Ophthalmology – Sturge–Weber Syndrome

What the Syndrome Represents

Sturge–Weber syndrome (SWS) is a sporadic congenital neurocutaneous vascular disorder characterized by variable involvement of:

• Facial port-wine birthmark/capillary malformation
• Leptomeningeal vascular malformation
• Ocular vascular abnormalities

The classic ophthalmic manifestations are:

• Glaucoma
• Diffuse choroidal hemangioma
• Episcleral/conjunctival vascular dilation

Not every patient has all three systems involved.

The Modern Genetic Basis

SWS is usually caused by a postzygotic somatic activating mutation in:

GNAQ

most commonly involving:

p.Arg183Gln (R183Q)

Because the mutation occurs after fertilization:

• Only a subset of cells carries it
• Disease distribution is mosaic
• Severity varies substantially
• SWS is usually not inherited

This explains why familial transmission is exceedingly uncommon.

Relationship to Port-Wine Birthmarks

The facial lesion traditionally called a nevus flammeus is more accurately termed a:

Port-wine birthmark or capillary malformation

It is caused by ectatic dermal capillaries and is present from birth.

Color may range from:

• Pale pink
• Red
• Dark red
• Purple

Over time, untreated lesions may become:

• Darker
• Thicker
• Nodular

Distribution of the Facial Birthmark

Older descriptions classified lesions according to:

• V1
• V2
• V3 trigeminal dermatomes

Modern understanding is that facial capillary malformations follow:

Embryologic vascular territories rather than true trigeminal nerve dermatomes.

The distribution most strongly associated with intracranial SWS is:

Forehead and upper-eyelid involvement

particularly when the lesion crosses the midline forehead or involves a broad frontotemporal region.

Why Upper-Eyelid Involvement Matters

A port-wine birthmark involving the:

Upper eyelid

substantially raises concern for:

• Ipsilateral glaucoma
• Ocular vascular abnormalities
• Possible intracranial involvement

These children warrant early ophthalmic assessment.

How Common It Is

SWS is rare, with an estimated frequency of roughly:

1 in 20,000–50,000 live births

depending on the population studied.

There is no strong:

• Sex predilection
• Racial predilection

The Main Eye Problems

Ocular manifestations can include:

• Glaucoma
• Diffuse choroidal hemangioma
• Dilated conjunctival vessels
• Dilated episcleral vessels
• Retinal vascular tortuosity
• Serous retinal detachment
• Refractive error
• Anisometropia
• Amblyopia
• Buphthalmos in early-onset glaucoma

Glaucoma in SWS

Glaucoma is one of the most important causes of visual morbidity.

It is usually:

• Ipsilateral to the facial capillary malformation
• More likely when the eyelids are involved

Glaucoma may present:

• In infancy
• During childhood
• In adolescence
• In adulthood

Therefore risk is:

Lifelong.

Why Glaucoma Develops

Two major mechanisms are recognized.

Early-Onset Glaucoma

Usually related to:

Developmental angle abnormalities

similar to congenital glaucoma.

Later-Onset Glaucoma

More often related to:

Elevated episcleral venous pressure

caused by abnormal episcleral and orbital venous drainage.

Many patients have a combination of both mechanisms.

Early-Onset Glaucoma Features

Infants may develop:

• Buphthalmos
• Enlarged corneal diameter
• Corneal edema
• Haab striae
• Photophobia
• Tearing

Because the infant eye is elastic, elevated IOP can enlarge the globe.

Later-Onset Glaucoma Features

Older children and adults may show:

• Elevated IOP
• Open angles
• Dilated episcleral vessels
• Progressive optic nerve cupping
• Visual-field loss

The eye may not be enlarged.

Episcleral Vascular Abnormalities

Dilated episcleral vessels are common and may appear:

• Tortuous
• Engorged
• Reddish-purple

These vessels reflect abnormal venous drainage and can contribute directly to:

Elevated IOP.

Why Glaucoma Surgery Is More Difficult

Eyes with SWS are at increased risk during glaucoma surgery because of:

• Elevated episcleral venous pressure
• Choroidal vascular congestion
• Diffuse choroidal hemangioma

Complications may include:

• Choroidal effusion
• Serous retinal detachment
• Suprachoroidal hemorrhage
• Hypotony-related complications

Careful surgical planning is therefore essential.

Diffuse Choroidal Hemangioma

A characteristic ocular finding is a:

Diffuse choroidal hemangioma

usually involving the eye ipsilateral to the facial birthmark.

