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Background: Pathological retinal neovascularization is marked by microvascular lesions manifested initially as endothelial cell dysfunction and metabolic disturbances. However, the regulatory mechanism guiding retinal vascular endothelial cell function remian controversial. Main body: Previous studies have demonstarted that high glucose or oxidative stress can induce premature senescence in endothelial cells, triggering inflammatory responses within the vascular system and promoting the secretion of pro‐inflammatory factors, ultimately leading to pathological angiogenesis. Endothelial cell senescence has thus become a key target for anti‐angiogenic therapies. Conclusion: This review delves into current research on the mechanisms driving senescence‐induced retinal angiogenesis and highlights potential target protein pathways, aiming to provide insights for future investigations. [ABSTRACT FROM AUTHOR]

Copyright of Arquivos Brasileiros de Oftalmologia is the property of Arquivos Brasileiros de Oftalmologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Retinal neovascularization (RNV), a typical pathological manifestation involved in most neovascular diseases, causes retinal detachment, vision loss, and ultimately irreversible blindness. Repeated intravitreal injections of anti-VEGF drugs were developed against RNV, with limitations of incomplete responses and adverse effects. Therefore, a new treatment with a better curative effect and more prolonged dosage is demanding. Here, we induced macrophage polarization to anti-inflammatory M2 phenotype by inhibiting cGAS-STING signaling with an antagonist C176, appreciating the role of cGAS-STING signaling in the retina in pro-inflammatory M1 polarization. C176-loaded and phosphatidylserine-modified dendritic mesoporous silica nanoparticles were constructed and examined by a single intravitreal injection. The biosafe nanoparticles were phagocytosed by retinal macrophages through a phosphatidylserine-mediated “eat me” signal, which persistently release C176 to suppress STING signaling and thereby promote macrophage M2 polarization specifically. A single dosage can effectively alleviate pathological angiogenesis phenotypes in murine oxygen-induced retinopathy models. In conclusion, these C176-loaded nanoparticles with enhanced cell uptake and long-lasting STING inhibition effects might serve as a promising way for treating RNV.

AIM:To investigate the effects of overexpressing α-Klotho(KL)in RAW264.7 cells stimulated by oxidative stress on the proliferation, migration, tube-formation and tight junction of human umbilical vein endothelial cells(HUVECs).METHODS:RAW264.7 cells were categorized into control, 4-hydroxynonenal(4HNE), and 4HNE+KL groups, with F4/80 expression assessed via immunofluorescence staining. Three groups of conditional media were prepared for HUVECs and culture divided into Mø-NC, Mø-4HNE, and Mø-4HNE+KL groups. Cell proliferation was evaluated using CCK8 assay, while scratch test and Transwell assays were employed to measure cell migration. Additionally, tube-formation assay was conducted to assess cell tubule formation, and Western blot assay was utilized to detect the protein expression levels of Claudin 5, Occludin and ZO 1.RESULTS:The results of immunofluorescence staining showed that the fluorescence intensity of F4/80 of RAW264.7 cells in the 4HNE group was significantly enhanced compared with the control group, while that of F4/80 in the 4HNE+KL group was significantly decreased compared with the 4HNE group(all P

Background: Diabetes retinopathy (DR) is a complication of diabetes that affects patients' vision. Previous studies have found blueberry anthocyanins extract (BAE) can inhibit the progression of DR, but its mechanism is not completely clear. Methods: To study the role of BAE in diabetes retinopathy, we treated human retinal endothelial cells (HRCECs) with 30 mM high glucose to simulate the microenvironment of diabetes retinopathy and used BAE to intervene the in vitro high glucose-induced retinopathy model. HRCEC cell viability and apoptosis rates were examined by Cell Counting Kit 8 (CCK-8) assay and flow cytometry assay. The binding sites between miR-33 and glucocorticoid-induced transcript 1 (GLCCI1) were assessed by luciferase reporter assay. Retinal neovascularization and oxidative stress contribute to diabetic retinopathy. The tubule formation assay was applied to detect the retinal neovascularization. The oxidative stress in the HRCECs was manifested by the reactive oxygen species (ROS) level, the malondialdehyde (MDA) level, and the superoxide dismutase (SOD) activity. Results: Compared with HRCECs cells cultured under normal conditions, high glucose (HG) can induce oxidative stress in HRCRCs, specifically manifested in the increase of ROS and MDA levels, and the decrease of SOD activity. BAE relieved the tubule formation in n the HRCEC. BAE also relieved the ROS and MDA levels and increased the SOD activity. Luciferase reporter assay revealed that GLCCI1 is a target molecule downstream of miR-33. In HRCEC, BAE significantly inhibited the expression of miR-33 induced by HG. miR-33 mimic inhibited the BAE's effects on oxidative stress and angiogenesis in an in vitro high glucose-induced retinopathy model. Conclusion: BAE alleviated the oxidative stress and microangiogenesis of HRCEC by regulating the miR-33 /GLCCI1 axis. [ABSTRACT FROM AUTHOR]

Diabetic retinopathy has a high probability of causing visual impairment or blindness throughout the disease progression and is characterized by the growth of new blood vessels in the retina at an advanced, proliferative stage. Microglia are a resident immune population in the central nervous system, known to play a crucial role in regulating retinal angiogenesis in both physiological and pathological conditions, including diabetic retinopathy. Physiologically, they are located close to blood vessels and are essential for forming new blood vessels (neovascularization). In diabetic retinopathy, microglia become widely activated, showing a distinct polarization phenotype that leads to their accumulation around neovascular tufts. These activated microglia induce pathogenic angiogenesis through the secretion of various angiogenic factors and by regulating the status of endothelial cells. Interestingly, some subtypes of microglia simultaneously promote the regression of neovascularization tufts and normal angiogenesis in neovascularization lesions. Modulating the state of microglial activation to ameliorate neovascularization thus appears as a promising potential therapeutic approach for managing diabetic retinopathy. [ABSTRACT FROM AUTHOR]

