Changes in Retinal Nonperfusion Associated with Suppression of Vascular Endothelial Growth Factor in Retinal Vein Occlusion

Multimodal imaging to distinguish microvascular and morphological changes in retinal vein occlusion after intravitreal ranibizumab with or without triamcinolone acetonide injection

BACKGROUND

The study was designed to investigate microvascular and morphological changes in retinal vein occlusion (RVO) using multimodal imaging after intravitreal ranibizumab (IVR) with or without triamcinolone acetonide (IVTA) injections.

METHODS

This was a retrospective and observational study. Fifty patients (52 eyes) diagnosed with RVO were enrolled. Best corrected visual acuity (BCVA), ophthalmoscopy, fundus fluorescein angiography (FFA), spectral domain optical coherence tomography (SDOCT), and optical coherence tomography angiography (OCTA) were employed sequentially both before treatment and at the last visit after treatment.

RESULTS

The mean logMAR VAs in BRVO eyes decreased significantly after treatment (P = 0.029). OCTA showed there was a significant difference in foveal avascular zone (FAZ) in BRVO eyes (P = 0.024), superificial foveal vessel density in both CRVO (P = 0.0004) and BRVO eyes (P = 0.02155). OCT showed the foveal thickness had significant differences after treatment in both CRVO (P < 0.0001) and BRVO eyes (P = 0.0001). BCVA was associated most commonly with ellipsoid zone integrity (P = 0.022). The BCVA in eyes treated with IVR and IVTA was significantly decreased compared with IVR only in BRVO group (P = 0.021). However, the combination of IVR + IVTA significantly improved intraocular pressure (IOP) compared with IVR only in BRVO group (P = 0.037).

CONCLUSION

Both IVR and IVR + IVTA can significantly improve the central vision, macular structure, and functions in BRVO group. Simultaneous IVR with IVTA can significantly increase BCVA compared with IVR only in BRVO group.

Month 60 Imaging Findings and Relationship to Treatment Outcomes Following Anti-VEGF Therapy for Macular Edema Due to Central or Hemi-Retinal Vein Occlusion

PURPOSE

To evaluate imaging findings from SCORE2 participants through 60 months, to describe the degree of resolution or progression of these variables, and to correlate changes in these imaging findings to treatment outcomes such as visual acuity and the number of treatments administered.

METHODS

SCORE2 participants were followed for up to 60 months. Visual acuity, injection frequency and imaging tests color fundus photography (CFP), optical coherence tomography (OCT), and ultra-widefield fluorescein angiography [UWFA]) were performed throughout this period.

RESULTS

Less than 6% of eyes had subretinal fluid at month 60. Disorganization of the retinal inner layers (DRIL) was the most likely finding to persist, present in 96% of eyes at baseline and unchanged at 95% at month 60. For UWFA, at baseline, there was a mean of 5.0% non-perfusion area (95% CI: 3.3%-6.8%) in the NETWORC grid with little change to month 60. For the Early Treatment Diabetic Retinopathy Study (ETDRS) grid, at baseline, there was a mean of 2.3% non-perfusion area (95% CI: 0.7%-3.9%) with little change to month 60. There was no correlation between any of the imaging variables at baseline and change in visual acuity to month 60 or in the number of injections following the variable treatment timeframe (month 12 to month 60).

CONCLUSIONS

These analyses provide an anatomic explanation for persistent functional deficits many years following initial treatment. Clinical practice patterns should consider evaluation with these imaging tests to help explain persistent functional deficits in many eyes. Additionally, these 8 baseline imaging variables generally should not be relied on to predict visual acuity or intensity of treatment. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Recurrence of macular edema in patients with branch retinal vein occlusion: a proteomic study

BACKGROUND

Branch retinal vein occlusion (BRVO) is a common retinal vascular disease leading to severe vision loss and blindness. This study aimed to investigate and reveal the pathophysiological mechanisms underlying macular edema (ME) recurrence in patients with BRVO through a proteomic approach.

METHODS

We detected proteins in the aqueous humor of 14 untreated, four refractory, and four post-operative patients with BRVO-ME and 12 age-matched cataract controls using four-dimensional label-free proteomic and bioinformatics analyses.

RESULTS

In total, 84 proteins exhibited significant differential expression between the BRVO and control samples (fold change [FC] ≥ 1.2 and adjusted p-value < 0.05). Compared to the control group, 43 and 41 proteins were upregulated and downregulated, respectively, in the BRVO group. These proteins were involved in cell adhesion, visual perception, retina homeostasis, and platelet activation. Several significantly enriched signaling pathways included complement and coagulation cascades and platelet activation. In the protein-protein interaction networks generated using the search tool for retrieval of interacting genes (STRING), the fibrinogen alpha chain and fibrinogen beta chain constituted a tightly connected cluster. Many common protein expression trends, such as the fibrinogen alpha chain and fibrinogen beta chain, were observed in both the recurrent and refractory groups. Differentially expressed proteins in the two groups were involved in complement activation, acute-phase response, platelet activation, and platelet aggregation. Important signaling pathways include the complement and coagulation cascades, and platelet activation. Protein-protein interaction analysis suggested that the fibrinogen alpha chain and fibrinogen beta chain constituted a tightly connected cluster. The expression of some differentially expressed proteins shared by the BRVO and the recurrent and refractory groups was reversed in the post-operative group.

CONCLUSIONS

Our study is the first to analyze the proteomics of recurrent, refractory, and post-operative groups treated for BRVO-ME, and may potentially provide novel therapeutic interventions for the recurrence of ME.

Red Blood Cells: A Newly Described Partner in Central Retinal Vein Occlusion Pathophysiology?

Central retinal vein occlusion (CRVO) is a frequent retinal disorder inducing blindness due to the occlusion of the central vein of the retina. The primary cause of the occlusion remains to be identified leading to the lack of treatment. To date, current treatments mainly target the complications of the disease and do not target the primary dysfunctions. CRVO pathophysiology seems to be a multifactorial disorder; several studies did attempt to decipher the cellular and molecular mechanisms underlying the vessel obstruction, but no consensual mechanism has been found. The aim of the current review is to give an overview of CRVO pathophysiology and more precisely the role of the erythroid lineage. The review presents emerging data on red blood cell (RBC) functions besides their role as an oxygen transporter and how disturbance of RBC function could impact the whole vascular system. We also aim to gather new evidence of RBC involvement in CRVO occurrence.

Tear Proteome Revealed Association of S100A Family Proteins and Mesothelin with Thrombosis in Elderly Patients with Retinal Vein Occlusion

Tear samples collected from patients with central retinal vein occlusion (CRVO; n = 28) and healthy volunteers (n = 29) were analyzed using a proteomic label-free absolute quantitative approach. A large proportion (458 proteins with a frequency > 0.6) of tear proteomes was found to be shared between the study groups. Comparative proteomic analysis revealed 29 proteins (p < 0.05) significantly differed between CRVO patients and the control group. Among them, S100A6 (log (2) FC = 1.11, p < 0.001), S100A8 (log (2) FC = 2.45, p < 0.001), S100A9 (log2 (FC) = 2.08, p < 0.001), and mesothelin ((log2 (FC) = 0.82, p < 0.001) were the most abundantly represented upregulated proteins, and β2-microglobulin was the most downregulated protein (log2 (FC) = −2.13, p < 0.001). The selected up- and downregulated proteins were gathered to customize a map of CRVO-related critical protein interactions with quantitative properties. The customized map (FDR < 0.01) revealed inflammation, impairment of retinal hemostasis, and immune response as the main set of processes associated with CRVO ischemic condition. The semantic analysis displayed the prevalence of core biological processes covering dysregulation of mitochondrial organization and utilization of improperly or topologically incorrect folded proteins as a consequence of oxidative stress, and escalating of the ischemic condition caused by the local retinal hemostasis dysregulation. The most significantly different proteins (S100A6, S100A8, S100A9, MSLN, and β2-microglobulin) were applied for the ROC analysis, and their AUC varied from 0.772 to 0.952, suggesting probable association with the CRVO.

Topographical Analysis of the Choriocapillaris Reperfusion After Loading Anti-VEGF Therapy in Neovascular AMD

Purpose

The purpose of this study was to evaluate choriocapillaris vascular density changes around macular neovascularization (MNV) before and after anti-vascular endothelium growth factor (VEGF) injections by optical coherence tomography angiography (OCTA).

Methods

Treatment-naïve eyes with a diagnosis of exudative AMD and type 1 MNV were included. En face optical coherence tomography angiograms were analyzed for percentage of choriocapillaris (CC) flow deficit percentage (FD%), the FD average area (FDa), and the FD number (FDn) in 5 progressive 200-µm-wide concentric rings (R1, R2, R3, R4, and R5) surrounding the dark halo around the MNV. The OCTA acquisition was performed at the following visits: (i) before the loading phase of intravitreal injection of aflibercept or ranibizumab (T1), and (ii) 1 month after the last intravitreal injection of loading phase comprising 3 monthly injections (T2).

