Anti-VEGF and Other Novel Therapies for Neovascular Age-Related Macular Degeneration: An Update

CBX7 promotes choroidal neovascularization by activating the HIF-1α/VEGF pathway in choroidal vascular endothelial cells

Vascular endothelial growth factor (VEGF) signaling is crucial for choroidal neovascularization (CNV), a major pathological feature of neovascular age-related macular degeneration (nAMD). Gene transcription of VEGF is mainly regulated by hypoxia-inducible factor 1-alpha (HIF-1α). The chromobox (CBX) family polycomb protein (Pc) subgroup includes CBX2, CBX4, CBX6, CBX7, and CBX8. CBX4 enhances hypoxia-induced VEGF expression and angiogenesis in hepatocellular carcinoma (HCC) cells by increasing HIF-1α's transcriptional activity. The objective of the study was to examine the functions of members of the CBX family Pc subgroup in choroidal vascular endothelial cells (CVECs) during CNV. CBX4 and CBX7 expression was up-regulated in hypoxic human choroidal vascular endothelial cells (HCVECs). In HCVECs, CBX7 facilitated HIF-1α transcription and expression, while CBX4 did not. In HCVECs, CBX7 stimulated HIF-1α's nuclear translocation and transcriptional activity, which in turn stimulated VEGF transcription and expression. The CBX7/HIF-1α/VEGF pathway promoted the migration, proliferation, and tube formation of HCVECs. The CBX7/HIF-1α/VEGF pathway was up-regulated in CVECs and in the mouse model with laser-induced CNV. Mouse CNV was lessened by the blockade of CBX7 through the down-regulation of HIF-1α/VEGF. In conclusion, CBX7 enhanced pro-angiogenic behaviors of hypoxic CVECs by up-regulating the HIF-1α/VEGF pathway, which contributing to the formation of mouse laser-induced CNV.

Monoclonal Antibodies for the Treatment of Ocular Diseases

Monoclonal antibodies (mAbs) have revolutionized the landscape of cancer therapy, offering unprecedented specificity and diverse mechanisms to combat malignant cells. These biologic agents have emerged as a cornerstone in targeted cancer treatment, binding to specific antigens on cancer cells and exerting their therapeutic effects through various mechanisms, including inhibition of signaling pathways, antibody-dependent cellular cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), and antibody-dependent cellular phagocytosis (ADCP). The unique ability of mAbs to engage the immune system and directly interfere with cancer cell function has significantly enhanced the therapeutic armamentarium against a broad spectrum of malignancies. mAbs were initially studied in oncology; however, today, treatments have been developed for eye diseases. This review discusses the current applications of mAbs for the treatment of ocular diseases, discussing the specificity and the variety of mechanisms by which these molecules exhibit their therapeutic effects. The benefits, drawbacks, effectiveness, and risks associated with using mAbs in ophthalmology are highlighted, focusing on the most relevant ocular diseases and mAbs currently in use. Technological advances have led to in vitro production methods and recombinant engineering techniques, allowing the development of chimeric, humanized, and fully human mAbs. Nowadays, many humanized mAbs have several applications, e.g., for the treatment of age-related macular disease, diabetic retinopathy, and uveitis, while studies about new applications of mAbs, such as for SARS-CoV-2 infection, are also currently ongoing to seek more efficient and safe approaches to treat this new ocular disease.

Two-year efficacy and safety of different anti-vascular endothelial growth factor regimens for neovascular age-related macular degeneration: a network meta-analysis of randomized controlled trials

OBJECTIVES

To compare the 2-year efficacy and safety of various anti-vascular endothelial growth factor (VEGF) regimens for neovascular age-related macular degeneration (nAMD).

METHODS

A comprehensive search was performed on multiple electronic databases up to April 2023 and updated in June 2024, to identify relevant randomized controlled trials (RCTs). Key outcomes included the proportion of patients achieving a vision gain of ≥15 letters and maintaining stable vision (loss of <15 letters) in best-corrected visual acuity (BCVA), changes in mean BCVA from baseline, serious ocular adverse events (SAEs), adverse events leading to treatment discontinuation and any cause of death at 2 years.

RESULTS

Nineteen trials with 12,654 patients and 25 treatment regimens were analyzed in the study. All anti-VEGF regimens showed superior efficacy compared to sham therapy. Specifically, faricimab 6 mg (4+up to Q16W) and ranibizumab 0.5 mg (2-week T&E) displayed top-level effect in vision gain. Bevacizumab 1.25 mg (2-week T&E) and aflibercept 2 mg (2-week T&E) demonstrated the most stable vision outcomes. Bevacizumab 1.25 mg (2-week T&E) and ranibizumab 0.5 mg (2-week T&E) exhibited the most pronounced mean BCVA improvement. Compared to sham therapy, the risk of SAEs was significantly higher for brolucizumab 6 mg (3 + Q12W/ Q8W) (RR = 6.04, 95% CI: 1.30-28.02) and PDS 100 mg/ml (Q24W) (RR = 10.95, 95% CI: 2.14-56.02), but not for other anti-VEGF regimens.

CONCLUSIONS

Ranibizumab 0.5 mg (2-week T&E) emerges as a potentially optimal regimen for nAMD over a 2-year period. Future studies need to consider the impact of baseline characteristics on treatment outcomes.

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-1α siRNA-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 7 days 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.

