Treatment for Retinal Venous Occlusion
Anti-VEGF agents should be the first-line treatment for macular edema associated with retinal vein occlusion (RVO), as they provide superior visual outcomes compared to other treatment modalities. 1
Types of Retinal Vein Occlusion
- Retinal vein occlusion (RVO) is classified based on the location of the obstruction 1:
- Central retinal vein occlusion (CRVO): Obstruction at or posterior to the optic nerve head
- Branch retinal vein occlusion (BRVO): Complete or partial obstruction at a branch or tributary of the central retinal vein
Pathophysiology and Complications
- The main cause of visual impairment in RVO is macular edema 2
- Serious complications include neovascularization of the retina and optic disc, which can lead to vitreous hemorrhage, retinal detachment, and neovascular glaucoma 2
- Risk factors include older age (>40 years), arteriosclerosis, systemic hypertension, and diabetes 1
Treatment Algorithm for Macular Edema in RVO
First-Line Treatment: Anti-VEGF Agents
- Multiple level I studies demonstrate the efficacy of anti-VEGF agents in treating macular edema associated with both BRVO and CRVO 1
- FDA-approved options include ranibizumab and aflibercept; bevacizumab is used off-label 1
- The BRAVO trial showed that monthly intravitreal ranibizumab injections resulted in significant visual gains (16-18 letters) compared to sham injections (7.3 letters) at 6 months 1
- Early treatment is crucial, as delay in treatment can lead to suboptimal visual outcomes 1
Second-Line Treatment: Intravitreal Corticosteroids
- Intravitreal corticosteroids (triamcinolone and dexamethasone implant) are effective but considered second-line due to significant ocular side effects 1:
- Secondary glaucoma
- Cataract formation
Third-Line Treatment: Laser Photocoagulation
- Grid laser photocoagulation was historically the standard treatment for macular edema in BRVO 1
- The Branch Vein Occlusion Study (BVOS) showed that grid-pattern laser photocoagulation resulted in better visual outcomes than no treatment 1
- However, recent clinical trials (BRIGHTER and RETAIN) demonstrated that adding laser to ranibizumab did not improve visual outcomes or reduce treatment burden 1
- Laser may be considered in patients with contraindications to anti-VEGF therapy or those unable to adhere to monthly follow-up 1
Treatment for Neovascular Complications
For Retinal Neovascularization in BRVO
- Sectoral panretinal photocoagulation (PRP) is recommended when complications such as vitreous hemorrhage occur 1
For Iris Neovascularization or Retinal Neovascularization in CRVO
- Dense peripheral panretinal photocoagulation (PRP) is the best treatment 1
- PRP decreases the risk of progression to iris neovascularization and may prevent neovascular glaucoma 1
- Anti-VEGF agents can be used adjunctively when PRP is insufficient to control angiogenesis 1
Follow-up Recommendations
- Monthly follow-up for 6 months in eyes with CRVO and in eyes with ischemic CRVO after discontinuing anti-VEGF to detect neovascularization 1
- Follow-up evaluations should include 1:
- Visual acuity assessment
- Undilated slit-lamp biomicroscopy and gonioscopy with careful iris examination
- Pupillary assessment for relative afferent pupillary defect
- Intraocular pressure measurement
- Stereoscopic examination of the posterior pole after pupil dilation
- OCT imaging when appropriate
- Peripheral retina and vitreous examination when indicated
Important Considerations and Pitfalls
- Delay in treatment can lead to poorer visual outcomes 1
- Patients with RVO are at risk for developing RVO in the fellow eye and have higher risk of cardiovascular disease and cerebrovascular accidents 1
- Communication with the primary care physician is essential for management of systemic risk factors 1
- There is no evidence to support routine testing for heritable thrombophilias in patients with RVO 2
- Anti-VEGF agents, laser, and intravitreal steroids are all cost-effective for the management of RVOs 1