What are the diagnostic criteria for retinal hemangioma?

Diagnostic Criteria for Retinal Hemangioma

Retinal hemangiomas are diagnosed primarily through characteristic fundoscopic appearance combined with multimodal imaging, with the specific diagnostic features varying by subtype: retinal capillary hemangiomas present as endophytic vascular tumors in the peripheral retina, retinal cavernous hemangiomas show grape-like clusters of dilated vascular sacs, and retinal racemose hemangiomas demonstrate arteriovenous communications without an intervening capillary bed.

Clinical Presentation and Fundoscopic Features

Retinal Capillary Hemangiomas

• Location and morphology: Most commonly located in the temporal peripheral retina with endophytic growth patterns 1
• Appearance: Present as well-defined vascular tumors that may be associated with exudative retinal detachment if untreated 1
• Juxtapapillary variant: Can occur adjacent to the optic disc with variable visual outcomes and potential visual field defects 1

Retinal Cavernous Hemangiomas

• Pathognomonic appearance: Grape-like clusters of dilated vascular sacs with variable surface gliosis 2
• Clinical behavior: Isolated, non-progressive vascular tumor typically discovered incidentally on fundus examination 2
• Associated findings: May present with vitreous hemorrhage, pre-retinal traction, hyphema, or macular scarring in symptomatic cases 2

Retinal Racemose Hemangiomas

• Vascular pattern: Congenital abnormality showing direct arteriovenous communications 3
• Secondary manifestations: Can cause macular edema and vision loss 3

Imaging Modalities for Diagnosis

Optical Coherence Tomography Angiography (OCT-A)

• Primary diagnostic tool: Provides high-resolution, non-invasive visualization of retinal vasculature without contrast injection 2, 4
• Sensitivity: More sensitive to vascular abnormalities with clearer imaging compared to traditional methods 4
• Specific findings for cavernous hemangiomas: Shows characteristic vascular changes with good correspondence to fundus imaging and fluorescein angiography 4
• Localization capability: Can identify the precise vascular layer involved, such as deep capillary plexus connections in racemose hemangiomas 3

Fluorescein Angiography (FA)

• Complementary role: Used alongside OCT-A to confirm diagnosis and characterize blood flow patterns 4
• Vascular filling patterns: Demonstrates characteristic filling of abnormal vessels 2

Ultrasonography

• For choroidal lesions: B-scan ultrasonography shows specific acoustic characteristics for circumscribed choroidal hemangiomas, though this applies to choroidal rather than retinal hemangiomas 5
• Standardized A-scan: Can measure tumor dimensions and internal reflectivity 5

Systemic Evaluation and Genetic Considerations

Von Hippel-Lindau (VHL) Disease Screening

• Referral criteria: The American College of Medical Genetics and Genomics recommends genetic counseling referral for individuals with retinal capillary hemangioma, as this is a major manifestation of VHL syndrome 6
• Additional VHL features to assess: Central nervous system hemangioblastoma, clear cell renal cell carcinoma (especially if bilateral, multifocal, or diagnosed before age 50), pheochromocytoma, and endolymphatic sac tumor 6
• Important caveat: Not all retinal capillary hemangiomas are associated with VHL disease—in one series, no patients with peripheral retinal capillary hemangiomas met diagnostic criteria for VHL 1

Bilaterality Assessment

• Examination requirement: Both eyes must be examined, as bilateral involvement can occur and suggests hereditary disease 1

Common Pitfalls and Caveats

• Incidental discovery: Many retinal hemangiomas are asymptomatic and discovered incidentally, requiring careful fundoscopic examination during routine screening 2
• Progressive complications: Untreated peripheral capillary hemangiomas may develop exudative retinal detachment with worse visual prognosis, emphasizing the importance of early diagnosis 1
• Imaging sequence: OCT-A should be the initial advanced imaging modality given its non-invasive nature and superior sensitivity, with FA reserved for cases requiring additional characterization 2, 4
• Genetic testing timing: VHL screening should be considered early in the diagnostic workup for retinal capillary hemangiomas to enable appropriate systemic surveillance 6