A posterior vitreous detachment (PVD) is a condition of the eye in which the vitreous membrane separates from the retina.
The condition is common for older adults; over 75% of those over the age of 65 develop it. Although less common among people in their 40s or 50s, the condition is not rare for those individuals.
Patients may notice flashing lights and floating spots. The floaters appear as tiny specks that float in your field of vision. They may also appear as cobwebs. The flashing lights are due to the vitreous pulling on the retina. They may seem like sparklers or lightening streaks. A PVD is a normal occurrence and requires no treatment. Eventually the flashes stop and the floaters become less noticeable. The floaters may never disappear completely, but do become less noticeable.
The vitreous humor is a gel which fills the eye behind the lens. Between it and the retina is the vitreous membrane. With age the vitreous humor changes, shrinking and developing pockets of liquefaction, similar to the way a gelatin dessert shrinks and detaches from the edge of a pan. At some stage the vitreous membrane may peel away from the retina. This is usually a sudden event, but it may also occur slowly over months.
Age and refractive error play a role in determining the onset of PVD in a healthy person. PVD is rare in emmetropic people under the age of 40 years, and increases with age to 86% in the 90s.
PVD may also occur in cases of cataract surgery, within weeks or months of the surgery.
Posterior vitreous detachment is diagnosed by slit-lamp biomicroscopy, which will usually show a prominent plane defining the posterior vitreous face. The presence of a glial annulus in the vitreous cavity (Weiss ring) is strong evidence of PVD.
Therapy is not required or indicated in posterior vitreous detachment, unless there are associated retinal tears, which need to be repaired. In absence of retinal tears, the usual progress is that the vitreous humor will continue to age and liquefy and floaters will usually become less and less noticeable, and eventually most symptoms will completely disappear. Prompt examination of patients experiencing vitreous humor floaters combined with expeditious treatment of any retinal tears has been suggested as the most effective means of preventing certain types of retinal detachments.