The Central Retinal Vein Bypass Study: A Trial of Laser-induced Chorioretinal Venous Anastomosis for Central Retinal Vein Occlusion

Benefits of a Laser Chorioretinal Anastomosis Plus Ranibizumab vs Ranibizumab Alone for Central Retinal Vein Occlusion: 4-Year Results

PURPOSE

To evaluate what clinical gains can be achieved over conventional treatment with ranibizumab alone for central retinal vein occlusion (CRVO) when causal pathology is additionally addressed successfully with a laser-induced chorio-retinal anastomosis (L-CRA).

DESIGN

Two-year extension of prospective, randomized controlled clinical trial.

METHODS

A total of 58 patients with macular edema secondary to CRVO were randomized 1:1 to receive either an L-CRA (n = 29) or sham procedure (n = 29) at baseline and then monthly intravitreal ranibizumab 0.5 mg. Outcomes (best corrected visual acuity [BCVA], central subfield thickness [CST], injection requirements) were monitored in the monthly pro re nata (PRN) ranibizumab phase from months 7 to 48.

RESULTS

Injection requirements for patients with a functioning L-CRA (24 of 29) during the monthly PRN period from 7 to 24 months were a mean (95% CI) of 2.18 (1.57, 2.78) injections compared to 7.07 (6.08, 8.06) (P < .0001) for control (ranibizumab alone). These decreased further over the next 2 years to 0.29 (0.14, 0.61) compared to 2.20 (1.68, 2.88) (P < .001) for the third year and 0.25 (0.11, 0.56) and 1.84 (1.34, 2.54) for the fourth year (P < .001). Mean BCVA was statistically different at all follow-up time points from month 7 through month 48 for the group with the functioning L-CRA compared to the control monotherapy group. This improved to 14.06 letters at month 48 (P = .009). There was no difference in CST between any of the groups over the 48 months of follow-up.

CONCLUSION

For CRVO patients, addressing causal pathology in addition to conventional therapy improves BCVA and reduces injection requirements.

Update on Retinal Vein Occlusion

Retinal vein occlusion represents the second leading cause of retinal vascular disorders, with a uniform sex distribution worldwide. A thorough evaluation of cardiovascular risk factors is required to correct possible comorbidities. The diagnosis and management of retinal vein occlusion have changed tremendously in the last 30 years, but the assessment of retinal ischemia at baseline and during follow-up examinations remains crucial. New imaging techniques have shed light on the pathophysiology of the disease and laser treatment, once the only therapeutic option, is now only one of the possible approaches with antivascular endothelial growth factors and steroid injections being preferred in most cases. Nowadays long-term outcomes are better than those achievable 20 years ago and yet, many new therapeutic options are under development, including new intravitreal drugs and gene therapy. Despite this, some cases still develop sight-threatening complications deserving a more aggressive (sometimes surgical) approach. The purpose of this comprehensive review is to reappraise some old but still valid concepts and to integrate them with new research and clinical data. The work will provide an overview of the disease's pathophysiology, natural history, and clinical features along with a detailed discussion on the advantages of multimodal imaging and of the different treatment strategies with the aim of providing retina specialists with the most updated knowledge in the field.

A narrative review on the association of high intraocular pressure and glaucoma in patients with retinal vein occlusion

BACKGROUND AND OBJECTIVE

Retinal vein occlusion (RVO) is a major cause of vision loss and elevated intraocular pressure (IOP), high ocular perfusion pressure, and glaucoma are known ophthalmic risk factors for RVO. The aim of this paper is to provide the update on the association and management of high IOP/glaucoma and RVO.

METHODS

A literature review was performed in PubMed and Medline until May 2022 utilizing specific keywords and cross-matched reference lists.

KEY CONTENT AND FINDINGS

The association of RVO with high IOP/glaucoma may be attributed to retinal ganglion cell loss due to retinal ischemia in high IOP and glaucoma. As new modalities showed, decreased optic disc perfusion, reduced density of blood vessels in the optic nerve head of glaucoma patients, changes in the peripapillary microvascular parameters, and decreased retinal nerve fiber layer (RNFL) thickness of the optic nerve head of eyes with RVO suggest a common pathway between RVO and glaucoma. Literature suggests the close follow up for glaucoma development among patients with non-arteriovenous (AV) crossing (optic cup or optic nerve sited) RVO in fellow eye and management of elevated IOP among RVO cases treated with anti-vascular endothelial growth factor (VEGF) antibodies/corticosteroids and those with preexisting primary open angle glaucoma (POAG).

CONCLUSIONS

Determining potential patient responses to treatment and considering therapeutic options are challenging among patients with RVO and glaucoma. However, IOP lowering managements in preventing IOP spikes in patients with preexisting glaucoma and early treatment of macular edema in eyes with RVO is recommended.

