Vitreous and preretinal hemorrhage of unknown origin in five diabetic patients

Five diabetic patients with nonproliferative retinopathy or controlled reti nopathy after photocoagulation developed intravitreous or preretinal hemorr ages of unknown origin. Intravitreous hemorrhage of unknown origin is characterized by the absence of angiographic hyperfluorescence suggestive of neovascularization. Examina tion of the retinal periphery with a three mirror lens reveals the absence of tears and an normally appearing arteriovenous network with no sign of bl eeding. The clinical cases reported here demonstrated: 1) the significance of poste rior vitreous detachment in the genesis of hemorrhage, 2) the difficulty en countered in assessing the seriousness of the hemorrhage and providing opti mal treatment, 3) the importance of initialing treatment early.