Amplifying factors in ocular surface diseases: apoptosis.

Apoptosis is a major cell death mechanism that occurs widely in normal tissues and is overstimulated in ocular surface diseases. Apoptosis has been studied specifically in regard to refractive surgery, contact lens wear, and dry eye syndrome. It appears to be closely related to inflammation, as many inflammatory cytokines may promote both inflammation and apoptosis, and their receptors trigger both pathways. A major mediator would play a key role in ocular surface diseases, both at the pro-apoptotic and pro-inflammatory levels, e.g., tumor necrosis factor alpha. This cytokine and its main receptors are, therefore, overexpressed in ocular surface diseases, which makes it a possible target for future therapeutic approaches.