Search Results (140)

Background/Objectives: The utility of optical coherence tomography angiography (OCTA) for neovascular age-related macular degeneration (nAMD) remains unclear. The current study investigated the choroidal neovascularization (CNV) detection rate by OCTA in comparison with standard fluorescein angiography (FA) and spectral-domain optical coherence tomography (SD-OCT). Methods: Subjects underwent multimodal imaging, including FA, SD-OCT, and OCTA imaging, which were compared. In patients with unilateral nAMD, the contralateral eye with dry AMD (n = 39) was included to determine imaging modality sensitivity and specificity. Eyes with inaccurate automated segmentation from retinal distortion were manually resegmented. Results: The diagnostic performance for nAMD was 86% sensitivity and 100% specificity by OCT (AUC: 0.93; 95% CI 0.87–0.99; p < 0.001); 82% sensitivity and 100% specificity by FA (AUC: 0.91; 95% CI 0.84–0.98; p < 0.001); and 68% sensitivity and 100% specificity by automatically segmented OCTA (AUC: 0.84; 95% CI 0.76–0.93; p < 0.001). OCTA diagnostic accuracy improved following manual resegmentation to 88% sensitivity and 100% specificity (AUC: 0.94; 95% CI 0.89–1.0; p < 0.001). Diagnostic accuracy of OCT combined with manually resegmented OCTA (AUC: 1.0; 95% CI 1.0–1.0; p < 0.001) was greater than that of OCT or FA combined (AUC: 0.96; 95% CI 0.92–1.0; p < 0.001) but both were very accurate. Conclusions: Manual segmentation of the OCTA images can help identify CNV in eyes otherwise undetected by automated segmentation algorithms due to errors in segmentation of retinal layers. Eyes with substantial elevation in one or more layers of the retina were most likely to benefit from resegmentation. Full article

Current treatments for choroidal neovascularization (CNV) and its associated subretinal fibrosis (SRF), major causes of vision loss, are limited by the need for frequent intravitreal injections and the emergence of drug resistance. This study evaluated the safety and efficacy of the intravitreal administration of engineered humanized anti-vascular endothelial growth factor Nanobodies, including a wild-type Nanobody (WHNb) and two mutated variants (MHNb136 and MHNb256), in a rat model of laser-induced CNV and associated SRF. Safety was assessed through in vivo electrophysiological and histopathological analyses following intravitreal injection of Nanobodies at doses of 12.5, 25, 50, and 100 µg. Efficacy was evaluated in rat models of laser-induced CNV and SRF using double immunohistochemistry for isolectin B4 and anti-collagen type I on sclerochoroidal flat mounts. Mean CNV and SRF areas in Nanobody-treated groups were compared with those in bevacizumab-treated and sham control groups. None of the Nanobodies showed retinal toxicity in safety assessments. Compared with bevacizumab, MHNb136 and MHNb256 reduced the CNV area by 1.72-fold and 1.8-fold, respectively (both p < 0.0001), whereas WHNb showed an effect nearly identical to that of bevacizumab. In addition, 12.5 µg MHNb136 and 100 µg MHNb256 reduced the SRF area by 1.3-fold (p = 0.047) and 1.6-fold (p = 0.0007), respectively, relative to bevacizumab. For CNV reduction, 12.5 µg MHNb136 was comparable to 25 µg MHNb256; both outperformed bevacizumab. For SRF reduction, 12.5 µg MHNb136 was more effective than bevacizumab and comparable to 100 µg MHNb256. These findings suggest that 12.5 µg MHNb136 may represent a cost-effective bioengineered Nanobody candidate for future clinical studies. Full article