Chorioretinal venous anastomosis for non-ischemic retinal vein occlusion

Retinal vein occlusion (RVO) refers to the occlusion of the central retinal vein or primary and secondary branches caused by multiple factors. Clinical treatments for it include intravitreal or systemic vasodilator application, local usage of steroids and NSAID (non-steroidal anti-inflammatory drugs), thrombolysis, hemodilution, retinal laser photocoagulation, vitrectomy with vascular sheath incision, chorioretinal venous anastomosis (CRVA), and so on. At present, most treatments are aimed at RVO complications, while chorioretinal vein anastomosis can fundamentally reflux retinal vein blood through the choroid by venous vascular remodeling. Reports on the treatment of retinal vein occlusion by chorioretinal anastomosis are numerous in various countries. As a treatment means, CRVA can drain the venous blood, skipping the thrombosis spot, thus partially relieving anatomical vascular occlusion to achieve a therapeutic purpose. In this study, CRVA is evaluated from the aspects of indications, implementation process, postoperative effect evaluation, complications, and combination with anti-VEGF treatment. Based on the development of laser technology and vitrectomy, we hope to further review this treatment and provide a new reference for the clinical treatment of RVO.

The Long-term Outcomes of Central Retinal Vein Occlusion and Factors Associated with Resolution of Macular Edema

Purpose: To report the long-term outcomes of patients with macular edema (ME) secondary to central retinal vein occlusion (CRVO) and to explore the ME incidence and factors associated with ME resolution.Methods: We retrospectively studied patients with ME secondary to CRVO. The visual acuity at baseline was compared to that at the final visit. The incidence and timing of ME resolution during treatment were evaluated and the visual outcomes of patients who did and did not experience ME resolution were compared. We also identified factors predictive of ME resolution.Results: We included 79 patients; the mean follow-up time was 50.1 ± 14.3 months. The mean logarithm of the minimal angle of resolution (logMAR) of visual acuity was 0.94 ± 0.75 at diagnosis and 1.00 ± 0.84 at the final visit (p = 1.000). A logMAR visual loss of 0.3 or greater was noted in 28 patients (35.4%). During follow-up, ME resolution was evident in 40 eyes (50.6%) at a mean of 16.9 ± 17.4 months. Visual improvement was greater in patients who evidenced ME resolution than in those who did not (p < 0.001). The ME resolution rate was higher in patients younger than 60 years (p = 0.039) and in those who lacked subretinal fluid at diagnosis (p < 0.001).Conclusions: In patients with ME secondary to CRVO, the risk of long-term recurrent ME was higher in older patients and those evidencing subretinal fluid at diagnosis indicating that such patients require close follow-up and aggressive treatment.

Functional benefits of a chorioretinal anastomosis at 2 years in eyes with a central retinal vein occlusion treated with ranibizumab compared with ranibizumab monotherapy

Objective

To evaluate the functional benefits (best corrected visual acuity (BCVA), central subfield thickness, injection loads, central venous pressure (CVP)) of a laser-induced chorioretinal anastomosis (L-CRA) in patients with central retinal vein occlusion (CRVO) treated with ranibizumab compared with ranibizumab monotherapy.

Methods and Analysis

This is a post-hoc analysis of the 2-year randomised ranibizumab plus L-CRA for CRVO trial. Twenty-four patients (82.5%) developed a functioning or successful L-CRA; outcome effects were monitored in the monthly as-needed ranibizumab phase from months 7 to 24 and compared with the ranibizumab monotherapy group (n=29).

Results

From months 7 to 24, the mean (95% CI) injection load for the functioning L-CRA group was 2.18 (1.57 to 2.78) compared with 7.07 (6.08 to 8.06) for the control group (p<0.0001). The mean BCVA was averaged across all timepoints between the control and functioning L-CRA groups (average difference=11.46 (3.16 to 19.75) letters, p=0.01). At 2 years, there was an 82.5% reduction in the odds of high CVP (greater or equal to central retinal artery diastolic pressure) for those with a successful L-CRA compared with controls (p<0.0001).

Conclusion

For patients with CRVO, adding L-CRA as a causal-based treatment to conventional therapy reduced CVP and injection loads and offered improved BCVA.

Trial registration number ACTRN12612000004864.

Chorioretinal Anastomosis for Central Retinal Vein Occlusion: A Review of Its Development, Technique, Complications, and Role in Management

Treatments for central retinal vein occlusion (CRVO) have improved dramatically with the advent of intravitreal agents aimed at blocking the effects of the dominant hypoxia-induced upreglulated cytokine, which is vascular endothelial growth factor (VEGF). This cytokine breaks down the capillary endothelial barriers and is a major component of the macular edema in this condition. These treatments although impressive only address some of the sequelae of CRVO and have no effect on the underlying cause which is an obstruction to venous outflow leading to retinal blood flow stagnation and an elevation of the retinal central venous pressure (CVP). The creation of a laser-induced chorioretinal anastomosis (L-CRA) between the obstructed high pressure retinal venous circulation and the unobstructed low pressure choroidal venous circulation is a means addressing the causal pathology. The L-CRA will help lower the elevated CVP, which has been up until now an unaddressed component of the macular edema in this condition.This article reviews the preclinical and clinical development of the L-CRA and the results of the studies into its effect on the natural history of CRVO. It now can be used in combination with existing anti-VEGF treatments with the intravitreal agents addressing the component of the CRVO-induced macular edema due to the cytokine dysregulation, and the L-CRA addressing the component due to the elevated CVP and retinal venous stagnation. Improvements in laser technology have led to higher success rates in L-CRA creation and potential complications are now minimized and better controlled. The combination of L-CRA with intravitreal anti-VEGF agents offers the potential of a permanent cure with a significant reduction in the burden of therapy and improved visual outcomes in this condition.

