Ophthalmology – Posterior Vitreous Detachment

Basics

Description

Posterior vitreous detachment (PVD) is separation of the posterior cortical vitreous from the internal limiting membrane (ILM) of the retina.

PVD is a normal age-related process in most people, but the acute separation can exert traction on the retina and occasionally produce:

• Retinal tear
• Vitreous hemorrhage
• Rhegmatogenous retinal detachment

Modern OCT shows that PVD usually develops gradually through stages of:

Perifoveal vitreous separation → persistent vitreofoveal attachment → release from the macula → eventual vitreopapillary separation

An uncomplicated PVD itself generally requires:

No treatment

but an acute symptomatic PVD requires a careful peripheral retinal examination to exclude a retinal break.

Clinical Importance

The most important question in a patient with new:

• Flashes
• Floaters

is not merely whether a PVD is present, but:

Has the PVD produced a retinal tear?

The major red flags are:

• Vitreous hemorrhage
• Shafer sign / tobacco dust
• Retinal or disc hemorrhage
• New field defect
• Reduced vision
• High-risk peripheral retinal pathology

Epidemiology

PVD becomes progressively more common with age.

It typically occurs:

• After middle age
• Earlier in myopic eyes

It may occur much earlier with:

• High myopia
• Trauma
• Intraocular inflammation
• Cataract surgery
• Hereditary vitreoretinopathies

Risk Factors for Earlier PVD

Important factors include:

• Increasing age
• Axial myopia
• Cataract surgery
• Aphakia
• Ocular trauma
• Intraocular inflammation
• Previous vitreoretinal surgery
• Hereditary connective-tissue disorders

High Myopia

Myopic eyes tend to undergo:

• Earlier vitreous liquefaction
• Earlier PVD

They also have an increased risk of:

• Lattice degeneration
• Retinal tears
• Rhegmatogenous retinal detachment

Hereditary Vitreoretinopathies

Earlier or abnormal vitreous separation may occur in:

• Stickler syndrome
• Marfan syndrome
• Other collagen disorders

Stickler syndrome is particularly important because of its high risk of:

Retinal detachment

Cataract Surgery

PVD becomes more common after cataract extraction.

Risk of retinal complications is particularly relevant in:

• Highly myopic patients
• Younger pseudophakic patients
• Eyes with lattice degeneration
• Surgery complicated by posterior capsule rupture or vitreous loss

Vitreous Anatomy

The vitreous is firmly attached at several sites, particularly:

• Vitreous base
• Optic nerve head
• Macula/fovea
• Retinal vessels

The vitreous base remains the strongest physiologic attachment and does not normally separate completely even after a conventional PVD.

Pathophysiology

Two processes are required for normal PVD:

1. Vitreous liquefaction (synchysis)
2. Weakening of vitreoretinal adhesion

When these processes occur in balance:

• Vitreous separates cleanly

When liquefaction occurs without adequate release of vitreoretinal adhesion:

• Abnormal traction may develop

leading to vitreomacular or retinal complications.

Vitreous Liquefaction

With age:

• Hyaluronic acid–collagen organization deteriorates
• Fluid-filled lacunae develop
• Collagen fibrils aggregate into visible strands

These condensations may be perceived as:

Floaters

Evolution of PVD

Posterior vitreous separation often begins:

Perifoveally

while attachment persists at the:

• Fovea
• Optic disc

With progression:

• Vitreous releases from the fovea
• Then eventually from the optic nerve head

Vitreomacular Adhesion

If the posterior vitreous has separated around the macula but remains attached at the fovea without retinal distortion, this is:

Vitreomacular adhesion (VMA)

VMA is frequently physiologic and asymptomatic.

Vitreomacular Traction

If persistent vitreofoveal adhesion produces retinal distortion, the condition becomes:

Vitreomacular traction (VMT)

Possible effects include:

• Foveal cysts
• Metamorphopsia
• Reduced vision
• Impending or full-thickness macular hole

Acute Symptomatic PVD

An acute PVD occurs when posterior vitreous separation progresses sufficiently to produce sudden symptoms.