Results

A total of 30 eyes of 30 Caucasian patients with treatment naïve neurovascular AMD (nAMD) were included in the study. All rings showed a progressive FD% reduction at T2 in comparison to T1 values indicating gradual CC reperfusion of the peripheral rings. Furthermore, we found a progressive contraction of the FD average area in all the rings considered (P < 0.05). On the other hand, at T2, a significant increase in the FD number of the 5 rings was displayed, as compared to T1 (P < 0.05).

Conclusions

Our analysis showed topographical CC reperfusion after loading anti-VEGF therapy. CC flow deficits were greater around the associated dark halo before treatment, followed by a progressive recovery of CC flow after intravitreal therapy.

Translational Relevance

OCTA may be used to assess the development and progression of MNV but also in assessing response to intravitreal injections of anti-VEGF.

Wide-field swept-source OCT angiography of the periarterial capillary-free zone before and after anti-VEGF therapy for branch retinal vein occlusion

BACKGROUND

The aim of the study was to investigate the changes in the periarterial capillary-free zone (paCFZ) after anti-vascular endothelial growth factor (VEGF) therapy in patients with branch retinal vein occlusion (BRVO) by wide-field swept-source optical coherence tomography angiography (SS-OCTA) and assess their associations with clinical outcomes.

METHODS

In this retrospective observational study of 54 treatment-naïve BRVO patients with macular edema, we reviewed the findings of 12 × 12 mm² SS-OCTA at baseline, 3, 6, and 12 months after intravitreal ranibizumab injections. The paCFZ and major retinal artery areas were measured on SS-OCTA images. The paCFZ area to artery area (P/A) ratio was calculated.

RESULTS

The paCFZ areas and P/A ratios of first- and second-order arteries were significantly greater in BRVO eyes than in contralateral eyes (all P < 0.01), but there were no differences in the first- and second-order artery areas (P = 0.20 and 0.25, respectively). The paCFZ areas and P/A ratios decreased significantly at 3, 6, and 12 months after anti-VEGF therapy (all P < 0.01). The baseline P/A ratio was significantly correlated with the baseline best-corrected visual acuity (BCVA), central retinal thickness, and their improvements at 3, 6, and 12 months (all P < 0.05). Baseline BCVA and P/A ratios of first- and second-order arteries were independently associated with the final BCVA in multivariate linear regression.

CONCLUSIONS

Wide-field SS-OCTA shows that anti-VEGF therapy can lead to a significant improvement in the paCFZ parameters in BRVO. Smaller baseline P/A ratios on SS-OCTA tend to predict better visual outcomes at 12 months after anti-VEGF therapy.

Final Outcomes from the Randomized RECOVERY Trial of Aflibercept for Retinal Nonperfusion in Proliferative Diabetic Retinopathy

PURPOSE

Retinal nonperfusion (RNP) is an important biomarker for diabetic retinopathy (DR). Data suggest that consistent anti-VEGF pharmacotherapy can slow RNP development. The RECOVERY trial evaluated the impact of aflibercept (Eylea, Regeneron) on RNP among eyes with proliferative DR (PDR).

DESIGN

Prospective, randomized clinical trial with treatment crossover in the second year.

SUBJECTS

Eyes with PDR and RNP.

METHODS

At baseline, the subjects were randomized 1:1 to monthly (arm 1) or quarterly (arm 2) intravitreal 2 mg aflibercept. At the beginning of year 2, the treatment arms were crossed over so that the monthly-dosed subjects subsequently received quarterly dosing and the quarterly-dosed subjects subsequently received monthly dosing.

MAIN OUTCOME MEASURES

Change in total RNP area (mm²) through year 2. Secondary outcomes included Diabetic Retinopathy Severity Scale (DRSS) scores; best-corrected visual acuity; central subfield thickness; additional measures of RNP, including ischemic index (ISI); and adverse event incidence. Means and 95% confidence intervals were calculated.

RESULTS

Among all subjects, from baseline to year 2, the mean RNP increased from 235 mm² to 402 mm² (P < 0.0001), and the ISI increased from 25.8% to 50.4% (P < 0.0001). Increases in the mean RNP (P < 0.0001) and ISI (P < 0.0001) were also observed from year 1 to year 2. The mean total RNP increased from 264 mm² at baseline to 386 mm² (P < 0.0001) at year 2 in arm 1 and from 207 mm² at baseline to 421 mm² (P < 0.0001) at year 2 in arm 2 (P = 0.023, arm 1 vs. arm 2). Increases in the mean RNP for both treatment arms (P < 0.0001) were also specifically observed within year 2 (P = 0.32, arm 1 vs. arm 2). Compared with baseline, the DRSS scores at the end of year 2 improved in 82% (n = 27) of subjects and remained stable in 18% (n = 6), with no subjects experiencing worsening; at 2 years, the DRSS scores had improved by 2 or more steps in 65% (n = 11) and 81% (n = 13) of subjects in arms 1 and 2, respectively.

CONCLUSIONS

Through year 2 of the RECOVERY trial, both treatment arms experienced significant increases in RNP. Despite the expansion of the RNP area in nearly all subjects, 82% of subjects demonstrated an improvement in DRSS levels from baseline, with no subjects experiencing worsening in DRSS scores.

Foveal Thickness Fluctuation in Anti-vascular Endothelial Growth Factor Treatment for Branch Retinal Vein Occlusion: A Long-term Study

OBJECTIVE OR PURPOSE

Branch retinal vein occlusion (BRVO) causes macular edema (ME) that can be controlled with anti-vascular endothelial growth factor (VEGF) treatments. However, these treatments are not curative, necessitating additional anti-VEGF treatments at recurrences. Long-term results, optimal anti-VEGF treatment regimens, and the comprehensive effects of ME recurrences are largely unknown. Thus, we aimed to examine the effects of foveal thickness (FT) fluctuation (FTF) on visual and morphologic outcomes following anti-VEGF treatments for BRVO-ME administered via a pro re nata regimen.

DESIGN

A retrospective, observational case series SUBJECTS, PARTICIPANTS AND/OR CONTROLS: This study analyzed 309 treatment-naïve patients (309 eyes) with BRVO-ME between 2012 and 2021 at a multi-center retinal practice.

METHODS, INTERVENTION, OR TESTING

FT was assessed via optical coherence tomography (OCT) at each study visit.

MAIN OUTCOME MEASURES

We evaluated the logarithm of the minimal angle of resolution best corrected visual acuity (logMAR BCVA) and the defect length of the foveal ellipsoid zone (EZ) band measured via OCT.

RESULTS

At baseline, the mean logMAR BCVA was 0.30±0.30 and the mean FT was 503±162 μm. The number of anti-VEGF injections for BRVO-ME was 5.8±4.6 during the mean follow-up period (50.6±22.2 months). At the final examination, the mean logMAR BCVA and FT values were significantly improved compared with the baseline. Multiple regression analyses showed that age, baseline logMAR BCVA, and FTF were significantly associated with the final logMAR BCVA (β=0.20, 0.35, and 0.30, respectively). FTF (divided into Groups 0-3 in ascending order of FTF) was significantly associated with the logMAR BCVA and the defect length of the foveal EZ band at the final examination. The defect lengths of the foveal EZ band were longitudinally shortened in Groups 0-1 and were slightly prolonged in Groups 2-3. The logMAR BCVA maintained improvements in Groups 0-1, and worsened slightly in Groups 2-3.

CONCLUSIONS

FTF was significantly associated with visual acuity and foveal photoreceptor status. Thus, may improve the morphologic and functional prognoses of eyes with BRVO by identifying the characteristics of eyes with a larger FTF, and consequently controlling the FTF more strictly.

[Prospects and Challenges of Anti-VEGF Drug Treatment for Pathological Angiogenesis of the Retina]

The number of patients with exudative age-related macular degeneration, diabetic retinopathy and retinal vein occlusion is expected to rise in proportion with the aging of the population and increasing diabetes patients. Also, they are the most common diseases caused by intraocular neovascularization and are often difficult to treat. Currently, anti-vascular endothelial growth factor (VEGF) therapy has been developed and has demonstrated excellent results in treating macular edema, and many patients have avoided blindness. Unfortunately, there are problems with cases that do not respond to the anti-VEGF drugs and complications of administration. It is necessary to deepen the understanding of the physiological and pathological retinal roles of VEGF and to optimize the anti-VEGF therapy. There are also no drugs indicated for the regression of neovascularization itself. The solution to this problem is to develop novel therapies targeting other than VEGF. In this symposium review, we introduce the roles of VEGF in the ischemic retina and anti-angiogenic factors as promising therapeutic targets.

