They may occur in such conditions as retinal vein occlusion, diabetic retinopathy, posterior vitreous detachment, retinal neovascularization, retinal tears, or ocular trauma. In the latter five conditions, retinal detachment may ensue. Vitreous hemorrhages tend to absorb slowly. Localized bleeding from retinal vessels can usually be controlled by photocoagulation. Periodic evaluation of vascular retinopathies by an ophthalmologist is important, particularly in diabetes mellitus.
Retinal hemorrhages are always significant, reflecting vascular disease that usually is systemic.
Floaters are usually most noticeable against a white homogeneous background and seem to move slowly when the eye is still. Floaters maintain their relative position in the visual field with eye movement. This leads to macroscopic opaque aggregates of vitreous fibers, which can be seen floating in the vitreous. Since the vitreous gel is denser where it attaches to the optic nerve, floaters are usually more apparent in this area. Although floaters usually are without significance, in a few patients they may indicate a tear in the retina.