The vitreous is a gel-like substance that fills most of the interior of the eye. Prior to birth, blood vessels course through it in order for the front structures of the eye to form properly. Thereafter, the vitreous serves no known purpose. The vitreous is composed of about 90% water and 10% proteins. Changes to these proteins over time cause it to become increasingly liquefied over time, leading to symptoms of floaters, small dark specks of varying sizes and shapes that seem to be influenced by movement of the head or eyes.
A posterior vitreous detachment (PVD) occurs when the vitreous has become sufficiently liquefied such that the back face of the vitreous that used to be adherent to the retina (which is located on inner aspect of the back wall of the eyeball) starts to separate from the retina. This is a natural process typically that occurs with age. By the age of 60, about 25% of eyes will have developed a PVD, and by 70 about 2/3 of eyes will have done so. Blunt trauma to the eye or eye surgery may cause a PVD as well.
Patients usually notice a PVD as a sudden onset of new floaters. Additionally, flashes of light indicating pulling upon the retina can be noted.
Sometimes, a PVD can result in a retinal tear, which in turn could cause a retinal detachment. The symptoms of a PVD are very similar to that of a torn retina or early retinal detachment; therefore, it is important that the retina be examined promptly with a dilated examination.
Typically, no treatment is indicated for a PVD in the absence of a tear or detachment of the retina. Over time, most patients notice floaters less prominently. However, a few patients are bothered by persistent floaters. In such cases, laser or a surgery called a vitrectomy can be considered as treatment for sy