The influence of anti-VEGF therapy on present day management of macular edema due to BRVO and CRVO: a longitudinal analysis on visual function, injection time interval and complications

An Analysis of Optical Coherence Tomography Angiography (OCT-A) Perfusion Density Maps in Patients Treated for Retinal Vein Occlusion with Intravitreal Aflibercept

AIM

The primary goal of this study was to evaluate the reduction in non-perfusion area and improvement in blood flow as well as the reduction in retinal edema on optical coherence tomography angiography (OCT-A) in patients with retinal vein occlusion treated with 2 mg intravitreal injections of aflibercept.

MATERIAL AND METHODS

Fifty eyes of nine patients with central retinal vein occlusion (CRVO) and sixteen patients with branch retinal vein occlusion (BRVO), aged 50 to 75 years, were collectively analyzed as retinal vein occlusion (RVO). The following parameters were analyzed: superficial vessel density (VDSF), deep vessel density (VDD), flow area in the outer retina (FAOR), choriocapillaris flow area (FACC), non-flow area (NFA) and the foveal avascular zone (FAZ).

RESULTS

OCT-A revealed a reduction in macular edema. The most significant change in central retinal thickness (CRT) was observed between measurement timepoint "5" and the baseline (46%). The non-flow area was also reduced. Following a significant decrease in superficial vessel density 30 days after the first dose of aflibercept, a non-significant increase was noted at the subsequent timepoints. An increase was also found in deep vessel density and choriocapillaris flow area. Improvements in the above OCT-A parameters resulted in increased retinal blood flow and improved visual acuity.

CONCLUSIONS

Patients with retinal vein occlusion treated with 2 mg aflibercept exhibited reduced macular edema and FAZ, increased vessel density, improved blood flow, and better visual acuity.

Hyaluronic Acid-PEG-Based Diels-Alder In Situ Forming Hydrogels for Sustained Intraocular Delivery of Bevacizumab

Retinal diseases are the leading cause of visual impairment worldwide. The effectiveness of antibodies for the treatment of retinal diseases has been demonstrated. Despite the clinical success, achieving sufficiently high concentrations of these protein therapeutics at the target tissue for an extended period is challenging. Patients suffering from macular degeneration often receive injections once per month. Therefore, there is a growing need for suitable systems that can help reduce the number of injections and adverse effects while improving patient complacency. This study systematically characterized degradable "in situ" forming hydrogels that can be easily injected into the vitreous cavity using a small needle (29G). After intravitreal injection, the formulation is designed to undergo a sol-gel phase transition at the administration site to obtain an intraocular depot system for long-term sustained release of bioactives. A Diels-Alder reaction was exploited to crosslink hyaluronic acid-bearing furan groups (HAFU) with 4 arm-PEG10K-maleimide (4APM), yielding stable hydrogels. Here, a systematic investigation of the effects of polymer composition and the ratio between functional groups on the physicochemical properties of hydrogels was performed to select the most suitable formulation for protein delivery. Rheological analysis showed rapid hydrogel formation, with the fastest gel formation within 5 min after mixing the hydrogel precursors. In this study, the mechanical properties of an ex vivo intravitreally formed hydrogel were investigated and compared to the in vitro fabricated samples. Swelling and degradation studies showed that the hydrogels are biodegradable by the retro-Diels-Alder reaction under physiological conditions. The 4APM-HAFU (ratio 1:5) hydrogel formulation showed sustained release of bevacizumab > 400 days by a combination of diffusion, swelling, and degradation. A bioassay showed that the released bevacizumab remained bioactive. The hydrogel platform described in this study offers high potential for the sustained release of therapeutic antibodies to treat ocular diseases.

Intravitreal ranibizumab improves macular sensitivity in patients with central retinal vein occlusion and macula edema

Background

Patients with central retinal vein occlusion (CRVO) and macular edema often are treated by intravitreal ranibizumab injection (IRI). The role of changes in macular sensitivity in the positive effects of IRI on visual functions is unclear. Therefore, we assessed the relationship between macular sensitivity and improvement of visual functions.

Methods

We included 15 eyes of 15 patients with treatment-naïve CRVO and followed patients for 6 months after pro re nata IRI. IRI was repeated if the central macular thickness was greater than or equal to 300 µm. Microperimetry-3 was used to measure macular sensitivity within the central 1-mm, 3-mm, and 6-mm fields before and monthly for 6 months after IRI.

