A nurse is preparing a client for fluorescein angiography to evaluate retinal blood vessels. Which instruction should the nurse provide to the client before the procedure?

Fluorescein angiography involves IV dye injection, which can cause allergic reactions. Assessing for allergies, especially to iodine or shellfish, is critical to prevent adverse events like anaphylaxis. Other instructions are less priority for safety.

Understanding Fluorescein Angiography
Fluorescein angiography (FA) is a diagnostic procedure where a fluorescent dye (fluorescein sodium) is injected intravenously to visualize the retinal and choroidal circulation. The dye travels through the blood vessels, and a specialized camera captures images to identify abnormalities such as leakage, blockage, or abnormal vessel growth. This test is crucial for differentiating conditions like neovascular age-related macular degeneration (nAMD) from polypoidal choroidal vasculopathy (PCV), as highlighted in the EVEREST study, where specific FA features help distinguish these pathologies ^[1].

Why Asking About Allergies is the Priority
Before any procedure involving contrast media or injectable dyes, the nurse's primary safety responsibility is to assess for potential allergic reactions. While fluorescein is not iodine-based and does not cross-react with shellfish allergies, the clinical protocol for any injectable agent mandates a thorough allergy history. The nurse must specifically inquire about prior reactions to fluorescein, contrast dyes, or any severe allergies, as anaphylaxis is a rare but life-threatening risk. This standard precaution ensures that the healthcare team is prepared to manage an adverse event immediately.

Analysis of Incorrect Options

Option 1: Inform the staff about any history of kidney stones.
This instruction is not relevant to fluorescein angiography. Fluorescein dye is primarily metabolized by the liver and excreted by the kidneys, but it is not nephrotoxic and does not precipitate kidney stones. Concerns about kidney stones are more commonly associated with certain medications or other types of contrast, not fluorescein.

Option 2: Avoid drinking water for 6 hours before the test.
This instruction is incorrect. Clients are generally encouraged to maintain their normal hydration status and take their regular medications unless specifically instructed otherwise. There is no requirement for fluid restriction before FA; in fact, adequate hydration supports renal excretion of the dye post-procedure.

Option 3: Stop taking blood thinners one week prior.
This is not a standard instruction for fluorescein angiography. FA is a non-invasive imaging procedure with no incisions or tissue trauma beyond a routine intravenous injection. The risk of bleeding from the injection site is minimal and does not warrant discontinuing anticoagulant or antiplatelet therapy, which could expose the client to a risk of thromboembolic events.

Clinical Application of the EVEREST Study Findings
The EVEREST study report 4 demonstrates that FA is a valuable tool for identifying features predictive of PCV, a subtype of neovascular AMD. The study analyzed FA images to differentiate PCV from typical nAMD, noting that specific dye leakage patterns and vascular abnormalities on FA can guide diagnosis, especially in settings where indocyanine green angiography (ICGA) is unavailable or contraindicated ^[1]. For the nurse preparing a client for this test, understanding its diagnostic purpose reinforces the need for a clear explanation of the procedure and a meticulous pre-procedure assessment, with allergy screening being the most critical safety checkpoint.