Choroidal Neovascularization Area Research Articles

A drug delivery system of HIF-1α siRNA nanoparticles loaded by mesenchymal stem cells on choroidal neovascularization.

Aim: To assess mesenchymal stem cells (MSCs) as carriers for HIF-1αsiRNA-loaded nanoparticles (NPs) for targeted therapy of experimental choroidal neovascularization (CNV).Materials & methods: A poly (lactic-co-glycolic acid) (PLGA)-core/lipid-shell hybrid NP was designed. The transfection efficacy of MSCs with the hybrid NPs was assessed. Mice were intravenously injected with MSCs after laser photocoagulation and CNV was assessed at 7days post-injection.Results & conclusion: The transfection efficiency of hybrid NPs into MSCs was 72.7%. HIF-1α mRNA expression in 661w cells co-cultured with MSC-hybrid-siRNA NPs was significantly lower. Intravenous delivery of MSC-hybrid-siRNA NPs greatly reduced CNV area and length. Intravenous injection of MSC-hybrid-siRNA NPs achieved therapeutic efficacy in reducing CNV area. The MSC-mediated homing enabled targeted inhibition of ocular angiogenesis.

MiR-199a-5p modulates choroidal neovascularization by regulating Wnt7b/Wnt/β-catenin signaling pathway.

Choroidal neovascularization (CNV) can be seen in many fundus diseases, and lead to fundus exudation, bleeding, or vision loss. miRNAs are vital regulator in CNV. miR-199a-5p has been proved to be involved in regulating vascular formation of endothelial cells, but its role in CNV remains unclear. This study aims to study the role of miR-199a-5p in CNV. Laser irradiation was used to induce CNV model. The lesion area of CNV was calculated by high-resolution angiography with fluorescein isothiocyanate-dextran. Wnt family member 7b (Wnt7b), β-catenin, and Wnt pathway proteins was measured by western blot. Immunofluorescence was performed to test Wnt7b, β-catenin, CD31, and p-p65. miR-199a-5p and Wnt7b mRNA were tested by reverse transcription real-time polymerase chain reaction. Cell count kit-8, wound healing, Transwell, tube formation, and flow cytometry were used to detect the function of miR-199a-5p and Wnt7b on human retinal microvascular endothelial cells (HRMEC). TargetScan database and dual-luciferase reporter assay verified the interaction between miR-199a-5p and Wnt7b. The results revealed that Wnt7b increased in CNV rats. Knocking down Wnt7b repressed cell proliferation, migration, invasion, and angiogenesis, and accelerated cell apoptosis of HRMEC. Dual-luciferase reporter assay verified that miR-199a-5p targeted Wnt7b. Overexpression of miR-199a-5p inhibited the angiogenesis of HRMEC and promoted cell apoptosis by inhibiting Wbt7b. In vivo experiment found that Wnt7b rescued the promotion of miR-199a-5p inhibition on CNV lesion of rats. In addition, Wnt7b positively regulated Wnt/β-catenin signaling pathway and promoted the angiogenesis of HRMEC. In conclusion, overexpression of miR-199a-5p inhibited the angiogenesis of HRMEC by regulating Wnt7b/Wnt/β-catenin signaling pathway, which may serve as a promising therapy target of CNV.

5-Aza-2'-Deoxycytidine Ameliorates Choroidal Neovascularization by Inhibiting the Wnt/β-Catenin Signaling Pathway.

Choroidal neovascularization (CNV) can constitute the final pathology of many ocular diseases and result in severe vision loss. Studies have demonstrated that DNA methylation is critical in retinal development, aging, and disorders. The current work investigated the effects and underlying mechanism of 5-Aza-2'-deoxycytidine (5-aza-dC), a suppressor of DNA methylation, in the pathological progression of CNV. The DNA methylation profiles of retinal pigment epithelial (RPE)/choroidal complexes in normal and laser-induced CNV mice were assessed by Arraystar Mouse RefSeq Promoter Arrays. The CNV area and blood flow density and intensity were observed by optical coherence tomography angiography, and fluorescence leakage was examined by fundus fluorescein angiography in CNV mice with systemic administration of 5-aza-dC. The effects of 5-aza-dC on the biological functions of bEnd.3 cells were estimated by related assays. Notum gene promoter methylation was measured using bisulfite sequencing PCR. Methyltransferases and Wnt signaling-related genes were detected in animal and cell culture experiments by real-time PCR and immunoblot. Methyltransferases were upregulated, but Notum (a secretion inhibitor of Wnt signaling) was downregulated in the RPE/choroidal complexes of mice with experimental CNV. Intraperitoneal injection of 5-aza-dC inactivated the Wnt pathway and ameliorated the lesion area and the intensity and density of blood flow, as well as the degree of leakage in CNV. In vitro, vascular endothelial growth factor A (VEGFA) stimulation promoted methyltransferases expression and suppressed Notum expression, consequently activating Wnt signaling, whereas exogenous 5-aza-dC reversed VEGFA-induced hyperpermeability, proliferation, migration, and tube formation in bEnd.3 cells via demethylation of Notum promoter. We observed that 5-aza-dC attenuates the growth of CNV by inhibiting the Wnt signaling pathway via promoter demethylation of the Wnt antagonist Notum. These findings provide a theoretical basis for methylation-based treatment with the Notum gene as a potential target for CNV treatment.