Vascular abnormalities may progress in branch vein occlusion despite resolution of macular edema

Progression of vascular abnormalities was assessed between resolved and persistent macular edema (ME) in branch retinal vein occlusion. Progression was more common in eyes with resolved ME, suggesting that resolved ME may not signify stability.

Optical-coherence tomography angiography and ultrawide-field angiography findings in eyes with refractory macular edema secondary to retinal vein occlusion switched to aflibercept: A subanalysis from a 48-week prospective study

PURPOSE:

To evaluate anatomical changes on ultra-wide-field fluorescein-angiography and optical coherence angiography (OCT-A) among a cohort with treatment-resistant macular edema secondary to retinal vein occlusions (RVO) switched to aflibercept.

MATERIALS AND METHODS:

Patients with persistent macular edema despite previous bevacizumab and/or ranibizumab were switched to aflibercept in a 48-week prospective trial. Ultra-wide-field fluorescein angiography (UWFFA) and OCT-A were performed at baseline, week-24 and week-48. The ischemic index was calculated from UWFFA and the areas of vascular perfusion. The foveal avascular zone (FAZ) were quantitatively evaluated on OCT-A.

RESULTS:

Eighteen patients (mean age, 70.3±8.6 years) were recruited. Mean central macular thickness (CMT) was significantly reduced at 48-weeks compared to baseline (-87.6±48.8 μm, P < 0.001 and -191.0±128.3μm, P < 0.001 among BRVO and CRVO eyes, respectively). The mean baseline ischemic index as measured on Optos wide-field angiography was 10.9%±8.3 and decreased to 5.7%±4.2 (P = 0.028), at week 48. The mean FAZ areas of the SCP and DCP reduced by -0.06 ± 0.12 mm 2 and -0.17± 0.45 mm 2 , respectively. FAZ area on OCT-A was stable in eyes with stable or improved vision but increased in size in eyes with baseline macular ischemia and those with lower gains in BCVA at week 48 (R 2 =0.719, P = 0.05 and R 2 =0.516, P = 0.01).

CONCLUSION:

There was a reduction in macular edema measured on OCT at 48-weeks in eyes switched to aflibercept with chronic macular edema due to retinal vein occlusion. There was also a reduction in retinal ischemia as measured using UWFFA.

Anatomic-Functional Correlates in Lesions of Retinal Vein Occlusion

Purpose

To evaluate anatomic–functional associations at sites of retinal lesions in retinal vein occlusion (RVO).

Methods

This pilot, prospective, observational study was conducted at the Northern Ireland Clinical Research Facility (NICRF) of Queen's University and the Belfast Health and Social Care Trust, Northern Ireland, between August 1, 2018, and September 30, 2019. The study included 10 treatment-naïve patients with RVO (10 RVO eyes and 10 fellow eyes). There were 81 points/sites assessed for each eye at baseline; six patients were re-assessed 6 months after anti-vascular endothelial growth factor therapy at the same locations. We investigated associations between retinal sensitivity and presence of structural RVO lesions, including retinal ischemia, hemorrhages, intraretinal fluid (IRF) and subretinal fluid outside the foveal/parafoveal regions. Comparisons were made between RVO eyes and fellow eyes at baseline, and between RVO eyes at baseline and at 6 months after treatment. Regression models were used to investigate anatomic–functional associations.

Results

At baseline, strong associations were found between reduced retinal sensitivity and presence of ischemia (estimate = −2.08 dB; P < 0.001), intraretinal fluid (estimate = −7.82 dB; P < 0.001), and subretinal fluid (estimate = −8.66 dB; P < 0.001). Resolution of subretinal fluid but not intraretinal fluid was associated with improved function (estimate = 2.40 dB [P = 0.022]; estimate = 1.16 dB [P = 0.228], respectively). However, reperfusion of ischemic retina, observed in 31 of 486 points (6%) 6 months after anti-vascular endothelial growth factor therapy, was associated with a further decrease in retinal sensitivity (estimate = −2.34 dB; P = 0.035).

Conclusions

Retinal sensitivity was decreased at sites of RVO lesions. Decreased function at sites of retinal ischemia did not recover after treatment, even when reperfusion occurred.

Long-term outcomes of intravitreal activated protein C injection for ischemic central retinal vein occlusion: an extension trial

Purpose

Our previous 1-year pilot study evaluated the efficacy of intravitreally injected activated protein C (APC) in 10 eyes with ischemic central retinal vein occlusion (CRVO). The reperfusion of the areas of retinal nonperfusion (RNP) exceeded 50% of the baseline in five (50%) eyes 1 year after the APC injection. The current study evaluated the long-term efficacy and safety of intravitreal APC.

Methods

The 10 eyes in the pilot study were included in this study. Other treatments were administered at the physicians’ discretion after the pilot study. We evaluated visual acuity (VA), central retinal thickness (CRT) and perfusion status, and adverse events and severity over the long term.

Results

The median follow-up was 60 months (range, 48–68 months). Compared with baseline, the post-treatment VA improved significantly (P < 0.001) from 1.39 to 1.06 logarithm of the minimum angle of resolution. The CRT improved significantly (P < 0.001) from 1090 to 195 μm at the last visit. The RNP areas decreased from an average 29.7 disc areas (DAs) at baseline to an average 16.5 DAs at the last examination (mean, 40 ± 6.5 months after the first APC treatment). No adverse events were related to intravitreal APC.

Conclusion

No complications were associated with intravitreal APC, the clinical course improved, and improved RNP was maintained for the long term, suggesting that intravitreal APC may be an alternative treatment for CRVO.

The Structural and Comparative Analysis of Intravitreal Dexamethasone Implant (Ozurdex) and Anti-VEGF Injection in Branched Retinal Vein Occlusion Patients by Optical Coherence Tomography Angiography Images Quantitation

Background and Objective: To evaluate and compare the structural changes of retinal vasculature after intravitreal dexamethasone implant (Ozurdex) insertion and antivascular endothelial growth factor (anti-VEGF) injection in patients with branched retinal vein occlusion (BRVO) using optical coherence tomography angiography (OCTA).Study Design/Materials and Methods: We retrospectively analyzed 39 patients with unilateral BRVO. Subjects were divided into two groups according to treatment agent: Ozurdex (n = 18) and anti-VEGF (n = 21). Swept Source (SS) OCT and OCTA were performed and images were analyzed quantitatively using ImageJ (National Institutes of Health) software. Intravitreal implant and anti-VEGF injections were performed following a prn regimen. The specific anti-VEGF agent used was chosen among bevacizumab, ranibizumab and aflibercept.Results: Of the 39 patients (mean ± SD age, 70.0 ± 8.9 years [range, 48-89 years]; 20 men [51.0%]) with unilateral BRVO, in an independent two-sample t test, there was greater vascular reperfusion of the choriocapillaris slab in the intravitreal Ozurdex implant group than in the anti-VEGF group using the angiography mode (P = .013). Increased number of particles was more prominent in intravitreal anti-VEGF injection group than intravitreal Ozurdex implant group in outer retina slab of En-face mode (P = .039). There was no statistically significant difference between the 2 treatment groups in relation to the Early Treatment Diabetic Retinopathy Study (ETDRS) density map and other angiography slabs; and the superficial, deep, and outer retina.Conclusions: Results of a quantitative analysis of OCTA images using ImageJ software suggest that the intravitreal Ozurdex implant induced increased retinal vascular perfusion compared with anti-VEGF injection for the treatment of BRVO.

Microvascular comparison in younger and older patients with retinal vein occlusion analyzed by OCT angiography

Background

To compare changes in retinal microvasculature of young and elderly patients with retinal vein occlusion (RVO) after anti-VEGF treatment.

Methods

RVO patients who underwent anti-VEGF treatment were retrospectively reviewed and categorized into two groups based on age. The OCT angiography images were obtained during each visit. Best corrected visual acuity (BCVA), vessel density (VD) and foveal avascular zone (FAZ) were measured and compared between the two groups. Vision improvements and retinal microvasculature changes were also correlated.

Results

Twenty patients with 20 eyes were enrolled in the younger group and 46 patients with 46 eyes were enrolled in the older group. Younger patients demonstrated better BCVA, higher VD and smaller FAZ than older patients at 12 months after the first anti-VEGF treatment. The improvement of VD was observed only in the younger group. A positive correlation between vision improvement and VD increase was noted.

Conclusions

Young patients with RVO can achieve rapid rehabilitation of deep retinal vasculature which lead to a better visual outcome.

