Posterior Vitreous Detachment
It is a separation of the posterior vitreous cortex from the neurosensory retina - the vitreous collapses anteriorly towards the vitreous base.
Initially there is liquefaction and syneresis → rupture in the posterior hyaloid → liquified vitreous flows out → separates the posterior hyaloid from the retina
Begins as a partial PVD at the perifoveal region → progresses to optic disc and formation of Weiss ring
Vitreous traction at firm sites of adhesion → retinal tear → retinal detachment
Risk factors: increasing age, myopes, inflammation, following cataract surgery, trauma
Symptoms: Floaters & Photopsias
Risk of Retinal Tear:
Acute PVD → 15% risk of retinal tear
PVD + Presence of vitreous hemorrhage or pigment → 50-70 % risk of retinal tear
PVD without VH → 10-12% risk of retinal tear
The chance of developing a retinal tear after acute PVD is high and so the patient has to be examined again in 4-6 weeks
Image from Rajan Eye Care Hospital