Optimal Humanized Scg3-Neutralizing Antibodies for Anti-Angiogenic Therapy of Diabetic Retinopathy

Secretogranin III (Scg3) is a diabetic retinopathy (DR)-restricted angiogenic factor identified in preclinical studies as a target for DR therapy. Previously, our group generated and characterized ML49.3, an anti-Scg3 monoclonal antibody (mAb) which we then converted into an EBP2 humanized antibody Fab fragment (hFab) with potential for clinical application. We also generated anti-Scg3 mT4 mAb and related EBP3 hFab. In this study, to identify the preferred hFab for DR therapy, we compared all four antibodies for binding, neutralizing and therapeutic activities in vitro and in vivo. Octet binding kinetics analyses revealed that ML49.3 mAb, EBP2 hFab, mT4 mAb and EBP3 hFab have Scg3-binding affinities of 35, 8.7, 0.859 and 0.116 nM, respectively. Both anti-Scg3 EBP2 and EBP3 hFabs significantly inhibited Scg3-induced proliferation and migration of human umbilical vein endothelial cells in vitro, and alleviated DR vascular leakage and choroidal neovascularization with high efficacy. Paired assays in DR mice revealed that intravitreally injected EBP3 hFab is 26.4% and 10.3% more effective than EBP2 hFab and aflibercept, respectively, for ameliorating DR leakage. In conclusion, this study confirms the markedly improved binding affinities of hFabs compared to mAbs and further identifies EBP3 hFab as the preferred antibody to develop for anti-Scg3 therapy.

Treatment of neovascular age-related macular degeneration with anti-vascular endothelial growth factor drugs: progress from mechanisms to clinical applications

Neovascular age-related macular degeneration (nARMD) is an important cause of visual impairment and blindness in the elderly, with choroidal neovascularization in the macula as the main pathological feature. The onset of nARMD is closely related to factors including age, oxidative stress, and lipid metabolism. Vascular endothelial growth factor (VEGF) is an important factor contributing to nARMD as well as choroidal neovascularization and retinal leakage formation. At present, anti-VEGF therapy is the only treatment that improves vision and halts disease progression in most patients, making anti-VEGF drugs a landmark development for nARMD treatment. Although intravitreal injection of anti-VEGF drugs has become the first-line treatment for nARMD, this treatment has many shortcomings including repeated injections, poor or no response in some patients, and complications such as retinal fibrosis. As a result, several new anti-VEGF drugs are being developed. This review provides a discussion of these new anti-VEGF drugs for the treatment of nARMD.

Melatonin and Risk of Age-Related Macular Degeneration

Importance

Melatonin has been shown to oppose several processes that are known to mediate age-related macular degeneration (AMD), but whether melatonin can confer benefits against AMD remains unclear.

Objective

To examine the association between melatonin supplementation and the risk of the development or progression of AMD.

Design, Setting, and Participants

This retrospective cohort study accessed data from TriNetX, a national database of deidentified electronic medical records from both inpatient and outpatient health care organizations across the US, between December 4, 2023, and March 19, 2024. Patients aged 50 years or older, 60 years or older, and 70 years or older with no history of AMD (AMD-naive group) and with a history of nonexudative AMD (nonexudative AMD group) were queried for instances of melatonin medication codes between November 14, 2008, and November 14, 2023. Patients were then classified into either a melatonin group or a control group based on the presence of medication codes for melatonin. Propensity score matching (PSM) was performed to match the cohorts based on demographic variables, comorbidities, and nonmelatonin hypnotic medication use.

Exposure

The presence of at least 4 instances of melatonin records that each occurred at least 3 months apart.

Main Outcomes and Measures

After PSM, the melatonin and the control cohorts were compared to evaluate the risk ratios (RRs) and the 95% CIs of having an outcome. For the AMD-naive group, the outcome was defined as a new diagnosis of any AMD, whereas for the nonexudative AMD group, the outcome was progression to exudative AMD.

Results

Among 121 523 patients in the melatonin-naive group aged 50 years or older (4848 in the melatonin cohort [4580 after PSM; mean (SD) age, 68.24 (11.47) years; 2588 female (56.5%)] and 116 675 in the control cohort [4580 after PSM; mean (SD) age, 68.17 (10.63) years; 2681 female (58.5%)]), melatonin use was associated with a reduced risk of developing AMD (RR, 0.42; 95% CI, 0.28-0.62). Among 66 253 patients aged 50 years or older in the nonexudative AMD group (4350 in the melatonin cohort [4064 after PSM; mean (SD) age, 80.21 (8.78) years; 2482 female (61.1%)] and 61 903 in the control cohort [4064 patients after PSM; mean (SD) age, 80.31 (8.03) years; 2531 female (62.3%)]), melatonin was associated with a reduced risk of AMD progression to exudative AMD (RR, 0.44; 95% CI, 0.34-0.56). The results were consistent among subsets of individuals aged 60 years or older (AMD-naive cohort: RR, 0.36 [95% CI, 0.25-0.54]; nonexudative AMD cohort: RR, 0.38 [95% CI, 0.30-0.49]) and 70 years or older (AMD-naive cohort: RR, 0.35 [95% CI, 0.23-0.53]; nonexudative AMD cohort: RR, 0.40 [95% CI, 0.31-0.51]).

Conclusions and Relevance

Melatonin use was associated with a decreased risk of development and progression of AMD. Although lifestyle factors may have influenced this association, these findings provide a rationale for further research on the efficacy of using melatonin as a preventive therapy against AMD.

