms & Signs, Diagnosis & Tests

• Blepharitis : Treatment

Review Date : 12/12/2008
Reviewed By : A.D.A.M. Editorial Team: David Zieve, MD, MHA, Greg Juhn, MTPW, David R. Eltz. Previously reviewed by Paul B. Griggs, MD, Department of Ophthalmology, Virginia Mason Medical Center, Seattle, WA. Review provided by VeriMed Healthcare Network (8/22/2008).

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