central retinal vein occlusion (crvo) treatment with bevacizumab and dexamethasone or bevacizumab only.

Conditions: Central Retinal Vein Occlusion

Summary: the purpose of this study is to determine whether bevacizumab (avastin) in combination with dexamethasone (ozurdex) will be effective in reducing if not eliminating the macular edema associated with the disease, central retinal vein occlusion (crvo) in comparison to bevacizumab (avastin) alone.

retinal venous occlusive disease is the second only to diabetic retinopathy as a major cause of blindness associated with retinal vascular disease. macular edema is a major cause of vision loss in patients presenting with central and hemi vein occlusions. until recently the standard of care for macular edema secondary to central retinal vein occlusion was observation. recent investigations of steroids for this condition has shown greater visual benefit but is associated with risks such as cataract formation and increased intraocular pressure. in the past laser photocoagulation has been used, but was found to offer no visual benefits over the natural history in the treatment of macular edema associated with crvo. bevacizumab, an anti-vegf agent, is a potent inhibitor of vascular permeability, with the potential to reduce retinal vascular leakage and diminish macular edema. in addition, as an anti-vegf agent, it may also inhibit neovascularization of the iris, a frequent complication of ischemic central retinal vein occlusion. bevacizumab use as an intravitreal agent does carry the risk of intraocular infection but probably carries very low risk of glaucoma or cataract formation, making it a potentially safer pharmacologic treatment for crvo associated macular edema as compared to steroids. ozurdex (dexamethasone) intravitreal implant is a steroid injected into the eye to treat swelling that may occur when there is a blockage of certain blood vessels in your eyes. ozurdex is also used to treat non-infectious uveitis affecting the posterior (rear) segment of the eye.

Eligibility criteria:
inclusion criteria: 1. written informed consent must be obtained before any study assessment is performed 2. diagnosis of visual impairment exclusively due to me secondary to crvo 3. bcva score at screening and baseline between 73 and 19 letters (etdrs) exclusion criteria: 1. pregnant or nursing (lactating) women 2. stroke or myocardial infarction less than 3 months before screening 3. uncontrolled blood pressure defined as systolic value of \>160 mm hg or diastolic value of \>100 mm hg at screening or baseline. 4. any active periocular or ocular infection or inflammation at screening or baseline in either eye 5. uncontrolled glaucoma at screening or baseline or diagnosed within 6 months before baseline in either eye 6. neovascularization of the iris or neovascular glaucoma in the study eye 7. use of any systemic antivascular endothelial growth factor (anti-vegf) drugs within 6 months before baseline 8. panretinal laser photocoagulation within 3 months before baseline or anticipated or scheduled within the next 3 months following baseline in the study eye 9. focal or grid laser photocoagulation within 4 months before baseline in the study eye 10. use of intra- or periocular corticosteroids (including sub-tenon) or ocular anti-vegf treatment within 3 months before screening in the study eye 11. any use of intraocular corticosteroid implants (eg, dexamethasone \[ozurdex®\], fluocinolone acetonide \[iluvien®\]) in the study eye