Myopic choroidal neovascularization with neovascular signal around perforating scleral vessel prone to recur after anti-VEGF therapy

BackgroundTo compare the recurrence of myopic choroidal neovascularization (mCNV) based on the neovascular signal of mCNV around the perforating scleral vessel (PSV).MethodsA consecutive series of naïve patients with mCNV accepted anti-VEGF therapy with a minimum 12-month follow-up period. The neovascular signal relationship between PSV and mCNV were classified into the presence of neovascular signal of CNV around PSV or not. The recurrence of mCNV, best-corrected visual acuity (BCVA), hyperreflective foci height, CNV area and CNV flow area were analyzed between two groups.ResultsNeovascular signal of CNV around PSV was detected in 20 eyes (39.2%). The one-year recurrence rate in the group with neovascular signal of CNV around PSV was significantly higher than that in the group without neovascular signal of CNV around PSV (P = 0.045). The recurrence time in the group with neovascular signal around PSV was shorter than that in the group without neovascular signal around PSV (P = 0.030). Cox proportional hazard model showed that the presence of neovascular signal of CNV around PSV [hazard ratio (HR): 2.904] and subfoveal choroidal thickness ≤ 50 μm (HR: 0.368) were risk factors for recurrence of mCNV. In the group with neovascular signal around PSV, the BCVA was worse (P = 0.024) and the CNV flow area was more unstable (P = 0.027) after therapy.ConclusionsPSV was commonly detected in patients with mCNV. The presence of neovascular signal of CNV around PSV was prone to recur with a shorter time in mCNV patients.

Efficacy and safety of intravitreal faricimab for neovascular age-related macular degeneration: a systematic review and meta-analysis

We conducted a systematic review and meta-analysis to evaluate the visual, anatomical, and safety outcomes of the intravitreal faricimab, a novel vascular endothelial growth factor (VEGF)/angiopoietin-2 (Ang-2) bispecific agent, in neovascular age-related macular degeneration (nAMD) patients. The follow-up times in the included studies ranged from a minimum of 36 weeks to a maximum of 52 weeks. EMBASE, Ovid-Medline, Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, Scopus, the WHO ICTRP, ClinicalTrial.gov, the EU Clinical Trials Register, and Chinese Clinical Trial Registry (ChiCTR) were searched (The last literature search was performed on August 17, 2023) for randomized controlled trials (RCTs) comparing faricimab with control groups for neovascular age-related macular degeneration (nAMD). The risk of bias for eligible RCTs was independently assessed using the Cochrane Risk of Bias Tool by two authors (W.-T.Y. and C.-S.W.). The meta-analysis was conducted using Review Manager 5.4 software. The mean best corrected visual acuity (BCVA), central subfield thickness (CST), total choroidal neovascularization (CNV) area, and total lesion leakage were analyzed as continuous variables and the outcome measurements were reported as the weighted mean difference (WMD) with a 95% confidence interval (CI). The ocular adverse events and ocular serious adverse events were analyzed as dichotomous variables and the outcome measurements were analyzed as the odds ratios (ORs) with a 95% CI. Random-effects model was used in our study for all outcome synthesizing due to different clinical characteristics. Four RCTs with 1,486 patients were eligible for quantitative analysis. There was no statistically significant difference between intravitreal faricimab and anti-VEGF in BCVA [weighted mean difference (WMD) = 0.47; 95% CI: (− 0.17, 1.11)]. The intravitreal faricimab group showed numerically lower CST [WMD = − 5.96; 95% CI = (− 7.11, − 4.82)], total CNV area [WMD = − 0.49; 95% CI = (− 0.68, − 0.30)], and total lesion leakage [WMD = − 0.88; 95% CI = (− 1.08, − 0.69)] after intravitreal therapy compared with the intravitreal anti-VEGF group. There were no statistically significant differences between intravitreal faricimab and anti-VEGF in ocular adverse events (AEs) [pooled odds ratio (OR) = 1.10; 95% CI = (0.81, 1.49)] and serious adverse events (SAEs) [pooled OR = 0.84; 95% CI = (0.37, 1.90)]. The intravitreal bispecific anti-VEGF/angiopoietin 2 (Ang2) antibody faricimab with a extended injection interval was non-inferior to first-line anti-VEGF agents in BCVA. It was safe and had better anatomical recovery. Large, well-designed RCTs are needed to explore the potential benefit of extended faricimab for nAMD. This systematic review was registered in the International Prospective Register of Systematic Reviews (PROSPERO) database (CRD42022327450).