Retinal neovascularization is a common feature of several ocular neovascular diseases, which are the leading cause of blindness in the world. Current treatments are administered through invasive intravitreal injections, leading to poor patient compliance, serious ocular complications and heavy economic burdens. Thus, an alternative less or non-invasive therapeutic strategy is in demand. Here, a non-invasive oral tyrosine kinase inhibitor, CM082, was evaluated in a retinal neovascularization model induced by hypoxia in zebrafish larvae. We found that CM082 effectively suppressed retinal neovascularization, rescued cell loss in the retinal ganglion cell layer, and rescued the visual function deficiency. Our results elucidated that CM082 mediated its therapeutic efficacy primarily through the inhibition of Vegfr2 phosphorylation. The findings demonstrated that CM082 possessed strong antiangiogenic effects and may serve as a potential treatment for angiogenesis in ocular neovascular diseases. [ABSTRACT FROM AUTHOR]

AbstractThe aim of this work was to identify the regulatory function of hsa_circ_0004776 in the progression of diabetic retinopathy (DR). The direct interactions between hsa_circ_0004776 and hsa-miR-382-5p and between hsa-miR-382-5p and BDNF, were confirmed via dual-luciferase reporter assays. Quantitative Real-Time PCR analysis indicated that hsa_circ_0004776 was highly expressed in aqueous humour samples of DR patients and human retinal microvascular epithelial cells (hRECs) under a high-glucose environment, whereas hsa-miR-382-5p showed the opposite trend. Overexpressed hsa_circ_0004776 significantly enhanced DNA synthesis, proliferation, migration, and tube formation in hRECs in hyperglycaemia, while hsa-miR-382-5p mimics reversed these changes. Additionally, in a streptozotocin-induced Sprague-Dawley rat model of DR, vitreous microinjection of rno-miR-382-5p agomir reversed the pathologic features in the progression of DR, including retinal vascular leakage, capillary decellularization, loss of pericytes, fibrosis, and gliosis. Our results indicated that under hyperglycaemic conditions, hsa_circ_0004776 influences the progression of DR via hsa-miR-382-5p and thus represents a potential therapeutic target. [ABSTRACT FROM AUTHOR]

Diabetic retinopathy (DR) is characterized by retinal vasculopathy and is a leading cause of visual impairment. Optical coherence tomography angiography (OCTA) is an innovative imaging technology that can detect various pathologies and quantifiable changes in retinal microvasculature. We briefly describe its functional principles and advantages over fluorescein angiography and perform a comprehensive review on its clinical applications in the screening or management of people with prediabetes, diabetes without clinical retinopathy (NDR), nonproliferative DR (NPDR), proliferative DR (PDR), and diabetic macular edema (DME). OCTA reveals early microvascular alterations in prediabetic and NDR eyes, which may coexist with sub-clinical neuroretinal dysfunction. Its applications in NPDR include measuring ischemia, detecting retinal neovascularization, and timing of early treatment through predicting the risk of retinopathy worsening or development of DME. In PDR, OCTA helps characterize the flow within neovascular complexes and evaluate their progression or regression in response to treatment. In eyes with DME, OCTA perfusion parameters may be of predictive value regarding the visual and anatomical gains associated with treatment. We further discussed the limitations of OCTA and the benefits of its incorporation into an updated DR severity scale. [ABSTRACT FROM AUTHOR]

We describe a case of vitreous haemorrhage and retinal neovascularization secondary to peripheral retinal ischemia associated with disseminated melanoma. A retrospective case report. A 48-year-old man presented with vitreous haemorrhage in the right eye, peripheral retinal ischemia, and retinal neovascularization in both eyes. CT and MRI scans were suggestive of disseminated malignancy and an ultrasound-guided biopsy of the abdominal mass confirmed metastatic melanoma. Immune checkpoint inhibitor therapy with ipilimumab/nivolumab was initiated. Regarding his ocular status, the vitreous haemorrhage cleared spontaneously, visual acuity improved to 6/7.5 and the patient underwent bilateral peripheral scatter laser photocoagulation to stabilize the retinopathy. The patient passed away 1 year after the initial presentation. Our patient presented with melanoma and peripheral retinal ischaemia, leading to retinal neovascularization and vitreous haemorrhage. Therefore, melanoma should be considered as a differential diagnosis when investigating the aetiology of peripheral retinal ischaemia. [ABSTRACT FROM AUTHOR]

Objective To investigate the impact of acacetin (Aca) on angiogenesis in diabetes retinopathy (DR) rats by regulating Hippo signaling pathway. Methods Sixty SD rats were grouped into the control group, the DR group, the Aca low dose group (10 mg/kg), the Aca medium dose group (20 mg/kg), the Aca high dose group (30 mg/kg) and Hippo-YAP signaling pathway inhibitor Verteporfin group (Aca high dose 30 mg/kg+Verteporfin 0.8 pmol/kg), with 10 rats in each group. Except the control group, streptozotocin and high-fat feed were used to construct the DR model. Body weight and fasting blood glucose (FBG) levels of rats were measured. Fluorescein angiography (FFA) was applied to observe retinal angiogenesis and fluorescein leakage. Enzyme linked immunosorbent assay was applied to detect serum levels of vascular endothelial growth factor (VEGF) and angiopoietin-2 (Ang-2). Pathological changes of retinal tissue were observed by hematoxylineosin staining. Western blot assay was applied to detect expression levels of VEGF, hypoxia-inducible factor 1 alpha (HIF1α), vascular cell adhesion molecule-1 (VCAM-1) and Hippo signaling pathway proteins. Results Compared with the control group, retinal cells of rats in the DR group were arranged in a disordered and loose manner, with neovascularization and a large amount of fluorescein leakage, and body weight, the expression of large tumor suppressor homolog 2 (LATS2), pYes-associated protein (YAP) were reduced. FBG and expression levels of VEGF, Ang-2, HIF-1α, VCAM-1, YAP, transcription activator with PDZ binding motif (TAZ), TEA domain family member 1 (TEAD1) were increased (P＜0.05). Compared with the DR group, retina cells of rats in the Aca low, medium and high-dose groups and the Verteporfin group were arranged neatly, with reduced neovascularization and fluorescence leakage, body weight and the expression levels of LATS2 and p-YAP were increased, and FBG, expression levels of VEGF, Ang-2, HIF-1α, VCAM-1, YAP, TAZ and TEAD1 were reduced (P＜0.05). The effect was more obvious in the Aca high dose group. However, there was no significant difference in each indicator between the Verteporfin group and the Aca high dose group. Conclusion Aca can inhibit angiogenesis and improve retinal pathological damage in DR rats, and its mechanism of action may be related to regulating the Hippo signaling pathway. [ABSTRACT FROM AUTHOR]

