Intravitreal Anti-Vascular Endothelial Growth Factor Therapies for Retinal Disorders

A look to the future: cyclodextrins and cyclodextrin-based drug delivery to the retina

INTRODUCTION

Retinal diseases are a leading cause of vision loss, affecting millions of people worldwide. Current treatment options are based on invasive methods such as intravitreal injections. Therefore, there is a need for alternative therapeutic strategies that are both effective and more patient-friendly.

AREAS COVERED

Topical drug delivery has gained attention as a preferred noninvasive approach, although it is hindered by several ocular barriers. Cyclodextrin (CD)-based nanoparticles have emerged as a promising strategy to overcome these limitations by enhancing drug permeability in the posterior segment of the eye. This review discusses the potential of CDs as enabling pharmaceutical excipients, their role in improving ocular drug bioavailability, and provides examples of CD-based eye drop formulations currently under development or undergoing clinical trials. Also, the role of CDs as active pharmaceutical agents in ophthalmology is discussed.

EXPERT OPINION

CD-based nanoparticle eye drops present a promising solution and have shown clinical success. CDs are approved pharmaceutical excipients for eye drop formulations and can act as active pharmaceutical ingredients for the treatment of inherent retinal diseases. Future innovations in hybrid CD-based delivery systems and integration of novel therapeutic compounds could provide more efficient and targeted treatment options for retinal diseases.

Advancements in regenerative medicine: a comprehensive review of stem cell and growth factor therapies for osteoarthritis

Osteoarthritis (OA) is a widely encountered degenerative joint disorder marked by gradual cartilage deterioration, inflammation, and pain, which collectively impose considerable strain on global healthcare systems. While traditional therapies typically offer relief from symptoms, they do not tackle the core pathophysiological aspects of the disease. Regenerative medicine has recently risen as a promising field for addressing OA, capitalizing on the regenerative capabilities of stem cells and growth factors to foster tissue healing and renewal. This thorough review delves into the most recent progress in stem cell and growth factor treatments for OA, covering preclinical studies, clinical trials, and novel technological developments. We discuss the diverse origins of stem cells, such as mesenchymal stem cells (MSCs), induced pluripotent stem cells (iPSCs), and adipose-derived stem cells (ASCs), underscoring their therapeutic actions and effectiveness in both preclinical and clinical environments. Moreover, we explore contributions of growth factors like transforming growth factor (TGF)-β, platelet-derived growth factor (PDGF), and insulin-like growth factor (IGF) in modifying OA's pathology and enhancing tissue restoration. Additionally, this review discusses the hurdles and constraints tied to current regenerative strategies, including the standardization of cell sources, the refinement of delivery techniques, and considerations for long-term safety. By meticulously assessing the latest research outcomes and technological breakthroughs, this review aims to shed light on the potential of stem cell and growth factor therapies as forthcoming therapeutic options for OA, thereby propelling forward the domain of regenerative medicine and enhancing clinical results for individuals afflicted with this incapacitating ailment.

Remote Monitoring of Patients with Retinal Vein Occlusions Treated with Anti-VEGF: A Pilot Study

Purpose: To assess the feasibility and effectiveness of remote monitoring for patients with retinal vein occlusion (RVO) treated with intravitreal anti-VEGF injections. Methods: A retrospective analysis was conducted at the Eye Clinic of the University of Catania. Thirty-four eyes of 34 patients with RVO were included for a 12-month follow-up period. After a comprehensive baseline ophthalmic examination, the patients received a loading treatment consisting of three monthly intravitreal injections of anti-VEGF, followed by monthly or bimonthly remote follow-up visits at peripheral centers. Optical coherence tomography (OCT) images and clinical data were shared online with our eye clinic for remote evaluations. Data on hospital and peripheral center visits, intravitreal injections, and OCT scans were collected and analyzed. Results: The patients had an average of 5.71 ± 1.14 visits to peripheral centers and 2.1 ± 0.8 visits to our center for fluorescein angiography. The mean number of injections was 5.26 ± 1.29 and the mean improvement in best-corrected visual acuity (BCVA) was 11.47 ± 5.56 letters. Remote OCT evaluations accounted for 194 scans, there was a high agreement between two expert in-hospital examinators (Cohen's κ = 0.927) with only 14 cases requiring hospital visits for inconclusive results. Conclusions: Remote monitoring for RVO patients significantly reduced hospital admissions for follow-up visits, reducing the clinical burden on medical staff, patients, and caregivers, while maintaining reliable patient assessments.