Monomeric C‐reactive protein exacerbates choroidal neovascularization in vivo: Implications for age‐related macular degeneration

Aims/Purpose: Increased systemic levels of the acute phase reactant C‐reactive protein (CRP) have been linked to increased risk of age‐related macular degeneration (AMD). CRP undergoes conformational changes upon activation in inflammatory microenvironments between pentameric (pCRP) and monomeric forms (mCRP). CRP conformations present different phenotypes, as mCRP has more proinflammatory properties and has been shown to induce blood retinal barrier disruption in vitro. Thus, we aimed to evaluate the impact of CRP forms on choroidal neovascularization (CNV) in vivo.Methods: pCRP and mCRP forms were intravenously (iv) or intravitreally (ivt) injected in C57BL6/J mice (n = 12) previously subjected to CNV induction by laser and compared to controls. CNV lesions were monitored by fluorescein angiography and mice were euthanized 11 days after lesion induction. CNV areas were measured in lectin stained choroidal flatmounts. To evaluate the CRP dissociation, pCRP was coupled to a fluorescent molecule before injection. After tissue extraction mCRP was detected by immunofluorescence in posterior pole flatmounts.Results: Both pCRP and mCRP injected significantly increased CNV areas compared to control mice. Retinal severe edema was also observed close to the lesion in retinographies, and was more severe in intravitreally injected groups. Finally, pCRP was observed to dissociate into mCRP in intravitreally injected animals with pCRP.Conclusions: We confirmed that CRP increases CNV areas and severe edema in the retina, suggesting that CRP is activated in the CNV inflammatory environment. Additionally, the pCRP form dissociates in vivo into mCRP close to CNV damaged tissue, hypothesizing that mCRP is the CRP conformation that contributes to the exacerbation of the CNV process. Further studies are needed to investigate anti‐mCRP molecules as candidates for mono‐ or anti‐VEGF combined therapy for AMD treatments.

No dye, no glory: FFA and ICGA in uveitis

Uveitis is a potentially sight‐threatening condition characterized by inflammation of the uvea. Accurate diagnosis of uveitis is crucial for appropriate management and preservation of vision. The diagnosis of uveitis can be challenging due to the overlapping clinical features with other ocular diseases. In this context, imaging techniques such as fluorescein angiography (FA) and indocyanine green angiography (ICGA) have become indispensable tools in the differential diagnosis of uveitis.FA is a widely used imaging modality in the diagnosis and management of uveitis. It involves the intravenous injection of fluorescein dye, which highlights the blood vessels of the retina and choroid. FA can reveal the presence of leakage, staining, and non‐perfusion areas in the retinal and choroidal vasculature, which are indicative of the inflammatory process in uveitis. Moreover, FA can detect complications such as occlusive vasculitis or choroidal neovascularization. FA can also be used to monitor the response to treatment and detect complications of uveitis such as cystoid macular oedema.ICGA is another imaging modality that complements FA in the diagnosis of uveitis. ICGA involves the intravenous injection of indocyanine green dye, which better highlights the choroidal vasculature. ICGA can identify areas of choroidal hypoperfusion, which are often seen in posterior uveitis such as Vogt‐Koyanagi‐Harada disease or Birdshot retinochoroiditis. ICGA can also delineate areas of choroidal neovascularization. Furthermore, ICGA can help differentiate between active and inactive uveitis, which is crucial in determining the appropriate course of treatment.In addition to their diagnostic value, FA and ICGA can provide valuable information on the pathogenesis of uveitis. FA and ICGA can reveal the presence of subclinical inflammation in asymptomatic patients, which can guide the early initiation of treatment and prevent irreversible damage to the retina and choroid. Additionally, FA and ICGA can identify the location and extent of inflammation in uveitis, which can help in the selection of appropriate treatment modalities such as corticosteroids, immunomodulators and biologic agents.In conclusion, FA and ICGA are invaluable tools in the differential diagnosis and management of uveitis. These imaging modalities can provide vital information on the presence, location and extent of inflammation in uveitis, which can guide the selection of appropriate treatment modalities and prevent irreversible visual loss.