Two-Year Efficacy of Ranibizumab Plus Laser-Induced Chorioretinal Anastomosis vs Ranibizumab Monotherapy for Central Retinal Vein Occlusion: A Randomized Clinical Trial

Importance

Adding a laser-induced chorioretinal anastomosis (L-CRA) to current treatments for central retinal vein occlusion (CRVO) may improve outcomes and lessen therapy burdens.

Objective

To determine the 2-year efficacy of intravitreal ranibizumab with an L-CRA vs ranibizumab alone for patients with macular edema caused by CRVO.

Design, Setting, and Participants

In this randomized clinical trial conducted at a single university clinic from March 2012 to June 2015, 58 participants with macular edema caused by CRVO were randomized 1:1 to either an L-CRA or sham procedure at baseline. All participants received monthly intravitreal injections of ranibizumab, 0.5 mg. Data were analyzed from April 2017 to September 2017.

Interventions

Random assignment to L-CRA plus monthly injections of intravitreal ranibizumab, 0.5 mg, (combination group; n = 29) or to a sham L-CRA procedure plus monthly injections of intravitreal ranibizumab, 0.5 mg, (ranibizumab alone group; n = 29) for 6 months. From month 7 to month 24, participants were evaluated monthly and received an injection of ranibizumab if a loss of 5 or more letters of best-corrected visual acuity (BCVA) on ETDRS chart from previous highest score occurred or if there was evidence of residual macular edema on optical coherence tomography.

Main Outcomes and Measures

Mean number of injections from month 7 to month 24, change in BCVA, and change in central subfield thickness (CST).

Results

Of the 58 included participants, 38 (66%) were men, and the mean (SD) age was 68.6 (11.8) years; participants had a mean (SD) BCVA of 57.09 (11.87) ETDRS letters (Snellen equivalent, 20/73) and a mean (SD) CST of 738.36 (175.54) μm. A successful L-CRA was created in 24 of 29 participants (83%) in the combination group. The mean number of injections from month 7 to month 24 was 3.2 (95% CI, 2.5-3.8) in the combination group and 7.1 (95% CI, 6.0-8.0) in the ranibizumab alone group. The ratio of the number of injections in the combination group compared with the ranibizumab alone group was 0.46 (95% CI, 0.36-0.61; P < .001). Mixed-effects regression modeling showed a difference in mean BCVA at 2 years between the combination and ranibizumab alone groups (combination, 70.3 letters [Snellen equivalent, 20/40]; ranibizumab alone, 61.6 letters [Snellen equivalent, 20/60]; difference, 8.8 letters; 95% CI, 0.2-17.3; P = .05). There was also a difference in CST at 2 years between the combination and ranibizumab alone groups (mean CST: combination, 303.6 μm; ranibizumab alone, 394.5 μm; difference, 90.9 μm; 95% CI, 24.3-157.5; P = .01). Four participants (14%) in the combination group required a vitrectomy for early macular traction or vitreous hemorrhage.

Conclusions and Relevance

For macular edema caused by CRVO, an L-CRA significantly reduced the number of ranibizumab injections required.

Trial Registration

anzctr.org.au Identifier: ACTRN12612000004864.

Recent advances in understanding and managing retinal vein occlusions

Retinal vein occlusions are the second most common form of retinal vascular disease. Previously, laser treatment for branch retinal vein occlusion and intravitreal triamcinolone acetonide for central retinal vein occlusion were the standard of care. Recent studies have demonstrated that anti-vascular endothelial growth factor (anti-VEGF) agents have a superior safety and efficacy profile for the treatment of both branch and central retinal vein occlusions. The use of wide-field fluorescein angiography has also allowed better visualization of the retinal periphery. Despite the better documentation of retinal non-perfusion, laser photocoagulation to the areas of non-perfusion does not seem to result in a reduction of macular edema or reduction in treatment burden and has been relegated to patients who develop rubeosis or neovascularization of the retina. More recently, several studies have demonstrated the use of a long-acting dexamethasone implant administered intravitreally or triamcinolone administered in the suprachoroidal space as a viable approach to treat retinal vein occlusion.

Retinal Vein Occlusion Review

Retinal vein occlusions are a very common condition with great importance in ophthalmology clinical practice. This article reviews the salient epidemiology, risk factors, clinical features, and treatments related to retinal vein occlusions.