Unlike a circumscribed choroidal hemangioma, the lesion:

• Has poorly defined borders
• Involves a broad area of choroid
• Produces generalized choroidal thickening

The Classic “Tomato-Ketchup” Fundus

Because of diffuse choroidal vascular thickening, the affected fundus may appear:

Deep red-orange

compared with the fellow eye.

This is classically described as the:

“Tomato-ketchup fundus.”

How a Diffuse Choroidal Hemangioma Affects Vision

The lesion itself may initially be asymptomatic.

Visual loss develops when it causes:

• Subretinal fluid
• Serous retinal detachment
• Macular edema
• RPE alterations
• Refractive changes

Chronic fluid can produce permanent photoreceptor damage.

Other Posterior Segment Findings

Additional findings can include:

• Retinal vascular tortuosity
• Dilated retinal vessels
• RPE mottling
• Serous retinal detachment
• Chronic macular structural damage

Ultrasound Findings

B-scan ultrasonography may demonstrate:

• Diffuse choroidal thickening

A-scan typically shows:

High internal reflectivity

consistent with a vascular lesion.

Ultrasound can be particularly useful when:

• Fundus visualization is difficult
• Tumor thickness needs documentation

OCT in Choroidal Disease

Enhanced-depth imaging OCT may demonstrate:

• Increased choroidal thickness
• Expanded choroidal vascular spaces
• Subretinal fluid
• RPE abnormalities

Macular OCT is particularly useful for monitoring:

Exudation and treatment response.

Fluorescein and Indocyanine Green Angiography

Angiography may help define vascular abnormalities.

ICGA can show:

• Diffuse choroidal hypervascularity
• Abnormal choroidal filling
• Late washout patterns

It is mainly used when treatment planning or diagnostic uncertainty exists.

Neurologic Involvement

The characteristic CNS lesion is:

Leptomeningeal capillary-venous malformation

usually affecting the cerebral hemisphere ipsilateral to the facial lesion.

Commonly involved regions include:

• Occipital lobe
• Parietal lobe
• Posterior frontal regions

Why the Brain Becomes Injured

Abnormal leptomeningeal venous drainage can produce:

• Chronic venous congestion
• Reduced cerebral perfusion
• Ischemic injury
• Cortical atrophy
• Calcification

Over time this can lead to:

• Seizures
• Stroke-like episodes
• Hemiparesis
• Visual-field defects
• Developmental impairment

Seizures

Seizures are the most common neurologic manifestation.

They often begin in:

• Infancy
• Early childhood

Early-onset and poorly controlled seizures are associated with greater risk of:

• Developmental delay
• Neurologic disability

Stroke-Like Episodes

Patients may develop transient or persistent:

• Hemiparesis
• Hemiplegia
• Language disturbance
• Visual-field loss

These episodes are thought to relate to:

• Venous congestion
• Perfusion abnormalities
• Seizure-related metabolic stress

rather than conventional embolic stroke in many cases.

Visual-Field Loss From Brain Disease

Occipital cortical involvement can produce:

Contralateral homonymous hemianopia

or other retrochiasmal visual-field defects.

Thus visual impairment in SWS may originate from:

• Eye disease
• Brain disease
• Both

Headache and Migraine

Headache is common and may resemble:

• Migraine with aura
• Migraine without aura

Headache can coexist with:

• Seizures
• Transient neurologic deficits

Developmental and Cognitive Effects

Neurologic disease may be associated with:

• Developmental delay
• Learning difficulties
• Intellectual disability
• Behavioral problems

Severity correlates broadly with:

• Extent of brain involvement
• Seizure burden
• Age at seizure onset

Best Neuroimaging Test

The preferred study is:

Contrast-enhanced MRI of the brain

often supplemented with:

• Susceptibility-weighted imaging
• Perfusion imaging
• Other advanced sequences

MRI can demonstrate:

• Leptomeningeal enhancement
• Cortical atrophy
• Enlarged deep medullary veins
• Abnormal venous drainage
• Calcification-related signal changes

Role of CT

CT may demonstrate classic:

Gyriform cortical calcification

historically called:

“Tram-track” calcification

However, CT is no longer the preferred screening modality in children because of:

• Ionizing radiation
• Lower sensitivity for early leptomeningeal disease

Important Limitation of Early MRI

A normal MRI in a young infant does:

Not always completely exclude early SWS brain involvement.

If clinical suspicion remains high or neurologic symptoms develop, repeat imaging may be necessary.

Who Needs Neurologic Evaluation

Particular concern exists in children with:

• Forehead port-wine birthmark
• Upper-eyelid involvement
• Seizures
• Developmental abnormalities
• Focal neurologic deficits

Evaluation should be coordinated with:

Pediatric neurology.