Longitudinal Changes on Optical Coherence Tomography Angiography in Retinal Vein Occlusion

Background: To evaluate the longitudinal changes on optical coherence tomography angiography (OCTA) in retinal vein occlusion (RVO). Methods: Retrospective study of patients with RVO treated with intravitreal anti-vascular endothelial growth factors (VEGF) for macular edema. Foveal avascular zone (FAZ) area, vessel density (VD), vessel length density (VLD), and adjusted flow index (AFI) were calculated. The unaffected eye of each participant was used as a control. Results: Twelve RVO eyes were included, receiving 6 ± 3 anti-VEGF injections over a follow-up of 10.4 ± 3.1 months. Compared to fellow eyes, RVO eyes had lower VD and VLD at inclusion (p = 0.07 and p = 0.04) and last visit (p = 0.002 and p < 0.001). VD, AFI, and VLD did not change over time, while FAZ area increased in RVO eyes (+0.016 ± 0.024 mm², p = 0.04). AFI correlated with duration of disease (r = 0.63, p = 0.02). Visual acuity was inversely related to VD and VLD over the follow-up. Conclusions: OCTA parameters remained stable with sustained anti-VEGF treatment in RVO, while changes in the FAZ area may suggest capillary remodeling after RVO.

Twenty-Four Month Results of Intravitreal Ranibizumab for Macular Edema after Branch Retinal Vein Occlusion: Visual Outcomes and Resolution of Macular Edema

Purpose: To report 24-month results after one intravitreal ranibizumab (IVR) injection followed by pro re nata (PRN) dosing for macular edema (ME) after branch retinal vein occlusion (BRVO).Methods: Eyes with BRVO met the followings were included: 77 letters or less best-corrected visual acuity (BCVA) (Early Treatment Diabetic Retinopathy Study [ETDRS] score) and central retinal thickness (CRT) of 250 µm or more. IVR injection was performed followed by a PRN regimen. The retreatment criteria included visual loss of five or more ETDRS letters compared with the previous visit, 250 µm or more of CRT, or presence of residual or recurrent ME including the parafoveal lesions. The primary outcome measures were the BCVA changes at month 12 and month 24 from baseline, and the secondary outcomes were changes in CRT, resolution of ME, the number of IVR injections, and changes of nonperfused areas (NPAs).Results: Twenty eyes of 20 patients (5 men, 15 women; mean age, 68.2 years) were enrolled. The mean BCVAs (ETDRS letters) at baseline, month 12, and month 24 were 62.0, 80.2, and 80.9, respectively. The mean ETDRS letters gains were 18.3 and 19.0 at month 12 and month 24, respectively. The percentages of patients with Snellen equivalent BCVAs of 20/20 or better at month 12 and month 24 were 75% and 70%, respectively. The mean CRTs at baseline, month 12, and month 24 were 480, 252, and 272 μm, respectively. Forty percent of all eyes had complete resolution of ME. The mean number of IVR injections was 8.3 times, which gradually decreased over time. The NPA change in either Zone 1 or Zone 2 was not significant during the follow-up. No adverse side effects were observed.Conclusion: IVR injection followed by a PRN regimen provided pretty good visual outcomes at month 24.

ANGIOGRAPHIC RISK FACTORS FOR RECURRENCE OF MACULAR EDEMA ASSOCIATED WITH BRANCH RETINAL VEIN OCCLUSION

PURPOSE

To examine angiographic risk factors for the recurrence of macular edema associated with branch retinal vein occlusion.

METHODS

We consecutively included 51 patients with treatment-naive branch retinal vein occlusion involving the macular area. Each eye initially received 3 monthly ranibizumab injections, with additional injections as necessary. At Month 3, we examined parafoveal vessel diameter indexes (VDI) in all sectors using optical coherence tomography angiography and determined the association with retinal thickness changes (Month 3-Month 5) and the number of ranibizumab injections during 12 months.

RESULTS

Parafoveal VDIs in the affected, nasal, and temporal sectors at Month 3 were significantly associated with corresponding parafoveal thickening (P = 0.020, 0.010, and <0.001, respectively), and the parafoveal VDIs in the affected and temporal sectors were significantly associated with future foveal thickening (P = 0.037, and 0.026, respectively). Moreover, the parafoveal VDI in the temporal sector showed a significant association with the total required number of ranibizumab injections (P = 0.040).

CONCLUSION

The parafoveal VDI may adequately represent the degree of congestion associated with branch retinal vein occlusion. Particularly, the VDI in the temporal sector may be a good predictor of future retinal thickening in the corresponding parafovea and the fovea and the number of ranibizumab injections.

Retinal vascular occlusions

Acute retinal vascular occlusions are common causes of visual impairment. Although both retinal artery occlusions and retinal vein occlusions are associated with increased age and cardiovascular risk factors, their pathophysiology, systemic implications, and management differ substantially. Acute management of retinal artery occlusions involves a multidisciplinary approach including neurologists with stroke expertise, whereas treatment of retinal vein occlusions is provided by ophthalmologists. Optimisation of systemic risk factors by patients' primary care providers is an important component of the management of these two disorders.

Sustained suppression of VEGF for treatment of retinal/choroidal vascular diseases

Neovascular age-related macular degeneration (NVAMD) is the most prevalent choroidal vascular disease, and diabetic retinopathy (DR) and retinal vein occlusion (RVO) are the most prevalent retinal vascular diseases. In each of these, hypoxia plays a central role by stabilizing hypoxia-inducible factor-1 which increases production of vascular endothelial growth factor (VEGF) and other hypoxia-regulated gene products. High VEGF causes excessive vascular permeability, neovascularization, and in DR and RVO, promotes closure of retinal vessels exacerbating hypoxia and creating a positive feedback loop. Hence once VEGF expression is elevated it tends to remain elevated and drives disease progression. While other hypoxia-regulated gene products also contribute to pathology in these disease processes, it is remarkable how much pathology is reversed by selective inhibition of VEGF. Clinical trials have demonstrated outstanding visual outcomes in patients with NVAMD, DR, or RVO from frequent intraocular injections of VEGF-neutralizing proteins, but for a variety of reasons injection frequency has been substantially less in clinical practice and visual outcomes are disappointing. Herein we discuss the rationale, preclinical, and early clinical results of new approaches that provide sustained suppression of VEGF. These approaches will revolutionize the management of these prevalent retinal/choroidal vascular diseases.

Evaluation of Microvascular Structure Changes after Conbercept Treatment on Macular Edema Secondary to Retinal Vein Occlusion

Aims

To confirm the therapeutic efficacy of conbercept for the treatment of macular edema (ME) secondary to retinal vein occlusion (RVO) by using optical coherence tomography angiography (OCTA) and to find out the differences in therapeutic efficacy between ischemic and nonischemic retinal vein occlusion (iRVO or non-iRVO) after conbercept treatment.

Methods

In this prospective, randomized, and comparative study, 60 unilateral eyes suffered from RVO combined with macular edema were included and fellow eye as controls. After an initial intravitreal injection of conbercept (IVIC), a pro re nata (PRN) strategy was adopted, and the follow-up time was 6 months. The foveal avascular zone (FAZ), vascular density of superficial capillary plexus (SCP), and vascular density of deep retinal capillary plexus (DCP), nonperfused areas (NPAs) were evaluated with OCTA on baseline and after treatment.

Results

The mean intravitreal injection number was 2.9 ± 0.89 times during six months in iRVO patients and 2.1 ± 0.86 times in non-iRVO patients, with statistically significant difference (p < 0.05). On baseline, central macular thickness (CMT) and FAZ were significantly thickened and enlarged compared to those of healthy fellow eyes; the vascular density of SCP and DCP were significantly decreased, and the differences were statistically significant (p < 0.05). Compared to baseline, after treatment, the best-corrected visual acuity (BCVA) was improved in either iRVO or non-iRVO (−0.601 ± 0.387, −0.241 ± 0.341 logMAR, p < 0.05). In iRVO, the improvement was more substantial than that of the non-iRVO group. FAZ in the non-iRVO group had significantly decreased compared to that in iRVO group (−0.044 ± 0.040 versus 0.014 ± 0.043 mm², p < 0.05). CMT, the vascular density of SCP, and DCP had no significant difference.

Conclusions

The changes of microvascular structure can be quantitatively evaluated by using OCTA for the patients with RVO. Conbercept had a significant effect on treatment of RVO with macular edema. A more profound effect was achieved in the iRVO group on visual improvement and FAZ reduction in the non-iRVO group after conbercept treatment.