Background: Retinal vascular diseases, including neovascular age-related macular degeneration (nAMD), diabetic macular edema (DME), retinal vein occlusion (RVO), and myopic choroidal neovascularization (mCNV), often require repeated intravitreal anti-vascular endothelial growth factor (anti-VEGF) therapy. Although ranibizumab is well established, long-term affordability remains challenging. Objective: To compare the functional, anatomical, treatment-burden, and safety outcomes of biosimilar ranibizumab (Ranieyes) and innovator ranibizumab (Lucentis/Accentrix) in routine clinical practice. Methods: This multicenter retrospective comparative study included 4997 eyes from 3577 patients treated across five tertiary eye-care centers in India. The biosimilar group comprised 2543 eyes from 1812 patients (10,893 injections), and the innovator group comprised 2454 eyes from 1765 patients (10,136 injections). Eligible indications were nAMD, DME, BRVO, CRVO, mCNV, and an exploratory miscellaneous preoperative adjunct subgroup. BCVA (logMAR), central subfield thickness (CST; µm), injection burden, and ocular/systemic adverse events were assessed over 24 months. Results: Both groups showed early improvement in BCVA and CST across the major disease categories, followed by long-term stabilization. Between-group differences were generally small, not sustained over follow-up, and of limited clinical magnitude. Serious ocular and systemic adverse events were rare in both groups, and no new safety signal emerged. Conclusions: In this large real-world cohort, the biosimilar ranibizumab Ranieyes showed outcomes broadly comparable to innovator ranibizumab across the major retinal disease subgroups, although these findings should be interpreted as observational comparative evidence rather than formal proof of equivalence. Full article

Background and Objectives: Myopic choroidal neovascularization (mCNV) is a vision-threatening complication of pathologic myopia. While anti-VEGF monotherapy is the current standard of care, recurrence and suboptimal responses remain challenges. Faricimab is a novel bispecific antibody that targets both vascular endothelial growth factor (VEGF) and angiopoietin-2 (Ang-2) to improve vascular stability. This study aims to evaluate the short-term efficacy and safety of a single intravitreal faricimab injection in eyes with active mCNV. Materials and Methods: This retrospective, single-center study included 27 eyes from 24 patients with active mCNV, including both treatment-naïve and previously treated cases. All eyes received a single intravitreal injection of faricimab (6.0 mg/0.05 mL). Best-corrected visual acuity (BCVA) in logMAR and central retinal thickness (CRT) via spectral-domain optical coherence tomography were assessed at baseline and one month post injection. Statistical significance was determined using paired and independent t-tests (p < 0.05). Results: The study population (mean age 55.5 ± 13.9 years; mean axial length 29.3 ± 1.6 mm) showed significant improvements at one month. Mean BCVA improved from 0.77 ± 0.71 logMAR to 0.51 ± 0.52 logMAR (p < 0.005). Mean CRT decreased from 290.2 ± 66.0 μm to 242.5 ± 45.7 μm (p < 0.005). No ocular adverse events, such as intraocular inflammation, retinal detachment, or endophthalmitis, were observed. Conclusions: A single intravitreal injection of faricimab provides significant short-term functional and anatomical improvement in this small retrospective series. Dual inhibition of VEGF-A and Ang-2 appears to be a safe and effective approach for stabilizing retinal vasculature in patients with high myopia. Larger, long-term prospective studies are needed to determine optimal treatment intervals for mCNV. Full article

Background: Multiple evanescent white dot syndrome (MEWDS) is usually acute and self-limited, whereas multifocal choroiditis (MFC)/punctate inner choroidopathy (PIC) is relapsing; overlap can obscure early diagnosis and requires longitudinal multimodal imaging. Methods: We report a 4-year follow-up of a 31-year-old woman with fundus autofluorescence (FAF), fluorescein angiography (FA), indocyanine green angiography (ICGA), and spectral-domain optical coherence tomography (SD-OCT), plus a systemic/neurologic/rheumatologic work-up. Treatment included intravenous methylprednisolone for presumed optic neuritis, followed by topical, periocular, intravitreal, and systemic corticosteroids, later escalated to adalimumab and an intravitreal dexamethasone implant. Because foveal granularity could not be documented, baseline was termed “MEWDS-like”. Diagnostic labelling was benchmarked against Standardization of Uveitis Nomenclature (SUN) criteria, and choroidal neovascularization (CNV) was assessed at each relapse by OCT and FA. Results: The right eye initially showed a MEWDS-like pattern with wreath-like FA lesions and disc leakage, hyperautofluorescent FAF lesions, focal ellipsoid zone disruption on SD-OCT, and multifocal ICGA hypofluorescent spots. A relapse at 6 months with peripapillary inflammatory foci and recurrent cystoid macular edema supported reclassification to a unilateral MFC/PIC-spectrum phenotype. At 2 years, the fellow eye developed mild vitritis, peripapillary hyperautofluorescence, peripapillary/arcade leakage on FA, delayed peripapillary filling on ICGA, and cystoid macular edema, establishing sequential bilateral MFC; no CNV developed and anti-vascular endothelial growth factor (anti-VEGF) therapy was not required. Complications included steroid-induced ocular hypertension and cataract surgery. Conclusions: The purpose of this report is to highlight longitudinal imaging “red flags” that supported reclassification from a MEWDS-like phenotype to a sequential bilateral MFC/PIC-spectrum disease. Full article

