Type of test Other
Normal findings
Normal retinal and choroidal vasculature
Test explanation and related physiology
With the use of fluorescein angiography, the patency and integrity of the retinal circulation can be determined. This test involves injection of sodium fluorescein into the systemic circulation followed by timed-interval photographs performed with a fundus camera. The timed images are then reviewed for specific patterns indicative of disease states. This test is performed to diagnose disease affecting the posterior eye, including the retina, choroid, and optic nerve. The test is often repeated at intervals to monitor treatment or disease progression.
Fluorescein enters the ocular circulation from the internal carotid artery and then the ophthalmic artery. Pathologic changes are recognized by the detection of either hyperfluorescence or hypofluorescence. Among the common groups of ophthalmologic disease, fluorescein angiography can detect diabetic retinopathy, vein occlusions, retinal artery occlusions, edema of the optic disc, and tumors. These abnormalities can be treated with a laser to help prevent loss of vision, and treatment results can be monitored using fluorescein angiography.
Potential complications
• Allergic reactions. Allergies to fluorescein dye are rare. If they occur, they may cause a skin rash and itching.
Procedure and patient care
Before
* Explain the procedure to the patient.
• Obtain an informed consent.
* Reinforce the need for the patient to remain still during the few seconds after fluorescein injection.
• Obtain an ocular history of cataracts, prior retinal surgery, and other diseases that may inhibit photography.
* Instruct the patient to remove any ocular lenses.
* Inform the patient that there are no dietary restrictions.
• Note that pupil dilatation can improve access to the posterior eye. If ordered, administer appropriate mydriatic medications.
Note, however, that these medications are contraindicated for patients with glaucoma because they may dangerously increase ocular pressures.
During
• Note the following procedural steps:
1. The patient is positioned in the fundus camera with the chin on the bar.
2. The patient is told to pick a spot in the far distance and to concentrate on that spot during the examination.
3. Intravenous access is obtained.
4. Fluorescein dye is injected with the assistance of an autoinjector.
5. Photographs are taken by the ophthalmologist at timed intervals.
• The test is performed and interpreted by an ophthalmologist, usually in the office setting. Results are available in less than 30 minutes.
After
• Remove the intravenous access device and apply pressure to the venipuncture site.
* Inform the patient that fluorescein dye is excreted by the kidneys and to expect very yellow urine for the next 24 hours.
Abnormal findings
Increased levels
- Tumor
- Detached retina
-Trauma
- Inflammation
- Retinitis pigmentosa
- Papilledema
- Diabetic retinopathy
Decreased levels
- Diabetes
- Vascular disease
- Radiation to the eye
- Hemorrhage
- Edema
- Prior photocoagulation therapy
