Indocyanine Green Angiography (ICGA)
Overview of ICGA
This section explains what ICGA is and why it is important for retinal care.
ICGA highlights the choroidal circulation, giving our retina specialists a clearer view of blood flow beneath the retina. This deeper perspective helps detect abnormalities that might not appear on standard retinal imaging.
The test uses indocyanine green dye, which binds to blood proteins. Because the dye remains inside the vessels longer, the resulting images are sharp and reveal fine details of the choroid.
Procedure Details
Here we outline what happens before, during, and immediately after the test.
You will sit comfortably while a small amount of indocyanine green dye is injected into a vein in your arm or hand. No special fasting or other preparation is usually required.
A specialized infrared camera records images as the dye travels through your eye. The process is observed in three phases:
- Early phase, within the first minute, when large choroidal arteries fill with dye.
- Middle phase, between five and fifteen minutes, when retinal and choroidal vessels are fully illuminated.
- Late phase, after fifteen minutes, when the dye fades and subtle abnormalities become easier to see.
Safety and Side Effects
ICGA is generally safe, but knowing possible reactions can help you feel at ease.
The test is well tolerated, and severe allergic reactions occur in less than 0.2 percent of cases. Our team monitors you closely throughout the procedure.
Most patients experience no serious problems, but a few mild reactions can occur:
- Brief warm sensation, metallic taste, or mild nausea just after injection.
- Rare itching, rash, or hives that resolve quickly with prompt care.
People with severe kidney or liver disease or those who are pregnant may need an alternative test. Discuss your medical history with us so we can choose the safest option.
Key Conditions That May Warrant ICGA
ICGA is especially valuable for diseases that involve deeper blood vessels in the eye.
The test uncovers abnormal vessel growth beneath the retina, helping determine the specific subtype of macular degeneration.
ICGA reveals balloon like vascular structures that can bleed or leak fluid, guiding targeted treatment.
By showing areas of excessive choroidal leakage, the test helps explain fluid accumulation under the retina.
Detailed images assist in distinguishing benign vascular tumors from more serious lesions such as melanomas.
Conditions like Birdshot Chorioretinopathy and Vogt Koyanagi Harada disease benefit from the deeper vascular insights provided by ICGA.
How ICGA Differs from Fluorescein Angiography
Although both tests use contrast dyes, they serve different purposes in eye care.
Indocyanine green dye absorbs infrared light, allowing it to image through pigments and blood to reveal deeper structures that fluorescein angiography may miss.
Because the dye binds to proteins, it remains inside the vessels longer, creating clearer images with less leakage into surrounding tissues.
Patient Experience During ICGA
Knowing what to expect can make the procedure feel straightforward.
After injection, the dye reaches the choroidal vessels within seconds. A high resolution infrared camera records images for about twenty to thirty minutes, covering early, middle, and late phases.
Most patients feel only a quick pinch from the needle and possibly a mild metallic taste, which fades almost immediately.
You may resume normal activities right away. The dye clears naturally within a few hours, and any slight green tint to skin or urine is temporary.
Comparative Imaging Techniques
ICGA complements other retina imaging tools, each offering unique strengths.
Fluorescein angiography excels at showing small retinal vessels but can leak into tissue. ICGA stays within the deeper choroidal vessels, producing sharper images of that layer.
Optical Coherence Tomography provides cross sectional views of retinal layers, while ICGA offers dynamic pictures of blood flow. Using both gives a comprehensive assessment of structure and circulation.
OCT Angiography is non invasive and ideal for routine monitoring of retinal microvasculature. ICGA adds detailed insight into choroidal circulation, revealing subtle changes that guide complex care plans.
Benefits of ICGA in Retinal Care
The unique features of ICGA translate into meaningful clinical advantages.
Clear images of choroidal vessels allow our specialists to detect issues such as polypoidal lesions that remain hidden on other tests.
By precisely identifying different disease subtypes and leakage points, ICGA supports tailored treatment plans and better outcomes.
Combining ICGA with fluorescein angiography and OCT paints a complete picture of retinal and choroidal health, guiding well informed care decisions.
Frequently Asked Questions
The following answers address common concerns about ICGA.
No. Apart from a brief pinch when the dye is injected, most patients feel little to no discomfort during the procedure.
The imaging portion lasts about twenty to thirty minutes, allowing us to capture detailed views throughout all circulation phases.
Special preparation is rarely required. Follow any instructions provided by our office, and inform us of relevant medical conditions or allergies.
You can resume normal activities right away. The dye leaves your system within a few hours, and any temporary color change in skin or urine is harmless.
Our Commitment to Your Eye Health
ICGA is one of many advanced tools we use to protect and improve your vision. If you have questions about this test or your retinal care, our team is ready to support you with clear information and personalized attention.
Fantastic! All staff, starting from the front desk all the way to Dr. Greene, are very friendly and professional. Thank you for the good job you do every day.
William Wolff
Having been a patient of Dr Kleiner for decades. I can attest to the professionalism and knowledge that he brings to his patients.
Carolee Bergey
Great first visit with Dr. Hugo Linares. Very patient, listened to our concerns, and understood. Each associate was attentive with a positive attitude. Truly appreciated their compassionate care.
Donna Lang
Staff was very friendly and efficient. I was a new patient add on and it didn’t feel that way.
F.T
Dr Kleiner has been my retina specialist during that time and I would not want to have to find a different Dr. I have absolute faith in his care of my eyes.
Linda Radiyah Paris-Pace