Photocoagulation for retinal vein occlusion

Exploring the potential of rho kinase inhibitors in ophthalmology: From mechanisms to clinical practice

INTRODUCTION

The therapeutic potential of rho kinase (ROCK) inhibitors in ophthalmology is gaining attention, given their multifaceted role in cellular regulation, particularly within ocular pathologies. This review synthesizes findings from clinical and preclinical studies on the efficacy and safety of ROCK inhibitors across glaucoma, corneal, and retinal diseases. We performed a systematic database search in Ovid MEDLINE and Ovid Embase on 5th April 2022 using the following keywords: 'primary open angle glaucoma', 'glaucoma surgery', 'corneal wound healing', 'corneal endothelial dysfunction', 'diabetic retinopathy', 'diabetic macular oedema', 'age-related macular degeneration', 'rho kinase inhibitor', 'rho-kinase inhibitor', rock inhibitor', 'ripasudil', 'netarsudil' and 'fasudil'. Abstracts were screened for relevant studies and results summarized in tables. The analysis of trials done for ROCK inhibitors reveals that they are safe and efficacious drugs, demonstrating noninferiority to existing medical treatments and effective when combined with existing treatments, and are approved for use in treating glaucoma, but not corneal or retinal diseases. Questions remain, however, regarding optimal dosage, patient selection, and cost-effectiveness. ROCK inhibitors demonstrate significant efficacy in reducing intraocular pressure by improving aqueous humour outflow. Additionally, ROCK inhibitors show promise in enhancing endothelial cell migration, thus providing a novel treatment avenue for corneal diseases such as Fuchs endothelial dystrophy. In retinal conditions, including diabetic retinopathy and age-related macular degeneration, ROCK inhibitors reduce vascular permeability, inflammation, and fibrosis, stabilising disease progression.

Catalytic neural stem cell exosomes for multi-stage targeting and synergistical therapy of retinal ischemia-reperfusion injury

Neuronal damage of the retina is a leading cause of visual impairment in patients with retinal ischemia-reperfusion injury (RIRI). Building on our clinical and experimental findings, the substantial decrease in catalase activity correlates with increased hydrogen peroxide (H2O2)-mediated oxidative stress that is primarily localized to the outer nuclear layer (ONL) situated in the posterior segment of the retina. Accordingly, we design a neural stem cell exosome with polylysine (K10) decoration and catalase expression, named CataKNexo, which reaches the ONL and exerts synergistic antioxidant and neuroprotective therapy. Utilizing an in vitro retinal model recapitulating the layered architecture of the retina, we confirm that CataKNexo reaches the ONL through K10-mediated transcytosis. In RIRI model mice, CataKNexo prevents the retina from H2O2-induced cell death, exerts neuroprotection, and restores vision function to near-normal levels. Moreover, CataKNexo shows promising antioxidative, neuroprotective, and safety profiles in RIRI model Bama miniature pigs, highlighting its potential for clinical translation.

Radiomics Analysis Based on Optical Coherence Tomography to Prognose the Efficacy of Anti-VEGF Therapy of Retinal Vein Occlusion-Related Macular Edema

Purpose

Anti-vascular endothelial growth factor (anti-VEGF) agents are the first-line treatment for retinal vein occlusion-related macular edema (RVO-ME). However, the availability of reliable radiomic markers for evaluating the effectiveness of these agents is currently limited. The aim of this study was to develop machine learning approaches to evaluate the post-therapeutic effect of anti-VEGF treatment based on optical coherence tomography (OCT) images.

Methods

A total of 152 patients diagnosed with RVO-ME who received at least one intravitreal injection of anti-VEGF were included in this study, as well as 81 patients as the external validation set. Pre-therapeutic B-scans of spectral-domain OCT images were collected and segmented using the Pyradiomics module within the 3D Slicer software platform. Radiomic features were extracted from the segmented images. We trained the logistic regression model and machine learning models using the selected features, and evaluated the performance of the three classifier models.

Results

In the back propagation neural network (BPNN) model, the area under the curve (AUC) of the training, test, and external validation sets were 0.977, 0.912, and 0.804, respectively. In the support vector machine (SVM) model, the AUC of the 3 sets were 0.916, 0.882, and 0.802. The OCT-omics scores indicated a high overall net benefit, as determined by decision curve analysis.

Conclusions

The machine learning models based on OCT technology developed here demonstrated a promising ability to prognose anti-VEGF therapeutic responses for RVO-ME. The utilization of machine learning provides a new promising approach to assessing radiomic markers in research related to RVO-ME, having a good prospect for the application of the using of precision medicine in ophthalmology.

Risk Factors for Developing Neovascular Glaucoma in Central Retinal Vein Occlusion: Two-Year Real-World Study

PURPOSE

To explore potential risk factors for the development of neovascular glaucoma (NVG) in central retinal vein occlusion (CRVO) over a two-year intensive follow-up period.

METHODS

This study reviewed 1545 patients with CRVO between 2005 and 2019 at Taipei Veterans General Hospital. Inclusion was restricted to (1) patients with acute CRVO within 3 months; (2) patients with ocular neovascularization at initial presentation (3) patients had not received any treatment at the time of CRVO; (4) at least bimonthly follow-up schedule over the course of 2 years. The included patients were screened for potential risk factors for developing NVG and assessed with Kaplan-Meier survival analysis and Cox regression model.

RESULTS

Among the included 123 patients, the cumulative probability of developing NVG was 26.8% (33/123 cases) in overall follow-up period. The mean interval between the onset of CRVO and NVG was 507 days. Neither macular edema nor central macular thickness at baseline was correlated with the development of NVG (p =.104 and .25, respectively). Patients with diabetes mellitus (DM), older age, and poor vision independently played significant risk factors for developing NVG after controlling other covariates. (p =.034, .001, and .013, respectively).

CONCLUSIONS

Patients presenting with CRVO who have comorbidities such as DM, older age, and worse VA warrant closer attention and intensive follow-up for the development of NVG. Additionally, the statistical analysis indicated that the presence of macular edema, increased central macular thickness, CV events, history of glaucoma, and early PRP within 3 months had no significant impact on the likelihood of developing NVG.

Risk factors of retinal vein occlusion in East Asia: a meta-analysis

Objective

With the intention of developing a more targeted control strategy for retinal vein occlusion (RVO) in East Asian populations, a meta-analysis was conducted to evaluate the risk factors associated with RVO in this region.

Methods

PubMed, Web of Science, Cochrane Library, CNKI, Wanfang and VIP databases were searched for studies that reported risk factors of RVO in East Asia, published from the establishment of the database to May 2024. To further filter the articles, Newcastle-Ottawa Scale (NOS) evaluation method was utilized to assess the quality of selected articles. After valid data were extracted, Meta-analysis was performed by Review Manager software.

