Vitreous role in the pathophysiology of retinal diseases has increased importantly over the recent years. This was possible using Optical Coherence Tomography which reviewed the way the vitreoretinal interface should be looked at and defined and classified new pathologies such as Vitreoretinal Traction Syndrome. Vitreous is not an empty space but an important anatomical structure with role in ocular physiology. With age biochemical changes occur so that vitreous starts to liquefy. Once the vitreous is liquefied (sinchisis) it collapses and passes in the retrohialoid space (sineresis). In complete PVD besides sinchisis there is a weakness of the adherence between the posterior cortex and ILM with total detachment of posterior cortex. Abnormal adhesions are associated with incomplete PVD. The definition and understanting of vitreoretinal pathology is an active and continuous process, PVD being the trigger of a lot of retinal pathologies: epiretinal membrane, macular hole, tractional macular oedema, VMTS, myopic traction maculopathy, exacerbations of exudative ARMD.