Vascular endothelial growth factors (VEGFs) are key mediator of retinal and choroidal neovascularization as well as retinal vascular leakage leading to macular edema. As such, VEGF plays an important role in mediating visually significant complications associated with common retinal disorders such as diabetic retinopathy, retinal vein occlusion, and age-related macular degeneration. Various drugs that inhibit vascular endothelial growth factors (anti-VEGF therapies) have been developed to minimize vision loss associated with these disorders. These drugs are injected into the vitreous cavity in a clinic setting at regular intervals. This article provides an overview of the various anti-VEGF drugs used in ophthalmology and the common retinal conditions that benefit from this therapy.

Abstract Background Pathological retinal neovascularization is marked by microvascular lesions manifested initially as endothelial cell dysfunction and metabolic disturbances. However, the regulatory mechanism guiding retinal vascular endothelial cell function remian controversial. Main body Previous studies have demonstarted that high glucose or oxidative stress can induce premature senescence in endothelial cells, triggering inflammatory responses within the vascular system and promoting the secretion of pro‐inflammatory factors, ultimately leading to pathological angiogenesis. Endothelial cell senescence has thus become a key target for anti‐angiogenic therapies. Conclusion This review delves into current research on the mechanisms driving senescence‐induced retinal angiogenesis and highlights potential target protein pathways, aiming to provide insights for future investigations.

Background: Ocular neovascular diseases, which contribute significantly to vision loss, lack effective preventive treatments. Recent studies have highlighted the significant involvement of immune cells in neovascular retinopathy. Myeloid-derived suppressor cells (MDSCs) promote the development of neovascularization, but it is unknown whether they participate in pathological neovascularization and whether they are expected to be a therapeutic target. Method: We investigated the role of MDSCs in promoting pathological angiogenesis using an oxygen-induced retinopathy (OIR) model, employing flow cytometry, immunofluorescence, and smart-seq analysis. Then, we evaluated the proportion of MDSCs in patient blood samples using flow cytometry. Additionally, we assessed the effect of MDSC depletion using an anti-Gr-1 monoclonal antibody on retinal vasculopathy and alterations in retinal microglia. Results: In the OIR model, an elevated ratio of MDSCs was observed in both blood and retinal tissue during phase II (Neovascularization). The depletion of MDSCs resulted in reduced retinal neovascularization and vaso-obliteration, along with a decrease in microglia within the neovascularization area. Furthermore, analysis of gene transcripts associated with MDSCs indicated activation of vascular endothelial growth factor (VEGF) regulation and inflammation. Importantly, infants with ROP exhibited a higher proportion of MDSCs in their blood samples. Conclusion: Our results suggested that excessive MDSCs represent an unrecognized feature of ocular neovascular diseases and be responsible for the retinal vascular inflammation and angiogenesis, providing opportunities for new therapeutic approaches to ocular neovascular disease.

Complications from diabetic retinopathy such as diabetic macular edema (DME) and proliferative diabetic retinopathy (PDR) constitute leading causes of preventable vision loss in working-age patients. Since vascular endothelial growth factor (VEGF) plays a major role in the pathogenesis of these complications, VEGF inhibitors have been the cornerstone of their treatment. Anti-VEGF monotherapy is an effective but burdensome treatment for DME. However, due to the intensive and burdensome treatment, most patients in routine clinical practice are undertreated, and therefore, their outcomes are compromised. Even in adequately treated patients, persistent DME is reported anywhere from 30% to 60% depending on the drug used. PDR is currently treated by anti-VEGF, panretinal photocoagulation (PRP) or a combination of both. Similarly, a number of eyes, despite these treatments, continue to progress to tractional retinal detachment and vitreous hemorrhage. Clearly there are other molecular pathways other than VEGF involved in the pathogenesis of DME and PDR. One of these pathways is the angiopoietin–Tie signaling pathway. Angiopoietin 1 (Ang1) plays a major role in maintaining vascular quiescence and stability. It acts as a molecular brake against vascular destabilization and inflammation that is usually promoted by angiopoietin 2 (Ang2). Several pathological conditions including chronic hyperglycemia lead to Ang2 upregulation. Recent regulatory approval of the bi-specific antibody, faricimab, may improve long term outcomes in DME. It targets both the Ang/Tie and VEGF pathways. The YOSEMITE and RHINE were multicenter, double-masked, randomized non-inferiority phase 3 clinical trials that compared faricimab to aflibercept in eyes with center-involved DME. At 12 months of follow-up, faricimab demonstrated non-inferior vision gains, improved anatomic outcomes and a potential for extended dosing when compared to aflibercept. The 2-year results of the YOSEMITE and RHINE trials demonstrated that the anatomic and functional results obtained at the 1 year follow-up were maintained. Short term outcomes of previously treated and treatment-naive eyes with DME that were treated with faricimab during routine clinical practice suggest a beneficial effect of faricimab over other agents. Targeting of Ang2 has been reported by several other means including VE-PTP inhibitors, integrin binding peptide and surrobodies. [ABSTRACT FROM AUTHOR]

Copyright of Arquivos Brasileiros de Oftalmologia is the property of Arquivos Brasileiros de Oftalmologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Retinal neovascularization (RNV) is primarily driven by vascular endothelial growth factor (VEGF). However, current anti-VEGF therapies are limited by short half-lives and repeated injections, which reduce patient quality of life and increase medical risks. Additionally, not all patients benefit from anti-VEGF monotherapy, and some problems, such as unsatisfactory vision recovery, persist after long-term treatment. In this study, we constructed a recombinant adeno-associated virus (AAV), AAV2-SPLTH, which encodes an anti-VEGF antibody similar to bevacizumab, and assessed its effects in a doxycycline-induced Tet-opsin-VEGFA mouse model of RNV. AAV2-SPLTH effectively inhibited retinal leakage, RNV progression, and photoreceptor apoptosis in a Tet-opsin-VEGF mouse model. However, proteomic sequencing showed that AAV2-SPLTH failed to rescue the expression of phototransduction-related genes, which corresponded to reduced photoreceptor cell numbers. This study suggests that anti-VEGF monotherapy can significantly inhibit RNV to some extent but may not be enough to save visual function in the long term.