Visualization of choroidal vasculature in pigmented mouse eyes from experimental models of AMD

A variety of techniques exist to investigate retinal and choroidal vascular changes in experimental mouse models of human ocular diseases. While all have specific advantages, a method for evaluating the choroidal vasculature in pigmented mouse eyes has been more challenging especially for whole mount visualization and morphometric analysis. Here we report a simple, reliable technique involving bleaching pigment prior to immunostaining the vasculature in whole mounts of pigmented mouse choroids. Eyes from healthy adult pigmented C57BL/6J mice were used to establish the methodology. The retina and anterior segment were separated from the choroid. The choroid with retinal pigment epithelial cells (RPE) and sclera was soaked in 1% ethylenediaminetetraacetic acid (EDTA) to remove the RPE. Tissues were fixed in 2% paraformaldehyde (PFA) in phosphate-buffered saline (PBS). Choroids were subjected to melanin bleaching with 10% hydrogen peroxide (H2O2) at 55 °C for 90 min, washed in PBS and then immunostained with anti-podocalyxin antibody to label vascular endothelium followed by Cy3-AffiniPure donkey anti-goat IgG at 4 °C overnight. Images of immunostained bleached choroids were captured using a Zeiss 710 confocal microscope. In addition to control eyes, this method was used to analyze the choroids from subretinal sodium iodate (NaIO3) RPE atrophy and laser-induced choroidal neovascularization (CNV) mouse models. The H2O2 pretreatment effectively bleached the melanin, resulting in a transparent choroid. Immunolabeling with podocalyxin antibody following bleaching provided excellent visualization of choroidal vasculature in the flat perspective. In control choroids, the choriocapillaris (CC) displayed different anatomical patterns in peripapillary (PP), mid peripheral (MP) and far peripheral (FP) choroid. Morphometric analysis of the vascular area (VA) revealed that the CC was most dense in the PP region (87.4 ± 4.3% VA) and least dense in FP (79.9 ± 6.7% VA). CC diameters also varied depending on location from 11.4 ± 1.97 mm in PP to 15.1 ± 3.15 mm in FP. In the NaIO3-injected eyes, CC density was significantly reduced in the RPE atrophic regions (50.7 ± 5.8% VA in PP and 45.8 ± 6.17% VA in MP) compared to the far peripheral non-atrophic regions (82.8 ± 3.8% VA). CC diameters were significantly reduced in atrophic regions (6.35 ± 1.02 mm in PP and 6.5 ± 1.2 mm in MP) compared to non-atrophic regions (14.16 ± 2.12 mm). In the laser-induced CNV model, CNV area was 0.26 ± 0.09 mm2 and luminal diameters of CNV vessels were 4.7 ± 0.9 mm. Immunostaining on bleached choroids with anti-podocalyxin antibody provides a simple and reliable tool for visualizing normal and pathologic choroidal vasculature in pigmented mouse eyes for quantitative morphometric analysis. This method will be beneficial for examining and evaluating the effects of various treatment modalities on the choroidal vasculature in mouse models of ocular diseases such as age-related macular degeneration, and degenerative genetic diseases.

NR4A1 deletion promotes pro-angiogenic polarization of macrophages derived from classical monocytes in a mouse model of neovascular age-related macular degeneration

BackgroundNeovascular age-related macular degeneration causes vision loss from destructive angiogenesis, termed choroidal neovascularization (CNV). Cx3cr1−/− mice display alterations in non-classical monocytes and microglia with increased CNV size, suggesting that non-classical monocytes may inhibit CNV formation. NR4A1 is a transcription factor that is necessary for maturation of non-classical monocytes from classical monocytes. While Nr4a1−/− mice are deficient in non-classical monocytes, results are confounded by macrophage hyper-activation. Nr4a1se2/se2 mice lack a transcriptional activator, resulting in non-classical monocyte loss without macrophage hyper-activation.Main bodyWe subjected Nr4a1−/− and Nr4a1se2/se2 mice to the laser-induced CNV model and performed multi-parameter flow cytometry. We found that both models lack non-classical monocytes, but only Nr4a1−/− mice displayed increased CNV area. Additionally, CD11c+ macrophages were increased in Nr4a1−/− mice. Single-cell transcriptomic analysis uncovered that CD11c+ macrophages were enriched from Nr4a1−/− mice and expressed a pro-angiogenic transcriptomic profile that was disparate from prior reports of macrophage hyper-activation.ConclusionsThese results suggest that non-classical monocytes are dispensable during CNV, and NR4A1 deficiency results in increased recruitment of pro-angiogenic macrophages.

Therapeutic Benefit of Melatonin in Choroidal Neovascularization During Aging Through the Regulation of Senescent Macrophage/Microglia Polarization.

