ABSTRACT
Posterior vitreous detachment (PVD) is the most common and most important event that occurs in the vitreous. PVD causes most rhegmatogenous retinal detachments (RRDs) via retinal tear formation. It is the instigator of the disorders of macular pucker and macular hole formation. PVD may tear blood vessels in the retina or in neovascular complexes causing haemorrhaging into the vitreous cavity. A PVD can be diagnosed by examining the eye with a 90-dioptre lens. If a Weiss ring is present, then a PVD has occurred. The posterior hyaloid membrane may be seen. A partial PVD is a diagnosis that should be made only rarely because it can be extremely difficult to determine whether there are remaining vitreous attachments. In most patients with retinal tears, retinal pigment epithelial cells, which migrate from the subretinal space through the tear, will be visible in the anterior vitreous. The pigment granules in Shafer's sign are relatively large, brown and are seen in the anterior vitreous.
