Retinal blood vessel disease encompasses a wide variety of vision-threatening conditions. Of these conditions, retinal vein occlusions are the most common. Vision loss can occur as a result of macular ischemia (loss of blood flow to the macula) or macular edema (fluid build-up at the macula).

OCT is an imaging technology that can perform non-contact cross-sectional imaging of retinal and choroidal tissue structures in real time. It is similar to ultrasound imaging, except that OCT measures the intensity of reflected light rather than sound waves.

The purpose of this study is to see if non-invasive OCT technology can changes due to retinal vein occlusions as well as the more invasive fluorescein angiography, which requires an injection of dye into the vein of an arm of a patient. The study will also compare the mapping of blood vessels (angiography) and loss of blood flow (ischemia) by fluorescein angiography and OCT. These studies will be evaluated to see how they relate to vision loss.

Inclusion Criteria:

• Diagnosis of branch or central retinal vein occlusion

Exclusion Criteria:

• Inability to give informed consent
• Inability to complete study tests within a 30 day period from date of enrollment
• Significant renal disease, defined as a history of chronic renal failure requiring dialysis or kidney transplant
• A prior history of reaction to fluorescein or other dyes.
• A condition that, in the opinion of the investigator, would preclude participation in the study (e.g., unstable medical status including blood pressure, cardiovascular disease, and glycemic control).
• Blood pressure > 180/110 (systolic above 180 OR diastolic above 110). If blood pressure is brought below 180/110 by anti-hypertensive treatment, subject can become eligible.
• Systemic anti-VEGF or pro-VEGF treatment within 4 months prior to treatment.
• Women of child-bearing potential: pregnant or lactating or intending to become pregnant within the next 12 months due to unknown safety of fluorescein angiography.
• Prior PRP or focal laser that would alter the macular perfusion and retino-vascular features.
• Inability to maintain fixation for OCT imaging.
• Other ocular condition is present such that, in the opinion of the investigator, may alter the retinal perfusion.
• An ocular condition is present that, in the opinion of the investigator, might affect or alter visual acuity during the course of the study (e.g., cataract).
• Substantial cataract that, in the opinion of the investigator, is likely to decrease visual acuity by 3 lines or more (i.e., cataract would be reducing acuity to 20/40 or worse if the eye was otherwise normal).
• Media opacity or otherwise that would prevent either fixation or ability to obtain adequate images as determined by the examiner.
• History of major ocular surgeries (including vitrectomy, cataract extraction, scleral buckle, any intraocular surgery, etc.) within 4 months prior to enrollment.

This study will measure blood vessel pattern/flow changes in up to 35 patients with retinal vein occlusions.