Construction of a predictive model for the efficacy of anti-VEGF therapy in macular edema patients based on OCT imaging: a retrospective study

Background

Macular edema (ME) is an ophthalmic disease that poses a serious threat to human vision. Anti-vascular endothelial growth factor (anti-VEGF) therapy has become the first-line treatment for ME due to its safety and high efficacy. However, there are still cases of refractory macular edema and non-responding patients. Therefore, it is crucial to develop automated and efficient methods for predicting therapeutic outcomes.

Methods

We have developed a predictive model for the surgical efficacy in ME patients based on deep learning and optical coherence tomography (OCT) imaging, aimed at predicting the treatment outcomes at different time points. This model innovatively introduces group convolution and multiple convolutional kernels to handle multidimensional features based on traditional attention mechanisms for visual recognition tasks, while utilizing spatial pyramid pooling (SPP) to combine and extract the most useful features. Additionally, the model uses ResNet50 as a pre-trained model, integrating multiple knowledge through model fusion.

Results

Our proposed model demonstrated the best performance across various experiments. In the ablation study, the model achieved an F1 score of 0.9937, an MCC of 0.7653, an AUC of 0.9928, and an ACC of 0.9877 in the test conducted on the first day after surgery. In comparison experiments, the ACC of our model was 0.9930 and 0.9915 in the first and the third months post-surgery, respectively, with AUC values of 0.9998 and 0.9996, significantly outperforming other models. In conclusion, our model consistently exhibited superior performance in predicting outcomes at various time points, validating its excellence in processing OCT images and predicting postoperative efficacy.

Conclusion

Through precise prediction of the response to anti-VEGF therapy in ME patients, deep learning technology provides a revolutionary tool for the treatment of ophthalmic diseases, significantly enhancing treatment outcomes and improving patients' quality of life.

To Treat or Not to Treat? Resolving the Question of Subretinal and Intraretinal Fluid in Age-Related Macular Degeneration: A Narrative Review

Neovascular age-related macular degeneration (nAMD) is associated with considerable quality of life and economic burden. nAMD is characterized by pathological neovascularization, leading to the accumulation of retinal fluid. Intraretinal fluid (IRF) is a major contributor to vision loss and may predict response to treatment. In contrast, the role of subretinal fluid (SRF) is less clear. Nevertheless, complete resolution of retinal fluid accumulation is often stated to be a key goal of therapy for nAMD, even though some eyes may never achieve a fluid-free macula despite regular anti-vascular endothelial growth factor treatment. In this article, we review the current literature regarding the role of retinal fluid in nAMD disease outcomes and assess whether and when it may be beneficial to leave retinal fluid untreated. In this context, we highlight the importance of correctly identifying retinal fluid types in nAMD and avoiding confusion with other optical coherence tomography signs that may respond differently to therapy, such as subretinal pseudocysts. Current evidence shows that IRF is associated with poor outcomes and an increased risk of developing atrophy and fibrosis; resolution of this retinal fluid type should remain a treatment target. However, the literature around SRF indicates that low levels of this fluid type, potentially up to 150-200 µm in thickness, may be tolerated with minimal impact on vision, and that SRF could be protective against the development and progression of macular atrophy and fibrosis. Although mild SRF may be protective in nAMD, cause and effect between SRF and reduced or slowed atrophy has not yet been proven and requires further research. Treatment should be given for the most aggressive component; when both IRF and SRF are present, treatment should be given for IRF.

Outcomes of Anti-VEGF Therapy in Eyes with Diabetic Macular Edema, Vein Occlusion-Related Macular Edema, and Neovascular Age-Related Macular Degeneration: A Systematic Review

Background

Anti-vascular endothelial growth factor (anti-VEGF) therapy has revolutionized the management of various ocular conditions, including diabetic macular edema (DME), retinal vein occlusion (RVO)-related macular edema (ME), and neovascular age-related macular degeneration (nAMD). However, there remains a need to systematically assess its effectiveness across these distinct conditions.

