Figure 1: A model of interaction of endogenous and exogenous factors, and subsequent neural cellular disorders in the retina. Intracellular signaling such as inflammatory signalings and ROS, can be activated by both endogenous and exogenous factors. The signalings themselves may cause neural functional disorders, and also abnormal gene expression, such as increased expression of inflammatory cytokines, leading to cell death. These events may influence exogenous factors. Autocrine and paracrine mechanisms may be involved.