Use of Anti-VEGF Drugs in Retinal Vein Occlusions

Retinal vein occlusion (RVO) is one of the most prevalent causes of visual loss in the Western World. Its pathogenesis is still not completely known. Chronic macular edema and ischemia compromise the functional and anatomical status of the retina. Antivascular endothelial growth factor (anti-VEGF) injections have demonstrated better results than other previous options, including observation or laser therapy. This narrative review aims to analyze the current aspects related to these drugs.

ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR THERAPY CAN IMPROVE DIABETIC RETINOPATHY SCORE WITHOUT CHANGE IN RETINAL PERFUSION

After three intravitreal anti–vascular endothelial growth factor injections, the severity of diabetic retinopathy on color fundus photographs improved, whereas no reperfusion occurred in the nonperfusion areas assessed on ultra–wide-field fluorescein angiography.

Purpose:

To compare the changes in retinal perfusion on ultra–wide-field fluorescein angiography with the changes in diabetic retinopathy lesions observed on ultra–wide-field fundus color photographs after 3 monthly anti–vascular endothelial growth factor injections.

Methods:

Retrospective interventional cohort study analyzing the files of 14 patients with DR (18 eyes). UWF color photos and FA were analyzed at baseline (M0) and 1 month after the third anti-VEGF injection (M3). The main outcomes included the count of the number of red dots (microaneurysms, hemorrhages) and assessment of DR severity score (DRSS); the analysis of non-perfusion areas and disappearance or reappearance of arterioles or venules in the non-perfusion areas on FA.

Results:

Eighteen eyes of 14 diabetic patients, with mean age of 63 ± 5 years, were included. The DRSS score improved by at least one stage in 11/18 (61%) eyes. The mean number of red dots significantly decreased at M3 (n = 80 ± 85) compared with M0 (n = 139 ± 130) (P < 0.0001). No reperfusion of arterioles or venules was observed in or around nonperfusion areas.

Conclusion:

After anti–vascular endothelial growth factor injections, the improvement in the DRSS score based on color fundus photographs can occur without retinal reperfusion on ultra–wide-field fluorescein angiography.

Angiographic Risk Features of Branch Retinal Vein Occlusion Onset as Determined by Optical Coherence Tomography Angiography

Purpose

Examine associations between the vasculature at arteriovenous (AV) crossings and the onset of branch retinal vein occlusion (BRVO).

Methods

We included 78 patients with major BRVO, 35 patients with macular BRVO, and 110 controls without BRVO and determined the vessel positions at AV crossings, where the first- or second-order branches of the retinal veins associate, using a viewing angle of 12 × 12 mm² in optical coherence tomography angiography (OCTA).

Results

We reviewed 1349 and 1276 AV crossings in BRVO patients and control subjects, respectively. The proportions of venous overcrossing were 26.5%, 28.6%, and 26.8% at non-causative crossings in BRVO eyes, non-BRVO fellow eyes, and unaffected control eyes, respectively; however, the rate of venous overcrossings at the causative crossings was 45.1%. In OCTA analyses, we divided the branches into macular- or non-macular veins. The rate of venous overcrossing was 52.5% at causative crossings in major BRVO but was 28.6% in macular BRVO. Odds ratios for whether venous overcrossing was a risk factor for BRVO were 3.09 (95% confidence interval [CI], 1.96–4.88) and 0.94 (95% CI, 0.44–2.00) for non-macular veins and macular veins, respectively. The patients with major BRVO caused by venous overcrossing were younger than patients for whom the cause was arterial overcrossing (P < 0.001). The onset of macular BRVO did not differ between crossing patterns at causative crossings (P = 0.60).

Conclusions

In eyes with BRVO, venous overcrossing was a common angiographic feature at causative crossings and might be a risk factor for major BRVO onset.

Retinal Nonperfusion Characteristics on Ultra-Widefield Angiography in Eyes With Severe Nonproliferative Diabetic Retinopathy and Proliferative Diabetic Retinopathy

Importance

Threshold of retinal nonperfusion for the development of proliferative diabetic retinopathy (PDR) is unclear.

Objectives

To identify a threshold of retinal nonperfusion for the presence of retinal neovascularization and the distribution and area of retinal nonperfusion in eyes with severe nonproliferative diabetic retinopathy (NPDR), PDR, neovascularization of the optic disc (NVD), and retinal neovascularization elsewhere (NVE).

Design, Setting, and Participants

This cross-sectional image analysis study was performed between September 24, 2018, and October 24, 2018, at a multicenter national study in the United Kingdom. Baseline images were obtained from 2 completed randomized clinical trials (Ranibizumab for Diabetic Macular Edema Panretinal Photocoagulation [RDP] study and Clinical Efficacy of Intravitreal Aflibercept vs Panretinal Photocoagulation for Best Corrected Visual Acuity in Patients With Proliferative Diabetic Retinopathy at 52 Weeks [CLARITY] study). The RDP study recruited eyes with severe NPDR between April 1, 2014, and December 31, 2015, and the CLARITY study recruited eyes with PDR between August 22, 2014, and November 20, 2015. Ultra-widefield angiography images of eyes with no prior panretinal photocoagulation treatment were included.

Main Outcomes and Measures

The total area of retinal nonperfusion, the area of posterior pole retinal nonperfusion, and the area of peripheral retinal nonperfusion were measured.

Results

A total of 92 patients (92 eyes) were included in the study: 59 in the PDR group (mean [SD] age, 42 [15] years; 20 female [33.9%]) and 33 in the NPDR group (mean [SD] age, 63 [10] years; 3 female [9.1%]). Forty eyes had NVE and 19 had NVD with or without NVE. We identified a retinal nonperfusion threshold of 118.3 disc areas (DA) with a specificity of 84.9% (95% CI, 68.1% to 94.9%) for PDR. The median area of retinal nonperfusion was 67.8 DA (95% CI, 44.2 to 107.3 DA) in the NPDR eyes and 147.9 DA (95% CI, 127.4 to 173.5 DA) for eyes with proliferative changes, with a difference of 69.0 DA (95% CI, 42.2 to 97.7 DA; P < .001). No difference was found in the median area of posterior nonperfusion between NPDR and PDR, with a difference of 0 DA (95% CI, -6.7 to 5.2 DA; P = .56). As for peripheral nonperfusion, NPDR eyes measured 64.1 DA and PDR eyes measured 130.6 DA, with a difference of 70.8 DA (95% CI, 48.4 to 94.9 DA; P < .001). Eyes with NVD had the largest total area of retinal nonperfusion, with a difference of 65.1 DA (95% CI, 28.6 to 95.8 DA; P < .001) compared with eyes with only NVE.

Conclusions and Relevance

These findings suggest eyes with at least 107.3 DA of nonperfusion are at risk of proliferative disease, and eyes with NVD have the largest area of retinal nonperfusion.

Oral and ocular administration of crocetin prevents retinal edema in a murine retinal vein occlusion model

Purpose

We investigated the effects of oral and ocular administration of crocetin in a murine retinal vein occlusion (RVO) model. Crocetin is a type of carotenoid contained in the fruit of gardenia (Gardenia jasminoides Ellis) and the stigma of saffron (Crocus staruts L).

Methods

This study was performed on a murine RVO model, which was created by laser irradiation of retinal veins. We evaluated the retinal thickness after the oral administration of crocetin (100 mg/kg) 1 and 6 h before laser irradiation, and immediately, 6 h, 12 h, and 18 h after laser irradiation in the murine RVO model. In addition, we measured the retinal layer thickness after administration of crocetin eye drops (0.03% or 0.10%) immediately, 6 h, and 12 h after laser irradiation. Western blotting of retinal tissue was used to determine the expression levels of matrix metalloproteinase (MMP-9), tumor nuclear factor (TNF-α), and occludin after oral administration of crocetin.

Results

Oral and ocular administration of crocetin improved retinal edema in the murine RVO model. Crocetin administration statistically significantly suppressed overexpression of MMP-9 and TNF-α, and reversed the reduction of occludin.

Conclusions

These findings indicate that crocetin can protect retinal tight junctions by suppressing retinal edema through an anti-inflammatory effect, which suggests that crocetin may be useful for RVO disease.

Loss to Follow-Up in Patients With Retinal Vein Occlusion Undergoing Intravitreal Anti-VEGF Injections

BACKGROUND AND OBJECTIVE

To identify the proportion of patients with retinal vein occlusion (RVO) with loss to follow-up (LTFU) along with potential risk factors after receiving an intravitreal anti-vascular endothelial growth factor (VEGF) injection.

PATIENTS AND METHODS

A retrospective review based on billing codes was performed from January 1, 2012, to January 1, 2017. LTFU was defined as no office visit within 12 months following an intravitreal injection. Potential risk factors for LTFU were screened using univariate analysis for inclusion in a final multivariate logistic regression model.