Results

A total of 21 literatures were included, including 27561 cases in the RVO group (Case group) and 514578 cases in the non-retinal vein occlusion (NRVO) group (Control group). Results of meta-analysis showed that chronic kidney disease [odds ratio (OR)=4.14, 95% confidence interval (CI): (1.86%, 9.24%)], hypertension [OR=4.11, 95% CI: (3.09%, 5.48%)], hyperlipidemia [OR=3.45, 95%CI: (2.32%, 5.12%)], diabetes mellitus [OR=3.00, 95%CI: (1.88%, 4.80%)], homocysteine [OR=0.87, 95%CI: (0.59%, 1.15%)], have statistically significant differences between the RVO group and the NRVO group(P<0.05).

Conclusion

The occurrence of RVO is closely related to its risk factors, such as chronic kidney disease, hypertension, hyperlipidemia, diabetes mellitus and high homocysteine. In the process of diagnosis and treatment of RVO, doctors should focus on the above risk factors to prevent the occurrence of the disease.

From Monotherapy to Combination Strategies: Redefining Treatment Approaches for Multiple-Cause Macular Edema

Macular edema (ME) is a leading cause of visual impairment in various retinal disorders. Current treatment modalities, including anti-vascular endothelial growth factor (anti-VEGF) agents and corticosteroids, often require repeated applications, increasing both medical and economic burdens. ME is driven by chronic inflammation and VEGF overexpression, causing fluid accumulation in the macula. Recent studies have highlighted the role of various cytokines in ME pathogenesis, necessitating a comprehensive approach to treatment. While monotherapies have shown efficacy, they are associated with limitations such as the need for frequent injections and potential side effects. Combination therapies, including anti-VEGF drugs with macular laser photocoagulation, triamcinolone acetonide, or dexamethasone intravitreal implant (Ozurdex), have emerged as promising strategies. This review analyzes the outcomes of various combination approaches in different types of ME, including diabetic macular edema (DME), retinal vein occlusion-associated ME (RVO-ME), and uveitic macular edema (UME). The potential benefits of combining anti-VEGF and anti-inflammatory treatments are discussed, along with the need for personalized treatment regimens. Future research directions are outlined, emphasizing the importance of large-scale, long-term studies to evaluate the sustained efficacy and safety of combination therapies. The integration of advanced imaging techniques, biomarker analysis, and innovative therapeutic approaches is expected to shape the future landscape of ME management, moving towards more targeted and effective combination therapies.

Structural and Vascular Features of Macula Related to the Recurrence of Macular Edema in Central Retinal Vein Occlusion After Anti-VEGF Therapy

Purpose: To identify the structural and vascular features of the macula related to the recurrence of macular edema (ME) in central retinal vein occlusion (CRVO) after intravitreal anti-VEGF injections. Methods: This was a cross-sectional study including CRVO patients without ME and age-matched individuals. CRVO patients were divided into the ME-resolved group and the ME-recurrence group on the basis of whether ME recurred within 3 months. All subjects provided a detailed history and underwent a comprehensive ophthalmological examination. Measurements of the macula by swept-source optical coherence tomography angiography (SS-OCTA) were recorded. We also created the Δparameter, which represents the difference in OCTA parameters between CRVO-affected eyes and their fellow eyes. Results: The study included 13 ME-resolved CRVO patients, 20 ME-recurrence CRVO patients, and 24 age-matched controls. Compared with the ME-recurrence group, the ME-resolved group had a longer CRVO duration, more previous intravitreal anti-VEGF injections, and a higher proportion of previous retinal photocoagulation (all p < 0.05). Additionally, retinal thickness (RT) and choroidal thickness (CT) were thinner in the ME-resolved group than in the ME-recurrence and control groups (all p < 0.01). The ME-resolved group also had significantly lower vessel density (VD) in both superficial and deep vascular complexes (SVC/DVC) and larger foveal avascular zone area (FAZa) in SVC and DVC than the ME-recurrence group and the control group (all p < 0.01). The results were the same with the Δparameters. Multivariate logistic regression revealed that ΔVD and ΔFAZa in SVC and DVC were independently associated with ME recurrence after adjusting for the effects of CRVO duration, previous anti-VEGF injections, and retinal photocoagulation (all p < 0.05). Conclusion: With prolonged CRVO duration, more anti-VEGF injections, and more retinal photocoagulation procedures, retinal, choroidal, and vascular atrophy in the macula occurs in CRVO eyes, making ME less likely to recur. Macular vascular atrophy is vital for the resolution of ME and might be a manifestation of capillary remodeling.

Dynamic Complement Protein Changes in Aqueous Humor and Plasma of Patients With Retinal Vein Occlusion During Ranibizumab Treatment

Purpose

To assess dynamic changes of complement protein in aqueous humor (AH) and plasma of retinal vein occlusion (RVO) patients during ranibizumab treatment, and to explore the differential expression of complement proteins in branch retinal vein occlusion (BRVO) and central retinal vein occlusion (CRVO).

Patients and Methods

This prospective, consecutive case series study collected AH and plasma samples from 27 RVO patients at baseline, 1 and 2 months after ranibizumab treatment, including 19 BRVO and 8 CRVO patients. The concentrations of 13 complement proteins and vascular endothelial growth factor A (VEGF-A) were measured using Luminex® × MAP® technology.

Results

During ranibizumab treatment, a reduction in the levels of C1q (p < 0.001), C2 (p = 0.030), C4 (p = 0.001), C4b (p = 0.026), C3b/iC3b (p < 0.001), C5 (p = 0.007), C5a (p = 0.005), CFD (p = 0.022), CFH (p < 0.001), and CFI (p < 0.001) in AH was observed. No significant changes were observed in the plasma levels of all measured factors. At baseline, CRVO had higher levels of C4 (p = 0.003), C4b (p < 0.001), C3b/iC3b (p < 0.001), C5 (p = 0.020), C5a (p = 0.007), CFD (p = 0.002), CFH (p < 0.001), and CFI (p < 0.001) in AH compared to BRVO.

Conclusion

Ranibizumab treatment reduced the intraocular but not circulating activation of classical and alternative complement pathways in RVO patients. Differences in intraocular complement proteins were observed between BRVO and CRVO patients, which may reflect different pathogenesis.

Untargeted Metabolomic Study of Patients with Macular Edema Secondary to Retinal Vein Occlusion in Aqueous Humor

Purpose

The aim of this study was to identify metabolic biomarkers and investigate the metabolic changes associated with aqueous humor in retinal vein occlusion macular edema (RVO-ME).

Methods

Aqueous humor (AH) samples were collected from patients, including those diagnosed with central retinal vein occlusion macular edema (CRVO-ME), branch retinal vein occlusion macular edema (BRVO-ME), and a control group undergoing cataract surgery. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was utilized to analyze the metabolomic profiles in aqueous humor.

Results

A total of 28 metabolites were identified as potential biomarkers capable of distinguishing RVO-ME patients from the control group. Of these, 26 metabolites were specific for distinguishing CRVO-ME patients from controls, and 24 metabolites were specific for differentiating BRVO-ME patients from controls. Additionally, 9 metabolites were identified that could differentiate CRVO-ME patients from BRVO-ME patients.