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

Background

To evaluate the efficacy and safety of Brolucizumab for neovascular age-related macular degeneration (n-AMD) through a systematic review and meta-analysis.

Materials and Methods

Cochrane, PubMed, Embase, and Web of Science databases were comprehensively searched for relevant studies. Stata and RevMan5.4 were applied for meta-analysis and risk of bias assessment. Data on the best-corrected visual acuity (BCVA), central subfield thickness (CSFT), presence of intraretinal fluid (IRF) and/or subretinal fluid (SRF), participants with ≥1 serious adverse events, and participants with ≥1 adverse events were analyzed.

Results

Six studies were finally included. Meta-analysis showed statistical differences in BCVA [SMD = -0.65, 95% CI [-0.17 to -0.23], P < 0.05], the presence of IRF and/or SRF [RR = 0.67, 95% CI [0.56-0.79], P < 0.05], and the safety of participants with ≥1 serious adverse events [RR = 0.57, 95% CI [0.39-0.84], P < 0.05] between the experimental group and the control group. However, no statistical differences were observed in CSFT [SMD = -1.16, 95% CI [-2.79 to 0.47], P > 0.05] or the safety of participants with ≥1 adverse events [RR = 1.07, 95% CI [0.97-1.17], P > 0.05].

Conclusions

Compared to other anti-VEGF drugs such as Aflibercept and Ranibizumab, intravitreal injection of 6 mg Brolucizumab is more effective and safer for n-AMD, especially in the presence of IRF and/or SRF, and for participants with ≥1 serious adverse events.

Clinical Pharmacology Perspective on Development of Adeno-Associated Virus Vector-Based Retina Gene Therapy

Adeno-associated virus (AAV) vector-based gene therapy is an innovative modality being increasingly investigated to treat diseases by modifying or replacing defective genes or expressing therapeutic entities. With its unique anatomic and physiological characteristics, the eye constitutes a very attractive target for gene therapy. Specifically, the ocular space is easily accessible and is generally considered "immune-privileged" with a low risk of systemic side effects following local drug administration. As retina cells have limited cellular turnover, a one-time gene delivery has the potential to provide long-term transgene expression. Despite the initial success with voretigene neparvovec (Luxturna), the first approved retina gene therapy, there are still challenges to be overcome for successful clinical development of these products and scientific questions to be answered. The current review paper aims to integrate published experience learned thus far for AAV-based retina gene therapy related to preclinical to clinical translation; first-in-human dose selection; relevant bioanalytical assays and strategies; clinical development considerations including trial design, biodistribution and vector shedding, immunogenicity, transgene expression, and pediatric populations; opportunities for model-informed drug development; and regulatory perspectives. The information presented herein is intended to serve as a guide to inform the clinical development strategy for retina gene therapy with a focus on clinical pharmacology.

Pluripotent stem cell-derived models of retinal disease: Elucidating pathogenesis, evaluating novel treatments, and estimating toxicity

Blindness poses a growing global challenge, with approximately 26% of cases attributed to degenerative retinal diseases. While gene therapy, optogenetic tools, photosensitive switches, and retinal prostheses offer hope for vision restoration, these high-cost therapies will benefit few patients. Understanding retinal diseases is therefore key to advance effective treatments, requiring in vitro models replicating pathology and allowing quantitative assessments for drug discovery. Pluripotent stem cells (PSCs) provide a unique solution given their limitless supply and ability to differentiate into light-responsive retinal tissues encompassing all cell types. This review focuses on the history and current state of photoreceptor and retinal pigment epithelium (RPE) cell generation from PSCs. We explore the applications of this technology in disease modelling, experimental therapy testing, biomarker identification, and toxicity studies. We consider challenges in scalability, standardisation, and reproducibility, and stress the importance of incorporating vasculature and immune cells into retinal organoids. We advocate for high-throughput automation in data acquisition and analyses and underscore the value of advanced micro-physiological systems that fully capture the interactions between the neural retina, RPE, and choriocapillaris.

Topical Ophthalmic Liposomes Dual-Modified with Penetratin and Hyaluronic Acid for the Noninvasive Treatment of Neovascular Age-Related Macular Degeneration

Introduction

Since intrinsic ocular barrier limits the intraocular penetration of therapeutic protein through eye drops, repeated intravitreal injections of anti-vascular endothelial growth factor (anti-VEGF) agents are the standard therapy for neovascular age-related macular degeneration (nAMD), which are highly invasive and may cause particular ocular complications, leading to poor patient compliance.

Methods

Using Penetratin (Pen) as the ocular penetration enhancer and hyaluronic acid (HA) as the retina-targeting ligand, a dual-modified ophthalmic liposome (Penetratin hyaluronic acid-liposome/Conbercept, PenHA-Lip/Conb) eye drop was designed to non-invasively penetrate the ocular barrier and deliver anti-VEGF therapeutic agents to the targeted intraocular tissue.

Results

PenHA-Lip effectively penetrates the ocular barrier and targets the retinal pigment epithelium via corneal and non-corneal pathways. After a single topical administration of conbercept-loaded PenHA-Lip (PenHA-Lip/Conb), the intraocular concentration of conbercept peaked at 18.74 ± 1.09 ng/mL at 4 h, which is 11.55-fold higher than unmodified conbercept. In a laser-induced choroidal neovascularization (CNV) mouse model, PenHA-Lip/Conb eye drops three times daily for seven days inhibited CNV formation and progression without any significant tissue toxicity and achieved an equivalent effect to a single intravitreal conbercept injection.

