Appendix
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Ophthalmology

Indocyanine Green (ICG) Angiography

Indocyanine green angiography is an important invasive imaging modality among many diagnostic imaging modalities used in retinochoroidal diseases. It helps to study the anatomy, physiology, and pathology of choroidal and retinal circulation. It has an important role in the diagnosis of various ocular pathologies. This activity describes the anatomy of choroidal circulation and reviews the techniques and interpretation of indocyanine green angiography. It also highlights the role of the interprof

v1 · Reviewed Nov 7, 2026 by Automated Clinical Reviewer (Strict Verbatim v1)
  • In patients who are allergic to iodide or shellfish, ICGA should not be performed.
  • Also, it is contraindicated in patients with uremia and those with a history of severe hypersensitivity.
  • ICG is exclusively eliminated through the liver. So in patients with liver disease, ICGA is not recommended.
  • A standard emergency kit for the management of anaphylaxis should always be kept ready before starting the procedure.
  • Anesthetists or critical care specialists are required in cases of severe allergy and anaphylactic reaction.
  • Indocyanine green angiography is an important invasive imaging modality among many diagnostic imaging modalities used in retinochoroidal diseases.
  • It helps to study the anatomy, physiology, and pathology of choroidal and retinal circulation.
  • It has an important role in the diagnosis of various ocular pathologies.
  • Indocyanine green angiography (ICGA) is used to image the choroidal circulation and its abnormalities.
  • ICGA continues to be an important imaging modality in clinical practice in evaluating various disorders, including idiopathic polypoidal choroidal vasculopathy (IPCV), retinal angiomatous proliferation (RAP), central serous chorioretinopathy (CSCR), ocular inflammatory conditions including sympathetic ophthalmia (SO) and Vogt Koyanagi Harada syndrome (VKH); and ocular tumors.
  • ICGA is highly recommended for identifying PCV lesions, and ICGA is considered the gold standard for diagnosing PCV.
  • ICGA helps to delineate the extent of occult CNVM.
  • ICGA also helps to differentiate CSCR from PCV and helps detect underlying CNVM in CSCR.
  • The standard intravenous dose of ICG for an adult individual is 25 mg in 5 ml solvent.
  • If SLO systems are used, 25 mg of ICG is dissolved in 3 ml of solvent, and only 1 ml of solution is injected.
  • A 5 ml saline flush should be given immediately after injecting the dye.
  • In patients who are allergic to iodide or shellfish, ICGA should not be performed.
  • Also, it is contraindicated in patients with uremia and those with a history of severe hypersensitivity.
  • ICG is exclusively eliminated through the liver. So in patients with liver disease, ICGA is not recommended.
  • According to FDA classification, ICG is a pregnancy category C drug.
  • The aqueous solution of ICG has to be used within 6 hours.
  • An interval of at least one week is necessary after ICGA for radioactive iodine uptake studies.
  • It is important to differentiate PCV from CNVM as PCV responds better with photodynamic therapy (PDT) or a combination of PDT and intravitreal anti-VEGF therapy rather than anti-VEGF therapy alone.
  • The incidence of adverse events is more common in patients with uremia compared to the general population.
  • Extravasation of the dye can cause a stinging sensation.
  • Mild side effects like nausea and vomiting are seen in 0.15% of patients.
  • Moderate adverse events like urticaria, vasovagal events are seen in 0.2% of patients.
  • Urticaria can be treated using antihistamines.
  • The incidence of severe adverse events is 0.05%.
  • Anaphylaxis can occur in patients with iodine allergies.
  • ICGA may be used to detect subclinical recurrence of VKH syndrome.
  • review
    Indocyanine Green (ICG) Angiography. StatPearls [Internet] — Sabareesh Muraleedharan, Koushik Tripathy — StatPearls Publishing, 2023

Decision support only. Verify against local protocols and current labeling. Source: www.ncbi.nlm.nih.gov