Fluorescein angiography/optical coherence tomography (OCT)
Your doctor may order fluorescein angiography or optical coherence tomography (OCT) to further evaluate your retina or to guide laser treatment if it is necessary. Fluorescein angiography is a diagnostic procedure that uses a special camera to take a series of photographs of the retina after a small amount of yellow dye (fluorescein) is injected into a vein in your arm. The photographs of fluorescein dye traveling throughout the retinal vessels show:

• Which blood vessels are leaking fluid;
• How much fluid is leaking;
• How many blood vessels are closed;
• Whether neovascularization is beginning.

OCT is a non-invasive scanning laser that provides high-resolution images of the retina, demonstrating its thickness. OCT can provide additional information regarding the presence and severity of macular edema.

These tests help the doctor determine:

• Why vision is blurred;
• Whether laser treatment should be started;
• Where to apply laser treatment.

Ultrasound
If your ophthalmologist cannot see the retina because of vitreous hemorrhage, an ultrasound test may be done in the office. The ultrasound can “see” through the blood to determine if your retina has detached. If there is detachment near the macula, this often calls for prompt surgery.

When the evaluation is complete, your ophthalmologist will decide when you need to be treated or re-examined.

People with diabetes should see their ophthalmologist right away if they have visual changes that:

• Affect only one eye;
• Last more than a few days;
• Are not associated with a change in blood sugar.