Methodology

A systematic review was conducted to identify studies evaluating the efficacy of anti-VEGF therapy in improving ocular outcomes in patients with DME, RVO-related ME, and nAMD. PubMed, Embase, and Cochrane Library databases were searched for relevant articles published up to 2024. Studies meeting the inclusion criteria were critically appraised, and data on the proportion of patients gaining ≥15 Early Treatment Diabetic Retinopathy Study (ETDRS) letters in best-corrected visual acuity (BCVA), mean change in BCVA (ETDRS letters), and reduction in central macular thickness (CMT) (μm) were extracted and synthesized.

Results

The systematic review identified 18 studies comprising randomized controlled trials, prospective studies, retrospective analyses, and observational studies. Anti-VEGF therapy demonstrated efficacy across all three conditions, with varying proportions of patients experiencing improvements in BCVA and reductions in CMT. Notably, the proportion of patients gaining ≥15 ETDRS letters ranged from 18.1% to 44.8% in DME, while mean changes in BCVA ranged from +4.2 letters to +21.4 letters in RVO-related ME and nAMD. Reductions in CMT ranged from 183.1 μm to 294 μm in DME and RVO-related ME.

Conclusion

Anti-VEGF therapy represents a cornerstone in the management of DME, RVO-related ME, and nAMD, with significant improvements observed in BCVA and reductions in CMT across diverse patient populations. While our findings support the effectiveness of anti-VEGF therapy in improving ocular outcomes, further research is warranted to compare its efficacy with alternative treatment modalities and to elucidate its long-term safety profile.

Intravitreal Faricimab for Previously Treated Neovascular Age-Related Macular Degeneration

Purpose

To report our real-world experience using intravitreal faricimab, a novel anti-vascular endothelial growth factor (anti-VEGF) therapy, in eyes with neovascular age-related macular degeneration (nAMD) previously treated with other anti-VEGF therapy.

Patients and Methods

A retrospective, single-center study of previously treated nAMD eyes treated with faricimab.

Results

In 88 eyes (73 patients), mean baseline best-corrected visual acuity (BCVA) was 20/63 (range 20/20 to CF) with mean anti-VEGF injection interval of 6.1+2.0 weeks. Mean baseline central subfield thickness (CST) was 291+73 µm. During mean follow-up of 30.1+13.5 (range 7.0 to 50.3) weeks on faricimab, the eyes received an average of 5.1+2.4 injections (range 1 to 11). Mean BCVA remained at 20/63 (p=0.11), but injection interval increased to 7.4+2.6 weeks (p<0.001), and CST decreased to 262+63 µm (p<0.001). Multiple linear regression analysis revealed that higher number of different anti-VEGF drugs used at baseline was associated with a lower decrease in CST on faricimab (p=0.04) while total number of anti-VEGF injections at baseline (p=0.56) and time on faricimab (p=0.68) were not associated. Faricimab was discontinued in 23 eyes (26.1%), including 8 eyes for poor response, 2 eyes for persistent new floaters and 4 eyes for new vision decrease which reversed after stopping faricimab.

Conclusion

In previously treated nAMD eyes, intravitreal faricimab was associated with increased mean treatment interval and decreased CST but no improvement in mean BCVA. The benefit of faricimab on CST reduction may be diminished in eyes previously treated with multiple different types of anti-VEGF therapy.

Suprachoroidal Triamcinolone Acetonide Injection to Treat Macular Edema: A Review

Purpose: To review the available literature on the efficacy and safety of suprachoroidal triamcinolone acetonide for the treatment of chorioretinal diseases. Methods: The results of the literature review were analyzed. Results: This review included 17 clinical studies of triamcinolone acetonide administration (6, diabetic macular edema; 1, central retinal vein occlusion [RVO]; 2, branch RVO; 7, noninfectious uveitis; 1, cystoid macular edema after cataract surgery). Overall, suprachoroidal triamcinolone acetonide was shown to be effective in decreasing macular thickness and increasing visual (VA) in cases of chorioretinal diseases. The most frequently reported adverse events were eye pain, cataract, and increased intraocular pressure. Conclusions: Except for 3 sufficiently powered trials of suprachoroidal triamcinolone acetonide for macular edema associated with noninfectious uveitis, most other studies were clinical trials with small samples. These studies found that suprachoroidal triamcinolone acetonide has a satisfactory safety and efficacy profile. Further research with sufficiently large samples is required to confirm the potential role of suprachoroidal triamcinolone acetonide in retinal diseases.

