Posterior Vitreous Detachment

Overview

Posterior vitreous detachment (PVD) is the separation of the posterior vitreous cortex from the neurosensory retina, an age-related process that occurs in the great majority of people by later life. Most PVDs are uncomplicated and require only reassurance and monitoring, but a clinically important minority are associated with retinal tears that, if missed, can progress to retinal detachment — making PVD one of the most common "see today" urgent ophthalmology consultations.

Epidemiology & Risk Factors

PVD becomes increasingly common with age as the vitreous gel undergoes progressive liquefaction (syneresis) and loses its attachment to the internal limiting membrane of the retina. Risk factors for a complicated PVD (i.e., one with an associated retinal tear) include high myopia, prior intraocular surgery, prior retinal tear or detachment in either eye, and lattice degeneration. A key risk-stratification insight: eyes with a prior retinal detachment in one eye require careful attention to the fellow eye, since posterior vitreous status on OCT in the fellow eye has been shown to predict its future retinal detachment risk.¹

Pathophysiology

With age, the vitreous gel liquefies and the cortical vitreous separates from the internal limiting membrane, typically beginning posteriorly and progressing toward the vitreous base. Where vitreoretinal adhesion is abnormally strong (over retinal blood vessels, areas of lattice degeneration, or the vitreous base), the separating vitreous can exert tractional force sufficient to tear the retina — the mechanism behind PVD-associated retinal tears and subsequent rhegmatogenous retinal detachment. Persistent, incomplete separation localized to the macula or optic disc (vitreomacular or vitreopapillary adhesion) can itself cause tractional pathology even without a tear.

Clinical Presentation

The classic presentation is the acute onset of new floaters (often described as a "cobweb," "spider," or ring-shaped floater corresponding to the detached peripapillary glial ring, known as a Weiss ring) and photopsias (flashes of light, typically in the peripheral vision, from vitreoretinal traction). Symptoms are usually unilateral at onset. A minority of patients report a "curtain" or shadow, which should raise concern for an associated retinal tear or detachment and prompt urgent, dilated exam.

Exam Findings

• Weiss ring (detached peripapillary glial tissue) visible on dilated fundus exam or OCT, confirming complete posterior vitreous separation from the disc
• Vitreous pigment cells ("tobacco dust" or Shafer's sign) on slit-lamp exam of the anterior vitreous, a strong indicator of an associated retinal tear
• Vitreous hemorrhage, which should prompt a very high index of suspicion for a retinal tear given the risk of an obscured view
• On OCT: posterior vitreous opacities, shown to be predictive of retinal tears in acute symptomatic PVD, and persistent focal vitreomacular or vitreopapillary adhesion²
• A careful 360-degree dilated peripheral retinal exam with scleral depression is required to rule out an associated retinal tear

Differential Diagnosis

• Retinal tear or rhegmatogenous retinal detachment (the critical diagnosis to exclude in every acute PVD presentation)
• Vitreous hemorrhage from other causes (proliferative diabetic retinopathy, retinal vein occlusion)
• Migraine with visual aura (typically bilateral, scintillating scotoma with a characteristic march across the visual field, distinct from the discrete, peripheral flashes of PVD)
• Vitritis/uveitis (associated with inflammatory cells and other signs of intraocular inflammation, not just vitreous syneresis)

Management

Every patient with acute symptomatic PVD requires a prompt, dilated fundoscopic exam with scleral depression to search for a retinal tear, ideally the same day symptoms begin or very soon after. Posterior vitreous opacities and pigment cells on exam/OCT help identify eyes at higher risk of an associated tear warranting especially careful peripheral retinal examination.² If a retinal tear is found, urgent laser photocoagulation or cryotherapy is performed to wall off the tear and prevent progression to rhegmatogenous retinal detachment.

If no tear is found initially, patients are counseled on warning symptoms (increased floaters, new flashes, a curtain or shadow in vision) and typically re-examined several weeks later, since a tear can develop after the initial presentation as vitreous traction evolves. A study of on-call resident triage of acute PVD found that structured protocols for same-day dilated exam and appropriate follow-up produced safe outcomes with low rates of missed retinal tears, supporting well-organized urgent-care pathways for this common presentation.³ In eyes with a retinal detachment history, OCT assessment of the fellow eye's posterior vitreous status can help stratify future detachment risk in that eye.¹

Complications

• Retinal tear progressing to rhegmatogenous retinal detachment if missed or inadequately treated
• Vitreous hemorrhage obscuring the view and complicating diagnosis of an underlying tear
• Persistent vitreomacular traction or epiretinal membrane formation from incomplete posterior vitreous separation
• Recurrent or delayed-onset retinal tear after an initially negative exam, underscoring the need for scheduled follow-up

Clinical Pearls

• New floaters and flashes require a same-day or very prompt dilated exam with scleral depression — the goal is to find a retinal tear before it becomes a detachment
• Vitreous pigment cells (Shafer's sign/"tobacco dust") on slit-lamp exam are a strong indicator of an associated retinal tear and should prompt an especially careful peripheral exam
• A negative initial exam does not exclude a future tear — scheduled follow-up in several weeks is standard, since traction can evolve after the initial presentation³
• Posterior vitreous opacities on OCT help predict which acute PVD patients are at higher risk of an associated retinal tear²
• In patients with a retinal detachment history in one eye, fellow-eye posterior vitreous status on OCT can inform future detachment risk stratification¹

Common Pitfalls

• Reassuring a patient with acute flashes/floaters without performing a dilated, scleral-depressed peripheral exam
• Missing a retinal tear obscured by vitreous hemorrhage, rather than recognizing hemorrhage itself as a red flag requiring especially careful evaluation (and repeat exam once the view clears)
• Failing to counsel patients on warning symptoms and schedule follow-up after an initially negative exam
• Confusing PVD-related photopsias with migrainous visual aura without considering the differences in laterality and character
• Overlooking fellow-eye risk assessment in patients with a unilateral retinal detachment history