Management of macular edema due to central retinal vein occlusion - The role of aflibercept

Central retinal vein occlusion (CRVO) can cause vision loss. The pathogenesis of CRVO involves a thrombus formation leading to increased retinal capillary pressure, increased vascular permeability, and possibly retinal neovascularization. Vision loss due to CRVO is commonly caused by macular edema. Multiple treatment modalities have been used to treat macular edema. Currently, the most common therapy used is intravitreal inhibition of vascular endothelial growth factor (VEGF). The three most widely used agents are aflibercept, bevacizumab, and ranibizumab and they are effective at blocking VEGF. In addition, intraocular steroids can be used to treat macular edema. This review will briefly cover the treatment options and discuss in greater detail the efficacy and safety of aflibercept.

RETINAL VEIN OCCLUSIONS, FROM BASICS TO THE LATEST TREATMENT

PURPOSE

To review the pathophysiology, diagnosis, and updated treatments of retinal vein occlusions (RVOs).

METHODS

A review of the literature was performed, focusing on the epidemiology, pathophysiology, diagnosis, and treatments (including both medical and surgical treatments) of RVO. Based on this review, a comprehensive overview was provided regarding the topic of RVO and focused on recent treatment updates.

RESULTS

Retinal vein occlusions have an age- and sex-standardized prevalence of 5.20 per 1,000 for any RVO, 4.42 per 1,000 for branch RVO, 0.80 per 1,000 for central RVO. Worldwide, an estimated 16.4 million adults are affected by RVOs, with 2.5 million affected by central RVO and 13.9 million affected by branch RVO. Retinal vein occlusion is recognized as an important cause of blindness and the diagnostic approaches and treatment options for RVO are reviewed and reported. The current treatment options including medical treatments (bevacizumab, ranibizumab, aflibercept, triamcinolone, and dexamethasone implants) and surgical alternatives were reviewed and reported with summaries on the corresponding strength of evidence.

CONCLUSION

Despite the understanding of this disease entity, challenges persist in the long-term treatment of RVO-related complications and visual loss. This review provided a detailed summary on the rationality and efficacy of recently developed treatment regimes and evaluated the potential benefit of combination therapy.

Central Retinal Vein Occlusion: A Review of Current Evidence-based Treatment Options

A central retinal vein occlusion (CRVO) can induce an ischemic and hypoxic state with resulting sequelae of macular edema and neovascularization. Many treatment options have been studied. Our review aims to investigate the safety and efficacy of the multiple treatment options of CRVO. A PubMed and Cochrane literature search was performed. Well-controlled randomized clinical trials that demonstrated strong level 1 evidence-based on the rating scale developed by the British Centre for Evidence-Based Medicine were included. Seven clinical trials met inclusion criteria to be included in this review. These included studies that investigated the safety and efficacy of retinal photocoagulation (1 study), intravitreal steroid treatment (2 studies), and antivascular endothelial growth factor treatment (4 studies) for the treatment of CRVO. In addition, studies evaluating surgical treatment options for CRVO were also included. Many treatment modalities have been demonstrated to be safe and efficacious in the treatment of CRVO. These treatment options offer therapeutic benefits for patients and clinically superior visual acuity and perhaps the quality of life after suffering from a CRVO.

Retinal angiomatous proliferation with chorioretinal anastomosis in childhood Coats disease: a reappraisal of macular fibrosis using multimodal imaging

PURPOSE

To describe the structural characteristics of retinal angiomatous proliferation and chorioretinal anastomosis in childhood Coats disease and redefine the previously described macular fibrosis.

METHODS

Prospective observational case series of consecutive patients with Coats disease examined over a 1-year study period. Multimodal imaging, including color fundus photography, wide-field fluorescein angiography, and spectral domain optical coherence tomography, was used to identify the features of macular retinal angiomatous proliferation and chorioretinal anastomosis.

RESULTS

Retinal angiomatous proliferation and chorioretinal anastomosis were present in 5 of 21 patients with Coats disease (24%). The lesions appeared as well demarcated, nodular retinal pigment epithelial detachments surrounded by exudate, with retinal vessels continuous with the underlying choroidal neovascularization.

CONCLUSION

Retinal angiomatous proliferation and chorioretinal anastomoses are features observed in a number of children (24% in the present series) with Coats disease and macular involvement. This lesion represents a distinct macular variant of Coats disease that underlies at least a proportion (all in the present series) of the previously described "macular fibrosis" and "subretinal mounds."