Results

IRI significantly improved mean macular sensitivity over time within the central 1-mm, 3-mm, and 6-mm fields (all P < 0.001). None of the fields showed significant differences in the change of mean macular sensitivity between patients with little improvement in best corrected visual acuity (BCVA; i.e., in patients with a change in logarithm of the minimum angle of resolution [logMAR] BCVA < 0.3) and those with marked improvement in BCVA (change in logMAR BCVA > 0.3). The mean macular sensitivity before IRI showed correlations with the improvement of macular sensitivity in every field.

Conclusion

These findings suggest that IRI improves macular sensitivity in patients with CRVO and macular edema independent of any improvement in BCVA and that macular sensitivity before treatment is associated with improvement of macular sensitivity after treatment.

Optical Coherence Tomography for Ophthalmology Imaging

Optical coherence tomography (OCT) is a depth-resolved imaging modality, which is able to achieve micrometer-scale resolution within biological tissue noninvasively. In the past 30 years, researchers all around the world had made several essential efforts on techniques relevant to OCT. OCT has become a routine process for eye diseases with different types. In this chapter, the three important stages in the development of OCT are briefly illustrated, including the time domain OCT (TD-OCT), the frequency domain OCT (FD-OCT) and the optical coherence tomography angiography (OCTA). Each of the technique has made great progress for use on living human eye imaging in clinical applications. TD-OCT was first proposed and commercialized, which is able to achieve acceptable 2D depth-resolved cross-sectional images of human retina in vivo. FD-OCT was the upgraded OCT technique compared with TD-OCT. By capturing the coherent signal within the Fourier space, the FD-OCT could improve the image sensitivity compared with TD-OCT, and achieve dozens of kilo hertz imaging speed. OCTA is the newest developments of OCT technique, which is able to visualize the micro vasculature networks of human retina in vivo. With OCTA technique, the newest ophthalmologic OCT system is able to achieve detailed diagnosis for both micro-structure and vasculature abnormalities for clinical applications. The further development of OCT technique on imaging speed, contrast, resolution, field of view, and so on will make OCT to be a more powerful tool for clinical usages.

A systematic review of real-world evidence of the management of macular oedema secondary to branch retinal vein occlusion

This review assessed the real-world evidence of the management of macular oedema secondary to branch retinal vein occlusion (BRVO). A meta-analysis of 2530 eyes from 48 real-world studies of therapies for macular oedema secondary to BRVO was conducted. Baseline characteristics, visual, anatomical and safety outcomes were recorded. The weighted mean and weighted estimates from random-effects models were calculated for visual acuity (VA) and central subfield thickness (CST) changes at 6, 12 and 24 months. Primary outcome was change in VA (logMAR letters) at 12 months. Study quality was assessed using the quality appraisal checklist for case series developed by Institute of Health Economics. The mean baseline VA for the pooled data was 54.0 (51.5, 56.5) letters and the mean baseline CST was 501.3 (483.5, 519.1) µm. The random-effects estimate for mean (95% CI) change in VA was 14.6 (12.5, 16.7) letters at 12 months (n = 1727). The random-effects estimate for mean (95% CI) change in CST was -181.7 (-230.7, -132.7) µm at 12 months (n = 1325). The quality of studies varied considerably. Ocular and systemic adverse events were discussed in 79% and 42% of treatment arms respectively, with possible under-reporting. Visual and anatomical gains achieved in the real-world for anti-VEGF therapy were not as impressive as seminal RCTs, possibly due to reduced injection frequency in the real world and differences in baseline characteristics. There is an urgent need for consensus on the minimum efficacy, treatment burden and safety data to collect to strengthen the real-world evidence base.

Current Outcomes of Anti-VEGF Therapy in the Treatment of Macular Oedema Secondary to Branch Retinal Vein Occlusions: A Meta-Analysis

PURPOSE

The current body of evidence on the efficacy and safety of anti-VEGFs for macular oedema secondary to branch retinal vein occlusion (BRVO) is steadily growing as large clinical trials and observational studies are continually completed. The aim of this meta-analysis is to analyse anatomical and functional outcomes in response to anti-VEGF therapy using evidence generated from a pooled analysis of current clinical trials and observational studies.