Aim: To evaluate an intravitreally injected nanoparticle platform designed to deliver VEGF-A siRNA to inhibit retinal neovascular leakage as a new treatment for proliferative diabetic retinopathy and diabetic macular edema. Materials & methods: Fusogenic lipid-coated porous silicon nanoparticles loaded with VEGF-A siRNA, and pendant neovascular integrin-homing iRGD, were evaluated for efficacy by intravitreal injection in a rabbit model of retinal neovascularization. Results: For 12 weeks post-treatment, a reduction in vascular leakage was observed for treated diseased eyes versus control eyes (p = 0.0137), with a corresponding reduction in vitreous VEGF-A. Conclusion: Fusogenic lipid-coated porous silicon nanoparticles siRNA delivery provides persistent knockdown of VEGF-A and reduced leakage in a rabbit model of retinal neovascularization as a potential new intraocular therapeutic.

Small interfering RNA (siRNA) has a promising future in the treatment of ocular diseases due to its high efficiency, specificity, and low toxicity in inhibiting the expression of target genes and proteins. However, due to the unique anatomical structure of the eye and various barriers, delivering nucleic acids to the retina remains a significant challenge. In this study, we rationally design PACD, an A-B-C type non-viral vector copolymer composed of a hydrophilic PEG block (A), a siRNA binding block (B) and a pH-responsive block (C). PACDs can self-assemble into nanosized polymeric micelles that compact siRNAs into polyplexes through simple mixing. By evaluating its pH-responsive activity, gene silencing efficiency in retinal cells, intraocular distribution, and anti-angiogenesis therapy in a mouse model of hypoxia-induced angiogenesis, we demonstrate the efficiency and safety of PACD in delivering siRNA in the retina. We are surprised to discover that, the PACD/siRNA polyplexes exhibit remarkable intracellular endosomal escape efficiency, excellent gene silencing, and inhibit retinal angiogenesis. Our study provides design guidance for developing efficient nonviral ocular nucleic acid delivery systems.

Small interfering RNA (siRNA) has a promising future in the treatment of ocular diseases due to its high efficiency, specificity, and low toxicity in inhibiting the expression of target genes and proteins. However, due to the unique anatomical structure of the eye and various barriers, delivering nucleic acids to the retina remains a significant challenge. In this study, we rationally design PACD, an A-B-C type non-viral vector copolymer composed of a hydrophilic PEG block (A), a siRNA binding block (B) and a pH-responsive block (C). PACDs can self-assemble into nanosized polymeric micelles that compact siRNAs into polyplexes through simple mixing. By evaluating its pH-responsive activity, gene silencing efficiency in retinal cells, intraocular distribution, and anti-angiogenesis therapy in a mouse model of hypoxia-induced angiogenesis, we demonstrate the efficiency and safety of PACD in delivering siRNA in the retina. We are surprised to discover that, the PACD/siRNA polyplexes exhibit remarkable intracellular endosomal escape efficiency, excellent gene silencing, and inhibit retinal angiogenesis. Our study provides design guidance for developing efficient nonviral ocular nucleic acid delivery systems. A rationally designed pH-responsive polymer PACD boosts robust cytosolic siRNA release in retinal cells and significantly inhibits retinal angiogenesis, providing design guidance for developing efficient nonviral ocular nucleic acid delivery systems. [Display omitted] [ABSTRACT FROM AUTHOR]

Retinopathy of prematurity (ROP) is one of the most common causes of childhood blindness worldwide. Its prevalence is rising as more premature infants are surviving owing to advances in neonatal care. The current treatments for ROP are invasive and may increase the risk of future eye complications. Nutraceuticals (dietary oils, carotenoids, and vitamin supplements) are generally safe for use in children without detrimental adverse effects. Research has demonstrated nutraceuticals' anti-angiogenesis properties and their potential to protect against ROP. Dietary oils suppress inflammation and neovascularization in ROP models when administered intravenously. Carotenoids, such as lutein, promote retinal revascularization in mice. Vitamin A, C, and E supplements are unable to prevent ROP pathogenesis, despite well-documented antioxidative effects. The discrepancy between laboratory and clinical trial results may be due to differences in the dosage that can affect the eye, the outcome measurements used, and the presence of confounders in clinical trials. Future studies should investigate the short- and longterm effects of nutraceuticals on infants' vision. [ABSTRACT FROM AUTHOR]

Purpose: To report a case of peripapillary pachychoroid syndrome (PPS) complicated with peripapillary retinal neovascularization causing vitreous hemorrhage. Observation: A 42-year-old man, with a history of a visual loss of the right eye (RE) for 4 years, presented for ophthalmological examination. Best-corrected visual acuity was «counting fingers» in the RE and 20/25 in the left eye. Fundus examination showed irregular pattern of hypopigmentation of the retinal pigmented epithelium in both eyes with retinal neovessels in the peripapillary region of the RE. Swept-source optical coherence tomography demonstrated a central serous pigment epithelial detachment with intraretinal cysts and serous retinal detachment in the nasal macula extending from the temporal disc margin in the RE. Fluorescein angiography showed multiple areas of hyperfluorescence without clear distinction of retinal neovessels. Indocyanine green angiography showed patches of choroidal hyperpermeability predominant in the peripapillary region in both eyes. Optical coherence tomography angiography provided a good visualization of the papillary and retinal neovessels without signs of choroidal neovascularization. Two months after initial examination, the patient presented with vitreous hemorrhage associated to juxtapapillary preretinal hemorrhage in the RE. After vitreous injections of bevacizumab, we observed a total resolution of the vitreous hemorrhage a partial decrease of the intraretinal and subretinal fluid. Conclusions and importance: We report an unusual case of peripapillary retinal neovascularization and vitreous hemorrhage complicating a PPS. OCTA was useful to detect retinal neovessels and peripapillary retinal and choriocapillaris hypoperfusion, supporting the understanding of the pathogenic mechanism of neovascularization in PPS.