Advancements in Ocular Therapy: A Review of Emerging Drug Delivery Approaches and Pharmaceutical Technologies

Eye disorders affect a substantial portion of the global population, yet the availability of efficacious ophthalmic drug products remains limited. This can be partly ascribed to a number of factors: (1) inadequate understanding of physiological barriers, treatment strategies, drug and polymer properties, and delivery systems; (2) challenges in effectively delivering drugs to the anterior and posterior segments of the eye due to anatomical and physiological constraints; and (3) manufacturing and regulatory hurdles in ocular drug product development. The present review discusses innovative ocular delivery and treatments, encompassing implants, liposomes, nanoparticles, nanomicelles, microparticles, iontophoresis, in situ gels, contact lenses, microneedles, hydrogels, bispecific antibodies, and gene delivery strategies. Furthermore, this review also introduces advanced manufacturing technologies such as 3D printing and hot-melt extrusion (HME), aimed at improving bioavailability, reducing therapeutic dosages and side effects, facilitating the design of personalized ophthalmic dosage forms, as well as enhancing patient compliance. This comprehensive review lastly offers insights into digital healthcare, market trends, and industry and regulatory perspectives pertaining to ocular product development.

The Role of Adjunctive Triamcinolone Acetonide in Post-traumatic Vitreoretinal Surgery: Current Insights and Future Perspectives

Post-traumatic vitreoretinal surgery is pivotal for repairing damage to the retina and vitreous body, commonly resulting from blunt or penetrating ocular trauma. Incorporating adjunctive pharmacological agents, particularly triamcinolone acetonide (TA), has gained considerable prominence in optimizing surgical outcomes. TA, a potent corticosteroid, is applied intraoperatively to improve the visualization of vitreous structures and epiretinal membranes, enabling surgeons to perform more precise maneuvers. Furthermore, its anti-inflammatory properties are instrumental in reducing postoperative complications such as macular edema and proliferative vitreoretinopathy (PVR), conditions that could hinder recovery and compromise visual acuity. TA use during vitrectomy enhances surgical precision and contributes to a smoother postoperative recovery. However, concerns surrounding potential side effects, such as steroid-induced ocular hypertension and cataract formation, necessitate careful patient selection and close monitoring throughout its use. Looking ahead, innovations in sustained-release formulations and combination therapies may further augment TA efficacy while reducing associated risks. This review provides current insights into TA application in post-traumatic vitreoretinal surgeries and highlights emerging trends poised to enhance its therapeutic role.

Oxygen, the Paradox of Life and the Eye

Oxidative stress, caused by the formation of free radicals, such as reactive oxygen species (ROS), leads to cell and tissue degradation, contributing to various diseases and aging. While oxygen is essential for aerobic organisms, it inevitably causes oxidative stress. Antioxidants protect against damage from free radicals, and oxidative stress arises when an imbalance occurs between free radical production and antioxidant defenses. However, when investigating whether an excess of antioxidants, almost eliminating oxidative stress, could benefit aging and disease susceptibility, it was observed that a basic level of oxidative stress appears necessary to maintain the correct homeostasis of tissues and organs and life in general. Therefore, this review aimed to compile the most significant and recent papers characterizing and describing the dual role of oxygen as a molecule essential for life and as a precursor of oxidative stress, which can be detrimental to life. We conducted targeted searches in PubMed and Google browsers to gather all relevant papers. We then focused on the eye, an organ particularly vulnerable due to its high metabolic activity combined with direct exposure to light and environmental pollutants, which produces a substantial number of free radicals (mainly ROS). We present a curated selection of relevant literature describing the main ocular pathologies of the posterior and anterior segments of the eye, highlighting oxidative stress as a significant contributing factor. Additionally, we report how endogenous and exogenous antioxidants can mitigate the development and progression of these diseases. Finally, we consider a frequently overlooked aspect: the balance between oxidants and antioxidants in maintaining the homeostatic equilibrium of tissues and organs. It is widely recognized that when oxidants overwhelm antioxidants, oxidative stress occurs, leading to negative consequences for the organism's homeostasis. However, we emphasize that a similarly dangerous situation can arise when the presence of antioxidants overwhelms the production of free radicals, drastically reducing their amount and adversely affecting aging and longevity. Unfortunately, no specific studies have addressed this particular situation in the eye.