Optimal Treatment of Retinal Vein Occlusion: Canadian Expert Consensus

Background: The availability of new therapeutic approaches, particularly intravitreal anti-vascular endothelial growth factor (anti-VEGF) therapies, has prompted significant changes to the established treatment paradigms for retinal vein occlusion (RVO). Better visual outcomes and significantly lower rates of adverse events have been noted in multiple large randomized clinical trials and have led to a new standard of care for this sight-threatening condition. Objective: To develop an expert consensus for the management of RVO and associated complications in the context of recent clinical evidence. Methods: The development of a Canadian expert consensus for optimal treatment began with a review of clinical evidence, daily practice, and existing treatment guidelines and algorithms. The expert clinicians (11 Canadian retina specialists) met on February 1, 2014, in Toronto to discuss their findings and to propose strategies for consensus. Results: The result of this expert panel is a consensus proposal for Canadian ophthalmologists and retina specialists treating patients presenting with RVO. Treatment algorithms specific to branch and central RVO (BRVO and CRVO) were also developed. Conclusions: The consensus provides guidelines to aid clinicians in managing RVO and associated complications in their daily practice. In summary, laser remains the therapy of choice when neovascularization secondary to RVO is detected. Adjunctive anti-VEGF could be considered in managing neovascularization secondary to RVO in cases of vitreous hemorrhage. Intravitreal anti-VEGF should be considered for symptomatic visual loss associated with center-involving macular edema on optical coherence tomography. Patients with BRVO and a suboptimal response to anti-VEGF could be treated with grid laser, and those with CRVO and an inadequate response to anti-VEGF may be candidates for intravitreal steroids.

Investigation of retinal morphology alterations using spectral domain optical coherence tomography in a mouse model of retinal branch and central retinal vein occlusion

Retinal vein occlusion is a leading cause of visual impairment. Experimental models of this condition based on laser photocoagulation of retinal veins have been described and extensively exploited in mammals and larger rodents such as the rat. However, few reports exist on the use of this paradigm in the mouse. The objective of this study was to investigate a model of branch and central retinal vein occlusion in the mouse and characterize in vivo longitudinal retinal morphology alterations using spectral domain optical coherence tomography. Retinal veins were experimentally occluded using laser photocoagulation after intravenous application of Rose Bengal, a photo-activator dye enhancing thrombus formation. Depending on the number of veins occluded, variable amounts of capillary dropout were seen on fluorescein angiography. Vascular endothelial growth factor levels were markedly elevated early and peaked at day one. Retinal thickness measurements with spectral domain optical coherence tomography showed significant swelling (p<0.001) compared to baseline, followed by gradual thinning plateauing two weeks after the experimental intervention (p<0.001). Histological findings at day seven correlated with spectral domain optical coherence tomography imaging. The inner layers were predominantly affected by degeneration with the outer nuclear layer and the photoreceptor outer segments largely preserved. The application of this retinal vein occlusion model in the mouse carries several advantages over its use in other larger species, such as access to a vast range of genetically modified animals. Retinal changes after experimental retinal vein occlusion in this mouse model can be non-invasively quantified by spectral domain optical coherence tomography, and may be used to monitor effects of potential therapeutic interventions.

Therapies for macular edema associated with central retinal vein occlusion: a report by the American Academy of Ophthalmology

PURPOSE

To review the available evidence regarding the safety and efficacy of therapies for the treatment of macular edema (ME) associated with central retinal vein occlusion (CRVO).

METHODS

A literature search of the PubMed database was last conducted in March 2014 with no date restrictions but limited to articles published in English. A literature search of the Cochrane Library was also conducted in March 2014 with no date restrictions and without a language limitation. The combined searches yielded 108 citations, of which 20 were deemed clinically relevant for the Ophthalmic Technology Assessment Committee Retina/Vitreous panel to review in full text. Three additional studies were also identified for panel review. The level of evidence of these selected studies was reviewed by the panel methodologist.

RESULTS

There were 7 citations representing 4 clinical trials that provided level I evidence supporting the use of anti-vascular endothelial growth factor (VEGF) pharmacotherapies for ME associated with CRVO, including intravitreal ranibizumab (2), aflibercept (3), and bevacizumab (2). There were 3 citations representing 2 studies with level I evidence for intravitreal corticosteroid injection with dexamethasone intravitreal implant (2 citations) or triamcinolone (1 citation), although cataract and glaucoma were observed in these studies. Level I evidence is available on the limited benefit of macular grid-pattern laser photocoagulation (1 citation). Eight other citations reviewed were rated as level II, and 4 citations were rated as level III. Long-term efficacy results (≥2 years of follow-up) are limited to intravitreal ranibizumab at this time, and few studies have evaluated combination therapy with anti-VEGF and corticosteroid versus monotherapy of either class of drug.

CONCLUSIONS

Level I evidence indicates that intravitreal anti-VEGF pharmacotherapy is safe and effective over 2 years for ME associated with CRVO and that delay in treatment is associated with worse visual outcomes. In addition, level I evidence demonstrates short-term efficacy of intravitreal corticosteroid but also an association with a higher frequency of adverse events.

A United Kingdom-based economic evaluation of ranibizumab for patients with retinal vein occlusion (RVO)

OBJECTIVE

This study compares the cost-effectiveness of intravitreal ranibizumab vs observation and/or laser photocoagulation for treatment of macular edema secondary to retinal vein occlusion in a UK-based model.

METHODS

A Markov model was constructed using transition probabilities and frequency of adverse events derived using data from the BRAVO, CRUISE, and HORIZON trials. Outcomes associated with treatments and health states were combined to predict overall health costs and outcomes for cohorts treated with each option.