Purpose: To assess whether the combination of en face OCT and OCT angiography (OCTA) can capture observable, but subtle, structural changes that precede clinically evident retinal neovascularization (RNV) in eyes with diabetic retinopathy (DR). Design: Retrospective, longitudinal study. Participants: Patients with DR that had at least 2 visits. Methods: We obtained wide-field OCTA scans of 1 eye from each participant and generated en face OCT, en face OCTA, and cross-sectional OCTA. We identified eyes with RNV sprouts, defined as epiretinal hyperreflective materials on en face OCT with flow signals breaching the internal limiting membrane on the cross-sectional OCTA without recognizable RNV on en face OCTA and RNV fronds, defined as recognizable abnormal vascular structures on the en face OCTA. We examined the corresponding location from follow-up or previous visits for the presence or progression of the RNV. Main Outcome Measures: The characteristics and longitudinal observation of early signs of RNV. Results: From 71 eyes, we identified RNV in 20 eyes with the combination of OCT and OCTA, of which 13 (65%) were photographically graded as proliferative DR, 6 (30%) severe nonproliferative DR, and 1 (5%) moderate nonproliferative diabetic retinopathy. From these eyes, we identified 38 RNV sprouts and 26 RNV fronds at the baseline. Thirty-four RNVs (53%) originated from veins, 24 (38%) were from intraretinal microabnormalities, and 6 (9%) were from a nondilated capillary bed. At the final visit, 53 RNV sprouts and 30 RNV fronds were detected. Ten eyes (50%) showed progression, defined as having a new RNV lesion or the development of an RNV frond from an RNV sprout. Four (11%) RNV sprouts developed into RNV fronds with a mean interval of 7.0 months. Nineteen new RNV sprouts developed during the follow-up, whereas no new RNV frond was observed outside an identified RNV sprout. The eyes with progression were of younger age (P = 0.014) and tended to be treatment naive (P = 0.07) compared with eyes without progression. Conclusions: Longitudinal observation demonstrated that a combination of en face OCT and cross-sectional OCTA can identify an earlier form of RNV before it can be recognized on en face OCTA. Financial Disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

We report the findings observed in a young woman with ocular syphilis complicated with retinal and disc neovascularization successfully treated with intravitreal bevacizumab. Fluorescein angiography revealed in both eyes intense hyperfluorescence at the level of the disc, multifocal venous wall staining, multifocal paravenous leakage, multiple peripheral saccular venular dilations, diffuse retinal and macular edema, and retinal and disc neovascularization. There was no evidence of retinal ischemia in both eyes. After antibiotic and corticosteroid treatment, the neovascularization persisted in both eyes. Three consecutive doses of intravitreal bevacizumab were administered, with total regression of the retinal and disc neovascularization. Disc and retinal neovascularization along with nonocclusive retinal vasculitis may be a form of presentation of ocular syphilis. Combination of specific treatment, oral corticosteroids, and intravitreal bevacizumab may be useful for treating this clinical manifestation.

Abstract Background Retinal neovascularization (RNV) is a leading cause of blindness worldwide. Long non-coding RNA (lncRNA) and competing endogenous RNA (ceRNA) regulatory networks play vital roles in angiogenesis. The RNA-binding protein galectin-1 (Gal-1) participates in pathological RNV in oxygen-induced retinopathy mouse models. However, the molecular associations between Gal-1 and lncRNAs remain unclear. Herein, we aimed to explore the potential mechanism of action of Gal-1 as an RNA-binding protein. Results A comprehensive network of Gal-1, ceRNAs, and neovascularization-related genes was constructed based on transcriptome chip data and bioinformatics analysis of human retinal microvascular endothelial cells (HRMECs). We also conducted functional enrichment and pathway enrichment analyses. Fourteen lncRNAs, twenty-nine miRNAs, and eleven differentially expressed angiogenic genes were included in the Gal-1/ceRNA network. Additionally, the expression of six lncRNAs and eleven differentially expressed angiogenic genes were validated by qPCR in HRMECs with or without siLGALS1. Several hub genes, such as NRIR, ZFPM2-AS1, LINC0121, apelin, claudin-5, and C-X-C motif chemokine ligand 10, were found to potentially interact with Gal-1 via the ceRNA axis. Furthermore, Gal-1 may be involved in regulating biological processes related to chemotaxis, chemokine-mediated signaling, the immune response, and the inflammatory response. Conclusions The Gal-1/ceRNA axis identified in this study may play a vital role in RNV. This study provides a foundation for the continued exploration of therapeutic targets and biomarkers associated with RNV.

Retinal neovascularization (NV) may lead to irreversible vision impairment, the main treatment for which is the inhibition of vascular endothelial growth factor (VEGF). Existing drugs show limited clinical benefits because of their high prices and short half-lives, which increase the financial burden and medical risks to patients. Gene therapy on the basis of adeno-associated viruses is a promising approach to overcome these limitations because of the nonintegrative nature, low immunogenicity, and potential long-term gene expression of adeno-associated viruses. In this study, we constructed a novel recombinant adeno-associated virus with the single-chain fragment variable (scFv) fragment of the anti-VEGF antibody, AAV2-antiVEGFscFv, consisting of the VH and VL structural domains of IgG. AAV2-antiVEGFscFv effectively inhibited NV, retinal leakage, and retinal detachment in oxygen-induced retinopathy (OIR) mice, Tet/opsin/VEGF double-transgenic mice, and VEGF-induced rabbit NV models. AAV2-antiVEGFscFv also significantly suppressed VEGF-induced inflammation. Furthermore, we showed that AAV2-antiVEGFscFv could be sustainably expressed for a prolonged period and exhibited low immunotoxicity in vivo. This study indicates that AAV2-antiVEGFscFv could be a potential approach for NV treatment and provides strong support for preclinical research.

