Frequently Asked Questions

Q: The SPY Imaging System laser is classified as IIIB. Doesn’t that mean that we are required to observe laser safety precautions regarding protective eyewear?

A: The laser classification of IIIB covers a very wide range of lasers; from very low-power to quite high-power. The SPY Imaging System laser falls into the very low-power end of that range. As such, protective eyewear for personnel and/or patients is not a recommended practice.

Q: Is the Fluorescence Imaging Agent a new drug? What are the contraindications for using it? Is it okay for use in patients with renal failure?

A: The Fluorescence Imaging Agent has been in use for more than 40 years and has been used in over 5,000,000 patients for various indications, including; ophthalmic angiography, liver function studies and to determine cardiac outputs.
b. Since there is a very small iodide component in the Fluorescence Imaging Agent, the package insert states that it should be used with caution in patients with an iodine allergy.
c. Since theFluorescence Imaging Agent is metabolized in the liver and excreted in the bile, there is no renal component to be concerned about.

Q: What’s the difference between the Fluorescence Imaging Agent and Fluorescein?

A: Many people confuse the Fluorescence Imaging Agent and Fluorescein, since both agents are used in imaging techniques. One of the major differences between the two drugs is that Fluorescein is metabolized in the kidney so should be used with caution in patients with compromised renal function. Use of the Fluorescence Imaging Agent has no impact on the kidneys, since it is metabolized in the liver. Both agents bind to the plasma proteins, but ICG holds a tighter bond and, as such, does not leak into the interstitial space as Fluorescein tends to do. This issue makes repetitive imaging with Fluroescein problematic. With the Fluorescence Imaging Agent, the half-life in the circulation is only 3 to 5 minutes, which is conducive to taking multiple images.