Clinical Outcomes and Experiences with Prefilled Syringes Versus Vials for Intravitreal Administration of Anti-VEGF Treatments: A Systematic Review

INTRODUCTION

Anti-vascular endothelial growth factor (VEGF) agents have been the standard treatment for retinal diseases for almost two decades. These treatments are administered via intravitreal injection using single-use vials or prefilled syringes (PFS). In this systematic review, we evaluate health care resource use and clinical outcomes and experiences with PFS for intravitreal injection of anti-VEGF treatments.

METHODS

MEDLINE, EMBASE, and The Cochrane Library were searched from January 1, 2015 to February 8, 2024 to identify literature reporting outcomes regarding procedural efficiency, health care resource use, patient and clinician experiences, and safety for currently approved anti-VEGFs (ranibizumab, aflibercept, brolucizumab) administered using PFS. Comparators were vial-based injections of the same anti-VEGFs.

RESULTS

A total of 36 publications met the criteria for inclusion in the systematic literature review; the majority were non-randomized studies, with a small number of reviews, case series, survey studies, and opinion articles. Publications reported that preparation times were significantly shorter for PFS (40.3-57.9 s) versus vials (ranibizumab, 62.8-98.0 s; aflibercept, 71.9-79.5 s), with no differences in product stability between PFS and vials. Clinicians expressed a preference for PFS and thought PFS were faster, easier to use, and had increased safety versus vials. Publications consistently reported significantly lower rates of endophthalmitis per injection with PFS versus vials (ranibizumab PFS, 0-0.02%; aflibercept PFS, 0.01-0.02%; ranibizumab vial, 0.02-0.05%; aflibercept vial, 0.02-0.06%). Four publications reported increased rates of transient vision loss after aflibercept PFS injection versus vial-based injection. No publications reported outcomes regarding health care resource use or patient experiences.

CONCLUSION

The available literature supports the increased procedural efficiency of PFS versus vial-based intravitreal injection of anti-VEGFs. PFS are positively perceived by clinicians and have a safety benefit in the form of a decreased risk of endophthalmitis versus vials.

Intravitreal Dexamethasone Implant Switch after Anti-VEGF Treatment in Patients Affected by Retinal Vein Occlusion: A Review of the Literature

Nowadays, retinal vein occlusion (RVO) is the second most prevalent cause of vision loss associated with retinal vascular disease. Intravitreal injections are currently known as a major advancement in ophthalmology, particularly in the treatment of RVO and other retinal disorders. Particularly, the first line of therapy is usually anti-vascular endothelial growth factor (VEGF) drugs. Notably, for RVO eyes that have not responded to anti-VEGF therapy, an intravitreal dexamethasone (DEX) implant 0.7 mg (Ozurdex®, AbbVie Inc., North Chicago, IL, USA) is considered a suitable therapeutical substitute. Actually, investigations carried out in the real world and clinical trials have shown the safety and the efficacy of intravitreal DEX implants for treating this retinal disease. For this reason, choosing patients carefully may thus be essential to reduce the number of injections that clinics and hospitals have to do to manage RVO and its complications. The primary aim of this review is to summarize the pathophysiology of this retinal vascular disease, as well as the clinical and ocular imaging features that may support a switch from prior anti-VEGF treatment to intravitreal DEX implant, to provide the RVO patients with the best possible treatment to ensure maximum visual recovery.

[Conbercept reverses TGF-β2-induced epithelial-mesenchymal transition in human lens epithelial cells by regulating the TGF-β/Smad signaling pathway]

OBJECTIVE

To investigate the mechanism by which conbercept reverses transforming growth factor-β2 (TGF-β2)-induced epithelial-mesenchymal transition (EMT) in human lens epithelial cells (HLECs).

METHODS

Cultured HLEC SRA01/04 cells were treated with TGF-β2, conbercept, or both, and the changes in cell proliferation, apoptosis, and migration were observed using MTT assay, flow cytometry, scratch assay, and Transwell assay. Western blotting and qRT-PCR were used to detect the changes in the expression of EMT-related epithelial cell markers (E-Cadherin, α-SMA, and Snail), extracellular matrix components, and genes related to the TGF-β/Smad signaling pathway.