RESULTS

A total of 3,400 unique patients with RVO with macular edema met the study inclusion criteria. Of these, 863 patients (25.4%) were LTFU. Rates of LTFU varied based on race / ethnicity, age, RVO type, distance from clinic, insurance status, and regional average adjusted gross income. In the multivariate analysis, patients with LTFU were more likely to be black (odds ratio [OR] = 1.37), Hispanic (OR = 2.37), and living more than 20 miles away from clinic (OR = 1.47). Patients who were 65 to 80 years old (OR = 0.71) and those with branch retinal vein occlusion (OR = 0.70) were less likely to be LTFU. Subgroup analysis showed that patients with baseline visual acuity better than 20/50 were also less likely to be LTFU.

CONCLUSIONS

Approximately one in four patients did not return for a year or more after receiving an intravitreal injection for RVO. Given the importance of ongoing therapy to prevent vision loss, these "real-world" findings are of significant concern. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:159-166.].

Longitudinal Panretinal Leakage and Ischemic Indices in Retinal Vascular Disease after Aflibercept Therapy: The PERMEATE Study

PURPOSE

To characterize the longitudinal panretinal retinal vascular dynamics in diabetic macular edema (DME) and retinal vein occlusion (RVO) over a 12-month period while being treated with intravitreal aflibercept injections (IAIs).

DESIGN

Prospective open-label study (clinicaltrials.gov identifier, NCT02503540).

PARTICIPANTS

Thirty-one treatment-naive eyes with foveal-involving retinal edema secondary to DME and RVO.

METHODS

Participants received 2 mg IAI every 4 weeks for the first 6 months, followed by 2 mg every 8 weeks. Ultra-widefield fluorescein angiography (UWFA; California Optos [Optos, Dunfermline, United Kingdom]) and spectral-domain OCT (Cirrus; Zeiss, Oberkochen, Germany) scans were obtained and analyzed using a novel quantitative assessment platform. Visual acuity, central subfield thickness, and adverse events also were collected.

MAIN OUTCOME MEASURES

The primary end point was the mean change in panretinal leakage index at month 12 from baseline as measured by UWFA.

RESULTS

Mean age was 67.1 years. At month 12, visual acuity significantly improved by a mean of 18.4±21.4 letters (P < 0.0001), and central subfield thickness also improved significantly, with a mean reduction of 301.3±250.3 μm (P < 0.0001). Mean panretinal leakage index improved significantly, decreasing from 3.4% at baseline to 0.5% at month 6 (P <0.0001) and 0.4% at month 12 (P < 0.0001). Panretinal ischemic index did not demonstrate any significant change but showed a nonsignificant increase from 5.5% at baseline to 6.1% at month 6 (P = 0.315) and 8.7% at month 12 (P = 0.193). Eyes with DME showed a decrease in leakage index from 3.5±2.7% at baseline to 1.6±0.8% at month 12 (P = 0.018) and overall stability in ischemic index from 5.0±4.1% at baseline to 4.7±3.5% at month 12 (P = 0.689). Participants with RVO showed a decrease in leakage index from 3.3±1.1% at baseline to 0.02±0.03% at 12 months (P < 0.0001) and a nonsignificant increase in ischemic index from 5.9±4.5% at baseline to 12.6±9.8% at month 12 (P = 0.172).

CONCLUSIONS

Intravitreal aflibercept injections resulted in a dramatic reduction in panretinal leakage index. Panretinal ischemic index did not improve and trended toward worsening.

Sustained intraocular vascular endothelial growth factor neutralisation does not affect retinal and choroidal vasculature in Ins2Akita diabetic mice

The purpose of this study was to understand the influence of sustained intravitreal vascular endothelial growth factor neutralisation on the retinal and choroidal vasculature in diabetic eyes. Ins2^Akita diabetic mice received five intravitreal injections of anti-mouse vascular endothelial growth factor antibody or goat immunoglobulin G (0.2 µg/µL/eye) over a 4-month period. Retinal and choroidal vascular changes were analysed by confocal microscopy of tissue flat-mounts. Retinal gene expression of vascular endothelial growth factor family members (vascular endothelial growth factors A, B, C and D), vascular endothelial growth factor receptors (sVEGFR-1 and VEGFR-2) and tight junctions (claudin 1, 2, 5; occludin and zonula occludens-1) were analysed by quantitative reverse transcription polymerase chain reaction. Vascular endothelial growth factor A and claudin 5 were significantly increased in diabetic retinae. Gene expression was unaffected by anti-vascular endothelial growth factor treatment. The number of acellular vessels was increased in diabetic retinae and reduced following anti-vascular endothelial growth factor treatment. Retinal and choroidal vascular density and area were unaffected by sustained vascular endothelial growth factor neutralisation. Our results suggest that five consecutive intravitreal anti-vascular endothelial growth factor injections do not cause significant vascular changes in the retina and choroid in diabetic and non-diabetic mice.

Widefield OCT-Angiography and Fluorescein Angiography Assessments of Nonperfusion in Diabetic Retinopathy and Edema Treated with Anti-Vascular Endothelial Growth Factor

PURPOSE

To assess change in retinal nonperfusion (NP) after anti-vascular endothelial growth factor (VEGF) therapy for diabetic macular edema (DME) using 2 different imaging modalities: swept-source widefield (SS-WF) OCT angiography (OCTA) and ultra-widefield (UWF) fluorescein angiography (FA).

DESIGN

Observational case series.

PARTICIPANTS

Ten eyes of 9 patients with severe nonproliferative diabetic retinopathy (NPDR) or proliferative DR (PDR) initiating 3 monthly anti-VEGF intravitreal injections for DME.

METHODS

All eyes were imaged with UWF color fundus photographs (CFPs), UWF FA, and SS-WF OCTA at baseline (M0) and 1 month after the third anti-VEGF injection (M3). All images were aligned and divided into 16 boxes for analysis of NP areas by 2 blinded retina specialists.

MAIN OUTCOME MEASURES

The number of discrepancies between SS-WF OCTA and UWF FA regarding the detection of NP areas and small vessels passing through NP areas; assessment of DR severity on UWF CFP; and change in each NP area between M0 and M3: number of boxes/eye with presence of at least 1 NP area, number of arterioles or venules that disappeared or reappeared, and number of NP areas in which capillaries disappeared or reappeared.

RESULTS

The diabetic retinopathy (DR) severity score improved by at least 1 stage in 8 of 10 eyes, with a significant decrease in the mean number of microaneurysms and retinal hemorrhages on UWF CFP at M3 versus M0 (n = 40±28 vs. 121±57; P = 0.0020) and regression of fundus neovascularization when present. All NP areas detected on FA were seen on SS-WF OCTA, but additional NP areas were detected on SS-WF OCTA at M0 in 29% (46/160) of boxes. No reperfusion of arterioles or venules was observed at M3 on FA or SS-WF OCTA. Retinal capillaries were only visible on OCTA, and no reperfusion in NP areas was observed even when a reduction in dark areas was visible on FA.

CONCLUSIONS

No reperfusion of vessels or capillary network was detected in NP areas using 2 imaging techniques, UWF FA and SS-WF OCTA, in eyes with DR after 3 anti-VEGF injections. The detection rate of NP areas was higher with SS-WF OCTA than with UWF FA.

RETINAL MICROVASCULATURE AND VISUAL ACUITY AFTER INTRAVITREAL AFLIBERCEPT IN EYES WITH CENTRAL RETINAL VEIN OCCLUSION: An Optical Coherence Tomography Angiography Study

PURPOSE

To investigate vascular perfusion and foveal avascular zone area in the superficial capillary plexus (SCP) and deep capillary plexus (DCP) after intravitreal aflibercept therapy in central retinal vein occlusion eyes and their association with best-corrected visual acuity.

METHODS

Thirty-five subjects with central retinal vein occlusion and macular edema were evaluated. After macular edema resolution following intravitreal aflibercept, subjects underwent optical coherence tomography angiography to measure SCP and DCP perfusion and the foveal avascular zone within a 3 × 3-mm area. Correlations between best-corrected visual acuity and optical coherence tomography angiography measurements were examined.

RESULTS

After intravitreal aflibercept therapy, mean retinal vascular area was 3.41 ± 0.74 mm in the SCP and 3.25 ± 0.91 mm in the DCP. Foveal avascular zone area was 1.03 ± 1.04 mm in the SCP and 1.78 ± 1.73 mm in the DCP. Improved best-corrected visual acuity was significantly associated with better SCP and DCP perfusion (both P < 0.001) and with smaller SCP and DCP foveal avascular zone areas (both P < 0.001). Additionally, SCP and DCP perfusion were negatively correlated with macular edema before treatment (P < 0.05) and ischemia (determined via pretreatment fluorescein angiography, P < 0.05), and positively correlated with photoreceptor integrity (P < 0.001).

