This is a study of subjects with retinal vein occlusion (RVO) specifically looking at the difference in outcomes between patients with posterior vitreous detachment (PVD) and those without PVD. Posterior vitreous detachment is a condition where the gel-like substance that occupies the space between the retina and the lens of the eye liquefies and separates from the retina. 20 subjects from Barnes Retina Institute will be enrolled in this study. Based on a pre-treatment ultrasound (a test utilizing high-frequency sound waves to look at the inside of the eye), high resolution OCT (a noninvasive procedure called optical coherence tomography to check the thickness of your retina) and clinical exam, subjects will be assigned to one of 2 groups at baseline: Group 1 will be those with PVD and Group 2 will be those without PVD. Then subjects will receive monthly intravitreal (inside the eye) injections of Ranibizumab.

Several retinovascular diseases have been shown to be VEGF dependent including retinal vein occlusion, wet age-related macular degeneration, and diabetic retinopathy. The role of the vitreous or composition of the vitreous cavity has been examined in diabetic retinopathy on many occasions in the past and clinically it has been felt that a posterior vitreous separation leads a quieting and involution of diabetic retinopathy, both proliferative as well as pre-proliferative retinopathy. This clinical observation has never had any basic science data to support it. However, it has recently been shown that in cat eyes with posterior vitreous separation the vitreous cavity has a much lower VEGF concentration than in cat eyes with an attached posterior vitreous. This may be due to the fact that flow of oxygen from the retinal vasculature is increased by PVD. Vitreous oxygen levels are inversely associated with vitreous VEGF levels. As oxygen tension increases, VEGF levels will decline. This suggests if higher amounts of VEGF are present in the eye without PVD perhaps a powerful anti-VEGF drug, such as ranibizumab, may be of greater benefit to treat VEGF dependent retinovascular disease. To try and answer this question clinically, we have suggested that an analysis of the vitreous status in treatment naive eyes with retinal vein occlusion beginning ranibizumab therapy be undertaken to see if eyes without a posterior vitreous separation would achieve greater improvement in vision and a return to more normal retinal physiology compared to eyes with a posterior vitreous separation. No study has assessed PVDs in RVO patients receiving potential treatment.

Inclusion Criteria:

• Ability to provide written informed consent and comply with study assessments for the full duration of the study
• Subjects of either gender, Age > 18 years
• Best corrected visual acuity in the study eye between 20/40 and 2/200 inclusive.
• Retinal venous occlusive disease (BRVO or CRVO)
• Clear ocular media and adequate papillary dilation to permit good quality stereoscopic fundus photography, scheimpflug photography and high resolution OCT
• Ability to return for all study visits

Exclusion Criteria:

• Pregnancy (positive pregnancy test) or lactation.
• Premenopausal women not using adequate contraception. The following are considered effective means of contraception: surgical sterilization or use of oral contraceptives, barrier contraception with either a condom or diaphragm in conjunction with spermicidal gel, an IUD, or contraceptive hormone implant or patch.
• Prior RVO in the study eye
• Duration of RVO greater than 6 months
• Laser photocoagulation for macular edema within 3 months of Day 0
• Patients prior eye treatment including anti-VEGF therapy (within 3 months) or, intravitreal corticosteroid therapy (within 6 months)
• Prior vitreoretinal surgery.
• Had ocular surgery within the past 60 days in the study eye.
• Concurrent use of more than two therapies for glaucoma.
• Uncontrolled glaucoma in the study eye (defined as intraocular pressure >30 mm Hg despite treatment with anti-glaucoma medication).
• Neovascular glaucoma
• Concurrent use of systemic anti-VEGF agents
• Has active infection in the study eye.
• Inability to obtain photographs.
• Has received investigational therapy within 60 days prior to study entry.
• Patients with significantly compromised visual acuity in the study eye due to concomitant ocular conditions.
• Has other conditions the investigator considers to be sound reasons for exclusion (e.g., lack of motivation, history of poor compliance, concomitant illnesses, personality disorder, mental condition, drug abuse, use of neuroleptics, physical or social condition predicting difficulty in long-term follow-up).
• Has an allergy to fluorescein sodium dye.
• Inability to comply with study or follow-up procedures.