TNFSF10 and macular degeneration: Diabetic Retinopathy: The detection of extremely high levels of soluble TRAIL in the conjunctival sac of the anterior surface of the eye, compared to other body fluids, has important implications for maintaining the immune surveillance of the eye, and has inspired the investigation of a possible role of TRAIL for the pathogenesis of diabetic ocular complications such as diabetic retinopathy and macular degeneration.