Preretinal hemorrhages

A preretinal (subhyaloid) hemorrhage develops when blood escapes into the potential space between retina and vitreous. A preretinal hemorrhage typically is larger than other retinal hemorrhages. Because it is anterior to the retina, a preretinal hemorrhage obscures underlying retinal vessels. In an erect patient, red cells settle, creating a horizontal line of demarcation between plasma above and cells below.