Conclusion

This study successfully identified significant metabolic biomarkers that enhance our understanding of the pathogenesis of RVO-ME. These findings may offer new avenues for the treatment of RVO-ME and aid in differentiating between CRVO-ME and BRVO-ME patients.

Teleguided photocoagulation treatments across continents with a remotely programmed laser for retinal diseases

Diabetic retinopathy and retinal vein occlusion represent two prevalent vision-threatening retinal diseases. Retinal laser therapy still plays an important role in treating these conditions, but its successful administration often requires referral to specialized centers and retina experts. It is, therefore, essential to develop a new treatment methodology that enables patients to benefit from the expertise of specialists from reference centers. For this purpose, we investigated the feasibility of teleguided photocoagulation conducted across continents to determine if different ophthalmologists can consensually devise and safely execute treatment plans remotely. Two patients from Italy (Europe) with diabetic retinopathy and one from Arizona (USA) with central retinal vein occlusion underwent retinal photocoagulation using Navilas® 577s with remote teleguidance from the corresponding continental counterpart. The process included remote planning and execution, supported by an audio connection for real-time communication. Teletreatment success criteria included treatment plan completion, patient tolerance, remote connection stability, and technical quality. All treatments have been successfully performed with accurate spot application and no technical issues. Follow-ups at three weeks confirmed positive outcomes for each patient. Remote teleguided retinal photocoagulation appears feasible, offering a promising tool for global collaborations in retina care and potential benefits to regions with limited access to expert supervision.

Near-infrared imaging retinal diagnostic applications-a review

OBJECTIVE

Near-infrared reflectance (NIR) is a commonly performed noncontact and rapid imaging technique. This paper reviews the clinical applications of NIR for diagnosing and monitoring retinal diseases.

METHODS

A comprehensive search was conducted across the Pubmed database. A total of 105 articles were finally included in this article. Images were acquired from the authors own clinical experience.

RESULTS

The article describes the imaging utility of NIR for diagnosing and deomonstrating findings in various conditions. These include retinal vascular diseases, age-related macular degeneration (AMD), vitreoretinal interface pathologies, retinal dystrophies, inflammatory chorioretinopathies, phakomatoses, retinal toxicities, photic injury, choroidal cavitary lesions, choroidal neoplasms, and choroidal Vascular Lesions.

CONCLUSION

NIR is widely acquired during OCT imaging, and is advantageous at imaging with low illumination levels and through narrow pupils or opaque media. NIR offers valuable information for the diagnosis and follow-up of retinal disease, and is highly recommended to utilize for clinical decision-making in ophthalmology.

Drug-induced retinal vein occlusion: a disproportionality analysis from the FDA adverse event reporting system (2004-2023)

Introduction

Retinal vein occlusion (RVO) often causes irreversible visual impairment, making early prevention crucial. This study aims to identify associations between different medications and RVO and provide information for clinical practice.

Method

This study included reports of RVO from the FDA Adverse Event Reporting System (FAERS) database from the first quarter (Q1) of 2004 to the fourth quarter (Q4) of 2023. The reported drugs were analyzed for adverse drug reaction (ADR) signals using four disproportionality algorithms. Kaplan-Meier curves and median time to onset were used to evaluate the drugs.

Results

From 2004 to 2023, the FAERS database recorded 6,151 reports associated with RVO. Disproportionality analyses identified 25 drugs significantly associated with RVO. Mirabegron showed the highest risk signal, followed by Raloxifene, Tadalafil, Fingolimod, and Bimatoprost. These high-risk drugs are distributed across different therapeutic areas, including urogenital system and sex hormones, ophthalmic drugs, nervous system drugs, musculoskeletal system drugs, anti-tumor and immune-modulating drugs, and anti-parasitic drugs. Specific drug targets such as adrenergic receptor agonists, hormone regulators, and PDE5 inhibitors were identified as high risk. Ophthalmic drugs exhibited the longest median time to adverse ocular reactions at 532.01 days, followed by anti-parasitic drugs, nervous system drugs, urogenital system and sex hormone drugs, anti-tumor and immune-modulating drugs, and musculoskeletal system drugs.

Conclusion

This study provides an overview of drug-induced RVO, identifying potential culprit drugs and their distribution characteristics. These findings enhance understanding of medication safety and help optimize clinical practice.

Baicalin alleviates the injury of human retinal pigment epithelium cells and improves branch retinal vein occlusion in rats by inhibiting the HIF-1α/VEGFA axis

BACKGROUND

At present, relevant studies have found that baicalin can improve macular edema (ME) caused by glaucoma, but the effect on branch retinal vein occlusion (BRVO) is still unclear.

METHODS

The CoCl2-stimulated ARPE-19 cells were treated with different concentrations of baicalin and detected cell viability, apoptosis and oxidative stress. Next, the hypoxia-inducible factor-1α (HIF-1α) overexpression vector or siRNA were transfected into CoCl2-stimulated ARPE-19 cells, and the cell changes were detected. We searched the potential binding proteins of HIF-1α through the online database, and screened vascular endothelial growth factor A (VEGFA) as the research object. The CoCl2-stimulated ARPE-19 cells were treated with baicalin alone, or transfected with HIF-1α overexpression vector, or transfected with HIF-1α overexpression vector and VEGFA siRNA, and the cell changes were detected. Finally, we verified the therapeutic effect of baicalin on BRVO rats in vivo.

RESULTS

Baicalin inhibited CoCl2-induced apoptosis, inflammation and oxidative stress in ARPE-19 cells, and baicalin inhibited HIF-1α protein expression. In CoCl2-induced hypoxia cells, HIF-1α aggravated apoptosis, inflammation and oxidative stress, while HIF-1α silencing alleviated cell damage. Mechanism study showed that in baicalin-treated CoCl2-induced cells, VEGFA protein expression decreased and cell damage was improved, but this protective effect was counteracted by HIF-1α, and VEGFA silencing again inhibited apoptosis, inflammation and oxidative stress. Baicalin inhibited HIF-1α and VEGFA protein expression in the retinal tissue of BRVO rats, reduced injury, and promoted the recovery of ganglion cell layer.

CONCLUSIONS

Baicalin alleviated ARPE-19 cell injury and improved BRVO in rats by inhibiting HIF-1α/VEGFA axis in vivo and in vitro.