An Important Modern Correction About Choroidal Hemangioma

Older teaching suggested that choroidal hemangioma almost always implies:

Leptomeningeal angiomatosis

This is too strong.

Diffuse choroidal hemangioma should raise suspicion for SWS, but intracranial involvement must be established by:

• Clinical evaluation
• Appropriate neuroimaging

rather than assumed.

How the Diagnosis Is Established

Diagnosis is clinical and based on some combination of:

• Facial capillary malformation
• Ocular abnormalities
• Leptomeningeal vascular malformation

Not every patient has the complete classic triad.

Patients With Only a Facial Port-Wine Birthmark

A facial port-wine birthmark alone does:

Not automatically mean Sturge–Weber syndrome.

Risk depends strongly on:

• Location
• Extent
• Associated ocular findings
• Neurologic findings

Important Differential Diagnoses

Consider:

• Klippel–Trénaunay syndrome
• Phakomatosis pigmentovascularis
• Isolated facial capillary malformation
• Other cerebral vascular malformations
• Diffuse choroidal hemangioma without classic SWS

Klippel–Trénaunay Syndrome

This condition typically features:

• Capillary malformation of an extremity
• Venous/lymphatic malformations
• Limb hypertrophy or overgrowth

It should not simply be considered “SWS plus an extremity port-wine stain”; it is a distinct vascular-overgrowth disorder.

Treating the Port-Wine Birthmark

The principal treatment is:

Pulsed-dye laser therapy

Treatment often begins in:

• Infancy
• Early childhood

Earlier treatment may improve:

• Lightening
• Cosmetic outcome
• Prevention of later thickening

Multiple sessions are usually required.

Treating Glaucoma Medically

Topical IOP-lowering therapy may include:

• Beta-blockers
• Carbonic anhydrase inhibitors
• Prostaglandin analogues
• Alpha-2 agonists when age-appropriate

There is no universal rigid first-, second-, and third-line order.

Treatment should be individualized according to:

• Age
• IOP
• Optic nerve status
• Systemic contraindications

Why Medical Therapy Often Becomes Insufficient

SWS glaucoma can be difficult to control because elevated episcleral venous pressure limits aqueous drainage.

Many patients eventually require:

Surgery.

Angle Surgery in Young Children

For early-onset glaucoma with developmental angle abnormality, options include:

• Goniotomy
• Trabeculotomy

These are most useful when angle dysgenesis is a major component.

Filtering Surgery

Older children and adults may require:

• Trabeculectomy
• Glaucoma drainage device

However, elevated episcleral venous pressure can reduce success and increase postoperative complications.

Glaucoma Drainage Devices

Tube shunts may be useful for:

• Refractory glaucoma
• Failed previous procedures
• High-risk filtering surgery

Examples include:

• Ahmed valve
• Baerveldt implant

Cyclodestructive Procedures

Cyclophotocoagulation may be considered in:

• Refractory glaucoma
• Limited visual potential
• Multiple prior surgical failures

It is generally not the first surgical choice in an eye with good visual potential.

Treating Diffuse Choroidal Hemangioma

Treatment is indicated when the hemangioma causes:

• Subretinal fluid
• Macular involvement
• Serous retinal detachment
• Significant visual loss

Observation is reasonable when the lesion is:

• Asymptomatic
• Nonexudative

Photodynamic Therapy

Verteporfin photodynamic therapy (PDT) is an important treatment for symptomatic choroidal hemangioma.

Advantages include:

• Selective vascular closure
• Resolution of subretinal fluid
• Relative preservation of surrounding retina

It is particularly useful when the exudative area is sufficiently localized for treatment.

Radiotherapy

Extensive diffuse choroidal hemangioma may require:

• Low-dose external beam radiotherapy
• Proton beam therapy
• Plaque radiotherapy in selected cases

Radiation is especially useful for:

• Broad diffuse lesions
• Extensive serous detachment
• Disease unsuitable for focal PDT

Why Conventional Laser Is Less Attractive

Thermal laser photocoagulation has historically been used, but it may produce:

• RPE damage
• Chorioretinal scarring

Modern management more commonly favors:

• PDT
• Radiotherapy

depending on lesion extent.

Correcting Refractive Error

SWS may produce:

• Myopia
• Hyperopia
• Astigmatism
• Anisometropia

Early optical correction is important, particularly in children.

Preventing Amblyopia

Amblyopia may result from:

• Anisometropia
• Glaucoma
• Corneal enlargement
• Retinal disease
• Strabismus

Treatment may include:

• Spectacle correction
• Contact lenses
• Patching
• Atropine penalization in selected cases

Early intervention is important for visual development.