This study aimed to investigate the age-dependent anti-angiogenic capability of melatonin in choroidal neovascularization (CNV) and to explore the underlying molecular mechanisms. In the present study, a laser-induced CNV model was established in both young (three months of age) and old (18 months of age) mice, and the size of CNV lesions and vascular leakage was detected by morphological and imaging examination. Next, Western blot and immunostaining were used to observe the levels of M2 markers, senescence-related markers, and molecules involved in IL-10/STAT3 pathway. Additionally, colivelin was used to study the effect of IL-10/STAT3 pathway activation on the expression of M2 markers and senescence-related markers by Western blot and immunostaining. Finally, the effects of colivelin on melatonin-induced reduction of CNV size and vascular leakage in mice at different ages were assessed using morphological and imaging examination. Our results revealed that aging promoted M2 macrophage/microglia polarization, and aggravated CNV and vascular leakage. Melatonin significantly inhibited the M2 polarization of senescent macrophage/microglia and reduced the CNV area and vascular leakage. Moreover, melatonin markedly suppressed IL-10/STAT3 pathway activation in the macrophage/microglia of old mice, and STAT3 activator colivelin reversed the suppressive effect of melatonin on M2 polarization of senescent macrophage/microglia and laser-induced CNV in old mice. Our data demonstrated that melatonin significantly prevented the M2 polarization of senescent macrophage/microglia by inhibiting the IL-10/STAT3 pathway, and eventually attenuated senescence-associated CNV. These findings suggested that melatonin could serve as a promising therapeutic agent to treat CNV and other age-related ocular diseases.

Targeted long-term noninvasive treatment of choroidal neovascularization by biodegradable nanoparticles.

Choroidal neovascularization (CNV) is the main cause of vision loss in patients with wet age-related macular degeneration (AMD). Currently, treatment of these conditions requires repeated intravitreal injections, which may lead to complications such as infection and hemorrhage. So, we have developed a noninvasive method for treating CNV with nanoparticles, namely, Angiopoietin1-anti CD105-PLGA nanoparticles (AAP NPs), which targets the CNV to enhance drug accumulation at the site. These nanoparticles, with PLGA as a carrier, can slowly release encapsulated Angiopoietin 1 (Ang 1) and target the choroidal neovascularization marker CD105 to enhance drug accumulation, increases vascular endothelial cadherin (VE-cadherin) expression between vascular endothelial cells, effectively reduce neovascularization leakage and inhibit Angiopoietin 2(Ang 2) secretion by endothelial cells. In a rat model of laser-induced CNV, intravenous injection of AAP NPs exerted a good therapeutic effect in reducing CNV leakage and area. In short, these synthetic AAP NPs provide an effective alternative treatment for AMD and meet the urgent need for noninvasive treatment in neovascular ophthalmopathy. STATEMENT OF SIGNIFICANCE: This work describes the synthesis, injection-mediated delivery, in vitro and in vivo efficacy of targeted nanoparticles with encapsulated Ang1; via these nanoparticles, the drug can be targeted to choroidal neovascularization lesions for continuous treatment. The release of Ang1 can effectively reduce neovascularization leakage, maintain vascular stability, and inhibit Ang2 secretion and inflammation. This study provides a new approach for the treatment of wet age-related macular degeneration.

Effects of endogenous dopamine induced by low concentration atropine eye drops on choroidal neovascularization in high myopia mice.

To evaluate effects of endogenous dopamine induced by low concentration atropine eye drops on choroidal neovascularization (CNV) in high myopia mice. The C57BL/6J mice were deprived of the right eye for 4wk, and the high myopia was diagnosed by optometry, the diopter was less than -6.00 D, and CNV was induced by 532 nm laser. The changes of dopamine D1 receptor (DRD1), dopamine D2 receptor (DRD2), and vascular endothelial growth factor A (VEGFA) were detected by Western blot technology at 0.5, 1, 2h, and 7d after 0.01%, 0.05%, and 0.1% atropine eye drops, respectively, the area of CNV was measured. Significant increases were observed on the expression of DRD2 in mouse high myopia model at 0.5, 1, 2h, 7d with 0.05% and 0.1% atropine eye drops (P<0.05). Significant decreases were observed on the expression of DRD1 and VEGFA in mouse high myopia model at 0.5, 1, 2h, 7d with 0.05% and 0.1% atropine eye drops (P<0.05). The area of CNV induced by laser in the drug-treated group was significantly smaller than that in the control group, and the higher the concentration, the more significant the inhibitory effect (P<0.05). The 0.01%, 0.05%, 0.1% atropine eye drops can decrease the level of VEGFA and inhibit high myopia CNV indirectly by up-regulating the level of DRD2 and down-regulating the level of DRD1, and the effect of 0.05% and 0.1% atropine eye drops is more significant.