Ganglion cell-derived LysoPS induces retinal neovascularisation by activating the microglial GPR34-PI3K-AKT-NINJ1 axis

Retinal neovascularisation is a major cause of blindness in patients with proliferative diabetic retinopathy (PDR). It is mediated by the complex interaction between dysfunctional ganglion cells, microglia, and vascular endothelial cells. Notably, retinal microglia, the intrinsic immune cells of the retina, play a crucial role in the pathogenesis of retinopathy. In this study, we found that lysophosphatidylserines (LysoPS) released from injured ganglion cells induced microglial extracellular trap formation and retinal neovascularisation. Mechanistically, LysoPS activated the GPR34-PI3K-AKT-NINJ1 signalling axis by interacting with the GPR34 receptor on the microglia. This activation upregulated the expression of inflammatory cytokines, such as IL-6, IL-8, VEGFA, and FGF2, and facilitated retinal vascular endothelial cell angiogenesis. As a result, inhibition of the GPR34-PI3K-AKT-NINJ1 axis significantly decreased microglial extracellular trap formation and neovascularisation by suppressing LysoPS-induced microglial inflammatory responses, both in vitro and in vivo. This study reveals the crucial role of apoptotic ganglion cells in activating microglial inflammation in PDR, thereby enhancing our understanding of the pathogenesis of retinal neovascularisation.

Associations between the Vessel Density in Deep Vascular Plexus and Macular Edema Recurrences in Patients with Retinal Vein Occlusion

INTRODUCTION

The aim of this study was to study the relationships between vessel density (VD) in different retinal vascular plexus and retinal vein occlusion-macular edema (RVO-ME) recurrence using wide-field swept source optical coherence tomography angiography (OCTA).

METHODS

Patients with a history of central retinal vein occlusion (CRVO) or branch retinal vein occlusion (BRVO) with macular edema in the Department of Ophthalmology, Shanghai General Hospital, from May 25, 2020, to January 12, 2023, were retrospectively reviewed and recruited. All patients were followed up for at least 6 months and divided in the release group and the recurrence group. The optical coherence tomography and OCTA examination were performed. Demographics, retinal structural, and angiographic data were collected and compared between two groups. The ordinal logistic regression was performed to assess the risk factors for RVO-ME.

RESULTS

A total of 85 patients were enrolled in this study. Among them, 30 patients had CRVO, while 55 had BRVO. The VD in the 6-9 mm ring in deep vascular plexus (DVP) was significantly higher in the recurrence group (25.414 ± 6.068% in the release group vs. 27.574 ± 7.767% in the recurrence group, p = 0.036). More patients with mean VD of the 6-9 mm ring in DVP no less than 30% were observed in the recurrence group (observed n = 20, expected n = 14.4, p = 0.043). The ordinal logistic regression reported that patients with mean VD of the 6-9 mm ring in DVP ≥30% had risk of RVO-ME increased to 11.508 (95% CI: 1.745-75.944, p = 0.011), when compared to the patients with mean VD of the 6-9 mm ring in DVP <20%, even with RVO type, baseline central macular thickness weighed.

CONCLUSION

High vessel density of the 6-9 mm ring in DVP, especially those ≥30%, was associated with macular edema recurrences in patients with retinal vein occlusion.

Visual Function Measurements in Eyes With Diabetic Retinopathy: An Expert Opinion on Available Measures

Clinical Relevance

Visual function impairment from diabetic retinopathy can have a considerable impact on patient's quality of life. Best-corrected visual acuity (BCVA) is most commonly used to assess visual function and guide clinical trials. However, BCVA is affected late in the disease process, is not affected in early disease, and does not capture some of the visual disturbances described by patients with diabetes. The goal of this report is to evaluate the relationship between diabetic retinal disease (DRD) and visual function parameters to determine which if any of them may be used in a future DRD staging system.

Methods

The visual functions working group was 1 of 6 areas of DRD studied as part of the DRD staging system update, a project of the Mary Tyler Moore Vision Initiative. The working group identified 12 variables of possible interest, 7 of which were judged to have sufficient preliminary data to suggest an association with DR to warrant further review: microperimetry, static automated perimetry, electroretinogram (ERG) oscillatory potentials, flicker ERG, low luminance visual acuity (LLVA), contrast sensitivity (CS), and BCVA. The objective field analyzer (OFA) was added after subsequent in-person workshops.

Results

Currently, the only visual function test available for immediate use is BCVA; the remaining tests are either promising (within 5 years) or have potential (>5 years) use. Besides BCVA, most visual function tests had a limited role in current clinical care; however, LLVA, CS, flicker ERG, and OFA demonstrated potential for screening and research purposes.

Conclusions

Although current visual function tests are promising, future prospective studies involving patients with early and more advanced retinopathy are necessary to determine if these tests can be used clinically or as endpoints for clinical studies.

Financial Disclosures

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

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.

Innovative Nanotechnology in Drug Delivery Systems for Advanced Treatment of Posterior Segment Ocular Diseases

Funduscopic diseases, including diabetic retinopathy (DR) and age-related macular degeneration (AMD), significantly impact global visual health, leading to impaired vision and irreversible blindness. Delivering drugs to the posterior segment of the eye remains a challenge due to the presence of multiple physiological and anatomical barriers. Conventional drug delivery methods often prove ineffective and may cause side effects. Nanomaterials, characterized by their small size, large surface area, tunable properties, and biocompatibility, enhance the permeability, stability, and targeting of drugs. Ocular nanomaterials encompass a wide range, including lipid nanomaterials, polymer nanomaterials, metal nanomaterials, carbon nanomaterials, quantum dot nanomaterials, and so on. These innovative materials, often combined with hydrogels and exosomes, are engineered to address multiple mechanisms, including macrophage polarization, reactive oxygen species (ROS) scavenging, and anti-vascular endothelial growth factor (VEGF). Compared to conventional modalities, nanomedicines achieve regulated and sustained delivery, reduced administration frequency, prolonged drug action, and minimized side effects. This study delves into the obstacles encountered in drug delivery to the posterior segment and highlights the progress facilitated by nanomedicine. Prospectively, these findings pave the way for next-generation ocular drug delivery systems and deeper clinical research, aiming to refine treatments, alleviate the burden on patients, and ultimately improve visual health globally.

Retinal Vein Occlusion-Background Knowledge and Foreground Knowledge Prospects-A Review

Thrombosis of retinal veins is one of the most common retinal vascular diseases that may lead to vascular blindness. The latest epidemiological data leave no illusions that the burden on the healthcare system, as impacted by patients with this diagnosis, will increase worldwide. This obliges scientists to search for new therapeutic and diagnostic options. In the 21st century, there has been tremendous progress in retinal imaging techniques, which has facilitated a better understanding of the mechanisms related to the development of retinal vein occlusion (RVO) and its complications, and consequently has enabled the introduction of new treatment methods. Moreover, artificial intelligence (AI) is likely to assist in selecting the best treatment option for patients in the near future. The aim of this comprehensive review is to re-evaluate the old but still relevant data on the RVO and confront them with new studies. The paper will provide a detailed overview of diagnosis, current treatment, prevention, and future therapeutic possibilities regarding RVO, as well as clarifying the mechanism of macular edema in this disease entity.

