Eventually, the vitreous may collapse in on itself, peeling away from the posterior retina as it does so. The vitreous peels from posterior to anterior but always remains attached to the most peripheral retina. Scintillating scotomas are flashes that move in a geometric pattern, last for several minutes, and are associated with a visual deficit in the affected area. These are usually migrainous in origin and often precede the onset of headache. They typically affect homonymous hemifields in both eyes though patients often misinterpret the symptoms as being unilateral.
Floaters are almost always due to opacities in the vitreous gel which cast shadows on the retina.
It is important to distinguish floaters from small fixed scotomas. Scotomas, on the other hand, are blank spots that remain fixed in position tracking eye movements exactly. When examining a patient with floaters, look carefully at the vitreous for cells or other vitreous opacities. Asking the patient to look down and then straight ahead will circulate the vitreous making it easier to see cells. If you re unsure whether the opacities you see are cells, compare them with what you see in the vitreous of the fellow eye.