Typical symptoms are:

• Photopsias
• New floaters

The onset may be abrupt.

Photopsias

Flashes occur because of:

Mechanical vitreoretinal traction stimulating the retina

They are often:

• Brief
• Peripheral
• Arc-like or lightning-like
• More noticeable in darkness

Floaters

Floaters may result from:

• Condensed vitreous collagen
• Weiss ring
• Pigment
• Red blood cells

Patients may describe:

• Spots
• Cobwebs
• Threads
• Rings
• Clouds

A sudden shower of numerous small floaters is especially concerning for:

Vitreous hemorrhage or pigment from a retinal tear

Weiss Ring

A Weiss ring is a circular or incomplete opacity representing tissue detached from around the optic nerve head.

It indicates:

Vitreopapillary separation

and strongly supports the diagnosis of an advanced PVD.

However, a visible Weiss ring does not absolutely prove that all posterior and peripheral vitreoretinal adhesions have released.

Symptoms Suggestive of Retinal Detachment

Urgent warning symptoms include:

• New curtain or shadow
• Peripheral field loss
• Sudden reduction in vision
• Rapid increase in floaters
• Persistent or increasing photopsias

These require:

Immediate retinal evaluation

Diagnosis

Diagnosis relies primarily on:

• History
• Slit-lamp vitreous examination
• Dilated peripheral retinal examination

The critical goal is to exclude:

Retinal tear or retinal detachment

Slit-Lamp Examination

Using a high-powered lens, look for:

• Weiss ring
• Vitreous pigment
• Vitreous hemorrhage
• Posterior hyaloid
• Retinal hemorrhage

Shafer Sign

Shafer sign is the presence of brown pigment granules in the anterior vitreous.

It is also called:

Tobacco dust

In an acute symptomatic PVD, Shafer sign is highly suspicious for:

A retinal break

until proven otherwise.

Vitreous Hemorrhage

Vitreous hemorrhage accompanying acute PVD markedly increases the likelihood of:

• Retinal tear
• Retinal detachment

A retinal tear should be assumed possible until a careful peripheral retinal examination has been completed.

Dilated Fundus Examination

The examination should include:

Indirect ophthalmoscopy with scleral depression whenever possible

because retinal tears may occur:

• Very anteriorly
• Near the vitreous base

and may be missed with posterior pole examination alone.

Scleral Depression

Scleral depression improves visualization of:

• Ora serrata
• Vitreous base
• Horseshoe tears
• Small peripheral retinal breaks

It remains an important part of acute symptomatic PVD evaluation.

Wide-Field Imaging

Ultra-widefield photography may document:

• Peripheral retinal lesions
• Hemorrhage
• Some retinal tears

but:

It does not reliably replace careful indirect ophthalmoscopy with scleral depression when a retinal tear is suspected.

Optical Coherence Tomography

OCT is particularly useful for assessing:

• Partial PVD
• Vitreomacular adhesion
• Vitreomacular traction
• Macular hole
• Epiretinal membrane

It can show the:

Posterior hyaloid face

over the macula.

Important OCT Limitation

Macular OCT does:

Not exclude a peripheral retinal tear.

A normal macular OCT does not eliminate the need for peripheral retinal examination in an acute symptomatic PVD.

B-Scan Ultrasonography

B-scan is particularly useful when the retina cannot be adequately visualized because of:

• Dense vitreous hemorrhage
• Cataract
• Corneal opacity
• Other media opacity

It may demonstrate:

• Mobile detached posterior hyaloid
• Retinal detachment
• Vitreous hemorrhage

PVD vs Retinal Detachment on B-Scan

A detached posterior hyaloid is generally:

• Thin
• Highly mobile
• Less reflective
• Not attached to the optic disc in the same way as detached retina

Retinal detachment is typically:

• More reflective
• Less mobile
• Tethered at the optic disc

Clinical correlation remains essential.