Tetrahedral framework nucleic acids-based delivery of MicroRNA-22 inhibits pathological neovascularization and vaso-obliteration by regulating the Wnt pathway

The objective of this study was to investigate the effects and molecular mechanisms of tetrahedral framework nucleic acids-microRNA22 (tFNAs-miR22) on inhibiting pathological retinal neovascularization (RNV) and restoring physiological retinal vessels. A novel DNA nanocomplex (tFNAs-miR22) was synthesised by modifying microRNA-22 (miR22) through attachment onto tetrahedral frame nucleic acids (tFNAs), which possess diverse biological functions. Cell proliferation, wound healing, and tube formation were employed for in vitro assays to investigate the angiogenic function of cells. Oxygen-induced retinopathy (OIR) model was utilised to examine the effects of reducing pathological neovascularization (RNV) and inhibiting vascular occlusion in vivo. In vitro, tFNAs-miR22 demonstrated the ability to penetrate endothelial cells and effectively suppress cell proliferation, tube formation, and migration in a hypoxic environment. In vivo, tFNAs-miR22 exhibited promising results in reducing RNV and promoting the restoration of normal retinal blood vessels in OIR model through modulation of the Wnt pathway. This study provided a theoretical basis for the further understanding of RNV, and highlighted the innovative and potential of tFNAs-miR22 as a therapeutic option for ischemic retinal diseases.

Novel fabrication of anti-VEGF drug ranibizumab loaded PLGA/PLA co-polymeric nanomicelles for long-acting intraocular delivery in the treatment of age-related macular degeneration therapy

Age associated macular degeneration is the 3rd primary cause of blind fundus diseases globally. A reliable and long-lasting method of intraocular drug delivery is still needed. Herein, this study was aim to develop the novel fabrication of ranibizumab loaded co-polymeric nanomicelles (Rabz-CP-NMs) for AMD. The CMC of co-polymeric nanomicelles was determined to be low, at 6.2 μg/ml. The ring copolymerization method was employed to fabricate the NMs and characterize via FTIR, XRD, TEM, DLS and Zeta potential. Rabz-CP-NMs was spherical shape with 10-50 nm in size. Stable and prolonged drug release was achieved with the Rabz from CP-NMs at 48 h. D407 and ARPE19 ocular cell lines showed dose-dependent cell viability with Rabz-CP-NMs. The Rabz-CP-NMs also had less toxicity, higher uptake, lower cell death and prolonged VEGF-A inhibition, as shown by cytoviability assay. Thus, Rabz-CP-NMs were safe for ocular use, suggesting that could be used to improve intraocular AMD treatment.

Multimodal deep transfer learning to predict retinal vein occlusion macular edema recurrence after anti-VEGF therapy

Purpose

To develop a multimodal deep transfer learning (DTL) fusion model using optical coherence tomography angiography (OCTA) images to predict the recurrence of retinal vein occlusion (RVO) and macular edema (ME) after three consecutive anti-VEGF therapies.

Methods

This retrospective cross-sectional study consisted of 2800 B-scan OCTA macular images collected from 140 patients with RVO-ME. The central macular thickness (CMT) > 250 μm was used as a criterion for recurrence in the three-month follow-up after three injections of anti-VEGF therapy. The qualified OCTA image preprocessing and the lesion area segmentation were performed by senior ophthalmologists. We developed and validated the clinical, DTL, and multimodal fusion models based on clinical and extracted OCTA imaging features. The performance of the models and experts predictions were evaluated using several performance metrics, including the area under the receiver operating characteristic curve (AUC), accuracy, sensitivity, and specificity.

Results

The DTL models exhibited higher prediction efficacy than the clinical models and experts' predictions. Among the DTL models, the Vgg19 performed better than that of the other models, with an AUC of 0.968 (95 % CI, 0.943-0.994), accuracy of 0.913, sensitivity of 0.922, and specificity of 0.902 in the validation cohort. Moreover, the fusion Vgg19 model showed the highest prediction efficacy among all the models, with an AUC of 0.972 (95 % CI, 0.946-0.997), accuracy of 0.935, sensitivity of 0.935, and specificity of 0.934 in the validation cohort.

Conclusions

Multimodal fusion DTL models showed robust performance in predicting RVO-ME recurrence and may be applied to assist clinicians in determining patients' follow-up time after anti-VEGF therapy.

Development of high-performance point-of-care aqueous VEGF detection system and proof-of-concept validation in RVO patients

OBJECTIVES

To develop a sensitive point-of-care testing (POCT) aqueous vascular endothelial growth factor (VEGF) detection system, and assess its role for predicting the response to anti-VEGF treatment in macular edema secondary to retinal vein occlusion (RVO-ME) patients.

METHODS

An automatic point-of-care aqueous humor Magnetic Particle Chemiluminescence Enzyme Immuno-Assay (MPCLEIA) VEGF detection system was developed. The predictive values of aqueous cytokine levels, in combination with imaging parameters, on anatomical treatment response (ATR, the relative central macular thickness change [ΔCMT/bl-CMT]) were analyzed.

RESULTS

The automatic MPCLEIA system was able to provide results in 45 min with only 20 μL sample. Among the 57 eyes with available pre- and post-treatment evaluation, ATR significantly correlated with levels of interleukin (IL)-6, IL-8, monocyte chemoattractant protein-1 (MCP-1) and VEGF measured by Luminex xMAP platform, and VEGF measured by MPCLEIA. Optimal cut-off values for these biomarkers were 13.26 ng/L, 23.57 ng/L, 1,110.12 ng/L, 105.52 ng/L, and 85.39 ng/L, respectively. Univariate analysis showed significant associations between ATR category (good response if ATR≤-25 % or poor response otherwise) and IL-6, IL-8, MCP-1, VEGF-xMAP, and VEGF-MPCLEIA (p<0.05). Multivariate logistic regression revealed that ATR category was significantly associated with aqueous VEGF-MPCLEIA (p=0.006) and baseline(bl)-CMT (p=0.008). Receiver operating characteristics analysis yielded an AUC of 0.959 for the regression model combining VEGF-MPCLEIA and bl-CMT, for predicting ATR category.

CONCLUSIONS

Our novel MPCLEIA-based automatic VEGF detection system enables accurate POCT of aqueous VEGF, which shows promise in predicting the treatment response of RVO-ME to anti-VEGF agents when combined with bl-CMT.

Progress in clinical research and applications of retinal vessel quantification technology based on fundus imaging

Retinal blood vessels are the only directly observed blood vessels in the body; changes in them can help effective assess the occurrence and development of ocular and systemic diseases. The specificity and efficiency of retinal vessel quantification technology has improved with the advancement of retinal imaging technologies and artificial intelligence (AI) algorithms; it has garnered attention in clinical research and applications for the diagnosis and treatment of common eye and related systemic diseases. A few articles have reviewed this topic; however, a summary of recent research progress in the field is still needed. This article aimed to provide a comprehensive review of the research and applications of retinal vessel quantification technology in ocular and systemic diseases, which could update clinicians and researchers on the recent progress in this field.

