Pathophysiology

The pathophysiologic mechanisms of OCP and its associated conjunctival fibrosis have not been completely elucidated. It is thought that a critical defect in immune system regulation causes production of autoantibodies (IgG and IgA) [9, 24] directed against key subunits of integrin, epiligrin and laminin in the conjunc-tival epithelium (hemidesmosome-epithelial membrane complex) [16,31].

Many potential "triggers" have been proposed. These include genetic predisposition and exposure to topical or systemic medication. It is thought that human leukocyte antigen DR2 (HLA-DR2), human leukocyte antigen DR4 (HLA-DR4) and human leukocyte antigen DQw7 (HLA-DQw7) genotypes confer an increased genetic susceptibility to development of OCP [1, 2]. This may occur in a "double-hit" manner where an environmental insult in a genetically susceptible individual leads to disease.

Some patients may develop drug-induced pemphigoid in response to systemic or topical medication. Drugs implicated include systemic practolol, topical pilocarpine, epinephrine, phospholine iodide, timolol, and idoxyuridine

Autoantibodies isolated from sera of patients with OCP recognize and bind to the b4-subunit of the a6b4-integrin [10]. Autoantibodies to epiligrin (laminin 5) [13], b4-integrin [29], and a6-integrin [15] have been identified in some patients. The antibodies bind to the target antigen and begin a sequence of events that results in chronic inflammation and, eventually, in fi-brosis. The fibrosis progresses to involve the lacrimal ductules and meibomian ducts, leading to tear film abnormalities (decreased mucin and aqueous component of tears), disorientation of lash follicles,with trichiasis, conjunctival shrinkage, and keratinization. These complications conspire to produce corneal damage and loss of vision.

How To Deal With Rosacea and Eczema

How To Deal With Rosacea and Eczema

Rosacea and Eczema are two skin conditions that are fairly commonly found throughout the world. Each of them is characterized by different features, and can be both discomfiting as well as result in undesirable appearance features. In a nutshell, theyre problems that many would want to deal with.

Get My Free Ebook


Post a comment