Conclusion

PenHA-Lip efficiently and safely delivered conbercept to the posterior eye segment and may be a promising noninvasive therapeutic option for nAMD.

Recent Developments in Gene Therapy for Neovascular Age-Related Macular Degeneration: A Review

Age-related macular degeneration (AMD) is a complex and multifactorial disease and a leading cause of irreversible blindness in the elderly population. The anti-vascular endothelial growth factor (anti-VEGF) therapy has revolutionized the management and prognosis of neovascular AMD (nAMD) and is currently the standard of care for this disease. However, patients are required to receive repeated injections, imposing substantial social and economic burdens. The implementation of gene therapy methods to achieve sustained delivery of various therapeutic proteins holds the promise of a single treatment that could ameliorate the treatment challenges associated with chronic intravitreal therapy, and potentially improve visual outcomes. Several early-phase trials are currently underway, evaluating the safety and efficacy of gene therapy for nAMD; however, areas of controversy persist, including the therapeutic target, route of administration, and potential safety issues. In this review, we assess the evolution of gene therapy for nAMD and summarize several preclinical and early-stage clinical trials, exploring challenges and future directions.

Randomized Trial of Biosimilar XSB-001 versus Reference Ranibizumab in Patients with Neovascular Age-Related Macular Degeneration

OBJECTIVE

To evaluate the efficacy, safety, and immunogenicity of a ranibizumab biosimilar candidate (XSB-001) versus reference product (Lucentis) for neovascular age-related macular degeneration (nAMD).

DESIGN

Phase III, multicenter, randomized, double-masked, parallel-group study.

PARTICIPANTS

Patients with nAMD.

METHODS

Eligible patients were randomized (1:1) to receive intravitreal injections of XSB-001 or reference ranibizumab (0.5 mg [0.05 ml]) in the study eye once every 4 weeks for 52 weeks. Efficacy and safety assessments continued through 52 weeks of treatment.

MAIN OUTCOME MEASURES

Primary end point was change from baseline in best-corrected visual acuity (BCVA) by ETDRS letters at week 8. Biosimilarity was concluded if the 2-sided 90% confidence interval (CI) (United States) or 95% CI (rest of world) for the difference in least-squares (LS) mean change in BCVA at week 8 between treatment groups was within the predefined equivalence margin of ± 3.5 letters.

RESULTS

In total, 582 patients (n = 292 XSB-001, n = 290 reference ranibizumab) were randomized. Mean age was 74.1 years, most patients (85.2%) were White, and 55.8% were women. Mean BCVA score at baseline was 61.7 and 61.5 ETDRS letters in the XSB-001 and reference ranibizumab groups, respectively. At week 8, the LS mean (standard error [SE]) change in BCVA from baseline was 4.6 (0.5) ETDRS letters in the XSB-001 group and 6.4 (0.5) letters in the reference ranibizumab group (LS mean [SE] treatment difference: -1.8 [0.7] ETDRS letters; 90% CI, -2.9 to -0.7; 95% CI, -3.1 to -0.5). The 90% CI and 95% CI for LS mean difference in change from baseline were within the predefined equivalence margin. At week 52, LS mean (SE) change in BCVA was 6.4 (0.8) and 7.8 (0.8) letters, respectively (LS mean [SE] treatment difference, -1.5 [1.1] ETDRS letters; 90% CI, -3.3 to 0.4; 95% CI, -3.6 to 0.7). There were no clinically meaningful differences between treatments in anatomical, safety, or immunogenicity end points through week 52.

CONCLUSIONS

XSB-001 demonstrated biosimilarity to reference ranibizumab in patients with nAMD. Treatment with XSB-001 for 52 weeks was generally safe and well tolerated, with a safety profile similar to the reference product.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Short-Term Treatment Outcomes of Brolucizumab in Patients with Neovascular Age-Related Macular Degeneration: A Multicentre Indian Real-World Evidence Study

Objective

To evaluate the short-term effectiveness and safety outcomes following brolucizumab treatment in patients with neovascular age-related macular degeneration (nAMD) as a part of real-world clinical practice in India.

Methods

This was a retrospective, observational, multicentre study including patients (≥50 years old) diagnosed with nAMD. Anonymized data of the patients receiving the first dose of brolucizumab intravitreal injection (IVI) who were either treatment-naïve or previously treated with a single or a combination of other anti-VEGF IVIs were included. The present study reported the change in retinal fluid levels from baseline to month 3, best-corrected visual acuity (BCVA), central retinal thickness (CRT), and the number of injections received. The adverse events in the three months after brolucizumab treatment initiation were also monitored.

Results

The study included 63 patients (65 eyes) from four study centres across India (mean age: 69.1 ± 9.7 years). A total of 82 brolucizumab injections were administered during the 3 months of study duration, with 52/65 (80.0%) eyes receiving only 1 injection. Resolution of IRF, SRF, and PED was observed in 76.9%, 64.6%, and 67.7% of eyes, respectively. Further, a significant reduction in CRT was observed (baseline: 403.5 ± 118.7 μm; month 3: 308.3 ± 73.8 μm; p < 0.001), and BCVA also improved notably from 0.7 ± 0.5 logMAR at baseline to 0.5 ± 0.4 logMAR at month 3 (p < 0.001). Adverse events (AEs) were reported in 3 eyes from 3 patients; retinal pigment epithelial rip (1) and subretinal hemorrhage (2) after the first injection of brolucizumab, however, none discontinued the treatment.