The progress of assessment methods and treatments of neovascular glaucoma secondary to central retinal vein occlusion

Neovascular glaucoma is a condition that results from central retinal vein occlusion and often leads to blindness. Accurate evaluation and appropriate treatment are crucial for patients. However, there is currently no uniform and clear standard to differentiate between ischemic and non-ischemic central retinal vein occlusion. Also, the assessment of neovascular glaucoma progression is uncertain. Meanwhile, although pan-retinal photocoagulation is a standard treatment to prevent the onset of neovascular glaucoma, its actual efficacy and the timing of intervention remain highly controversial. It is still challenging to balance the risks of side effects in the visual field against the uncertain effectiveness of the treatment. This paper delves into the pathogenesis of neovascular glaucoma to understand the development of therapeutic approaches. By taking into account various assessment criteria of central retinal vein occlusion and neovascular glaucoma over the years, combining functional tests and morphological tests provides the most accurate and rigorous solution. The age of patients, the extent, location, and duration of retinal ischemia are the primary factors that affect the severity and extent of ischemic central retinal vein occlusion and induce serious complications. From the perspective of prevention and treatment, the ischemic index is closely related to the development of neovascularization. The paper provides essential insights into the mechanism, efficacy, complications, and optimal timing of pan-retinal photocoagulation. Comparing the treatment effects of pan-retinal photocoagulation and intravitreal anti-VEGF injections, we suggest a combination of both treatments to explore effective treatment with fewer side effects in the long term. This article details the debate on the above issues and explores ideas for the clinical diagnosis and preventive treatment of neovascular glaucoma that results from ischemic central retinal vein occlusion.

An artificial intelligence system for the whole process from diagnosis to treatment suggestion of ischemic retinal diseases

Ischemic retinal diseases (IRDs) are a series of common blinding diseases that depend on accurate fundus fluorescein angiography (FFA) image interpretation for diagnosis and treatment. An artificial intelligence system (Ai-Doctor) was developed to interpret FFA images. Ai-Doctor performed well in image phase identification (area under the curve [AUC], 0.991-0.999, range), diabetic retinopathy (DR) and branch retinal vein occlusion (BRVO) diagnosis (AUC, 0.979-0.992), and non-perfusion area segmentation (Dice similarity coefficient [DSC], 89.7%-90.1%) and quantification. The segmentation model was expanded to unencountered IRDs (central RVO and retinal vasculitis), with DSCs of 89.2% and 83.6%, respectively. A clinically applicable ischemia index (CAII) was proposed to evaluate ischemic degree; patients with CAII values exceeding 0.17 in BRVO and 0.08 in DR may be associated with increased possibility for laser therapy. Ai-Doctor is expected to achieve accurate FFA image interpretation for IRDs, potentially reducing the reliance on retinal specialists.

Enhanced therapeutic effect of PEDF-loaded mesenchymal stem cell-derived small extracellular vesicles against oxygen-induced retinopathy through increased stability and penetrability of PEDF

BACKGROUND

Several common retinal diseases that cause blindness are characterised by pathological neovascularisation accompanied by inflammation and neurodegeneration, including retinopathy of prematurity (ROP), diabetic retinopathy (DR), age-related macular degeneration (AMD), and retinal vein occlusion (RVO). The current treatment strategies for these diseases have limited benefits. Thus, safer and more effective alternative approaches are required. In this study, we loaded small extracellular vesicles (sEVs) derived from mesenchymal stem cell (MSC) with pigment epithelium-derived factor (PEDF), and tested the therapeutic effect of PEDF-loaded sEVs (PEDF-sEVs) using an oxygen induced retinopathy (OIR) mouse model, aiming to establish a new therapy strategy for the treatment of retinal pathological angiogenesis.

RESULTS

We formulated PEDF-loaded sEVs (PEDF-sEVs) containing high concentrations of PEDF and evaluated their effects through in vivo and in vitro experiments. In OIR mice, PEDF-sEVs showed significantly better effects on retinal avascular areas, inflammation, and neuronal degeneration compared with the anti-vascular endothelial growth factor (VEGF) drug, which may indicate a possible advantage of PEDF-sEVs over anti-VEGF drugs in the treatment of pathological neovascularisation. In vitro, PEDF-sEVs greatly inhibited endothelial cell (EC) proliferation, migration, and tube formation by suppressing the VEGF-induced phosphorylation of extracellular signal-regulated kinase (ERK) and AKT (also known as Protein Kinase B). All experiments and analyses were performed in triplicate. PEDF-sEVs were more effective than PEDF or sEVs alone, both in vitro and in vivo. Furthermore, to determine the distribution of PEDF-sEVs, we used DiD-labelled sEVs and FITC-labelled PEDF to track the sEVs and PEDF, respectively. We found that PEDF-sEVs effectively reduced the degradation of PEDF.

CONCLUSIONS

Loading PEDF on sEVs effectively enhanced the anti-angiogenic, anti-inflammatory, and neuroprotective effects of PEDF by increasing the stability and penetrability. These results suggest a potential role for PEDF-sEVs in retinal pathological neovascularisation.

Foveal Eversion is Associated with High Persistence of Macular Edema and Visual Acuity Deterioration in Retinal Vein Occlusion

INTRODUCTION

Foveal eversion (FE) is a recently described optical coherence tomography (OCT) finding associated with negative outcome in diabetic macular edema. The main goal of the present study was to investigate the role of the FE metric in the diagnostic workup of retinal vein occlusion (RVO).

METHODS

This study was a retrospective, observational case series. We included 168 eyes (168 patients) affected by central RVO (CRVO) and 116 eyes (116 patients) affected by branch (RVO). We collected clinical and imaging data from CRVO and BRVO eyes affected by macular edema with a minimum follow-up of 12 months. On structural OCT, we classified FE as pattern 1a, characterized by thick vertical intraretinal columns, pattern 1b, presenting thin vertical intraretinal lines, and pattern 2, showing no signs of vertical lines in the context of the cystoid macular edema. For statistical purposes, we considered data collected at baseline, after 1 year and at the last follow-up.

RESULTS

The mean follow-up was 40 ± 25 months for CRVO eyes and 36 ± 24 months for BRVO eyes. We found FE in 64 of 168 CRVO eyes (38%) and in 25 of 116 BRVO eyes (22%). Most of the eyes developed FE during the follow-up. For CRVO eyes, we found 6 eyes (9%) with pattern 1a, 17 eyes (26%) with pattern 1b and 41 eyes (65%) with pattern 2. Of those BRVO eyes with FE, we found 8 eyes (32%) with pattern 1a + 1b and 17 eyes (68%) with pattern 2. In both CRVO and BRVO the presence of FE was significantly associated with higher persistence of macular edema and worse outcome, with FE pattern 2 representing the most severe condition. Remarkably, FE patterns 1a and 1b were characterized by BCVA stability over the follow-up, whereas FE pattern 2 showed significant bestcorrected visual acuity (BCVA) worsening at the end of the follow-up.