3K3A-Activated Protein C Inhibits Choroidal Neovascularization Growth and Leakage and Reduces NLRP3 Inflammasome, IL-1β, and Inflammatory Cell Accumulation in the Retina.

3K3A-Activated Protein C (APC) is a recombinant variant of the physiological anticoagulant APC with cytoprotective properties and reduced bleeding risks. We studied the potential use of 3K3A-APC as a multi-target therapeutic option for choroidal neovascularization (CNV), a common cause of vision loss in age-related macular degeneration. CNV was induced by laser photocoagulation in a murine model, and 3K3A-APC was intravitreally injected. The impact of 3K3A-APC treatment on myeloid and microglia cell activation and recruitment and on NLRP3 inflammasome, IL-1β, and VEGF levels was assessed using cryosection, retinal flat-mount immunohistochemistry and vascular imaging. Additionally, we evaluated the use of fluorescein angiography as a surrogate marker for in vivo evaluation of the efficacy of 3K3A-APC treatment against leaking CNV lesions. Our results demonstrated that 3K3A-APC treatment significantly reduced the accumulation and activation of myeloid cells and microglia in the CNV area and decreased the NLRP3 and IL-1β levels at the CNV site and the surrounding retina. Furthermore, 3K3A-APC treatment resulted in leakage regression and CNV growth suppression. These findings indicate that the anti-inflammatory activities of 3K3A-APC contribute to CNV inhibition. Our study suggests the potential use of 3K3A-APC as a novel multi-target treatment for CNV.

Comparison of anatomical and functional outcomes of treating myopic choroidal neovascularization with bevacizumab or ranibizumab.

To compare results of treatment with bevacizumab and ranibizumab injections in myopic choroidal neovascularization (mCNV). Retrospective, observational case series. patients with mCNV treated with bevacizumab or ranibizumab injections. Best corrected visual acuity (BCVA) and central retinal thickness (CRT) on optical coherence tomography (OCT) scans were collected at baseline, after 3, 6, 12, 24months and the last visit. mean change in BCVA and CRT. We included 85 eyes treated with bevacizumab and 125 eyes treated with ranibizumab. There was no difference between the groups regarding BCVA and CRT change. CNV recurrence occurred at the mean time of 66.1 ± 3.7 and 57.3 ± 6.4months in the bevacizumab- and ranibizumab-treated eyes, respectively (p = 0.006). During the first year 6.9% eyes in the bevacizumab group vs. 27.5% in the ranibizumab group had CNV recurrence (p = 0.001). Risk factors for recurrence of CNV were baseline CNV area (aHR 1.20, 95%CI 1.0-1.32, p = 0.04), subfoveal CNV (aHR 2.13, 95% CI 1.16-3.93, p = 0.01) and ranibizumab treatment (aHR 2.31, 95% CI 1.16-3.93, p = 0.008). Eyes treated with bevacizumab and ranibizumab can achieve similar anatomical and functional improvement. CNV recurrence may occur earlier and more frequently during the first year in eyes treated with ranibizumab.

Delineating effects of angiopoietin-2 inhibition on vascular permeability and inflammation in models of retinal neovascularization and ischemia/reperfusion.

Clinical trials demonstrated that co-targeting angiopoietin-2 (Ang-2) and vascular endothelial growth factor (VEGF-A) with faricimab controls anatomic outcomes and maintains vision improvements, with strong durability, through 2 years in patients with neovascular age-related macular degeneration and diabetic macular edema. The mechanism(s) underlying these findings is incompletely understood and the specific role that Ang-2 inhibition plays requires further investigation. We examined the effects of single and dual Ang-2/VEGF-A inhibition in diseased vasculatures of JR5558 mice with spontaneous choroidal neovascularization (CNV) and in mice with retinal ischemia/reperfusion (I/R) injuries. In JR5558 mice, Ang-2, VEGF-A, and dual Ang-2/VEGF-A inhibition reduced CNV area after 1 week; only dual Ang-2/VEGF-A inhibition decreased neovascular leakage. Only Ang-2 and dual Ang-2/VEGF-A inhibition maintained reductions after 5 weeks. Dual Ang-2/VEGF-A inhibition reduced macrophage/microglia accumulation around lesions after 1 week. Both Ang-2 and dual Ang-2/VEGF-A inhibition reduced macrophage/microglia accumulation around lesions after 5 weeks. In the retinal I/R injury model, dual Ang-2/VEGF-A inhibition was statistically significantly more effective than Ang-2 or VEGF-A inhibition alone in preventing retinal vascular leakage and neurodegeneration. These data highlight the role of Ang-2 in dual Ang-2/VEGF-A inhibition and indicate that dual inhibition has complementary anti-inflammatory and neuroprotective effects, suggesting a mechanism for the durability and efficacy of faricimab in clinical trials.