CONCLUSION

Patients with better retinal perfusion and less retinal ischemia are associated with better visual outcomes after aflibercept in eyes with central retinal vein occlusion.

Microvascular changes after conbercept therapy in central retinal vein occlusion analyzed by optical coherence tomography angiography

AIM

To investigate microvascular changes in eyes with central retinal vein occlusion (CRVO) complicated by macular edema before and after intravitreal conbercept injection and evaluate correlations between these changes and best-corrected visual acuity (BCVA) and retinal thickness.

METHODS

Twenty-eight eyes of 28 patients with macular edema caused by CRVO were included in this retrospective study. All patients received a single intravitreal conbercept injection to treat macular edema. BCVA and the results of optical coherence tomography angiography (OCTA) automatic measurements of the vessel density in the superficial (SCP) and deep retinal capillary plexus (DCP), the foveal avascular zone (FAZ) area, the FAZ perimeter (PERIM), the vessel density within a 300-µm wide ring surrounding the FAZ (FD-300), the acircularity index (AI), the choriocapillaris flow area, and retinal thickness were recorded before and at one month after treatment and compared with the results observed in age- and sex-matched healthy subjects.

RESULTS

The vessel density in the SCP and DCP, the FD-300, and the flow area of the choriocapillaris were all significantly lower in CRVO eyes than in healthy eyes, while the AI and retinal thickness were significantly higher (all P<0.05). After treatment, retinal thickness was significantly decreased, and the mean BCVA had markedly improved from 20/167 to 20/65 (P=0.0092). The flow area of the choriocapillaris was also significantly improved, which may result from the reduction of shadowing effect caused by the attenuation of macular edema. However, there were no significant changes in SCP and DCP vessel density after treatment. The flow area of the choriocapillaris at baseline was negatively correlated with retinal thickness.

CONCLUSION

OCTA enables the non-invasive, layer-specific and quantitative assessment of microvascular changes both before and after treatment, and can therefore be used as a valuable imaging tool for the evaluation of the follow-up in CRVO patients.

Branch Retinal Vein Occlusion: Treatment Outcomes According to the Retinal Nonperfusion Area, Clinical Subtype, and Crossing Pattern

This prospective study examined 58 eyes with branch retinal vein occlusion (BRVO) to investigate the effects of the nonperfusion area (NPA), clinical subtype, and crossing pattern on the 2-year outcomes of ranibizumab therapy for the macular edema (ME). All eyes received three initial monthly injections, followed by additional pro re nata (PRN) injections. The final best corrected visual acuity (BCVA) and ranibizumab injection number were not associated with the macular NPA or total NPA at baseline or month 12, and they showed no significant differences between the clinical subtypes. However, the incidence of neovascular changes was higher in the major BRVO group than in the macular BRVO group (P = 0.030). Twelve and 19 of the 34 eyes with major BRVO exhibited arterial overcrossing and venous overcrossing, respectively. At baseline, the total NPA did not differ according to the crossing pattern, however, the total NPA was significantly larger in the venous overcrossing group at month 12 (P = 0.047). At month 24, the incidence of neovascular changes was higher in the venous overcrossing group (P = 0.030). Following ranibizumab therapy for BRVO-associated ME, the clinical subtype and the arteriovenous crossing pattern may be associated with neovascular changes.

Five-year outcomes of retinal vein occlusion treated with vascular endothelial growth factor inhibitors

Purpose

Report 5-year outcomes of patients receiving anti-vascular endothelial growth factor (VEGF) for the treatment of macular oedema secondary to retinal vein occlusion (RVO.

Methods

Retrospective review of eyes with RVO which initiated anti-VEGF treatment. Data including age, gender, visual acuity (VA) and injection numbers were obtained from medical records. Optical coherence tomography scans were graded for presence or absence of macular oedema and central foveal thickness (CFT). Macular perfusion was assessed on fundus fluorescein angiography by masked graders.

Results

68 eyes (31 branch RVO, BRVO; 35 central RVO, CRVO and 2 hemi-RVO) with 5 years of follow-up after initiation of anti-VEGF treatment. Mean change in VA at 5 years was + 9.6 ± 21.6 letters among CRVO eyes and + 14.2 ± 15.6 letters among eyes with BRVO (p=0.001). Vision of 20/40 or better was achieved in 65 % of treated eyes. The proportion of eyes with a three-line improvement of vision (15 letters) at 5 years was 22 %. Mean CFT decreased by 257.6 ± 249.8 µm in eyes with CRVO and 145.6 ± 143.3 µm in eyes with BRVO.

Conclusion

The results confirm good long-term outcomes can be achieved with anti-VEGF therapy for RVO.

Longitudinal Quantification of Retinal Nonperfusion in the Macula of Eyes With Retinal Vein Occlusion Receiving Anti-VEGF Therapy: Secondary Analysis of the WAVE Randomized Trial

BACKGROUND AND OBJECTIVE

Longitudinal quantification of retinal nonperfusion (RNP) in eyes with retinal vein occlusion (RVO) undergoing anti-vascular endothelial growth factor therapy.

PATIENTS AND METHODS

Thirty eyes with ischemic RVO were randomized to ranibizumab (Lucentis; Genentech, South San Francisco, CA) (monotherapy) or ranibizumab plus peripheral laser (combination therapy) in a 12-month, prospective trial. RNP on fluorescein angiography was quantified within the macula through 12 months of follow-up.

RESULTS

Baseline mean macular RNP areas were 5.04 mm² and 8.30 mm² in the monotherapy (n = 5) and combination therapy (n = 15) cohorts, respectively. Through month 12, mean macular RNP area increased 0.36 mm² and 0.53 mm² in the monotherapy and combination therapy cohorts, respectively (P = .77). Marked, progressive RNP was observed in three eyes (12%). No areas of reperfusion were detected in any eye.

CONCLUSION

Among ischemic RVO eyes in WAVE, macular RNP was common at baseline and remained stable over time in most eyes, though marked RNP progression occurred in a minority of eyes. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:258-264.].

Changes in Retinal Microvasculature and Visual Acuity After Antivascular Endothelial Growth Factor Therapy in Retinal Vein Occlusion

Purpose

To investigate the changes in the retinal microvasculature during the course of anti-VEGF therapy in eyes with macular edema due to retinal vein occlusion (RVO) and their association with visual outcomes.

Methods

The vessel density (VD) and foveal avascular zone (FAZ) area in the superficial capillary plexus (SCP) and deep capillary plexus (DCP) were quantitatively measured by optical coherence tomography angiography (OCTA) in 48 consecutive eyes with RVO before and 1, 3, 6, 9, and 12 months after anti-VEGF therapy. Anti-VEGF therapy was performed either with ranibizumab or aflibercept following a pro re nata (PRN) regimen. The correlation between post-treatment best-corrected visual acuity (BCVA) and changes in the retinal microvasculature evaluated by OCTA were assessed.

Results

The BCVA improved significantly at 12 months (P < 0.001). Better BCVA at 12 months was significantly associated with a better VD in the SCP and DCP both at baseline (R2 = 0.524, P < 0.001 and R2 = 0.457, P < 0.001, respectively) and at 12 months (R2 = 0.521, P < 0.001 and R2 = 0.662, P < 0.001, respectively). Overall, both VD and FAZ did not change significantly during the 12 months. However, the progression of nonperfusion was observed in the SCP in 6 (13%) eyes and in the DCP in 10 (21%) eyes. The number of macular edema recurrence was significantly associated with a decrease in the VD (P = 0.006 [SCP] and P < 0.001 [DCP]) and less visual gain (P = 0.02) after treatment.

Conclusions

Anti-VEGF therapy maintains retinal perfusion in most patients with RVO. Preserving retinal perfusion is crucial for better visual outcomes.

Effect of funding source on reporting bias in studies of intravitreal anti-vascular endothelial growth factor therapy for retinal vein occlusion

PURPOSE

To examine the relationship between industry funding and outcome reporting bias in high-quality studies investigating the use of intravitreal anti-vascular endothelial growth factor (VEGF) agents for patients with macular oedema secondary to branch or central retinal vein occlusion (RVO).

METHODS

This systematic review in PubMed and Ovid MEDLINE examined all randomized clinical trials and meta-analyses published in journals with impact factor of ≥2 that investigated effectiveness of intravitreal anti-VEGF therapy in patients with RVO. The main outcome measure was correspondence between statistical outcome and abstract conclusion wording.

RESULTS

Forty-five studies met inclusion criteria; 38 (84%) showed correspondence between outcome and abstract conclusion without difference between industry-funded and nonindustry-funded publications (p = 0.39) or between publications in journals with impact factor ≥3 versus <3 (p = 0.96).