METHODS

The current meta-analysis includes treatment of BRVO with aflibercept, bevacizumab and ranibizumab from randomised controlled trials and observational studies. Inclusion criteria included peer-reviewed publications with at least a 12-month follow-up period. On literature review using multiple electronic databases (PubMed, Embase and Cochrane), 22 studies met the inclusion criteria. Baseline patient characteristics, study design, sample size and 12- and 24-month change in best corrected visual acuity (BCVA) and central foveal thickness (CFT) as measured on optical coherence tomography imaging were pooled in a meta-analysis. Data were then stratified by study design and anti-VEGF therapy in subgroup analyses.

RESULTS

A total of 1,236 eyes from 22 studies were included in this meta-analysis. Mean baseline BCVA ranged from 66 ETDRS letters (20/50 Snellen equivalent) to 35 letters (20/200 Snellen). Mean baseline CFT ranged from 406.0 to 681.0 µm. Anti-VEGF treatment demonstrated an overall mean improvement in BCVA at 12 months of 14 letters (95% CI 12.0 to 16.2, p < 0.001) and CFT reduction of 228 µm (95% CI -278.9 to -176.1, p < 0.001). The BCVA gains at 12 months were maintained to month 24 with a mean gain of 12.5 letters (95% CI 6.3 to 18.8, p < 0.001), as well as reduction of CFT of 238 µm (95% CI -336.0 to -140.2, p < 0.001). No cases of endophthalmitis or glaucoma were reported in any study.

CONCLUSION

This meta-analysis confirms the comparable safety and efficacy of anti-VEGF therapies for patients with cystoid macular oedema secondary to BRVO. There is a need for randomised prospective comparative trials of anti-VEGF agents for BRVO.

The Effects of Intravitreal Ranibizumab, Aflibercept or Dexamethasone Implant Injections on Intraocular Pressure Changes

BACKGROUND The aim of this study was to compare the alterations in intraocular pressure (IOP) values during the early postoperative period after intravitreal ranibizumab, aflibercept, or dexamethasone implant injections. MATERIAL AND METHODS In this retrospective study, a total of 188 patients were grouped into 3 groups: the ranibizumab group, the aflibercept group, and the dexamethasone group. Ocular axial length (AXL) and anterior chamber depth (ACD) were measured in the pre-injection period. IOP was measured just before the injection at 1 minute,10 minutes, 1 hour, 1 day, and 1 month after injection. RESULTS There was a transient peak in the ranibizumab group and the aflibercept group at 1 minute that started to decrease at 10 minutes and IOP values returned to preoperative values at approximately 1 hour. Similar alterations were also determined for the dexamethasone group with a lesser increase noted. In the correlation analysis, only alterations in IOP levels at 1 minute were negatively correlated with preoperative AXL values. There was not any correlation between preoperative AXL or ACD values and IOP alterations at any other time points. CONCLUSIONS There was a sudden, transient increase in IOP values after intravitreal ranibizumab or aflibercept injections; which return to normal values in a short time without requirement of any medical treatments. This transient peak was determined to be negatively correlated with the preoperative AXL.

The main aspects of retinal vein occlusion etiopathogenisis in young adults. Part I. Neuroretinovasculitis (prothrombotic potential, clinical manifestations)

This review is dedicated to the neuroretinovasculitis, which is the leading cause of retinal vein occlusion in young adults. Presumed etiological factors, possible pathogenic mechanisms, and clinical manifestation are analyzed. Advisability of multidisciplinary approach in management and individual approach in treatment of patients with neuroretinovasculitis with secondary retinal vein occlusion are justified.

Quantitative physiological measurements to evaluate the response of antivascular endothelial growth factor treatment in patients with neovascular diseases

Antivascular endothelial growth factor (VEGF) treatment is still used intravitreally worldwide for various neovascular diseases, despite other available, approved treatments. We performed a systematic search of the literature focused on visual physiology studies. We used the online biomedical search engine PubMed and searched key words including “M-chart,” “Preferential Hyperacuity Perimetry,” “microperimetry,” (MP) “electroretinography,” and “contrast sensitivity” to estimate treatment efficacy of anti-VEGF treatments in a quantitative manner. Many studies were identified which used a variety of methodologies, disease entities, injected agents, and patient populations, making it difficult to obtain a direct comparison of their results. However, favorable functional outcomes achieved using current quantitative methods would lend further confidence to the effectiveness of a treat-and-extend protocol using intravitreal anti-VEGF for the management of patients with neovascular diseases. Despite anti-VEGF's wide use, a well-designed longitudinal multicenter study to systematically evaluate and compare different physiological methods or parameters in patients with neovascular diseases is still lacking, though it would benefit therapeutic decisions.