CONCLUSIONS

FE can be considered a negative prognostic biomarker in RVO, associated with higher persistence of macular edema and worse visual outcome. Müller cell impairment might represent the pathogenic mechanism leading to the loss of macular structural support and impairment of fluid homeostasis.

Prevention and Treatment of Retinal Vein Occlusion: The Role of Diet-A Review

Retinal vein occlusion (RVO) is the second most common retinal disorder. In comparison to diabetic retinopathy or age-related macular degeneration, RVO is usually an unexpected event that carries a greater psychological impact. There is strong evidence to suggest that cardiovascular diseases are the most common risk factors in this pathology and it has long been known that a higher consumption of fish, nuts, fruits, and vegetables has a protective effect against these types of conditions. In the last several years, interest in plant-based diets has grown in both the general population and in the scientific community, to the point to which it has become one of the main dietary patterns adopted in Western countries. The aim of this review is to investigate the potential impact of macro- and micronutrients on retinal vein occlusion.

Artificial intelligence to distinguish retinal vein occlusion patients using color fundus photographs

PURPOSE

Our aim is to establish an AI model for distinguishing color fundus photographs (CFP) of RVO patients from normal individuals.

METHODS

The training dataset included 2013 CFP from fellow eyes of RVO patients and 8536 age- and gender-matched normal CFP. Model performance was assessed in two independent testing datasets. We evaluated the performance of the AI model using the area under the receiver operating characteristic curve (AUC), accuracy, precision, specificity, sensitivity, and confusion matrices. We further explained the probable clinical relevance of the AI by extracting and comparing features of the retinal images.

RESULTS

Our model achieved an average AUC was 0.9866 (95% CI: 0.9805-0.9918), accuracy was 0.9534 (95% CI: 0.9421-0.9639), precision was 0.9123 (95% CI: 0.8784-9453), specificity was 0.9810 (95% CI: 0.9729-0.9884), and sensitivity was 0.8367 (95% CI: 0.7953-0.8756) for identifying fundus images of RVO patients in training dataset. In independent external datasets 1, the AUC of the RVO group was 0.8102 (95% CI: 0.7979-0.8226), the accuracy of 0.7752 (95% CI: 0.7633-0.7875), the precision of 0.7041 (95% CI: 0.6873-0.7211), specificity of 0.6499 (95% CI: 0.6305-0.6679) and sensitivity of 0.9124 (95% CI: 0.9004-0.9241) for RVO group. There were significant differences in retinal arteriovenous ratio, optic cup to optic disc ratio, and optic disc tilt angle (p = 0.001, p = 0.0001, and p = 0.0001, respectively) between the two groups in training dataset.

CONCLUSION

We trained an AI model to classify color fundus photographs of RVO patients with stable performance both in internal and external datasets. This may be of great importance for risk prediction in patients with retinal venous occlusion.

Novel pharmaceuticals for the management of retinal vein occlusion and linked disorders

INTRODUCTION

Retinal vein occlusion (RVO) is the second leading cause of blindness from retinal vascular disease behind diabetic retinopathy. Anti-vascular endothelial growth factor (VEGF) and glucocorticoid therapy are the cornerstones of pharmaceutical treatment for RVO. There is considerable interest in developing new pharmaceuticals in and out of these two classes to reduce costs, lower injection burden, and treat the occlusion itself, rather than the complications.

AREAS COVERED

In this review, we discuss novel pharmaceuticals for the treatment of RVO outside of current standard of care. We performed a comprehensive literature search encompassing pharmaceuticals that have recently been approved or have shown promising results in early clinical trials or animal models.

EXPERT OPINION

Anti-VEGF therapy remains the most efficacious treatment for RVO with a very favorable side effect profile. New biosimilars reduce costs while maintaining efficacy. Novel glucocorticoids may be a useful therapy in patients for whom anti-VEGF therapy has failed, or as an adjunct. Pharmaceuticals in other drug classes, particularly those with neuroprotective or regenerative properties, as well as those geared toward treating the occlusion itself, represent exciting options for early RVO therapy, but are likely years away from clinical relevance.

Tetrahedral framework nucleic acids inhibit pathological neovascularization and vaso-obliteration in ischaemic retinopathy via PI3K/AKT/mTOR signalling pathway

This study aimed to explore the effect and the molecular mechanism of tetrahedral framework nucleic acids (tFNAs), a novel self-assembled nanomaterial with excellent biocompatibility and superior endocytosis ability, in inhibition of pathological retinal neovascularization (RNV) and more importantly, in amelioration of vaso-obliteration (VO) in ischaemic retinopathy. tFNAs were synthesized from four single-stranded DNAs (ssDNAs). Cell proliferation, wound healing and tube formation assays were performed to explore cellular angiogenic functions in vitro. The effects of tFNAs on reducing angiogenesis and inhibiting VO were explored by oxygen-induced retinopathy (OIR) model in vivo. In vitro, tFNAs were capable to enter endothelial cells (ECs), inhibit cell proliferation, tube formation and migration under hypoxic conditions. In vivo, tFNAs successfully reduce RNV and inhibit VO in OIR model via the PI3K/AKT/mTOR/S6K pathway, while vascular endothelial growth factor fusion protein, Aflibercept, could reduce RNV but not inhibit VO. This study provides a theoretical basis for the further understanding of RNV and suggests that tFNAs might be a novel promising candidate for the treatment of blind-causing RNV.

Update on Retinal Vein Occlusion

Retinal vein occlusion represents the second leading cause of retinal vascular disorders, with a uniform sex distribution worldwide. A thorough evaluation of cardiovascular risk factors is required to correct possible comorbidities. The diagnosis and management of retinal vein occlusion have changed tremendously in the last 30 years, but the assessment of retinal ischemia at baseline and during follow-up examinations remains crucial. New imaging techniques have shed light on the pathophysiology of the disease and laser treatment, once the only therapeutic option, is now only one of the possible approaches with antivascular endothelial growth factors and steroid injections being preferred in most cases. Nowadays long-term outcomes are better than those achievable 20 years ago and yet, many new therapeutic options are under development, including new intravitreal drugs and gene therapy. Despite this, some cases still develop sight-threatening complications deserving a more aggressive (sometimes surgical) approach. The purpose of this comprehensive review is to reappraise some old but still valid concepts and to integrate them with new research and clinical data. The work will provide an overview of the disease's pathophysiology, natural history, and clinical features along with a detailed discussion on the advantages of multimodal imaging and of the different treatment strategies with the aim of providing retina specialists with the most updated knowledge in the field.

Red Blood Cells: A Newly Described Partner in Central Retinal Vein Occlusion Pathophysiology?

