Causes of vitreous hemorrhage.

It is often a challenge for the ophthalmologist to find the underlying cause of a vitreous hemorrhage. Unless clinical signs clearly point in another direction, the first suspicion should always be a posterior vitreous detachment causing a retinal tear. The other two major causes, diabetic retinopathy and retinal vein occlusion, remain common complications in spite of recent years' improvement in retinal treatment. Macroaneurysm is one of the most often overlooked causes of vitreous hemorrhage. An ocular tumor sometimes presents with a vitreous hemorrhage. In all cases of dense vitreous hemorrhages, the use of diagnostic ultrasonography is mandatory.