The potential pathophysiological role of tissue factor in age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of irreversible central vision loss in the elderly. Although the precise pathogenesis of AMD remains unknown, the pathology of advanced AMD is characterized by the degeneration of the retinal pigment epithelium and photoreceptors in the macular region, either with choroidal neovascularization (neovascular AMD) or without (geographic atrophy). Tissue factor (TF) is the primary cellular initiator of blood coagulation. An increased expression of TF has been implicated in the pathogenesis of neoplasia, specifically in angiogenesis, inflammation and apoptosis, all of which also appear to be involved in the pathogenesis of AMD. This article reviews the pathogenesis of AMD, biological functions of TF and the potential association of increased TF expression with AMD.