Multimodal imaging of laser-induced choroidal neovascularization in pigmented rabbits

This study aimed to demonstrate longitudinal multimodal imaging of laser photocoagulation-induced choroidal neovascularization (CNV) in pigmented rabbits. Six Dutch Belted pigmented rabbits were treated with 12 laser lesions in each eye at a power of 300 mW with an aerial diameter spot size of 500 μm and pulse duration of 100 ms. CNV progression was monitored over a period of 4 months using different imaging techniques including color fundus photography, fluorescein angiography (FA), photoacoustic microscopy (PAM), and optical coherence tomography (OCT). All treated eyes developed CNV with a success rate of 100%. The margin and morphology of CNV were detected and rendered in three dimensions using PAM and OCT. The CNV was further distinguished from the surrounding melanin and choroidal vessels using FDA-approved indocyanine green dye-enhanced PAM imaging. By obtaining PAM at 700 nm, the location and density of CNV were identified, and the induced PA signal increased up to 59 times. Immunohistochemistry with smooth muscle alpha-actin (αSMA) antibody confirmed the development of CNV. Laser photocoagulation demonstrates a great method to create CNV in pigmented rabbits. The CNV was stable for up to 4 months, and the CNV area was measured from FA images similar to PAM and OCT results. In addition, this study demonstrates that contrast agent-enhanced PAM imaging allows for precise visualization and evaluation of the formation of new blood vessels in a clinically-relevant animal model of CNV. This laser-induced CNV model can provide a unique technique for longitudinal studies of CNV pathogenesis that can be imaged with multimodal imaging.

ENLARGEMENT OF CHOROIDAL NEOVASCULARIZATION BEFORE RECURRENCE AFTER PHOTODYNAMIC THERAPY FOR PACHYCHOROID NEOVASCULOPATHY.

To investigate predictors of recurrent exudation in choroidal neovascularization (CNV) of pachychoroid neovasculopathy (PNV) after photodynamic therapy (PDT). Consecutive, treatment-naïve, symptomatic patients with PNV with subfoveal retinal fluid (SRF) treated with PDT and followed for 18 months were studied retrospectively. CNV areas were calculated from optical coherence tomography angiography (OCTA) images obtained at various time points after the initial PDT. In 52 eyes, the SRF resolved completely 3 months after PDT, in 23 (44%) eyes the exudation recurred during the 18-month follow-up period. In 29 eyes with no recurrence, the mean baseline square root of the CNV area of 1.91 mm [95% confidence interval (CI), 0.27] decreased significantly (P = 0.006) to 1.47 mm (95% CI, 0.16) at 3 months after PDT and decreased further until 12 months after PDT (mean, 1.26 mm; 95% CI, P < 0.001) and was maintained thereafter. In 23 eyes with a recurrence, the square root of the CNV area enlarged significantly (P = 0.028) from 1.43 mm (95% CI, 0.21) at the examination 3 months before the recurrence to 1.73 mm (95% CI, 0.18) at the recurrence. CNV enlargement during the follow-up period after PDT for PNV may predict recurrence.

Exploring the Therapeutic Potential of Elastase Inhibition in Age-Related Macular Degeneration in Mouse and Human.

Abnormal turnover of the extracellular matrix (ECM) protein elastin has been linked to AMD pathology. Elastin is a critical component of Bruch's membrane (BrM), an ECM layer that separates the retinal pigment epithelium (RPE) from the underlying choriocapillaris. Reduced integrity of BrM's elastin layer corresponds to areas of choroidal neovascularization (CNV) in wet AMD. Serum levels of elastin-derived peptides and anti-elastin antibodies are significantly elevated in AMD patients along with the prevalence of polymorphisms of genes regulating elastin turnover. Despite these results indicating significant associations between abnormal elastin turnover and AMD, very little is known about its exact role in AMD pathogenesis. Here we report on results that suggest that elastase enzymes could play a direct role in the pathogenesis of AMD. We found significantly increased elastase activity in the retinas and RPE cells of AMD mouse models, and AMD patient-iPSC-derived RPE cells. A1AT, a protease inhibitor that inactivates elastase, reduced CNV lesion sizes in mouse models. A1AT completely inhibited elastase-induced VEGFA expression and secretion, and restored RPE monolayer integrity in ARPE-19 monolayers. A1AT also mitigated RPE thickening, an early AMD phenotype, in HTRA1 overexpressing mice, HTRA1 being a serine protease with elastase activity. Finally, in an exploratory study, examining archival records from large patient data sets, we identified an association between A1AT use, age and AMD risk. Our results suggest that repurposing A1AT may have therapeutic potential in modifying the progression to AMD.

