What is Posterior Vitreous Separation?
The eye is a very complex functional and anatomic organ. The retina is a thin, delicate and transparent sheet of tissue that lines the inside of the back of the eye. Directly in front of the retina is a cavity that contains a gel called vitreous, a complex structure consisting of aqueous fluid, macromolecules and collagen fibrils. In children the vitreous is an optically clear, transparent, and formed gel However, as life progresses the vitreous gel naturally and gradually liquifies. By mid to late life, the vitreous has mostly liquified except for a layer of gel up against the retina. At some point in nearly all people this layer of gel will spontaneously begin to peel away, or separate, from the retina. This natural development in the eye is called a posterior vitreous separation (PVS).
Some people have no symptoms from a PVS. However when symptoms do occur they consist of “flashes and floaters”. The flashes occur because the layer of gel mechanically pulls on the retina as it separates and the brain interprets this mechanical irritation of the retina as light. Flashes occur most prominently when the PVS initially occurs and then gradually die down over a few weeks. The floaters occur because the layer of gel up against the retina contains fibers that clump together when the PVS occurs, then float around within the liquified vitreous and are symptomatic in the vision. These floaters usually gradually diminish in prominence over several weeks or months. Occasionally people will continue to perceive flashes and/or floaters for a prolonged period of time, but as long as a retinal examination discloses no vision threatening findings no treatment is necessary.
Vision threatening complications can occasionally develop after a PVS. In some cases, as the gel separates from the retina it may pull on and break a small retinal blood vessel and cause vitreous hemorrhage. Although vitreous hemorrhage will usually resolve on it’s own, it is important to examine the retina in case the gel has pulled on the retina hard enough to cause a retinal tear to develop. While retinal tears can be treated and stabilized with a laser treatment, they can also lead to a retinal detachment which is a very serious and potentially blinding complication of a PVS.
The abrupt onset of flashes and floaters should prompt a careful and complete examination of the back of the eye and the retina within a day or two of onset of symptoms. Since a retinal tear and/or retinal detachment may not be initially present but can occasionally occur later, a second examination is often done 3-4 weeks after the onset of the PVS. If no complications are identified at that examination future risk is low.
VitreoRetinal Surgery, P.A. is a group practice of fellowship trained Retina Specialists. We specialize exclusively in the treatment of retinal diseases. We are actively involved in research into new treatments and are capable of rapidly bringing newly approved treatments to our patients with retinal diseases.