Treating Seizures

Neurologic therapy commonly includes:

Antiseizure medication

with the objective of rapid and sustained seizure control.

Refractory epilepsy may require evaluation at a:

Pediatric epilepsy center.

Neurosurgical Options

For severe medically refractory epilepsy arising predominantly from one damaged hemisphere, surgery may include:

• Focal cortical resection
• Hemispherotomy
• Functional hemispherectomy

Modern epilepsy surgery generally favors disconnection procedures rather than older anatomical hemispherectomy techniques.

Role of Low-Dose Aspirin

Low-dose aspirin has been used in selected children with SWS in an attempt to reduce:

• Stroke-like episodes
• Seizure-associated ischemic events

However:

It is not a universal treatment for every SWS patient.

Use should be individualized by neurology after weighing:

• Potential benefit
• Bleeding risk
• Age
• Clinical phenotype

Multidisciplinary Follow-Up

Depending on disease involvement, care may include:

• Ophthalmology
• Neurology
• Dermatology
• Epileptology/neurosurgery
• Developmental pediatrics
• Physical and occupational therapy

Ophthalmic Surveillance

Children at ocular risk require regular assessment of:

• IOP
• Corneal diameter
• Axial length in selected cases
• Optic nerve
• Refraction
• Amblyopia
• Choroid
• Retina

Follow-up frequency depends on:

• Age
• Glaucoma status
• Ocular findings

Why Lifelong Eye Follow-Up Is Needed

Glaucoma may first appear:

Years after infancy

even when neonatal examinations were normal.

Therefore patients with high-risk facial or ocular involvement require:

Long-term surveillance.

Expected Visual Outcome

Visual prognosis depends primarily on:

• Glaucoma control
• Amblyopia prevention
• Macular involvement from choroidal hemangioma
• Serous retinal detachment
• Neurologic visual-field defects

Good vision can be maintained when ocular disease is identified and managed early.

Factors Affecting Neurologic Outcome

Poorer neurologic prognosis is associated with:

• Early seizure onset
• Frequent uncontrolled seizures
• Extensive bilateral or hemispheric brain involvement
• Recurrent stroke-like episodes

Some patients with limited disease have:

Normal intelligence and near-normal life expectancy.

Major Long-Term Complications

Important complications include:

• Glaucoma
• Buphthalmos
• Optic nerve damage
• Amblyopia
• Serous retinal detachment
• Macular photoreceptor damage
• Homonymous visual-field loss
• Seizures
• Hemiparesis
• Developmental impairment

High-Yield Takeaways

• Sturge–Weber syndrome is a sporadic neurocutaneous vascular disorder usually caused by a somatic mosaic GNAQ mutation.
• The classic manifestations involve facial capillary malformation, leptomeningeal vascular malformation, and ocular vascular disease, but not every patient has the full triad.
• The facial lesion is better termed a port-wine birthmark/capillary malformation, not simply a nevus distributed along trigeminal dermatomes.
• Forehead and upper-eyelid involvement carries particularly important risk for ocular and neurologic disease.
• The major ophthalmic threats are glaucoma and diffuse choroidal hemangioma.
• SWS glaucoma may be caused by developmental angle abnormalities in early childhood and elevated episcleral venous pressure later in life.
• Glaucoma risk is lifelong, so a normal infant examination does not eliminate the need for later surveillance.
• Early-onset glaucoma can produce buphthalmos, corneal enlargement, and Haab striae.
• The classic diffuse choroidal hemangioma produces the “tomato-ketchup fundus.”
• Choroidal hemangioma becomes clinically important when it causes subretinal fluid, macular edema, or serous retinal detachment.
• PDT is useful for selected symptomatic choroidal hemangiomas; extensive diffuse disease may require low-dose radiotherapy or proton therapy.
• Contrast-enhanced MRI is preferred for evaluating leptomeningeal involvement; CT mainly demonstrates later cortical calcification.
• Early MRI can occasionally be falsely reassuring, so repeat imaging may be needed when neurologic suspicion remains high.
• Choroidal hemangioma does not automatically prove leptomeningeal involvement.
• Seizures are the most frequent neurologic manifestation and require early aggressive management.
• Low-dose aspirin is used in selected neurologic cases but is not routine therapy for every patient.
• Glaucoma surgery may be technically difficult because of elevated episcleral venous pressure and the risk of choroidal effusion or hemorrhage.
• Early refraction and amblyopia therapy are essential in children.
• Long-term care requires coordinated ophthalmic, neurologic, dermatologic, and developmental follow-up.