Posterior vitreous detachment (PVD)
The vitreous is clear jelly-like substance filling the cavity of the eye. It lies directly in front of the retina (the nerve tissue lining the back of the eye). With age, the vitreous jelly degenerates and liquefies, developing pockets of water. This may cause the vitreous to collapse and separate from the retina. This is called a posterior vitreous detachment (PVD).
Posterior vitreous detachment
Separation of the vitreous from the retina is a common occurrence that increases with age. In most cases there is no cause for concern. The vitreous cannot be reattached.
Signs and symptoms
You may notice small spots moving in your vision, described as floaters. They are more obvious when looking at a plain bright background, such as reading against a white page or driving against a clear blue sky.
Flashing lights can accompany this experience. These are white and very short-lived, for a split-second, and are similar to lightning or a camera flash.
Flashing lights are explained by the vitreous jelly pulling on the retina. The flashes of light can appear on and off for several days, and in some cases a few weeks.
These symptoms can be caused by a PVD but can also occur with rarer retinal conditions, such as a retinal detachment that is more serious. You should consult an eye doctor if you have new symptoms of worsening floaters and/or flashing lights to confirm the diagnosis and to exclude a retinal detachment.
Diagnosis and treatment
There is no treatment for PVD. The floaters remain, but in time become less noticeable. The flashing lights usually settle.
If you notice an increase in the number of floaters or flashing lights, or a shadow on the edge of your vision which persists, you should see an eye doctor immediately to exclude the possibility of any retinal problems.