Conclusion

The study reports on the short-term effectiveness and tolerability of brolucizumab therapy in the management of nAMD in both treatment-naïve and switch eyes. Brolucizumab was observed to have a favourable benefit-risk profile, and study results were within the known safety profile, with no instances of intraocular inflammation.

Anti-Scg3 Gene Therapy to Treat Choroidal Neovascularization in Mice

Neovascular age-related macular degeneration (nAMD) with choroidal neovascularization (CNV) is a leading cause of blindness in the elderly in developed countries. The disease is currently treated with anti-angiogenic biologics, including aflibercept, against vascular endothelial growth factor (VEGF) but with limited efficacy, treatment resistance and requirement for frequent intravitreal injections. Although anti-VEGF gene therapy may provide sustained therapy that obviates multiple injections, the efficacy and side effects related to VEGF pathway targeting remain, and alternative strategies to block angiogenesis independently of VEGF are needed. We recently reported that secretogranin III (Scg3) induces only pathological angiogenesis through VEGF-independent pathways, and Scg3-neutralizing antibodies selectively inhibit pathological but not physiological angiogenesis in mouse proliferative retinopathy models. Anti-Scg3 antibodies synergize dose-dependently with VEGF inhibitors in a CNV model. Here, we report that an adeno-associated virus-8 (AAV8) vector expressing anti-Scg3 Fab ameliorated CNV with an efficacy similar to that of AAV-aflibercept in a mouse model. This study is the first to test an anti-angiogenic gene therapy protocol that selectively targets pathological angiogenesis via a VEGF-independent mechanism. The findings support further safety/efficacy studies of anti-Scg3 gene therapy as monotherapy or combined with anti-VEGF to treat nAMD.

The Evolution of Triamcinolone Acetonide Therapeutic Use in Retinal Diseases: From Off-Label Intravitreal Injection to Advanced Nano-Drug Delivery Systems

Ophthalmic drug delivery to the posterior segment of the eye has been challenging due to the complex ocular anatomy. Intravitreal injection of drugs was introduced to deliver therapeutic doses in the posterior segment. Different posterior segment diseases including age-related macular degeneration, diabetic macular edema, retinal vein occlusions, uveitis, and cystoid macular edema, among others, have been historically treated with intravitreal corticosteroids injections, and more recently with intravitreal corticosteroids drug implants. Triamcinolone acetonide (TA) is the most frequently used intraocular synthetic corticosteroid. Using nanoparticle-based TA delivery systems has been proposed as an alternative to intravitreal injections in the treatment of posterior segment diseases. From these novel delivery systems, topical liposomes have been the most promising strategy. This review is oriented to exhibit triamcinolone acetonide drug evolution and its results in treating posterior segment diseases using diverse delivery platforms.

Oxidative Stress and Antioxidants in Age-Related Macular Degeneration

Oxidative stress plays a crucial role in aging-related eye diseases, including age-related macular degeneration (AMD), cataracts, and glaucoma. With age, antioxidant reparative capacity decreases, and excess levels of reactive oxygen species produce oxidative damage in many ocular cell types underling age-related pathologies. In AMD, loss of central vision in the elderly is caused primarily by retinal pigment epithelium (RPE) dysfunction and degeneration and/or choroidal neovascularization that trigger malfunction and loss of photo-sensing photoreceptor cells. Along with various genetic and environmental factors that contribute to AMD, aging and age-related oxidative damage have critical involvement in AMD pathogenesis. To this end, dietary intake of antioxidants is a proven way to scavenge free radicals and to prevent or slow AMD progression. This review focuses on AMD and highlights the pathogenic role of oxidative stress in AMD from both clinical and experimental studies. The beneficial roles of antioxidants and dietary micronutrients in AMD are also summarized.

Anti-vascular endothelial growth factor for diabetic macular oedema: a network meta-analysis

Background

Diabetic macular oedema (DMO) is a common complication of diabetic retinopathy. Antiangiogenic therapy with anti-vascular endothelial growth factor (anti-VEGF) can reduce oedema, improve vision, and prevent further visual loss. These drugs have replaced laser photocoagulation as the standard of care for people with DMO. In the previous update of this review, we found moderate-quality evidence that, at 12 months, aflibercept was slightly more effective than ranibizumab and bevacizumab for improving vision in people with DMO, although the difference may have been clinically insignificant (less than 0.1 logarithm of the minimum angle of resolution (logMAR), or five Early Treatment Diabetic Retinopathy Study (ETDRS) letters, or one ETDRS line).

Objectives

The objective of this updated review was to compare the effectiveness and safety of the different anti-VEGF drugs in RCTs at longer followup (24 months).

Search methods

We searched various electronic databases on 8 July 2022.

Selection criteria

We included randomised controlled trials (RCTs) that compared any anti-angiogenic drug with an anti-VEGF mechanism of action versus another anti-VEGF drug, another treatment, sham, or no treatment in people with DMO.

Data collection and analysis

We used standard Cochrane methods for pairwise meta-analysis and we augmented this evidence using network meta-analysis (NMA) methods. We used the Stata 'network' meta-analysis package for all analyses. We used the CINeMA (Confidence in Network Meta-Analysis) web application to grade the certainty of the evidence.

