A meta-analysis of patients with treatment-resistant macular oedema secondary to retinal vein occlusions following switching to aflibercept

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.

Patient-reported outcomes from a phase IV study of aflibercept in patients with refractory retinal vein occlusions

PURPOSE

To determine the patient-centered effectiveness of switching patients with persistent macular edema due to retinal vein occlusion (RVO) to aflibercept using the National Eye Institute Visual Function Questionnaire 25 (NEI-VFQ-25).

MATERIALS AND METHODS

Prospective study of eyes with persistent cystoid macular edema due to RVO despite regular treatment with bevacizumab or ranibizumab switched to aflibercept. Three loading doses of intravitreal aflibercept were administered every 4 weeks and thereafter every 8 weeks until week 48. Vision-related quality of life (VRQoL) using NEI-VFQ-25 was measured at baseline, 24 weeks, and 48 weeks following the switch. Baseline scores were compared to week 24 and 48 using paired t-test. Relationship between best-corrected visual acuity (BCVA) in the study eye and the NEI-VFQ-25 composite and subscale scores was investigated.

RESULTS

Eighteen patients with RVO were enrolled in the study with a mean age of 70.3 ± 8.6 years. The mean change in BCVA and central macular thickness (CMT) from baseline to 48 weeks was +20.6 ± 5.2 Early Treatment of Diabetic Retinopathy Score letters and -109.2 ± 82.8 µm, respectively. VRQoL improved significantly, with an increase of mean NEI-VFQ composite score of 11.5 ± 9.5; the corresponding improvements in near and distant activities were 13.3 ± 19.4 and 8.4 ± 10.4, respectively (P < 0.001 for both). Logistic regression analysis demonstrated that BCVA gain of >15 letters and CMT < 300 µm at the end of the study predicted a higher change in VFQ-25.

CONCLUSION

Switching eyes with persistent macular edema due to RVO to aflibercept resulted in significant improvement in visual function and patient satisfaction.

Measuring intraocular antibodies in eyes treated with anti-vascular endothelial growth factor

OBJECTIVE

To characterize the total intraocular aqueous humour antibody profiles in cases receiving anti-vascular endothelial growth factor (anti-VEGF) for retinal vascular disease compared with controls without retinal pathology.

DESIGN

Cross-sectional.

PARTICIPANTS

93 aqueous humour samples: 22 eyes undergoing cataract surgery (controls) and 71 eyes receiving intravitreal injections (IVI) (cases) for macular edema or neovascularization.

METHODS

Antibody isotyping of aqueous humour was performed using Milliplex MAP Human Isotyping Multiplex Assay. Cases and controls were compared for several outcome measures.

RESULTS

The primary outcome measure was total mean antibody isotype concentration quantified in the aqueous humour. Secondary outcomes included comparing aqueous humour concentrations with visual acuity, number of IVI received, type of anti-VEGF agent injected, and persistence intra-/subretinal fluid post injection. Mean immunoglobulin M (IgM) concentrations in cases were 19-fold higher compared with controls. Aqueous immunoglobulin G (IgG)_1,2,3,4 and immunoglobulin A (IgA) were 2-4-fold higher in cases compared with controls. Disease-specific trends were observed, with diabetic retinopathy (DR) eyes containing the highest amounts of aqueous antibodies. Total number of injections correlated with higher titres of IgG₁ (p < 0.001), IgG₂ (p < 0.009), and IgG₃ (p < 0.001) in all cases analyzed with the strongest correlations seen in DR eyes (r = 0.77, p < 0.001). Presence of aqueous humour antibodies correlated with worse post-IVI best-corrected visual acuity; IgG₁ (p < 0.01), IgG₂ (p < 0.005), IgG₃ (p < 0.01), and IgA (p < 0.003) in all cases analyzed, with the strongest correlations seen in DR eyes (r = 0.74, p < 0.001).

CONCLUSIONS

Intraocular antibodies are present in the aqueous humour at significantly higher concentrations in eyes receiving IVIs for retinal vascular diseases compared with controls.

Effects of Switching to Aflibercept in Treatment Resistant Macular Edema Secondary to Retinal Vein Occlusion

PURPOSE

The aim of this study was to examine 12-month outcomes of eyes switched from intravitreal ranibizumab or bevacizumab to aflibercept for cystoid macular edema due to retinal vein occlusion (RVO).

DESIGN

Retrospective, observation, case series.

METHODS

A retrospective study was performed assessing eyes with RVO switched to aflibercept for at least 12 months. To be included in the study, eyes had to have macular edema despite treatment for at least 6 months with bevacizumab and/or ranibizumab before the switch, central foveal thickness (CFT) ≥300 μm at time of switch, and visual acuity (VA) ≤60 early treatment of diabetic retinopathy score (ETDRS) letters (20/40 Snellen equivalent). Outcome measures included change in VA (in ETDRS letters), CFT, and interval between intravitreal injections.

RESULTS

27 eyes of 27 patients were included in the analysis: 13 with branch RVO, and 14 with central RVO. Mean VA before switch was 54.2 ± 23.7 letters (20/80 Snellen equivalent) and mean CFT was 460.4 ± 178.2 μm. Mean number of previous anti-vascular endothelial growth factor (VEGF) injections was 29.5 ± 19.2. At 12 months, mean VA improved by 8.7 ± 13.2 letters (P < 0.01) and mean CFT decreased by 180.9 ± 207.7 μm compared with baseline (P < 0.01). Mean injection interval increased by 1.6 ± 2.0 weeks to 6.9 ± 1.2 weeks, but this was not statistically significant (P = 0.18).