β-thalassemia patients often experience ocular abnormalities such as angioid streaks (ASs), retinal pigmented epithelium degradation, visual field defects, and in rare instances choroidal neovascularization (CNV). Although ASs are common in individuals with hemoglobinopathies, the occurrence of choroidal neovascularization without preceding ASs is exceptionally rare. In this report, we describe a β-thalassemia patient who had developed CNV at the age of 27 years and also had experience of renal stones at the age of 19 years. He had undergone splenectomy and was under conservative therapy of iron supplementation. We conducted whole-exome sequencing (WES) in search of CNV-associated variants. Through variant filtering and Phenolyzer analysis, we have identified a rare heterozygous missense variant in the ABCC6 gene, ABCC6:NM_001171:exon25:c.3524T>C (rs376062004). In silico analysis revealed that this variant is present in the highly conserved region and is likely to decrease the stability of the protein. Mutation in the ABCC6 gene leads to pseudoxanthoma elasticum (PXE). Previously, it was believed that ASs and subsequent CNV-like ocular complication may develop due to the pathophysiological condition of thalassemia. However, our study provides compelling evidence that rare mutations in the ABCC6 gene, in combination with oxygen insufficiency, may contribute to the development of CNV in β-thalassemia patients. This finding highlights the potential genetic basis of PXE-mediated CNV development in β-thalassemia. Full article

Aging reduces the tissue regenerative capacity, promotes chronic inflammation, and contributes to neurodegenerative diseases, including age-related macular degeneration (AMD). AMD is a leading cause of vision loss in older adults and manifests as dry (atrophic) or wet (neovascular) disease. Although dry AMD is more prevalent, neovascular AMD (nAMD) causes the most severe vision impairment and remains a major public health burden. Oxidative stress-mediated inflammation and dysfunction of retinal pigment epithelium (RPE) cells and choriocapillaris drive early AMD. Neovascular AMD is marked by pathologic choroidal neovascularization (CNV), driven largely by dysregulated VEGF signaling. Anti-VEGF therapies are the current standard of care for nAMD but require frequent intravitreal injections, carry procedure-related risks, and are ineffective in a substantial subset of patients, underscoring the need for new therapeutic approaches. Caffeine, a widely consumed and well-tolerated adenosine receptor antagonist, has emerging relevance in vascular regulation and inflammatory signaling. Extracellular ATP and its metabolites, including adenosine, accumulate under stress and act through purinergic receptors to influence angioinflammatory processes. We recently showed that systemic caffeine administration suppressed CNV in vivo, an effect partly reproduced by the adenosine receptor A_2A antagonist Istradefylline. Here, we investigated the cell-autonomous effects of caffeine on mouse choroidal endothelial cells, focusing on its role as an adenosine receptor antagonist and its potential to inhibit pathological neovascularization. Full article

Background/Objectives: Neovascular age-related macular degeneration (nAMD) poses a serious threat to the eyesight of older adults, representing a leading cause of irreversible vision loss. Anti-vascular endothelial growth factor (anti-VEGF) treatments are effective but require repeated intraocular injections and show poor responses in some patients. CGK012 is a novel derivative of decursin that inhibits the Wnt/β-catenin pathway. This study aimed to elucidate the mode of action of CGK012 and examine its therapeutic effects. Methods: We performed in vitro cellular studies in a retinal pigment epithelial (RPE) cell line (ARPE-19) and human umbilical vein endothelial cells (HUVECs). We examined the in vivo efficacy of CGK012-loaded implants in laser-induced choroidal neovascularization (CNV) rabbit models. We also determined the implants’ in vitro dissolution, intraocular release, and disposition characteristics. Results: CGK012 decreased angiogenic/proinflammatory factor expression and suppressed the epithelial–mesenchymal transition (EMT) in RPE cells by promoting intracellular β-catenin degradation. Additionally, it repressed the expression of cyclin D1 and c-myc, downstream target genes of β-catenin, and inhibited HUVEC capillary tube formation. CGK012-loaded poly (lactic-co-glycolic acid) (PLGA) intravitreal implants significantly reduced vascular leakage in a laser-induced CNV rabbit model. Notably, CGK012 released from the implant was highly permeable to retina/choroid tissue and downregulated β-catenin, angiogenic/inflammatory factors, and vimentin in the rabbit model. The CGK012 concentration reached a plateau at 28–42 days in the vitreous humor and decayed with a half-life of 14 days without systemic exposure. Conclusions: Our findings demonstrate that CGK012 implants prevent choroidal neovascularization through the Wnt/β-catenin pathway suppression and produce high concentrations of CGK012 in the posterior eye segment with prolonged release. Thus, these implants provide more therapeutic choices for nAMD treatment. Full article