Purpose: To present two cases of concomitant retinal neovascularization (RNV) in acquired peripheral retinoschisis and analyze its characteristics on optical coherence tomography angiography and based on a literature review. Methods: This was an observational, retrospective case study. Results: Case 1 presented with bullous retinoschisis and RNV near the schisis cavity. Optical coherence tomography angiography revealed no angioflow into the retinal arterioles of the cavity. An arterial filling delay to the retinoschisis with extensive leakage from the RNV was noted on fluorescein angiography. Case 2 involved the superficial retinoschisis and telangiectatic vessels inside the schisis cavity. Optical coherence tomography angiography revealed damage to the superficial capillary plexus of the cavity, absence of angioflow to the inner schisis layer, and increased angioflow to the RNV. Fluorescein angiography showed focal leakage from the RNV and diffuse leakage from telangiectasia. No vision-threatening complications were identified in either patient up to the last followup, subsequent to laser photocoagulation. Conclusion: Acquired peripheral retinoschisis is associated with RNV. Inner retinal ischemia caused by hemodynamic resistance or a damaged superficial capillary plexus can interrupt angioflow to the inner schisis retinal layer on optical coherence tomography angiographic findings and develop RNV inside or outside the retinoschisis. [ABSTRACT FROM AUTHOR]

Hypoxia-induced retinal neovascularization is a leading cause of blindness worldwide. Oxygen-induced retinopathy (OIR) mouse, a well-established angiogenesis model, has been extensively used to evaluate the effect of anti-angiogenic agents through intravitreal injection. Here, we serendipitously found that the needles used for intravitreal injection caused an unexpected "anti-angiogenic" effect in the OIR mice. To evaluate the effects of various intravitreal puncture sizes on retinal neovascularization and explore the potential underlying mechanism, intravitreal punctures using 0.5 mm (25 G), 0.3 mm (30 G), or 0.21 mm (33 G) needles were performed in OIR mice. Compared with 0.3 mm and 0.21 mm puncture, the 0.5 mm puncture remarkably suppressed the formation of pathological angiogenesis, inhibited vascular leakage, and remodeled the retinal vasculature. Mechanistically, the 0.5 mm puncture induced a substantial reduction in intraocular pressure (IOP), leading to an improvement in oxygen partial pressure (pO2) and significant reduction in Hif1a expression, resulting in resolution of angiogenic and inflammatory responses. Furthermore, IOP-lowering drugs, Travatan or Azarga, also promoted the alleviation of hypoxia and exhibited a potent anti-angiogenesis efficacy. Our study revealed an acute and significant reduction in IOP caused by a large puncture, which could remarkably suppress HIF-1α-mediated retinal neovascularization, indicating that lowering IOP may be a promising therapeutic avenue for treating retinal neovascular diseases. [ABSTRACT FROM AUTHOR]

We report a case of successful management of intravitreal injections of anti-vascular endothelial growth factor antibody bevacizumab in two unusual complications, preretinal neovascularization and vitreous hemorrhage, secondary to a combined hamartoma of the retina and retinal pigment epithelium (CHRRPE). A male pediatric patient suffered from decreased vision in the right eye at 5-year-old. His ophthalmologic examination revealed a CHRRPE involving the superior area of the optic disc and macula in the right eye. The patient's family history and neurological examinations of tuberous sclerosis were absent. While no lesion growth was observed over time, preretinal vascularization and recurrent nonclearing hemorrhage occurred 2 years after the initial presentation. The patient was successfully managed with two intravitreal injections of bevacizumab. No recurrences of vitreous hemorrhage were observed at a 7-year post-treatment follow-up. Intravitreal injections of bevacizumab were safe and effective in the management of uncommon complications of preretinal neovascularization and vitreous hemorrhage of CHRRPE in a pediatric patient in long-term follow-up. [ABSTRACT FROM AUTHOR]

To investigate the mechanism of sodium tanshinone IIA sulfonate inhibiting hypoxia induced retinal neovascularization in rats. Forty 7 d old clean grade C57BL/6J male neonatal rats were randomly divided into control group, model group, low-dose group and high-dose group. The control group was kept in normal air for 10 d. Oxygen-induced retinopathy was studied in the model group, low-dose group, and high-dose group 30 mg/kg sodium tanshinone IIA sulfonate. The body weight of mice in all groups was measured on the 12th and 17th d after birth, and the area without perfusion around the optic disc was observed and calculated. The number of neovascular endothelial cells was calculated using hematoxylin and eosin staining. The expression of vascular endothelial growth factor, vascular endothelial growth factor-2 and hypoxia-inducible factor-1 were detected by Western blot. The no perfusion area around the optic disc in the model group was raised than that in the control group, and the no perfusion area around the optic disc in the low-dose group, and high-dose group was reduced than that in the model group (p<0.01). In the model group, the inner limiting membrane of retina was proliferated and disordered, and the surface was not smooth; in low-dose group, smooth limiting membrane of the retina, and a small number of endothelial cells could be seen breaking through the limiting membrane; in the high-dose group, the limiting membrane of retina was relatively complete and smooth, and the tissue structure of each layer could be seen. The number of neovascular endothelial cells in the model group was raised than that in the control group, and the number of neovascular endothelial cells in the lowdose group, and high-dose group was reduced than that in the model group, as the dose increased, it decreased (p<0.01). Vascular endothelial growth factor, vascular endothelial growth factor-2 and hypoxia-inducible factor-1 in low-dose group, and high-dose group were raised than those in control group, and those proteins expression level of in model group was reduced than control group, as the dose increased, it decreased (p<0.05). Sodium tanshinone IIA sulfonate can inhibit hypoxia induced retinal neovascularization in a dose-dependent manner, and its mechanism may be related to the regulation of vascular endothelial growth factor pathway related proteins by sodium tanshinone IIA sulfonate. [ABSTRACT FROM AUTHOR]