RESULTS

In branch retinal vein occlusion, ranibizumab produced a gain of 0.518 quality-adjusted life years at an incremental cost of £8141, compared with laser photocoagulation. The incremental cost-effectiveness ratio was £15,710 per quality-adjusted life year, and the incremental cost per month free from blindness was £658. In central retinal vein occlusion, ranibizumab produced a gain of 0.539 quality-adjusted life years at an incremental cost of £9216, compared with observation only. The incremental cost-effectiveness ratio was £17,103, and the incremental cost per month free from blindness was £423.

CONCLUSIONS

These incremental cost-effectiveness ratios are below the £20,000-30,000 range typically accepted as a threshold for cost-effectiveness. This suggests that ranibizumab may be regarded as a cost-effective therapy for patients with macular edema secondary to retinal vein occlusion, relative to grid laser photocoagulation (for BRVO) and observation (for CRVO). Limitations include sparse data for utilities associated with the severity of visual impairment in the WSE in patients with RVO. A lack of direct comparative evidence between ranibizumab and the dexamethasone intravitreal implant for the treatment of BRVO and CRVO and the infeasibility of an indirect comparison due to significant heterogeneity in trial designs prevented the inclusion of this treatment as a comparator in the Markov model.

Anti-vascular endothelial growth factor for macular oedema secondary to central retinal vein occlusion

BACKGROUND

Central retinal vein occlusion (CRVO) is a relatively common retinal vascular disorder in which macular oedema may develop, with a consequent reduction in visual acuity. Until recently there has been no treatment of proven benefit, but growing evidence supports the use of anti-vascular endothelial growth factor (anti-VEGF) agents.

OBJECTIVES

To investigate the effectiveness and safety of anti-VEGF therapies for the treatment of macular oedema secondary to CRVO.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Central Register of Controlled Trials (CENTRAL) and the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2013, Issue 10), Ovid MEDLINE (January 1950 to October 2013), EMBASE (January 1980 to October 2013), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to October 2013), Cumulative Index to Nursing and Allied Health Literature (CINAHL) (January 1937 to October 2013), OpenGrey, OpenSIGLE (January 1950 to October 2013), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov), the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en) and Web of Science Conference Proceedings Citation Index-Science (CPCI-S). There were no language or date restrictions in the electronic search for trials. The electronic databases and clinical trials registers were last searched on 29th October 2013.

SELECTION CRITERIA

We considered randomised controlled trials (RCTs) that compared intravitreal anti-VEGF agents of any dose or duration to sham injection or no treatment. We focused on studies that included individuals of any age or gender and a minimum of six months follow-up.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. The primary outcome was the proportion of participants with a gain in best-corrected visual acuity (BCVA) from baseline of greater than or equal to 15 letters (3 lines) on the Early Treatment of Diabetic Retinopathy Study (ETDRS) chart. Secondary outcomes included the proportion of participants with a loss of 15 letters or more of BCVA, the mean change from baseline BCVA, the mean change in central retinal thickness (CRT), the number and type of complications or adverse outcomes, and the number of additional interventions administered. Where available, we also presented quality of life and economic data.

MAIN RESULTS

We found six RCTs that met the inclusion criteria after independent and duplicate review of the search results. These RCTs included 937 participants and compared outcomes at six months to sham injection for four anti-VEGF agents: aflibercept (VEGF Trap-Eye, Eylea), bevacizumab (Avastin), pegaptanib sodium (Macugen) and ranibizumab (Lucentis). Three trials were conducted in Norway, Sweden and the USA, and three trials were multicentre, one including centres in the USA, Canada, India, Israel, Argentina and Columbia, a second including centres in the USA, Australia, France, Germany, Israel, and Spain, and a third including centres in Austria, France, Germany, Hungary, Italy, Latvia, Australia, Japan, Singapore and South Korea. We performed meta-analysis on three key visual outcomes, using data from up to six trials. High-quality evidence from six trials revealed that participants receiving intravitreal anti-VEGF treatment were 2.71 times more likely to gain at least 15 letters of visual acuity at six months compared to participants treated with sham injections (risk ratio (RR) 2.71; 95% confidence intervals (CI) 2.10 to 3.49). High-quality evidence from five trials suggested anti-VEGF treatment was associated with an 80% lower risk of losing at least 15 letters of visual acuity at six months compared to sham injection (RR 0.20; 95% CI 0.12 to 0.34). Moderate-quality evidence from three trials (481 participants) revealed that the mean reduction from baseline to six months in central retinal thickness was 267.4 µm (95% CI 211.4 µm to 323.4 µm) greater in participants treated with anti-VEGF than in participants treated with sham. The meta-analyses demonstrate that treatment with anti-VEGF is associated with a clinically meaningful gain in vision at six months. One trial demonstrated sustained benefit at 12 months compared to sham. No significant ocular or systemic safety concerns were identified in this time period.