Main results

We included 23 studies (13 with industry funding) that enrolled 3513 people with DMO (median central retinal thickness (CRT) 460 microns, interquartile range (IQR) 424 to 482) and moderate vision loss (median best-corrected visual acuity (BCVA) 0.48 logMAR, IQR 0.42 to 0.55. One study that investigated ranibizumab versus sham and one study that mainly enrolled people with subclinical DMO and normal BCVA were not suitable for inclusion in the efficacy NMA. Consistent with the previous update of this review, we used ranibizumab as the reference drug for efficacy, and control (including laser, observation, and sham) as the reference for systemic safety. Eight trials provided data on the primary outcome (change in BCVA at 24 months, in logMAR: lower is better). We found no evidence of a difference between the following interventions and ranibizumab alone: aflibercept (mean difference (MD) -0.05 logMAR, 95% confidence interval (CI) -0.12 to 0.02; moderate certainty); bevacizumab (MD -0.01 logMAR, 95% CI -0.13 to 0.10; low certainty), brolucizumab (MD 0.00 logMAR, 95% CI -0.08 to 0.07; low certainty), ranibizumab plus deferred laser (MD 0.00 logMAR, 95% CI -0.11 to 0.10; low certainty), and ranibizumab plus prompt laser (MD 0.03 logMAR, 95% CI -0.04 to 0.09; very low certainty). We also analysed BCVA change at 12 months, finding moderate-certainty evidence of increased efficacy with brolucizumab (MD -0.07 logMAR, 95%CI -0.10 to -0.03 logMAR), faricimab (MD -0.08 logMAR, 95% CI -0.12 to -0.05), and aflibercept (MD -0.07 logMAR, 95 % CI -0.10 to -0.04) compared to ranibizumab alone, but the difference could be clinically insignificant. Compared to ranibizumab alone, NMA of six trials showed no evidence of a difference with aflibercept (moderate certainty), bevacizumab (low certainty), or ranibizumab with prompt (very low certainty) or deferred laser (low certainty) regarding improvement by three or more ETDRS lines at 24 months. There was moderate-certainty evidence of greater CRT reduction at 24 months with brolucizumab (MD -23 microns, 95% CI -65 to -1 9) and aflibercept (MD -26 microns, 95% CI -53 to 0.9) compared to ranibizumab. There was moderate-certainty evidence of lesser CRT reduction with bevacizumab (MD 28 microns, 95% CI 0 to 56), ranibizumab plus deferred laser (MD 63 microns, 95% CI 18 to 109), and ranibizumab plus prompt laser (MD 72 microns, 95% CI 25 to 119) compared with ranibizumab alone. Regarding all-cause mortality at the longest available follow-up (20 trials), we found no evidence of increased risk of death for any drug compared to control, although effects were in the direction of an increase, and clinically relevant increases could not be ruled out. The certainty of this evidence was low for bevacizumab (risk ratio (RR) 2.10, 95% CI 0.75 to 5.88), brolucizumab (RR 2.92, 95% CI 0.68 to 12.58), faricimab (RR 1.91, 95% CI 0.45 to 8.00), ranibizumab (RR 1.26, 95% CI 0.68 to 2.34), and very low for conbercept (RR 0.33, 95% CI 0.01 to 8.81) and aflibercept (RR 1.48, 95% CI 0.79 to 2.77). Estimates for Antiplatelet Trialists Collaboration arterial thromboembolic events at 24 months did not suggest an increase with any drug compared to control, but the NMA was overall incoherent and the evidence was of low or very low certainty. Ocular adverse events were rare and poorly reported and could not be assessed in NMAs.

Authors' conclusions

There is limited evidence of the comparative efficacy and safety of anti-VEGF drugs beyond one year of follow-up. We found no clinically important differences in visual outcomes at 24 months in people with DMO, although there were differences in CRT change. We found no evidence that any drug increases all-cause mortality compared to control, but estimates were very imprecise. Evidence from RCTs may not apply to real-world practice, where people in need of antiangiogenic treatment are often under-treated, and the individuals exposed to these drugs may be less healthy than trial participants.

Recent Advances of Ocular Drug Delivery Systems: Prominence of Ocular Implants for Chronic Eye Diseases

Chronic ocular diseases can seriously impact the eyes and could potentially result in blindness or serious vision loss. According to the most recent data from the WHO, there are more than 2 billion visually impaired people in the world. Therefore, it is pivotal to develop more sophisticated, long-acting drug delivery systems/devices to treat chronic eye conditions. This review covers several drug delivery nanocarriers that can control chronic eye disorders non-invasively. However, most of the developed nanocarriers are still in preclinical or clinical stages. Long-acting drug delivery systems, such as inserts and implants, constitute the majority of the clinically used methods for the treatment of chronic eye diseases due to their steady state release, persistent therapeutic activity, and ability to bypass most ocular barriers. However, implants are considered invasive drug delivery technologies, especially those that are nonbiodegradable. Furthermore, in vitro characterization approaches, although useful, are limited in mimicking or truly representing the in vivo environment. This review focuses on long-acting drug delivery systems (LADDS), particularly implantable drug delivery systems (IDDS), their formulation, methods of characterization, and clinical application for the treatment of eye diseases.