CONCLUSION

In high-quality studies of intravitreal anti-VEGF therapy for RVO, neither industry funding nor journal impact factor affected the rate of outcome reporting bias.

Molecular mechanisms of retinal ischemia

Each day, the retina converts an immense number of photons into chemical signals that are then transported to higher order neural centers for interpretation. This process of photo transduction requires large quantities of cellular energy and anabolic precursors, making the retina one of the most metabolically active tissues in the body. With such a large metabolic demand, the retina is understandably sensitive to perturbations in perfusion and hypoxia. Indeed, retinal ischemia underlies many prevalent retinal disorders including diabetic retinopathy (DR), retinal vein occlusion (RVO), and retinopathy of prematurity (ROP). Retinal ischemia leads to the expression of growth factors, cytokines, and other cellular mediators which promote inflammation, vascular dysfunction, and ultimately, vision loss. This review aims to highlight the most recent and compelling findings that have advanced our understanding of the molecular mechanisms underlying retinal ischemias.

Effects of ripasudil, a ROCK inhibitor, on retinal edema and nonperfusion area in a retinal vein occlusion murine model

Rho-associated coiled-coil containing protein kinase (ROCK) inhibitors are used to treat glaucoma patients and have protective effects on ischemic states. However, it is poorly understood how the ROCK pathway affects the pathological signs of retinal vein occlusion (RVO). In this study, we evaluated the effects of ripasudil, a ROCK inhibitor, on a murine RVO model. In vivo, RVO was induced by retinal vein laser irradiation in mice, and evaluated with ripasudil. In vitro, the effects of ripasudil were examined on tight junction protein integrity in human retinal microvascular endothelial cells (HRMECs). Moreover, we investigated the expression level of the phosphorylated myosin phosphatase target protein (MYPT)-1 after administration of ripasudil. Ripasudil significantly prevented deterioration, such as retinal edema, reduced the size of the nonperfusion area, and improved retinal blood flow. Ripasudil treatment inhibited disintegration of ZO-1 in HRMECs. Administration of ripasudil suppressed retinal phosphorylation of MYPT-1 in a murine RVO model. These findings indicate that ripasudil might be as a possible therapeutic agent for RVO.

Changes in retinal ischaemic index correlate with recalcitrant macular oedema in retinal vein occlusion: WAVE study

AIM

To evaluate changes in the ischaemic index (ISI) after targeted retinal photocoagulation (TRP) and to investigate the correlation between these changes and macular oedema (ME).

METHOD

Twenty-four eyes of 24 patients with retinal vein occlusion (RVO) with recurrent ME were included. Ultra-widefield fluorescein angiography (UWFFA; Optos 200Tx) was obtained at baseline and every 4 months. The regions of retinal non-perfusion and the total gradable retina were manually segmented on UWFFA images for calculating the global ISI. ISI was also computed for specific regions defined by a standardised grid: perimacular area (PMA), near-peripheral area (NPA), mid-peripheral area (MPA) and far-peripheral area (FPA). Global and regional ISIs and change in ISI over time were correlated with central macular thickness (CMT).

RESULTS

The ISIs of entire retina, PMA, NPA, MPA and FPA at baseline were 30.5%±23.3, 17.7%±20.6, 21.9%±19.0, 33.0%±27.9 and 48.0%±32.9, respectively. The ISIs at final follow-up were 23.5%±19.9, 15.7%±22.2, 16.5%±16.7, 24.7%±24.7 and 24.7%±24.7, respectively. A significant correlation was found between CMT and global ISI during follow-up (r=0.22, p=0.03). Among the different retinal zones, PMA showed a correlation with CMT (r=0.27, p=0.007). The change in ISI for the total retina (Δtotal), PMA (ΔPMA) and NPA (ΔNPA) retinal regions was positively correlated with the change in CMT (ΔCMT) (r=0.45, 0.42 and 0.50, respectively, p=0.006, 0.009 and 0.002, respectively).

CONCLUSION

The severity of ME was correlated with the ISIs of the entire retina and the PMA. The reduction in ME was correlated with the reduction in ISI of the entire retina as well as the ISIs for the NPA and PMA following TRP. The role of TRP, particularly to these regions (NPA, PMA), warrants further investigation in recalcitrant RVO-associated ME.

Use of OCTA, FA, and Ultra-Widefield Imaging in Quantifying Retinal Ischemia: A Review

As ischemia remains a key prognostic factor in the management of various diseases including diabetic retinopathy, an increasing amount of research has been dedicated to its quantification as a potential biomarker. Advancements in the quantification of retinal ischemia have been made with the imaging modalities of fluorescein angiography (FA), ultra-widefield imaging (UWF), and optical coherence tomography angiography (OCTA), with each imaging modality offering certain benefits over the others. FA remains the gold standard in assessing the extent of ischemia. UWF imaging has allowed for the assessment of peripheral ischemia via FA. It is, however, OCTA that offers the best visualization of retinal vasculature with its noninvasive depth-resolved imaging and therefore has the potential to become a mainstay in the assessment of retinal ischemia. The primary purpose of this article is to review the use of FA, UWF, and OCTA to quantify retinal ischemia and the various methods described in the literature by which this is achieved.

Reversible retinal vessel closure from VEGF-induced leukocyte plugging

Clinical trials in patients with macular edema due to diabetic retinopathy or retinal vein occlusion (RVO) have shown that suppression of VEGF not only improves macular edema, but also reopens closed retinal vessels, prevents progression of vessel closure, and improves retinopathy. In this study, we show the molecular basis for those clinical observations. Increased retinal levels of VEGF in mice cause plugging of retinal vessels with leukocytes, vessel closure, and hypoxia. Suppression of VEGF reduces leukocyte plugging, causing reperfusion of closed vessels. Activation of VEGFR1 contributes to leukocyte recruitment, because it is significantly reduced by an anti-VEGFR1-neutralizing antibody. High VEGF increases transcriptional activity of NF-κB and expression of NF-κB target genes, particularly Vcam1. Injection of an anti-VCAM-1-neutralizing antibody reduces VEGF-induced leukocyte plugging. These data explain the broad range of benefits obtained by VEGF suppression in patients with ischemic retinopathies, provide an important insight into the pathogenesis of RVO and diabetic retinopathy, and suggest that sustained suppression of VEGF early in the course of these diseases may prevent vessel closure, worsening ischemia, and disease progression. This study also identifies VEGFR1 and VCAM-1 as molecular targets whose suppression could supplement VEGF neutralization for treatment of RVO and diabetic retinopathy.

Short-term results of endovascular surgery with tissue plasminogen activator injection for central retinal vein occlusion

PURPOSE

To examine the effects of retinal endovascular surgery (REVS) with tissue plasminogen activator injection into the retinal vein in central retinal vein occlusion (CRVO) eyes.

METHODS

Sixteen consecutive CRVO patients with macular edema and decreased visual acuity who were referred to Toyama University Hospital between March 2014 and February 2016 were included in this study. Changes in visual acuity (VA) and central retinal thickness (CRT) were evaluated up to 6 months after REVS. Staining and leakage of the retinal veins in fluorescein angiography (FA) was graded in nine patients.

RESULTS

Ten of 16 eyes were determined to be non-ischemic while the remaining six were ischemic. The mean logarithm of the minimum angle of resolution (logMAR) of VA was significantly improved from 0.98 ± 0.58 (mean ± standard deviation) at baseline to 0.78 ± 0.61 at 3 months (p = 0.002), and 0.64 ± 0.60 at 6 months (p = 0.003) after REVS. At 6 months, VA was improved in eight eyes (50%), while the other eight (50%) showed no change; none showed worsening. In the 10 eyes with non-ischemic CRVO, the mean VA was significantly improved at 6 months (p = 0.002), whereas no improvement was found in the six eyes with ischemic CRVO, . In all eyes, the mean CRT was significantly improved from 804 ± 343 μm at baseline to 506 ± 304 μm at 2 months (p = 0.014), 332 ± 229 μm at 3 months (p = 0.0001), and 305 ± 235 μm at 6 months (p = 0.00001). The postoperative complications observed were prolonged vitreous hemorrhage in one eye and neovascular glaucoma in two eyes. For postoperative recurrence of macular edema, sub-tenon injection of triamcinolone acetonide was given to five eyes, and intravitreal injection of an anti-VEGF agent was given to five eyes. Pan-retinal photocoagulation was performed on six eyes with ischemic type CRVO. The FA score was significantly improved after REVS (p = 0.018).

CONCLUSIONS

REVS using a specially made micro-needle may be a surgical treatment option for non-ischemic CRVO, but it did not seem effective for ischemic CRVO.