AUTHORS' CONCLUSIONS

Compared to no treatment, repeated intravitreal injection of anti-VEGF agents in eyes with CRVO macular oedema improved visual outcomes at six months. All agents were relatively well tolerated with a low incidence of adverse effects in the short term. Future trials should address the relative efficacy and safety of the anti-VEGF agents and other treatments, including intravitreal corticosteroids, for longer-term outcomes.

The ABCs of RVO: a review of retinal venous occlusion

Retinal vein occlusions are important causes of loss of vision; indeed, they are the second most common retinal vascular disease, following diabetic retinopathy. For this reason alone, primary eye-care providers must be well versed in diagnosis and management. Risk factors, though not universally agreed upon, include but are not limited to advancing age, systemic hypertension, arteriolarsclerosis, diabetes, hyperlipidaemia, blood hyperviscosity, thrombophilia, ocular hypertension and glaucoma. Typically, visual loss is secondary to macular oedema and/or retinal ischaemia. Treatment modalities have included observation, systemic thrombolysis and haemodilution, radial optic neurotomy, chorioretinal anastomosis, vitrectomy, laser photocoagulation and intravitreal injection of anti-inflammatory and, most recently, anti-vascular endothelial growth factors.

Pars plana vitrectomy with multiple transvenous chorioretinotomies for macular edema due to retinal vein occlusion

BACKGROUND AND OBJECTIVE

To review results of vitreous surgery for branch and central retinal vein occlusion (BRVO and CRVO).

PATIENTS AND METHODS

All cases of vitrectomy with multiple transvenous chorioretinotomies for retinal vein occlusion at a vitreoretinal subspecialty practice were reviewed.

RESULTS

Twenty eyes of 20 patients (four with BRVO and 16 with CRVO) were included. Mean time from diagnosis to surgery was 15 months, and mean postoperative follow-up was 22 months. Injections of bevacizumab or ranibizumab decreased postoperatively (P < .0001; Poisson regression model), while log-MAR visual acuity improved (P = .0396; Wilcoxon signed-rank test). Ten eyes required no further injections postoperatively, and three eyes required one postoperative injection. Macular edema expressed as OCT maximum macular thickness was significantly reduced postoperatively at 6 months and 12 months (P = .0077 and .0093, respectively).

CONCLUSION

In a pilot study of retinal vein occlusion treatment, multiple transvenous chorioretinotomy surgery significantly improved visual acuity and macular edema and reduced intravitreal drug dependency. Further study is warranted.

Aflibercept: newly approved for the treatment of macular edema following central retinal vein occlusion

OBJECTIVE

To review the pharmacology, efficacy, and safety data available for aflibercept and compare the drug to other therapeutic options for treatment of macular edema following central retinal vein occlusion (CRVO) to determine its likely role in therapy.

DATA SOURCES

A PubMed search using the terms aflibercept and VEGF trap-eye was conducted to identify initial literature sources. No timeframe was used for exclusion of older trials. All trials referenced were published between January 1995 and December 2012.

STUDY SELECTION AND DATA EXTRACTION

Trials pertaining to oncologic use were excluded, as were studies conducted in animals and those written in a language other than English. Abstracts of the remaining trials were evaluated for determination of relevance to this review. Additional information sources were obtained via Internet and PubMed following a review of references.

DATA SYNTHESIS

While previous Phase 1, 2, and 3 trials for other indications (age-related macular degeneration and diabetic macular edema) have shown intravitreal injections of aflibercept to be safe and well tolerated in many patients, preliminary results from the ongoing COPERNICUS and GALILEO trials proved the efficacy of this medication in treating macular edema secondary to CRVO. Of the combined 358 patients studied in COPERNICUS and GALILEO, 56% and 60%, respectively, of the patients receiving aflibercept 2 mg monthly achieved at least a 15-letter improvement in best-corrected visual acuity (BCVA) from baseline over 6 months compared with just 12% and 22% in the control group (p < 0.01 for both). Additionally, in COPERNICUS and GALILEO, patients achieved a 21.3- and 14.7-letter improvement, respectively, in BCVA compared with placebo (p < 0.01 for both).

CONCLUSIONS

In September 2012, aflibercept became the second vascular endothelial growth factor (VEGF) inhibitor approved for treatment of macular edema secondary to CRVO. While efficacy and safety appear similar to other anti-VEGF treatments, the higher potency, binding affinity, and duration of action make aflibercept an appealing new option.

Best practices for treatment of retinal vein occlusion

PURPOSE OF REVIEW

Retinal vein occlusion (RVO) is a sight-threatening retinal vascular disorder associated with macular edema and neovascularization. Until recently, the standard of care for branch RVO-associated macular edema was grid laser photocoagulation and observation for central RVO-associated macular edema. Neovascularization was treated with scatter laser photocoagulation. The purpose of this article is to review recent findings that have changed our treatments of RVO.