RESULTS

Conbercept significantly reduced TGF-β2-induced EMT of SRA01/04 cells, decreased the expression levels of mesenchymal and extracellular matrix markers α-SMA, Snail, collagen I, collagen IV, and FN1, and upregulated the protein and mRNA expressions of E-cadherin (P <0.05). Transwell assay showed significantly lower cell migration ability in TGF-β2+conbercept group than in TGF-β2 group (P <0.05). Conbercept also inhibited the increase in Smad2/3 phosphorylation levels in HLEC-SRA01/04 cells with TGF-β2-induced EMT (P <0.01).

CONCLUSION

Conbercept inhibits TGF-β2 induced EMT by downregulating the expression of pSmad2/3 in TGF-β/Smad signaling pathway, indicating a potential therapeutic strategy against visual loss induced by posterior capsule opacification.

Olink Profiling of Aqueous Humor Identifies Novel Biomarkers for Wet Age-Related Macular Degeneration

Metabolic dysfunction is recognized as a contributing factor in the pathogenesis of wet age-related macular degeneration (wAMD). However, the specific metabolism-related proteins implicated in wAMD remain elusive. In this study, we assessed the expression profiles of 92 metabolism-related proteins in aqueous humor (AH) samples obtained from 44 wAMD patients and 44 cataract control patients. Our findings revealed significant alterations in the expression of 60 metabolism-related proteins between the two groups. Notably, ANGPTL7 and METRNL displayed promising diagnostic potential for wAMD, as evidenced by area under the curve values of 0.88 and 0.85, respectively. Subsequent validation studies confirmed the upregulation of ANGPTL7 and METRNL in the AH of wAMD patients and in choroidal neovascularization (CNV) models. Functional assays revealed that increased ANGPTL7 and METRNL played a pro-angiogenic role in endothelial biology by promoting endothelial cell proliferation, migration, tube formation, and spouting in vitro. Moreover, in vivo studies revealed the pro-angiogenic effects of ANGPTL7 and METRNL in CNV formation. In conclusion, our findings highlight the association between elevated ANGPTL7 and METRNL levels and wAMD, suggesting their potential as novel predictive and diagnostic biomarkers for this condition. These results underscore the significance of ANGPTL7 and METRNL in the context of wAMD pathogenesis and offer new avenues for future research and therapeutic interventions.

A promising case of preclinical-clinical translation: β-adrenoceptor blockade from the oxygen-induced retinopathy model to retinopathy of prematurity

Although compartmentalization of the eye seems to promote its experimental manipulation, drug penetration to its posterior part is severely limited by hard barriers thus hindering drug development for eye diseases. In particular, angiogenesis-related retinal diseases share common mechanisms and are responsible for the majority of cases of blindness. Their prevalence is globally increasing mostly because of the increased incidence of systemic pathologies in the adult. Despite the number of preclinical findings demonstrating the efficacy of novel treatments, therapy of retinal neovascular diseases still remains confined to intravitreal anti-vascular endothelial growth factor treatments with some extension to anti-inflammatory therapy. In the mare magnum of preclinical findings aimed to develop novel avenues for future therapies, most compounds, despite their efficacy in experimental models, do not seem to meet the criteria for their therapeutic application. In particular, the groove between preclinical findings and their clinical application increases instead of decreasing and the attempt to bridging the gap between them creates intense frustration and a sense of defeat. In this complex scenario, we will discuss here the role that overactivation of the sympathetic system plays in retinal vessel proliferation in response to hypoxia using the oxygen-induced retinopathy (OIR) model. The potential application of the beta-adrenoceptor (β-AR) blockade with propranolol to the treatment of retinopathy of prematurity will be also discussed in light of preclinical findings in the OIR model and clinical trials using propranolol in preterm infants either per os or as eye drops.

Retrospective analysis of the etiology and drugs for vitreous hemorrhage caused by non-diabetic retinopathy and non-traumatic factors

OBJECTIVE

To retrospectively analyze the etiology of non-diabetic retinopathy (DR) and non-traumatic vitreous haemorrhage (VH), and the effects of different anti-vascular endothelial growth factor (VEGF) drugs.