To address the shortcomings of existing anti-VEGF monotherapy in neovascular age-related macular degeneration (nAMD), we investigated the therapeutic capabilities of exosomes obtained from human induced pluripotent stem cell (hiPSC)-derived retinal organoids in a mouse model of laser-induced choroidal neovascularization (CNV). To evaluate Retinal Organoid-derived exosome (RO-Exo) distribution after intravitreal (IVT) injection, calcein-labeled RO-Exo was observed using confocal microscopy. CNV was induced in C57BL/6 J mice by laser photocoagulation. RO-Exo was isolated from retinal organoids (differentiation days 55–65) and injected 5 days post-laser. Therapeutic efficacy was evaluated on day 12. Vascular leakage and CNV size were assessed by angiography and CD31 immunostaining. We also examined HIF-1α/VEGF-A expression (Western blotting), Retinal Pigment Epithelium (RPE) integrity markers (immunofluorescence staining for α-SMA, fibronectin, and ZO-1), and the activation of the Mitogen-Activated Protein Kinase (MAPK) pathway (phospho-ERK, -p38, -JNK) in CNV lesions. After IVT injection, RO-Exo migrated to the RPE layer, showing high retinotropic distribution. In the CNV model, RO-Exo significantly reduced vascular leakage and CNV size, with greater suppression of HIF-1α and VEGFA expression than aflibercept, the standard-of-care anti-VEGF drug. CD31-positive vasculature was decreased, accompanied by downregulation of fibronectin (a fibrotic marker) and restoration of RPE hexagonality and integrity. Furthermore, RO-Exo inhibited the activation of ERK, P38, and JNK in CNV lesions. Our study results demonstrate that RO-Exo exhibits multi-target therapeutic effects—including anti-angiogenic, anti-fibrotic, and neuroprotective actions—offering a promising alternative to conventional anti-VEGF therapy for nAMD. Full article

Purpose: This study aims to develop a method for detecting referable (intermediate and advanced) age-related macular degeneration (AMD) and neovascular AMD, as well as providing an automatic segmentation of choroidal neovascularisation (CNV) on colour fundus retinal images. We also demonstrated that brain health risk scores estimated by AI-based Retinal Image Analysis (ARIA), such as white matter hyperintensities and depression, are significantly associated with AMD and neovascular AMD. Methods: A primary dataset of 1480 retinal images was collected from Zhongshan Hospital of Fudan University for training and 10-fold cross-validation. Additionally, two validation subdataset comprising 238 images (retinal images and wide-field images) were used. Using fluorescein angiography-based labels, we applied the InceptionResNetV2 deep network with the ARIA method to detect AMD, and a transfer ResNet50_Unet was used to segment CNV. The risks of cerebral white matter hyperintensities and depression were estimated using an AI-based Retinal Image Analysis approach. Results: In a 10-fold cross-validation, we achieved sensitivities of 97.4% and 98.1%, specificities of 96.8% and 96.1%, and accuracies of 97.0% and 96.4% in detecting referable AMD and neovascular AMD, respectively. In the external validation, we achieved accuracies of 92.9% and 93.7% and AUCs of 0.967 and 0.967, respectively. The performances on two validation sub-datasets show no statistically significant difference in detecting referable AMD (p = 0.704) and neovascular AMD (p = 0.213). In the segmentation of CNV, we achieved a global accuracy of 93.03%, a mean accuracy of 91.83%, a mean intersection over union (IoU) of 68.7%, a weighted IoU of 89.63%, and a mean boundary F1 (BF) of 67.77%. Conclusions: The proposed method shows promising results as a highly efficient and cost-effective screening tool for detecting neovascular and referable AMD on both retinal and wide-field images, and providing critical insights into CNV. Its implementation could be particularly valuable in resource-limited settings, enabling timely referrals, enhancing patient care, and supporting decision-making across AMD classifications. In addition, we demonstrated that AMD and neovascular AMD are significantly associated with increased risks of WMH and depression. Full article

