PanOph

Sturge-Weber Syndrome

GlaucomaTriadHigh YieldAlso: Encephalotrigeminal Angiomatosis

Key Points

  • •Sturge-Weber is caused by a somatic mosaic GNAQ R183Q mutation (not heritable) — the mutation is post-zygotic.
  • •Glaucoma in SWS has two mechanisms: early-onset trabeculodysgenesis and later-onset elevated episcleral venous pressure.
  • •Not all port-wine stains indicate SWS — only V1 distribution involvement carries significant risk for leptomeningeal and ocular involvement.

Hallmark Features(Triad)

1

Port-wine stain (nevus flammeus) in V1 distribution

2

Leptomeningeal angiomatosis

3

Ipsilateral glaucoma

Finder Clues

Port-wine stain (nevus flammeus)Ipsilateral glaucomaLeptomeningeal angiomatosisSeizures (contralateral)Episcleral hemangiomaBuphthalmosChoroidal hemangioma (diffuse)Contralateral hemiparesis
1. Definition

Neurocutaneous (phakomatosis) disorder characterized by a facial port-wine stain in the trigeminal V1 distribution, ipsilateral leptomeningeal angiomatosis, and glaucoma.

2. Genetics

Somatic mosaic mutation in GNAQ gene (R183Q). Not inherited — occurs as a post-zygotic event.

3. Pathogenesis

Mutation and signaling:

  • The somatic GNAQ R183Q mutation activates Gq-alpha signaling
  • Promotes endothelial cell proliferation and vascular malformation

Tissue involvement:

  • The timing and distribution of the mutation during embryogenesis determines which tissues are affected:
  • Facial skin — port-wine stain
  • Leptomeninges — angioma
  • Episcleral/choroidal vasculature — elevated episcleral venous pressure

Glaucoma mechanisms:

  • Elevated episcleral venous pressure from episcleral vascular malformation
  • Trabeculodysgenesis — developmental angle abnormalities
4. Clinical Features

Cutaneous findings:

  • Port-wine stain (nevus flammeus) — present at birth, typically in V1 (ophthalmic) distribution
  • Flat, deep red to purple vascular malformation that does not blanch
  • Bilateral involvement in ~10-15% of cases

Neurological findings:

  • Seizures (contralateral to leptomeningeal angioma) — most common neurological manifestation, often beginning in infancy
  • Progressive cortical calcification produces the characteristic 'tram-track' sign on imaging
  • Intellectual disability and hemiparesis may develop, correlating with extent of cortical involvement
5. Ocular Manifestations

Glaucoma:

  • Primary ocular concern, occurring in 30-70% of patients
  • Can present as congenital/infantile glaucoma (buphthalmos) or develop later in childhood/adulthood
  • Mechanisms:
  • Trabeculodysgenesis — early-onset
  • Elevated episcleral venous pressure from episcleral hemangioma — later-onset

Posterior segment:

  • Diffuse choroidal hemangioma — gives the classic 'tomato ketchup' fundus appearance
  • Can cause exudative retinal detachment, hyperopic shift, and amblyopia

Anterior segment:

  • Episcleral and conjunctival vascular tortuosity — visible on slit-lamp examination
  • Heterochromia iridis may be present ipsilaterally
6. Systemic Manifestations

Neurological:

  • Seizures — 75-90% of patients
  • Hemiparesis, hemianopia
  • Intellectual disability
  • Migraine-like headaches and stroke-like episodes
  • The leptomeningeal angioma causes venous stasis, ischemia, and progressive cortical calcification

Endocrine:

  • Growth hormone deficiency and hypothyroidism may occur in severe cases
7. Diagnosis

Clinical:

  • Diagnosis based on the classic triad (port-wine stain + leptomeningeal angioma + glaucoma)
  • Port-wine stain diagnosed clinically; dermoscopy may aid early identification

Neuroimaging:

  • MRI with contrast (gadolinium-enhanced T1-weighted) — gold standard for detecting leptomeningeal angiomatosis, showing pial enhancement
  • CT — may show tram-track calcifications

Ocular assessment:

  • Tonometry and gonioscopy for glaucoma
  • B-scan ultrasonography — reveals diffuse choroidal thickening
  • Fluorescein angiography — shows the choroidal hemangioma pattern
8. Differential Diagnosis

Key differentials:

  • Klippel-Trenaunay syndrome — port-wine stain with limb hypertrophy, no CNS involvement
  • Isolated port-wine stain — without SWS features
  • Phakomatosis pigmentovascularis — port-wine stain with melanocytic nevi
  • Congenital/infantile glaucoma — from other causes
  • Other phakomatoses:
  • NF1
  • Tuberous sclerosis
  • Von Hippel-Lindau
9. Management

Glaucoma:

  • Medical therapy (first line) — topical beta-blockers, prostaglandin analogues, carbonic anhydrase inhibitors
  • Surgical options:
  • Trabeculotomy/goniotomy — for infantile glaucoma
  • Trabeculectomy with antimetabolites — for older patients
  • Glaucoma drainage devices — for refractory cases

Choroidal hemangioma:

  • Photodynamic therapy (PDT) with verteporfin
  • Low-dose external beam radiotherapy
  • Anti-VEGF for associated exudative detachment

Port-wine stain:

  • Pulsed dye laser (585-595 nm) for cosmetic improvement

Neurological:

  • Anticonvulsant therapy for seizures
  • Hemispherectomy considered for intractable epilepsy

Multidisciplinary care involving ophthalmology, neurology, dermatology, and pediatrics is essential.

10. Prognosis

Variable depending on extent of involvement:

  • Glaucoma — can be challenging to control, often requires multiple surgical interventions
  • Vision loss — may result from refractory glaucoma, amblyopia, or retinal detachment secondary to choroidal hemangioma
  • Neurological prognosis — correlates with extent of leptomeningeal involvement and seizure control

Early diagnosis and coordinated multidisciplinary management improve outcomes.

Clinical Pearls

1

The 'tomato ketchup' fundus from diffuse choroidal hemangioma is highly characteristic and best visualized with indirect ophthalmoscopy.

2

Intraoperative choroidal effusion is a known risk during glaucoma filtration surgery in SWS due to abnormal choroidal vasculature — slow decompression and prophylactic sclerotomies help mitigate this.

3

V1 involvement alone is insufficient for diagnosis; MRI brain with contrast should be performed in any infant with a V1 port-wine stain to rule out leptomeningeal angioma.

Mnemonics

Sturge-Weber Triad

S—Stain (port-wine, V1)

W—Web (leptomeningeal angiomatosis)

G—Glaucoma

Classic triad of Sturge-Weber syndrome

References

  1. textbookKanski's Clinical Ophthalmology: A Systematic Approach— Elsevier (2020)
  2. paperSturge-Weber Syndrome and Port-Wine Stains Caused by Somatic Mutation in GNAQ— New England Journal of Medicine (2013)
  3. paperSturge-Weber Syndrome: Age of Onset of Glaucoma and Outcome of Surgical and Medical Management— Journal of Glaucoma (2019)
  4. textbookWills Eye Manual: Office and Emergency Room Diagnosis and Treatment of Eye Disease— Wolters Kluwer (2022)
Was this helpful?
← PreviousPosner-Schlossman Syndrome