Recent advances of exosomes in age-related macular degeneration

Exosomes are 30-150 nm extracellular vesicles that are secreted by almost all types of cells. Exosomes contain a variety of biologically active substances, such as proteins, nucleic acids, and lipids, and are important in the intercellular communication of biological mediators involved in nerve injury and repair, vascular regeneration, immune response, fibrosis formation, and many other pathophysiological processes. Although it has been extensively studied in the field of cancer, the exploration of ocular diseases has only just begun. Here, we discuss the latest developments in exosomes for age-related macular degeneration (AMD), including the pathogenesis of exosomes in age-related macular degeneration, their potential as diagnostic markers, and therapeutic vectors of the disease. Finally, the study of exosomes in age-related macular degeneration is still relatively few, and more detailed basic research and clinical trials are needed to verify its application in treatment and diagnosis, so as to adopt more personalized diagnosis and treatment strategies to stop the progression of age-related macular degeneration.

The state-of-the-art pharmacotherapeutic management of neovascular age-related macular degeneration

INTRODUCTION

Age-related macular degeneration (AMD) is a major cause of central visual loss in the developed world. Although the pathogenesis is not fully understood, vascular endothelial growth factor (VEGF) is considered the most important growth factor involved in angiogenesis and exudation in neovascular AMD eyes. Advances in anti-VEGF agents have changed the treatment approach for wet AMD, allowing better outcomes in visual acuity and retinal anatomy.

AREAS COVERED

The present review describes the main pharmacological and clinical characteristics of anti-VEGF drugs, focusing firstly on the molecules commonly in use and then on the new candidate therapies. We performed a comprehensive literature search using the PubMed database from 1 January 1993 to 1 June 2022, with search terms including anti-VEGF, biosimilar, neovascular macular degeneration, AMD, and safety.

EXPERT OPINION

The management of AMD is still onerous for both the physician and patient due to the great number of required injections. Current research is underway to resolve not only the economic burden but also the discomfort of patients, aiming to develop a drug with a different or a multiple target, increasing the potency whilst maintaining a good safety profile. Furthermore, clinical research is currently investigating different forms of drug administration.

Proteotranscriptomic analyses reveal distinct interferon-beta signaling pathways and therapeutic targets in choroidal neovascularization

Aim

To investigate the molecular mechanism underlying the onset of choroidal neovascularization (CNV).

Methods

Integrated transcriptomic and proteomic analyses of retinas in mice with laser-induced CNV were performed using RNA sequencing and tandem mass tag. In addition, the laser-treated mice received systemic interferon-β (IFN-β) therapy. Measurements of CNV lesions were acquired by the confocal analysis of stained choroidal flat mounts. The proportions of T helper 17 (Th17) cells were determined by flow cytometric analysis.

Results

A total of differentially expressed 186 genes (120 up-regulated and 66 down-regulated) and 104 proteins (73 up-regulated and 31 down-regulated) were identified. The gene ontology and KEGG pathway analyses indicated that CNV was mainly associated with immune and inflammatory responses, such as cellular response to IFN-β and Th17 cell differentiation. Moreover, the key nodes of the protein-protein interaction network mainly involved up-regulated proteins, including alpha A crystallin and fibroblast growth factor 2, and were verified by Western blotting. To confirm the changes in gene expression, real-time quantitative PCR was performed. Furthermore, levels of IFN-β in both the retina and plasma, as measured by enzyme-linked immunosorbent assay (ELISA), were significantly lower in the CNV group than in the control group. IFN-β treatment significantly reduced CNV lesion size and promoted the proliferation of Th17 cells in laser-treated mice.

Conclusions

This study demonstrates that the occurrence of CNV might be associated with the dysfunction of immune and inflammatory processes and that IFN-β could serve as a potential therapeutic target.

PAF-induced inflammatory and immuno-allergic ophthalmic diseases and their mitigation with PAF receptor antagonists: Cell and nuclear effects

Ocular allergies are becoming more prevalent as more airborne pollutants, irritants and microbes pervade our environment. Inflammatory and allergic mediators released by dendritic and mast cells within the conjunctiva cause allergic conjunctivitis (AC), a prevalent ocular surface disorder that affects >40% of the world's human population on a seasonal or perennial basis. Even though histamine is a major culprit, platelet-activating factor (PAF) also contributes to AC, acting either directly or synergistically with histamine and other mediators. PAF receptor-meditated inflammatory reactions, via cell-membrane-bound and nuclear-membrane-bound and nuclear PAF receptors, are also implicated in the etiology of other eye diseases such as uveitis, diabetic retinopathy, corneal and choroidal neovascularization, and age-related macular degeneration which cause serious visual impairment and can lead to blindness. This review highlights the various deleterious elements implicated in the pathological aspects of ocular allergic reactions and inflammation and provides concepts and treatment options to mitigate these eye disorders with a special focus on PAF and PAF receptor antagonists.