The retinal pigment epithelium (RPE) is essential for maintaining retinal integrity, and its dysfunction underlies several progressive ocular diseases, including age-related macular degeneration, choroidal neovascularization (CNV), inherited retinal disorders (IRDs), and proliferative vitreoretinopathy (PVR). Although current therapies have improved disease management, they mainly target secondary pathological mechanisms and do not directly preserve or restore RPE function. Moreover, the delivery of therapeutic molecules or genes to the RPE remains a major challenge due to the presence of multiple ocular barriers and the need for sustained, localized action. Nanomedicine offers innovative solutions to these limitations by enabling precise, controlled, and cell-specific delivery of drugs and genetic materials. Engineered nanocarriers can be optimized to traverse ocular barriers, enhance bioavailability, and modulate the retinal microenvironment. This review summarizes recent advances in nanoscale delivery systems for RPE-targeted therapies, focusing on design principles, targeting strategies, and therapeutic applications, and discusses the translational challenges that must be addressed to bring nanotechnology-based treatments closer to clinical application. Full article

Diabetic Macular Edema (DME) poses a significant threat to vision, often leading to permanent blindness if not detected and addressed swiftly. Existing manual diagnostic methods are arduous and inconsistent, highlighting the pressing necessity for automated, accurate, and personalized solutions. This study presents a novel methodology for diagnosing DME and categorizing choroidal neovascularization (CNV), drusen, and normal conditions from fundus images through the application of transfer learning models and bio-inspired optimization methodologies. The methodology utilizes advanced transfer learning architectures, including VGG16, VGG19, ResNet50, EfficientNetB7, EfficientNetV2-S, InceptionV3, and InceptionResNetV2, for analyzing both binary and multi-class Optical Coherence Tomography (OCT) datasets. We combined the OCT datasets OCT2017 and OCTC8 to create a new dataset for our study. The parameters, including learning rate, batch size, and dropout layer of the fully connected network, are further adjusted using the bio-inspired Particle Swarm Optimization (PSO) method, in conjunction with thorough preprocessing. Explainable AI approaches, especially Shapley additive explanations (SHAP), provide transparent insights into the model’s decision-making processes. Experimental findings demonstrate that our bio-inspired optimized transfer learning Inception V3 significantly surpasses conventional deep learning techniques for DME classification, as evidenced by enhanced metrics including the accuracy, precision, recall, F1-score, misclassification rate, Matthew’s correlation coefficient, intersection over union, and kappa coefficient for both binary and multi-class scenarios. The accuracy achieved is approximately 98% in binary classification and roughly 90% in multi-class classification with the Inception V3 model. The integration of contemporary transfer learning architectures with nature-inspired PSO enhances diagnostic precision to approximately 95% in multi-class classification, while also improving interpretability and reliability, which are crucial for clinical implementation. This research promotes the advancement of more precise, personalized, and timely diagnostic and therapeutic strategies for Diabetic Macular Edema, aiming to avert vision loss and improve patient outcomes. Full article