METHODS

A retrospective analysis was conducted on VH patients diagnosed as non-diabetic retinopathy or trauma. Among 101 patients treated with anti-VEGF drugs, there were 48 cases in the Conbercept group and 53 cases in the Ranibizumab group. The causes of bleeding and gender distribution of the included cases were analyzed.

RESULTS

In cases of retinal vein occlusion, the proportion of males was much higher than females (p < 0.05). After treatment, the best corrected visual acuity (BCVA), intraocular pressure, central macular thickness (CMT), aqueous humor VEGF, TNF-α, IL-10, and IL-6 of the two groups showed a decreasing trend (p < 0.05). The Conbercept group had markedly lower CMT than the Ranibizumab group (p < 0.05). In addition, there existed no significant statistical differences between the two groups in terms of BCVA, intraocular pressure, aqueous humor VEGF, TNF-α, IL-10, IL-6, incidence of adverse reactions, and recurrence rate (p > 0.05).

CONCLUSION

In patients with non-DR and traumatic VH, retinal vein occlusion, perivenous retinitis, retinal tears/detachment, exudative AMD, and polypoidal choroidal vasculopathy were the main etiologies. Conbercept and Ranibizumab had comparable efficacy and could effectively improve visual acuity and aqueous humor inflammation, with high safety and low recurrence rate. Conbercept had a more pronounced effect on the reduction of CMT in patients.

Regression of Neovascularization after Panretinal Photocoagulation Combined with Anti-VEGF Injection for Proliferative Diabetic Retinopathy-A Review

Proliferative diabetic retinopathy (PDR) poses a significant therapeutic problem that often results in severe visual loss. Panretinal photocoagulation (PRP) has long been a mainstay treatment for this condition. Conversely, intravitreal anti-VEGF therapy has served as an alternative treatment for PDR. This review aimed to evaluate the effects of PRP combined with anti-VEGF therapy on the regression of neovascularization (NV), including functional outcomes and incidence of complications. The MEDLINE database was searched for articles evaluating regression of NV using a combination of the following terms: "proliferative diabetic retinopathy", "anti-VEGF", "panretinal photocoagulation", and "combined treatment". The search yielded a total of 22 articles. The analysis of their results indicated PRP combined with ant-VEGF therapy as superior over PRP alone in the management of PDR. Combination treatment yields better and faster regression of NV and a lower incidence of serious complications, such as vitreous hemorrhage and the need for pars plana vitrectomy. Nevertheless, complete regression of NV is not achieved in a significant proportion of patients. Further research is needed to establish the most effective schedule for intravitreal injections as an adjunct to PRP. The current literature shows that in some cases, cessation of anti-VEGF injection in combination treatment for PDR can lead to relapse of NV.

Release of Pro-Inflammatory/Angiogenic Factors by Retinal Microvascular Cells Is Mediated by Extracellular Vesicles Derived from M1-Activated Microglia

The interactions between the neuronal and vascular sides of the retina during diabetic retinopathy (DR) have gained increasing attention. Microglia is responsible for the immune response to inflammation inside the retina, which could be mediated by paracrine signals carried by extracellular vesicles (EVs). We aimed to characterize EVs released from immortalized human microglial cells in inflammation and investigate their effects on the retinal microvasculature and the anti-inflammatory potential of thiamine in this context. M1 pro-inflammatory polarization in microglia was induced through a cytokine cocktail. EVs were isolated from the supernatants, characterized, and used to stimulate human retinal endothelial cells (HRECs) and pericytes (HRPs). Microvascular cell functions and their release of pro-inflammatory/angiogenic factors were assessed. M1-derived EVs showed increased content of miR-21, miR-155, CCL2, MMP2, and MMP9, and enhanced apoptosis, proliferation, migration, and ROS production in HRPs and HRECs. IL-1β, IL-6, MMP9, CCL2, and VEGF release increased in HRPs exposed to M1-derived EVs, while HRECs showed augmented IL-6, Ang2, VEGF, and PDFG-B. Addition of thiamine to M1-microglial cultures reverted most of these effects. In conclusion, M1-derived EVs stimulate functional changes and secretion of pro-inflammatory/angiogenic molecules in microvascular cells, exacerbating inflammatory damage and retinopathy features. Thiamine added to microglia exerts anti-inflammatory effects.