Introduction: Murine models provide microvascular insights into the 3-D network disarray seen in retinopathy and cardiovascular diseases. Light-sheet fluorescence microscopy (LSFM) has emerged to capture retinal vasculature in 3-D, allowing for assessment of the progression of retinopathy and the potential to screen new therapeutic targets in mice. We hereby coupled LSFM, also known as selective plane illumination microscopy, with topological quantification, to characterize the retinal vascular plexuses undergoing preferential obliteration. Method and Result: In postnatal mice, we revealed the 3-D retinal microvascular network in which the vertical sprouts bridge the primary (inner) and secondary (outer) plexuses, whereas, in an oxygen-induced retinopathy (OIR) mouse model, we demonstrated preferential obliteration of the secondary plexus and bridging vessels with a relatively unscathed primary plexus. Using clustering coefficients and Euler numbers, we computed the local versus global vascular connectivity. While local connectivity was preserved (p > 0.05, n = 5 vs. normoxia), the global vascular connectivity in hyperoxia-exposed retinas was significantly reduced (p < 0.05, n = 5 vs. normoxia). Applying principal component analysis (PCA) for auto-segmentation of the vertical sprouts, we corroborated the obliteration of the vertical sprouts bridging the secondary plexuses, as evidenced by impaired vascular branching and connectivity, and reduction in vessel volumes and lengths (p < 0.05, n = 5 vs. normoxia). Conclusion: Coupling 3-D LSFM with topological quantification uncovered the retinal vasculature undergoing hyperoxia-induced obliteration from the secondary (outer) plexus to the vertical sprouts. The use of clustering coefficients, Euler's number, and PCA provided new network insights into OIR-associated vascular obliteration, with translational significance for investigating therapeutic interventions to prevent visual impairment.

Retinopathy of prematurity (ROP) is a vasoproliferative retinal disease affecting premature infants. In addition to prematurity itself and oxygen treatment, genetic factors have been suggested to predispose to ROP. We aimed to identify potentially pathogenic genes and biological pathways associated with ROP by analyzing variants from whole exome sequencing (WES) data of premature infants. As part of a multicenter ROP cohort study, 100 non-Hispanic Caucasian preterm infants enriched in phenotypic extremes were subjected to WES. Gene-based testing was done on coding nonsynonymous variants. Genes showing enrichment of qualifying variants in severe ROP compared to mild or no ROP from gene-based tests with adjustment for gestational age and birth weight were selected for gene set enrichment analysis (GSEA). Mean BW of included infants with pre-plus, type-1 or type 2 ROP including aggressive posterior ROP (n = 58) and mild or no ROP (n = 42) were 744 g and 995 g, respectively. No single genes reached genome-wide significance that could account for a severe phenotype. GSEA identified two significantly associated pathways (smooth endoplasmic reticulum and vitamin C metabolism) after correction for multiple tests. WES of premature infants revealed potential pathways that may be important in the pathogenesis of ROP and in further genetic studies.

Objective: The aim of the study was to evaluate the effect of the RhoA/ROCK inhibitor Fasudil on retinal neovascularization (NV) in vivo and angiogenesis in vitro. Methods: C57BL/6 was used to establish an OIR model. First, RhoA/ROCK expression was first examined and compared between OIR and healthy controls. Then, we evaluated the effect of Fasudil on pathological retinal NV. Whole-mount retinal staining was performed. The percentage of NV area, the number of neovascular tufts (NVT), and branch points (BP) were quantified. Finally, human umbilical vein endothelial cells (HUVECs) were used to investigate the effect of Fasudil on angiogenesis. Results: Real-time PCR and Western blotting showed that ROCK expression in retinal tissue was statistically upregulated in OIR. Furthermore, we found that Fasudil attenuated the percentage of NV area, the number of NVT, and BP significantly. In addition, Fasudil could suppress the proliferation and migration of HUVECs induced by VEGF. Conclusions: RhoA/ROCK might be involved in the pathogenesis of OIR. And its inhibitor Fasudil could suppress retinal NV in vivo and angiogenesis in vitro. Fasudil may be a potential treatment strategy for retinal vascular diseases. [ABSTRACT FROM AUTHOR]

Background: Retinal neovascularization (RNV) is a leading cause of blindness worldwide. Long non-coding RNA (lncRNA) and competing endogenous RNA (ceRNA) regulatory networks play vital roles in angiogenesis. The RNA-binding protein galectin-1 (Gal-1) participates in pathological RNV in oxygen-induced retinopathy mouse models. However, the molecular associations between Gal-1 and lncRNAs remain unclear. Herein, we aimed to explore the potential mechanism of action of Gal-1 as an RNA-binding protein. Results: A comprehensive network of Gal-1, ceRNAs, and neovascularization-related genes was constructed based on transcriptome chip data and bioinformatics analysis of human retinal microvascular endothelial cells (HRMECs). We also conducted functional enrichment and pathway enrichment analyses. Fourteen lncRNAs, twenty-nine miRNAs, and eleven differentially expressed angiogenic genes were included in the Gal-1/ceRNA network. Additionally, the expression of six lncRNAs and eleven differentially expressed angiogenic genes were validated by qPCR in HRMECs with or without siLGALS1. Several hub genes, such as NRIR, ZFPM2-AS1, LINC0121, apelin, claudin-5, and C-X-C motif chemokine ligand 10, were found to potentially interact with Gal-1 via the ceRNA axis. Furthermore, Gal-1 may be involved in regulating biological processes related to chemotaxis, chemokine-mediated signaling, the immune response, and the inflammatory response. Conclusions: The Gal-1/ceRNA axis identified in this study may play a vital role in RNV. This study provides a foundation for the continued exploration of therapeutic targets and biomarkers associated with RNV. [ABSTRACT FROM AUTHOR]

