OCT in Retinal Vein Occlusions

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.