Background: Metabolic stress from amino acid (AA) insufficiency is increasingly linked to pathological angiogenesis, but specific essential AA (EAA) roles remain undefined. Neovascular age-related macular degeneration (AMD), a major cause of blindness driven by aberrant ocular neovascularization, has limited efficacy with current VEGFA-targeting therapies. We sought to identify specific EAAs that regulate pathological angiogenesis and dissect their mechanisms to propose new therapeutic strategies. Methods: Human retinal microvascular endothelial cells (HRMVECs) were used to identify angiogenesis-regulating amino acids through systematic EAA screening. The molecular mechanism was investigated using shRNA-mediated knockdown of key stress response regulators (HRI, PKR, PERK, GCN2) and ATF4. Angiogenesis was assessed via tubule formation and migration assays. Therapeutic potential was examined in a laser-induced choroidal neovascularization (CNV) mouse model, evaluated by fluorescein angiography and histomorphometry. Results: Deprivation of methionine, lysine, and threonine potently induced capillary-like tube formation (p < 0.01). Mechanistically, restriction of these three EAAs activated HRI and GCN2 kinases, converging on eIF2α phosphorylation to induce ATF4 and its target VEGFA. Dual, but not single, knockdown of HRI and GCN2 abolished eIF2α-ATF4 signaling and angiogenic responses. Restricting these EAAs exacerbated CNV area in mice. Conclusions: Our findings reveal a coordinated HRI/GCN2-ATF4-VEGFA axis linking EAA scarcity to vascular remodeling, establishing proof-of-concept for targeting this pathway in CNV. This work highlights the therapeutic potential of modulating specific AA availability or targeting the HRI/GCN2-ATF4 axis to treat CNV. Full article

Age-related macular degeneration (AMD) represents a leading cause of irreversible blindness in the elderly, primarily by choroidal neovascularization (CNV) leakage. While intravitreal injections of anti-angiogenic antibodies (e.g., aflibercept) provide clinical benefits, their short half-life necessitates frequent administrations, potentially causing ocular infections or retinal detachment. There is an urgent need for effective antibody delivery systems. Mesoporous silica nanoparticles (MSN) have emerged as promising nanocarriers due to their tunable porosity, surface modifiability, and biocompatibility, though their application in ophthalmology for antibody delivery remains underexplored. We developed two MSN carries: spiky mesoporous silica nanospheres (S-MSN) without amino groups and amine-functionalized hollow dendritic mesoporous silica nanospheres (A-HDMSN). Characterization revealed that A-HDMSN exhibited superior properties, including a larger surface area (550.32 vs. 257.72 m²/g), larger mesoporous pore size (17 vs. <10 nm), and 5.28 times higher drug loading capacity (286.31 ± 8.14 vs. 54.26 ± 3.61 μg/mg) compared to S-MSN (n = 3, p < 0.001), attributable to pore size effects and hydrogen bonding. FITC-labeled A-HDMSN demonstrated efficient uptake by retinal pigment epithelial cells (ARPE-19). Notably, A-HDMSN loaded with Aflibercept (A-HDMSN@Afl) showed significant inhibitory effect on VEGF-induced cell migration even 10 days after drug release in vitro, indicating a favorable sustained-release effect of the drug. These findings highlight A-HDMSN as a promising antibody delivery platform that could extend clinical dosing intervals, offering potential for improved AMD management. Full article

Age-related macular degeneration (AMD) is a leading cause of irreversible blindness worldwide, primarily due to pathological choroidal neovascularization (CNV). Our study investigates a chemically modified heparin derivative as a novel strategy to selectively modulate angiogenic signaling, offering a reduced anticoagulant risk and preclinical support for AMD treatment. We explored the therapeutic potential of 6-O-desulfated heparin (Hep-6Od) as an antiangiogenic agent with diminished anticoagulant activity. Synthesized via selective 6-O-desulfation and characterized using nuclear magnetic resonance (NMR), Hep-6Od demonstrated safety in retinal pigment epithelial cells with no cytotoxic effects at various concentrations. In vitro, the compound significantly inhibited endothelial cell proliferation, migration, and capillary tube formation. Differential scanning fluorimetry (DSF) assays confirmed molecular interaction between Hep-6Od and fibroblast growth factor 2 (FGF-2), suggesting interference with pro-angiogenic signaling pathways. In vivo, a laser-induced CNV model in lean Zucker rats showed a dose-dependent reduction in neovascular lesion areas after an intravitreal Hep-6Od injection. Compared to unfractionated heparin, Hep-6Od exhibited reduced anticoagulant effects in PT and aPTT assays while maintaining robust antiangiogenic properties. These findings support Hep-6Od as a promising alternative to anti-vascular endothelial growth factor (VEGF) therapies for AMD treatment, potentially expanding current retinal vascular disease interventions. The results underscore its potential to transform AMD management, pending further clinical validation and awaiting confirmation in further studies. Full article