Definition: As we age, the thick vitreous gel inside the back of our eyes becomes less like a gel and more like a fluid. Small pockets of fluid form within the gel of the vitreous material. As the eyeball moves, the liquefied vitreous moves around inside the vitreous cavity. Because of this movement of fluid, the vitreous begins to pull on the retina. With time, the vitreous can pull free and separate from the retina in the back of the eye. This is called a "posterior vitreous detachment" (PVD). This kind of detachment happens eventually in most people and infrequently causes problems. The prevalence increases with age and natural eye length (myopia). It is found in 60% of people above 70 years of age.
Symptoms: Patients with acute PVD experience brief flashes of light (photopsia) and/or "floaters". Flashes represent retinal stimulation from vitreous traction, whereas floaters are shadow cast from particulate matter suspended in the vitreous over the retina, and these can be: vitreous collagen fibers, hemorrhage, or epiretinal glial tissue torn from the optic disk. At least one retinal tear is found in 15% of patients with acute PVD, and if vitreous hemorrhage is seen, a tear is found in 2/3 of cases. PVD can tear the retina at areas where the vitreous is firmly attached. When a piece of the retina is torn free, the remaining tear is called an operculated tear. When the torn retina remains adherent, we have a flap or Horseshoe tear. Flap tears are more likely to progress into retinal detachment, then operculated tears, because of the continuing vitreal traction on the retinal flap.
Treatment: The retina should be carefully examined to rule out tears, and treated appropriately. If no tears are found, the patient is monitored for several months, as tears may occur after the acute PVD. The floater(s) do not go away unless surgically removed, which is only performed for very large, visually significant floaters. Usually if left alone, the floaters are ignored by the mind. Patients are urged to report any new floaters or flashing lights to be re-examined.