Most of the interior chamber of the eye is filled with a clear, gelatinous mass known as the vitreous, (from the Latin word for ‘glassy’). It is made up of 99% water and about 1% other substances, such as collagen and hyaluronic acid. Its main functions are to help maintain the shape of the eye, to keep the retina in contact with the back wall of the eye, to allow transmission of light to the retina, and to act as a shock absorber.
Symptoms of a posterior vitreous detachment include flashes of light, a sudden increase in floaters and a cobweb effect across your vision. As the vitreous shrinks and liquifies, its collagen fibres can cluster together and float freely, which causes the ‘floaters’ and ‘cobwebs’ to appear. Sometimes flashes of light in your peripheral vision accompany these symptoms.
PVD usually requires no treatment, other than a thorough eye examination. If the vitreous detaches fully without tearing or pulling the retina, then there is no need for concern. The problem occurs when the vitreous pulls or tears the retina as it shrinks. The resulting macular holes or detached retinas can cause vision loss and require immediate treatment.
Floaters and flashes become less and less noticeable for most people over time, until they eventually disappear altogether or cause very little frustration. In the very unusual case where floaters persist to a level that they affect quality of life, the vitreous can be removed and replaced in a procedure known as a vitrectomy. This is very rarely required.