PurposeRetinopathy of prematurity (ROP) is a leading cause of childhood blindness. ROP occurs as a consequence of postnatal hyperoxia exposure in premature infants, resulting in vasoproliferation in the retina. The tetraspan protein epithelial membrane protein-2 (EMP2) is highly expressed in the retinal pigment epithelium (RPE) in adults, and it controls vascular endothelial growth factor (VEGF) production in the ARPE-19 cell line. We, therefore, hypothesized that Emp2 knockout (Emp2 KO) protects against neovascularization in murine oxygen-induced retinopathy (OIR).MethodsEyes were obtained from wildtype (WT) and Emp2 KO mouse pups at P7, P12, P17, and P21 after normoxia or hyperoxia (P7-P12) exposure. Following hyperoxia exposure, RNA sequencing was performed using the retina/choroid layers obtained from WT and Emp2 KO at P17. Retinal sections from P7, P12, P17, and P21 were evaluated for Emp2, hypoxia-inducible factor 1α (Hif1α), and VEGF expression. Whole mount images were generated to assess vaso-obliteration at P12 and neovascularization at P17.ResultsEmp2 KO OIR mice demonstrated a decrease in pathologic neovascularization at P17 compared with WT OIR mice through evaluation of retinal vascular whole mount images. This protection was accompanied by a decrease in Hif1α at P12 and VEGFA expression at P17 in Emp2 KO animals compared with the WT animals in OIR conditions. Collectively, our results suggest that EMP2 enhances the effects of neovascularization through modulation of angiogenic signaling.ConclusionsThe protection of Emp2 KO mice against pathologic neovascularization through attenuation of HIF and VEGF upregulation in OIR suggests that hypoxia-induced upregulation of EMP2 expression in the neuroretina modulates HIF-mediated neuroretinal VEGF expression.

The tightly structured neural retina has a unique vascular network comprised of three interconnected plexuses in the inner retina (and choroid for outer retina), which provide oxygen and nutrients to neurons to maintain normal function. Clinical and experimental evidence suggests that neuronal metabolic needs control both normal retinal vascular development and pathological aberrant vascular growth. Particularly, photoreceptors, with the highest density of mitochondria in the body, regulate retinal vascular development by modulating angiogenic and inflammatory factors. Photoreceptor metabolic dysfunction, oxidative stress, and inflammation may cause adaptive but ultimately pathological retinal vascular responses, leading to blindness. Here we focus on the factors involved in neurovascular interactions, which are potential therapeutic targets to decrease energy demand and/or to increase energy production for neovascular retinal disorders.

Among genome engineering tools, Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-based approaches have been widely adopted for translational studies due to their robustness, precision, and ease of use. When delivered to diseased tissues with a viral vector such as adeno-associated virus, direct genome editing can be efficiently achieved in vivo to treat different ophthalmic conditions. While CRISPR has been actively explored as a strategy for treating inherited retinal diseases, with the first human trial recently initiated, its applications for complex, multifactorial conditions such as ocular angiogenesis has been relatively limited. Currently, neovascular retinal diseases such as retinopathy of prematurity, proliferative diabetic retinopathy, and neovascular age-related macular degeneration, which together constitute the majority of blindness in developed countries, are managed with frequent and costly injections of anti-vascular endothelial growth factor (anti-VEGF) agents that are short-lived and burdensome for patients. By contrast, CRISPR technology has the potential to suppress angiogenesis permanently, with the added benefit of targeting intracellular signals or regulatory elements, cell-specific delivery, and multiplexing to disrupt different pro-angiogenic factors simultaneously. However, the prospect of permanently suppressing physiologic pathways, the unpredictability of gene editing efficacy, and concerns for off-target effects have limited enthusiasm for these approaches. Here, we review the evolution of gene therapy and advances in adapting CRISPR platforms to suppress retinal angiogenesis. We discuss different Cas9 orthologs, delivery strategies, and different genomic targets including VEGF, VEGF receptor, and HIF-1α, as well as the advantages and disadvantages of genome editing vs. conventional gene therapies for multifactorial disease processes as compared to inherited monogenic retinal disorders. Lastly, we describe barriers that must be overcome to enable effective adoption of CRISPR-based strategies for the management of ocular angiogenesis.

We report a case of successful management of intravitreal injections of anti-vascular endothelial growth factor antibody bevacizumab in two unusual complications, preretinal neovascularization and vitreous hemorrhage, secondary to a combined hamartoma of the retina and retinal pigment epithelium (CHRRPE). A male pediatric patient suffered from decreased vision in the right eye at 5-year-old. His ophthalmologic examination revealed a CHRRPE involving the superior area of the optic disc and macula in the right eye. The patient's family history and neurological examinations of tuberous sclerosis were absent. While no lesion growth was observed over time, preretinal vascularization and recurrent nonclearing hemorrhage occurred 2 years after the initial presentation. The patient was successfully managed with two intravitreal injections of bevacizumab. No recurrences of vitreous hemorrhage were observed at a 7-year post-treatment follow-up. Intravitreal injections of bevacizumab were safe and effective in the management of uncommon complications of preretinal neovascularization and vitreous hemorrhage of CHRRPE in a pediatric patient in long-term follow-up.

AIM: To investigate the anti-angiogenic effect of apolipoprotein A1 (apoA1) on primary human retinal vascular endothelial cells (HRECs) and explore the possible mechanism. METHODS: The primary HRECs were transfected with apoA1-GFP recombinant lentiviral and were compared with cells undergoing transfection with empty lentiviral vectors. Hypoxia chambers were used to simulate the anoxic environment of cells under pathological condition. The concentrations of secreted vascular endothelial growth factor (VEGF) and placental growth factor (PlGF) were measured by enzyme-linked immunosorbent assay (ELISA). Cell migration ability was detected by wound healing assay. The sprouting of HRECs was determined by tube formation assay. The protein levels of extracellular signal regulated kinase 1/2 (ERK1/2) and phosphorylated ERK1/2 (p-ERK1/2) were measured by Western blot. RESULTS: Overexpressed apoA1 in hypoxia-induced HRECs significantly suppressed PlGF (0.67±0.10 folds, P=0.007). Overexpressed apoA1 also attenuated hypoxia-induced cell migration (0.32±0.11 folds, P