Definition:

Blepharitis is a chronic inflammatory condition of the eyelids associated with itchiness, redness, flaking, and crusting. It is among the most common ocular conditions affecting both children and adults. The etiology is complex and not fully understood, but the general consensus is that bacteria and inflammation contribute to the pathology. Blepharitis can be classified into anterior blepharitis and posterior blepharitis. Anterior blepharitis describes inflammation of the eyelid skin and eyelash follicles and may be accompanied by squamous debris or collarettes. Anterior blepharitis has classically been associated with Staphylococcus infection and seborrheic dermatitis. Posterior blepharitis describes inflammation of the meibomian glands and their orifices and may be a result of or cause of meibomian gland dysfunction (MGD). MGD is one cause of posterior blepharitis but others include infectious or allergic conjunctivitis, and rosacea. The diagnosis of blepharitis is almost always based on the history and clinical examination. Long-term management of symptoms may include daily eyelid cleansing routines and the use of therapeutic agents that reduce infection and inflammation. Recent clinical trials have shown that antibiotics and topical corticosteroids can produce significant improvement in signs and symptoms of blepharitis.