Differential Diagnosis of Flashes and Floaters

Important differentials include:

• Retinal tear
• Rhegmatogenous retinal detachment
• Vitreous hemorrhage
• Migraine aura
• Vitritis
• Ocular trauma
• Posterior uveitis
• Vitreomacular traction
• Intraocular foreign body in appropriate circumstances

Retinal Tear

The most important retinal tear associated with acute PVD is a:

Horseshoe / flap tear

It develops when persistent focal vitreoretinal adhesion pulls strongly enough to tear the retina.

Common locations include the:

• Superior temporal retina
• Other areas of lattice degeneration or strong adhesion

Risk of Retinal Tear

Among patients with acute symptomatic PVD, a retinal tear is found in approximately:

8–15% at the initial examination

depending on the population studied.

Risk is considerably higher when:

• Vitreous hemorrhage is present
• Shafer sign is positive
• Lattice degeneration is present
• Patient is highly myopic
• There is a previous retinal tear/detachment

Delayed Retinal Tears

A normal initial examination does not reduce the future risk to zero.

A small proportion of patients develop:

Delayed retinal breaks

over the subsequent weeks or months as vitreous separation progresses.

This is why appropriate follow-up and patient education are important.

High-Risk Features for Delayed Breaks

Closer surveillance is appropriate with:

• Vitreous hemorrhage
• Retinal hemorrhage
• Shafer sign
• Lattice degeneration
• High myopia
• Previous retinal tear
• Previous retinal detachment
• Retinal tear/detachment in the fellow eye
• Recent intraocular surgery
• Trauma

Associated Macular Conditions

Partial PVD can be associated with:

• Vitreomacular adhesion
• Vitreomacular traction
• Epiretinal membrane
• Full-thickness macular hole
• Lamellar macular hole
• Myopic traction maculopathy
• Vitreopapillary traction

Epiretinal Membrane

An anomalous PVD may leave residual cortical vitreous on the retinal surface.

This can facilitate:

• Cellular proliferation
• Epiretinal membrane formation

Macular Hole

Persistent focal vitreofoveal traction can contribute to:

Full-thickness macular hole formation

Spontaneous release of traction can occasionally arrest or reverse very early tractional changes.

Vitreopapillary Traction

Persistent adhesion to the optic nerve may cause:

• Optic disc elevation
• Peripapillary hemorrhage
• Apparent disc swelling

This can occasionally mimic:

• Papilledema
• Other optic disc edema

OCT can help demonstrate the tractional mechanism.

Treatment

Uncomplicated PVD

An uncomplicated PVD requires:

No medical or surgical treatment

The key intervention is:

• Retinal examination
• Appropriate follow-up
• Patient education

Activity Restriction

Routine restriction of:

• Exercise
• Bending
• Lifting
• Normal daily activity

after uncomplicated PVD has not been shown to prevent retinal tears.

Reasonable individualized caution may be advised in selected high-risk cases, but strict activity restriction is not standard treatment.

Retinal Tear Treatment

A retinal tear at significant risk of progression to detachment is treated with:

• Laser retinopexy
• Cryopexy in selected cases

The treatment creates a chorioretinal adhesion around the break.

Symptomatic Horseshoe Tear

An acute symptomatic horseshoe tear associated with persistent vitreoretinal traction generally requires:

Prompt retinopexy

because of its substantial risk of progressing to retinal detachment.

Operculated Retinal Hole

Not every operculated hole requires treatment.

Management depends on:

• Symptoms
• Residual traction
• Subretinal fluid
• Location
• Other retinal risk factors

Rhegmatogenous Retinal Detachment

If retinal detachment is present, urgent vitreoretinal management may involve:

• Pneumatic retinopexy
• Scleral buckle
• Pars plana vitrectomy
• Combination surgery

depending on:

• Break configuration
• Lens status
• Extent of detachment
• Macular status

Persistent Floaters

Floaters often become less intrusive over:

Weeks to months

because of:

• Neuroadaptation
• Movement of opacities away from the visual axis
• Changes in vitreous configuration

Vitrectomy for Floaters

Pars plana vitrectomy can remove severe symptomatic vitreous opacities.