Molecular and Functional Characterization of BDNF-Overexpressing Human Retinal Pigment Epithelial Cells Established by Sleeping Beauty Transposon-Mediated Gene Transfer

More and more patients suffer from multifactorial neurodegenerative diseases, such as age-related macular degeneration (AMD). However, their pathological mechanisms are still poorly understood, which complicates the development of effective therapies. To improve treatment of multifactorial diseases, cell-based gene therapy can be used to increase the expression of therapeutic factors. To date, there is no approved therapy for dry AMD, including late-stage geographic atrophy. We present a treatment option for dry AMD that transfers the brain-derived neurotrophic factor (BDNF) gene into retinal pigment epithelial (RPE) cells by electroporation using the plasmid-based Sleeping Beauty (SB) transposon system. ARPE-19 cells and primary human RPE cells were co-transfected with two plasmids encoding the SB100X transposase and the transposon carrying a BDNF transcription cassette. We demonstrated efficient expression and secretion of BDNF in both RPE cell types, which were further increased in ARPE-19 cell cultures exposed to hydrogen peroxide. BDNF-transfected cells exhibited lower apoptosis rates and stimulated neurite outgrowth in human SH-SY5Y cells. This study is an important step in the development of a cell-based BDNF gene therapy that could be applied as an advanced therapy medicinal product to treat dry AMD or other degenerative retinal diseases.

Clinical Effect of Tongmai Fuming Decoction on Neovascular Ophthalmopathy

Background

The incidence of neovascular eye disease is increasing year by year, seriously threatening human vision health and becoming an urgent public health problem. Tongmai fuming decoction as an experienced prescription can treat ischemic eye disease.

Objective

To investigate the therapeutic effect of Tongmai fuming decoction combined with anti-VEGF therapy on neovascular ophthalmopathy.

Methods

52 patients (62 eyes) with neovascular ophthalmopathy who met the inclusion criteria from January 2018 to July 2020 were randomly divided into the control and observation groups. The control group was given an intravitreal injection of antivascular endothelial growth factor (VEGF) drugs once a day combined with on-demand treatment. The observation group was treated with traditional Chinese medicine Tongmai fuming decoction in addition to the treatment of anti-VEGF drugs. The best-corrected visual acuity (BCVA) was examined before and after treatment, and optical coherence tomography angiography (OCTA) was used to examine the mean retinal thickness and neovascularization in the macular area. Patients were followed for one year and the number of anti-VEGF injections was recorded.

Results

After treatment, the average thickness of BCVA and macular retina in the two groups significantly improved. The BCVA of the control group was 0.59 ± 0.39 3 months after treatment, and that of the experimental group was 0.42 ± 0.25 3 months after treatment. The average thickness of the macular retina in the control group was 304.8 ± 79.7 3 months after treatment, and that in the experimental group was 267.7 ± 64.6 3 months after treatment; The average number of injections of anti-VEGF therapy in the control group was 2.32 ± 1.15 times, and that in the experimental group was 1.74 ± 0.76 times. There was a significant difference between the two groups.

Conclusion

Tongmai fuming decoction and anti-VEGF therapy have a synergistic effect in the treatment of neovascular ophthalmopathy, which can reduce the treatment times of anti-VEGF drugs.

Penetrating-peptide-mediated non-invasive Axitinib delivery for anti-neovascularisation

The unique physiological makeup of the eye limits the use of small-molecule drugs for treating the posterior segment of the eye. Nevertheless, transmembrane-peptide-mediated non-invasive drug delivery can serve as an ideal treatment strategy, as it is capable of delivering small-molecule drugs across the membrane in the form of eye drops, thereby achieving the effective treatment of neovascularisation in the posterior cavity. In this study, we screened and compared the posterior segment distribution of two poly(ethylene glycol)-distearoylphosphatidylethanolamine carriers modified using targeting-peptides. Thereafter, a transmembrane peptide (i.e., PENE) with a greater ability of transmembrane delivery was selected for delivering the anti-vascular drug (i.e., Axitinib) to the posterior segment of the eye. Using two different mouse models with fundus neovascular diseases, the complete non-invasive delivery of Axitinib to the posterior segment of the eye was confirmed using the targeted system; the designed eye drops (i.e., PENE-nanoparticles) could achieve drug distribution to the retina and veins of the eye as well as good drug permeability for renewal. Moreover, using the eye-drop treatment, neovascularisation was substantially reduced, demonstrating the high efficacy of this drug delivery system. This study, which combines nanodrug-loading technology and the transmembrane delivery of penetrating-peptides to achieve the goal of the non-invasive delivery of small-molecule drugs through the dense blood vessels of the sclera, shows wide applicability and considerably expands the use of ocular drugs. Thus, this study is expected to help develop a more acceptable drug administration strategy for the drug treatment of the posterior segment of the eye.

The interplay of autophagy and oxidative stress in the pathogenesis and therapy of retinal degenerative diseases

Oxidative stress is mainly caused by intracellular reactive oxygen species (ROS) production, which is highly associated with normal physiological homeostasis and the pathogenesis of diseases, particularly ocular diseases. Autophagy is a self-clearance pathway that removes oxidized cellular components and regulates cellular ROS levels. ROS can modulate autophagy activity through transcriptional and posttranslational mechanisms. Autophagy further triggers transcription factor activation and degrades impaired organelles and proteins to eliminate excessive ROS in cells. Thus, autophagy may play an antioxidant role in protecting ocular cells from oxidative stress. Nevertheless, excessive autophagy may cause autophagic cell death. In this review, we summarize the mechanisms of interaction between ROS and autophagy and their roles in the pathogenesis of several ocular diseases, including glaucoma, age-related macular degeneration (AMD), diabetic retinopathy (DR), and optic nerve atrophy, which are major causes of blindness. The autophagy modulators used to treat ocular diseases are further discussed. The findings of the studies reviewed here might shed light on the development and use of autophagy modulators for the future treatment of ocular diseases.