Prevalence of Macular Atrophy in the MARINA Study of Ranibizumab versus Sham for Neovascular Age-Related Macular Degeneration

Determine prevalence, progression rates, and associations of newly detectable macular atrophy (MA) in patients with choroidal neovascularization (CNV) secondary to neovascular age-related macular degeneration (nAMD) with/without ranibizumab treatment. Post hoc analysis of MA in patients with occult/minimally classic nAMD who received monthly intravitreal ranibizumab (0.3 or 0.5 mg) or sham injections for 24 months (M) in MARINA, a phase III trial in treatment-naive patients (NCT00056836). Seven hundred six patients with nAMD: ranibizumab 0.3 mg, n= 236; 0.5 mg, n= 237; sham, n=233. Macular atrophy, assessed by color fundus photographs/fluorescein angiography, was classified as "within," "adjacent," or "nonadjacent" to the original CNV lesion. Factors associated with MA were assessed by multivariate logistic regression. Prevalence/incidence of newly detectable MA over time, association with CNV area, MA progression rate, association of MA with visual acuity (VA), changes in CNV/leakage area, and factors predictive of new MA at 24M. At 24M, new MA was detected in 36.8%, 40.4%, and 21.0% of eyes for ranibizumab 0.3 mg, 0.5 mg, and sham, respectively, most frequently within the area of the baseline CNV lesion (93.2%, 85.0%, and 69.0%). Rate of MA progression was similar across arms (∼ 0.3 to 0.4 mm/year). There was strong association between absence of fibrosis and detectable MA (odds ratio, 2.7; 95% confidence interval [CI], 1.29-5.56), whereas an association was not identified between detectable MA and baseline VA, baseline fellow eye atrophy, ranibizumab treatment, or change in leakage/CNV area at 24M. Ranibizumab-treated eyes gained VA with (0.3 mg: 5.3 letters [95% CI, -3.3, 13.8]; 0.5 mg: 9.8 [4.7-15.0]) or without new MA (0.3 mg: 6.4 [4.1-8.6]; 0.5 mg: 8.0 [5.3-10.6]), whereas VA in sham-treated eyes deteriorated with/without new MA (-14.7 [-23.6, -5.8] and-14.0 [-16.9, -11.1], respectively). New MA was more frequently detected in ranibizumab-treated than sham-treated eyes. Macular atrophy progression was similar across arms. Multivariate analysis showed that absence of fibrosis was the only variable associated with increased MA. Regardless of MA presence/location at baseline or throughout the study, ranibizumab-treated eyes showed clinically significant improvements in VA, whereas VA in sham-treated eyes worsened. Proprietary or commercial disclosure may be found after the references.

Fiji-Assisted Automatic Quantitative Volumetric Analysis of Choroidal Neovascularization in a Laser-Induced Choroidal Neovascularization Mouse Model.

The laser-induced choroidal neovascularization (CNV) mouse model is the most frequently used animal model of CNV. To test new therapeutic agents that suppress CNV, CNV measurement in an accurate, precise, and efficient manner is important. We present the utility of Fiji-assisted automatic volumetric quantification of CNV in comparison with two-dimensional CNV analyses. Laser-induced CNV was induced in C57BL/6J mice according to the established protocol. After CNV induction, mice were treated with intravitreal injection of either phosphate-buffered saline solution (PBS) or Aflibercept, an anti- vascular endothelial growth factor agent. One week after intravitreal injection treatment, retina pigment epithelium/choroid flat mounts were stained with rhodamine-conjugated Griffonia simplicifolia lectin B4. Z-stacks of the entire CNV lesion obtained using laser confocal microscopy were converted to binary stacks using Fiji for volumetric analysis. Data from volumetric analysis and multiple area analyses from z-stack projection, the maximum, blindly selected, and mean area were compared using Fiji. Fiji-assisted automatic quantitative volumetric analysis of CNV was useful in detecting experimental outliers in laser-induced CNV genesis and provided accurate and precise measurements of total areas of CNV with a lower coefficient of variance (63%) than in multiple area analyses, including the z-stack projection, maximum, blindly selected, and mean areas (67%, 67%, 76%, and 69%, respectively). A lower coefficient of variance in volumetric analysis than in multiple area analyses resulted in increased statistical significance when comparing CNV lesions in PBS, and Aflibercept-treated groups; P = 0.004 in volumetric analysis versus P value range between 0.03 and 0.05 in multiple area analyses. Fiji-assisted automatic quantitative volumetric analysis can be useful for accurate, precise, and efficient measurements of total areas of CNV. Volumetric measurement for CNV lesions can be advantageous in verifying the efficacy of therapeutic agents in the laser-induced CNV mouse model.