CONCLUSIONS

In our small retrospective study, eyes switched to intravitreal aflibercept for persistent cystoid macular edema (CME) due to RVO improved vision and macular thickness; however, larger prospective studies are required to validate our findings.

FGF2-induced STAT3 activation regulates pathologic neovascularization

Cell-autonomous endothelial cell (EC) fibroblast growth factor receptor (FGFR) signaling through FGFR1/2 is essential for injury-induced wound vascularization and pathologic neovascularization as in blinding eye diseases such as age-related macular degeneration. Which FGF ligand(s) is critical in regulating angiogenesis is unknown. Utilizing ex vivo models of choroidal endothelial sprouting and in vivo models of choroidal neovascularization (CNV), we demonstrate here that only FGF2 is the essential ligand. Though FGF-FGFR signaling can activate multiple intracellular signaling pathways, we show that FGF2 regulates pathogenic angiogenesis via STAT3 activation. The identification of FGF2 as a critical mediator in aberrant neovascularization provides a new opportunity for developing multi-target therapies in blinding eye diseases especially given the limitations of anti-VEGF monotherapy.

Efficacy and safety of dexamethasone intravitreal implant in patients with retinal vein occlusion resistant to anti-VEGF therapy: a 12-month prospective study

Purpose: To evaluate the safety and efficacy of repeated intravitreal dexamethasone implant (Ozurdex) injections administrated on an "as-needed" protocol for retinal vein occlusion patients with macular oedema, previously subjected to at least five anti-vascular endothelial growth factor (VEGF) injections with poor or no response. Methods: Prospective interventional case series of 13 branch retinal vein occlusion (BRVO) and 10 central retinal vein occlusion (CRVO) patients with persistent macular oedema (>250 μm) after at least five anti-VEGF injections. Exclusion criteria included: baseline visual acuity worse than 1.5 logMAR, previous intravitreal implant, history of vitreoretinal surgery, manifest glaucoma or ocular hypertension, epiretinal membrane, retinal neovascularization, massive retinal or macular ischaemia, vitreous haemorrhage or severe lens opacity, previous laser photocoagulation treatment. Each patient received an initial intraocular dexamethasone implant and the procedure was repeated at 6 months "as needed." Patients were followed up at months 2, 4, 6, 8, 10 and 12 with spectral domain optical coherence tomography and best corrected visual acuity measurements. Exclusion criteria included: baseline visual acuity worse than 1.5 logMAR, previous intravitreal implant, history of vitreoretinal surgery, manifest glaucoma or ocular hypertension, epiretinal membrane, retinal neovascularization, retinal or macular ischaemia, vitreous haemorrhage or severe lens opacity, previous laser photocoagulation treatment. Patients on topical or systemic corticosteroid therapy (during the last 3 months), and known steroid responders as well as diabetic patients were also excluded. Results: In the BRVO group, the mean central retinal thickness (CRT) and best corrected visual acuity (BCVA) significantly improved from 482.92 ± 139.99 μm (0.55 ± 0.12 logMAR) at baseline, to 369.31 ± 119.72 μm (0.43 ± 0.18 logMAR) at 6 months (p = 0.011/p = 0.019). At 12 months CRT was 295.82 ± 135.48 μm (p = 0.026) and BCVA 0.29 ± 0.17 logMAR (p = 0.002). Minimum CRT values were achieved at 3.45 months after the first injection, and 2.46 months after the second injection (197.00 ± 84.27 and 180.00 ± 76.89 μm, respectively). Best BCVA values were achieved at a mean of 4 ± 0.853 months after the first injection, and 4 months after the second injection (0.219 ± 0.129 and 0.222 ± 0.078 logMAR, respectively). In the CRVO group, neither the mean CRT nor BCVA improved significantly at 6 months: from 669.70 ± 203.20 μm (0.80 ± 0.231 logMAR) at baseline, to 586.20 ± 237.63 μm (0.740 ± 0.268 logMAR) at 6 months (p = 0.131/p = 0.333). At 12 months CRT was significantly improved: 549.90 ± 191.26 μm (p = 0.047), but BCVA lacked significant improvement: 0.690 ± 0.285 logMAR (p = 0.072). Minimum CRT values were achieved at a mean of 2 months after the first injection, and also 2 months after the second injection (261.60 ± 121.31 and 280.00 ± 177.43 μm, respectively). Best BCVA values were achieved at a mean of 2 months after the first injection, and 2 months after the second injection and were 0.390 ± 0.173 and 0.385 ± 0.233 logMAR, respectively. Cataract progression was a rare event (2/23 eyes), while transient steroid-induced ocular hypertension (5/23 eyes) was managed successfully with IOP-lowering medication Conclusion: Dexamethasone implant should be considered as an effective and safe alternative in patients with BRVO and CRVO who have failed anti-VEGF therapy. Shortening the re-injection interval especially for CRVO cases should be considered.

VEGF in Signaling and Disease: Beyond Discovery and Development

The discovery of vascular endothelial-derived growth factor (VEGF) has revolutionized our understanding of vasculogenesis and angiogenesis during development and physiological homeostasis. Over a short span of two decades, our understanding of the molecular mechanisms by which VEGF coordinates neurovascular homeostasis has become more sophisticated. The central role of VEGF in the pathogenesis of diverse cancers and blinding eye diseases has also become evident. Elucidation of the molecular regulation of VEGF and the transformative development of multiple therapeutic pathways targeting VEGF directly or indirectly is a powerful case study of how fundamental research can guide innovation and translation. It is also an elegant example of how agnostic discovery and can transform our understanding of human disease. This review will highlight critical nodal points in VEGF biology, including recent developments in immunotherapy for cancer and multitarget approaches in neovascular eye disease.