RECENT FINDINGS

The recent development of intravitreal pharmacotherapy has demonstrated benefit with anti-vascular endothelial growth factor (VEGF) agents and corticosteroids for the treatment of RVO-associated macular edema. The intravitreal use of FDA-approved ranibizumab (Lucentis) and a sustained release dexamethasone implant (Ozurdex), along with off-label bevacizumab (Avastin) and preservative-free triamcinolone, has significantly expanded our treatment options and replaced standard of care for treatment of RVO-associated macular edema. Whereas anti-VEGF agents can also induce rapid regression of neovascularization, scatter laser photocoagulation remains the standard of care to prevent neovascular complications.

SUMMARY

Intravitreal pharmacotherapy has revolutionized our treatment of retinal vascular diseases, including RVO. Although these intravitreal agents are effective, our understanding of their specific indications and long-term roles is still evolving. Furthermore, until the underlying occlusive pathophysiology of RVO can be addressed, our treatments will be limited to temporizing therapies against a chronic disease.

Retinal vein occlusion: beyond the acute event

Retinal vein occlusion is a major cause of vision loss. We provide an overview of the clinical features, pathogenesis, natural history, and management of both branch retinal vein occlusion and central retinal vein occlusion. Several recent multicenter randomized clinical trials have been completed which have changed the approach to this disorder. Management of retinal vein occlusions can be directed at the underlying etiology or the resulting sequelae. Options include surgical intervention, laser photocoagulation, intravitreal pharmacotherapy, and sustained drug delivery devices.

Management of macular edema secondary to central retinal vein occlusion: an evidence-based

Retinal vein occlusions are common retinal vascular disorders with the potential for significant vision-related morbidity. Retinal vein occlusions are classified as either branch retinal vein occlusion (BRVO), central retinal vein occlusion (CRVO), or hemiretinal vein occlusion (HRVO) based on the specific occlusion site. Decreased vision in patients afflicted with CRVO may result from retinal ischemia and/or the accumulation of fluid within the center of the retina (macular edema). The Central Vein Occlusion Study (CVOS) Group demonstrated that grid laser photocoagulation is not an effective treatment for decreased vision due to CRVO-related macular edema. Since publication of that report, the standard of care for patients with decreased vision due to CRVO-associated macular edema was observation. However, in the past 5 years, several major randomized controlled clinical trials have investigated new therapeutic modalities for the treatment of macular edema secondary to CRVO. This article aims to provide insight into current evidence-based approaches to the management of macular edema secondary to CRVO. A companion article reviews approaches for the management of macular edema secondary to BRVO.

Anti-vascular endothelial growth factor for macular edema secondary to central retinal vein occlusion

BACKGROUND

Central retinal vein occlusion (CRVO) is a common retinal vascular disorder in which macular edema (ME) may develop, with a consequent reduction in visual acuity. The visual prognosis in CRVO-ME is poor in a substantial proportion of patients, especially those with the ischemic subtype, and until recently there has been no treatment of proven benefit. Macular grid laser treatment is ineffective, and whilst a few recent randomized controlled trials (RCTs) suggest short-term gains in visual acuity with intravitreal steroids for patients with non-ischemic CRVO-ME, there is no established treatment for ischemic CRVO-ME. Anti-vascular endothelial growth factor (anti-VEGF) agents have been used to treat ME resulting from a variety of causes and may represent a treatment option for CRVO-ME.

OBJECTIVES

To investigate the effectiveness and safety of intravitreal anti-VEGF agents in the treatment of CRVO-ME.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2010, Issue 8), MEDLINE (January 1950 to August 2010), EMBASE (January 1980 to August 2010), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to August 2010), Cumulative Index to Nursing and Allied Health Literature (CINAHL) (January 1937 to August 2010), OpenSIGLE (January 1950 to August 2010), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com) and ClinicalTrials.gov (www.clinicaltrials.gov). There were no language or date restrictions in the search for trials. The electronic databases were last searched on 10 August 2010.

SELECTION CRITERIA

We considered RCTs that compared intravitreal anti-VEGF agents of any dose or duration to sham injection or no treatment. We focused on studies that included individuals of any age or gender with unilateral or bilateral disease and a minimum of six months follow up. Secondarily, we considered non-randomized studies with the same criteria, but did not conduct a separate electronic search for these.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data.

MAIN RESULTS

We found two RCTs that met the inclusion criteria after independent and duplicate review of the search results. These RCTs utilized different anti-VEGF agents which cannot be assumed to be directly comparable. We, therefore, performed no meta-analysis. Evidence from these trials and from other non-randomized case series is summarized in this review.

AUTHORS' CONCLUSIONS

Ranibizumab and pegaptanib sodium have shown promise in the short-term treatment of non-ischemic CRVO-ME. However, effectiveness and safety data from larger RCTs with follow up beyond six months are not yet available. There are no RCT data on anti-VEGF agents in ischemic CRVO-ME. The use of anti-VEGF agents to treat this condition therefore remains experimental.

Retinal vein occlusion: pathophysiology and treatment options

This paper reviews the current thinking about retinal vein occlusion. It gives an overview of its pathophysiology and discusses the evidence behind the various established and emerging treatment paradigms.