However, because an otherwise benign symptom is being treated, risks must be carefully weighed, including:

• Cataract
• Retinal tear
• Retinal detachment
• Endophthalmitis
• Hypotony

It is reserved for:

Carefully selected patients with persistent, functionally disabling floaters.

YAG Vitreolysis

Nd:YAG laser vitreolysis has been used for selected vitreous floaters.

However:

• Evidence for long-term benefit is limited
• Not all floaters are suitable
• Retinal and lens complications are possible

It is not routine treatment for uncomplicated acute PVD.

Follow-Up

Patients with an acute symptomatic PVD and no tear on initial examination commonly undergo:

Repeat dilated retinal examination within several weeks

often around:

4–6 weeks

depending on clinical risk.

Earlier Follow-Up

Earlier or additional examination is warranted with:

• Vitreous hemorrhage
• Shafer sign
• Retinal hemorrhage
• Lattice degeneration
• High myopia
• Prior retinal tear/detachment
• Poor view of peripheral retina

Return Precautions

Regardless of planned follow-up, patients should return immediately for:

• Sudden increase in floaters
• New or increasing flashes
• Curtain or shadow
• Loss of peripheral vision
• Sudden reduction in visual acuity

Fellow Eye

PVD often eventually develops in the fellow eye.

Patients with a retinal tear or detachment in one eye have increased risk of:

• Peripheral retinal pathology
• Retinal tear
• Retinal detachment

in the fellow eye.

Patient Education

Patients should understand that:

• PVD itself is usually benign
• Flashes usually diminish as traction releases
• Floaters often become less noticeable
• Retinal tears can occur during the evolution of PVD

The danger signs of retinal detachment should be explained clearly.

Prognosis

For uncomplicated PVD:

Prognosis is excellent.

Photopsias generally diminish as vitreoretinal traction resolves.

Floaters may persist but often become much less noticeable.

Prognosis After Retinal Tear

When a retinal tear is recognized and treated before retinal detachment occurs:

Visual prognosis is generally excellent.

Delayed detection increases the risk of:

• Rhegmatogenous retinal detachment
• Macular involvement
• Permanent visual loss

Complications

Important complications include:

• Retinal tear
• Rhegmatogenous retinal detachment
• Vitreous hemorrhage
• Retinal hemorrhage
• Epiretinal membrane
• Vitreomacular traction
• Macular hole
• Vitreopapillary traction

Ophthalmology Pearls

• PVD is separation of the posterior cortical vitreous from the retinal ILM and becomes increasingly common with age.
• The classic acute symptoms are new flashes and floaters.
• The most important question in an acute symptomatic PVD is: Is there a retinal tear?
• A Weiss ring indicates vitreopapillary separation and strongly supports an advanced PVD, but does not guarantee that every peripheral vitreoretinal adhesion has released.
• Shafer sign (“tobacco dust”) is highly suspicious for a retinal tear.
• Vitreous hemorrhage dramatically increases concern for an associated retinal break.
• Acute symptomatic PVD should be examined with a dilated peripheral retinal examination, ideally including scleral depression.
• Macular OCT is excellent for detecting partial PVD and vitreomacular traction but cannot exclude a peripheral retinal tear.
• B-scan ultrasonography is important when vitreous hemorrhage or other media opacity prevents adequate retinal visualization.
• Approximately 8–15% of symptomatic acute PVDs have a retinal tear at initial examination, with additional delayed tears occurring in a smaller proportion.
• A normal first examination does not completely eliminate later risk; many patients are re-examined at approximately 4–6 weeks, with earlier/more frequent review for high-risk findings.
• New curtain, field loss, sudden visual decline, increased flashes, or a shower of floaters requires urgent reassessment.
• Uncomplicated PVD requires no treatment.
• Acute symptomatic horseshoe tears generally require prompt laser retinopexy or cryopexy to prevent retinal detachment.
• Persistent symptomatic floaters usually improve with time; vitrectomy is reserved for carefully selected, severely affected patients because it carries meaningful surgical risk.