Central retinal vein occlusion (CRVO) is a frequent retinal disorder inducing blindness due to the occlusion of the central vein of the retina. The primary cause of the occlusion remains to be identified leading to the lack of treatment. To date, current treatments mainly target the complications of the disease and do not target the primary dysfunctions. CRVO pathophysiology seems to be a multifactorial disorder; several studies did attempt to decipher the cellular and molecular mechanisms underlying the vessel obstruction, but no consensual mechanism has been found. The aim of the current review is to give an overview of CRVO pathophysiology and more precisely the role of the erythroid lineage. The review presents emerging data on red blood cell (RBC) functions besides their role as an oxygen transporter and how disturbance of RBC function could impact the whole vascular system. We also aim to gather new evidence of RBC involvement in CRVO occurrence.

Long-term real-world outcomes in retinal vein occlusions: How close are we to the trials?

Purpose

To assess and analyze the visual outcomes of patients with retinal vein occlusions in a real-world setting with a long-term follow-up of more than 5 years.

Methods

Retrospective analysis of 56 patients having retinal vein occlusions from a tertiary eye center, with a mean follow-up of 7 years was performed. Primary outcome measures were mean change in best-corrected visual acuity (BCVA) from baseline at 6 months, 1 year, 2 years, 3 years, and final visit (≥5 years), proportion of patients having BCVA better than 20/40 and worse than 20/200, and mean number of injections. Secondary outcome measures were change in central macular thickness (CMT), development of subsequent retinal vein occlusion (RVO) in same eye or the other eye, and development of neovascular complications.

Results

The mean change in letter score was + 11.84 in branch RVO (BRVO), +7.14 in non-ischemic central RVO (CRVO), and -9.5 in ischemic CRVO at 1 year, which changed to + 8.57, -5 and - 24, respectively, at the end of follow-up. CMT had improved from 506 ± 98.8 μm, 576.44 ± 149 μm, and 618 ± 178.27 μm, respectively, at baseline to 267 ± 94 μm, 345.20 ± 122.61 μm, and 265.50 ± 107.75 μm, respectively, in BRVO, non-ischemic, and ischemic hemi RVO (HRVO)/CRVO groups. The total mean number of injections given in BRVO, non-ischemic CRVO, and ischemic CRVO groups were 4.6, 6.6, and 4.1, respectively. None of the patients with BRVO developed neovascular glaucoma (NVG). Non-ischemic to ischemic HRVO/CRVO conversion was noted in 4/11 eyes at a mean duration of 12.6 months. NVG was noted in 7/9 eyes (77.8%) in initial ischemic CRVO/HRVO group and 3/4 (75%) converted eyes.

Conclusion

Patients with BRVO have good visual outcomes with anti-VEGF, while in CRVO results may vary considerably owing to patient compliance and treatment burden on long-term follow-up in a real-world setting.

[Ischemia and laser photocoagulation in retinal vein occlusion]

BACKGROUND

Retinal vein occlusions (RVO) are associated with retinal ischemia to a highly variable extent. An ischemic retina may lead to the development of neovascularization and further to secondary complications such as neovascular glaucoma, vitreous hemorrhage or tractional retinal detachment. Numerous factors such as vascular endothelial growth factor (VEGF) and other cytokines are produced in the ischemic area, which cause macular edema. Before the introduction of intravitreal drug injections (IVI), retinal laser photocoagulation was the leading form of treatment. Macular laser photocoagulation was applied in the form of focal laser or grid laser in patients with branch retinal vein occlusion (BRVO) to treat macular edema. In patients with ischemic RVO, panretinal laser photocoagulation (PRP) was recommended for treatment of secondary neovascular complications. The value of laser treatment in the management of patients with RVO changed after the introduction of IVI treatment.

AIM

This article presents a review of the current study results and the recommendations for performing laser photocoagulation of the central and peripheral retina in patients with RVO.

CONCLUSION

Conventional focal or grid laser photocoagulation has been replaced by IVI treatment in the management of macular edema secondary to BRVO; however, macular laser treatment can still be considered in patients with BRVO if the macular edema persists despite the use of available IVI drugs. The use of central laser photocoagulation in these cases is based on the findings of fluorescein angiography. Disseminated panretinal laser photocoagulation is still indicated in RVO patients who have large areas of nonperfusion, have developed neovascularization and/or late complications. Targeted laser photocoagulation of the peripheral areas of nonperfusion has recently been recommended by several authors and is expected to improve not only the visual outcome of IVI treatment, but more importantly to also reduce the duration of treatment and the number of re-injections needed. Clear evidence for targeted laser treatment is not yet available and is a focus of currently ongoing prospective randomized studies.

Predicting OCT images of short-term response to anti-VEGF treatment for retinal vein occlusion using generative adversarial network

To generate and evaluate post-therapeutic optical coherence tomography (OCT) images based on pre-therapeutic images with generative adversarial network (GAN) to predict the short-term response of patients with retinal vein occlusion (RVO) to anti-vascular endothelial growth factor (anti-VEGF) therapy. Real-world imaging data were retrospectively collected from 1 May 2017, to 1 June 2021. A total of 515 pairs of pre-and post-therapeutic OCT images of patients with RVO were included in the training set, while 68 pre-and post-therapeutic OCT images were included in the validation set. A pix2pixHD method was adopted to predict post-therapeutic OCT images in RVO patients after anti-VEGF therapy. The quality and similarity of synthetic OCT images were evaluated by screening and evaluation experiments. We quantitatively and qualitatively assessed the prognostic accuracy of the synthetic post-therapeutic OCT images. The post-therapeutic OCT images generated by the pix2pixHD algorithm were comparable to the actual images in edema resorption response. Retinal specialists found most synthetic images (62/68) difficult to differentiate from the real ones. The mean absolute error (MAE) of the central macular thickness (CMT) between the synthetic and real OCT images was 26.33 ± 15.81 μm. There was no statistical difference in CMT between the synthetic and the real images. In this retrospective study, the application of the pix2pixHD algorithm objectively predicted the short-term response of each patient to anti-VEGF therapy based on OCT images with high accuracy, suggestive of its clinical value, especially for screening patients with relatively poor prognosis and potentially guiding clinical treatment. Importantly, our artificial intelligence-based prediction approach's non-invasiveness, repeatability, and cost-effectiveness can improve compliance and follow-up management of this patient population.

Progress and Challenges of Anti-VEGF Agents and Their Sustained-Release Strategies for Retinal Angiogenesis

Currently, the treatment for ocular neovascular diseases, including diabetic macular edema (DME) and age-related macular degeneration (AMD), mainly involves repeated intravitreal injection of anti-vascular endothelial growth factor (VEGF) drugs. Although it can preserve vision, repeated injections are an invasive treatment modality, leading to serious complications and reducing patient adherence to treatment. To reduce the frequency of administration, prolong the time of drug action, and avoid repeated intravitreal injections, the combination of sustained-release materials with anti-VEGF drug therapy has become an emphasis in ophthalmology. In this review, we highlight the current state of anti-VEGF technology, its challenges, and the sustained-release strategies under investigation or being used in clinical practice. Both continuous release and considerable therapeutic effects can be achieved by encapsulating anti-VEGF drugs in sustained-release materials to minimize the number of intravitreal injections. At present, two sustained-release materials are being tested in clinical research, and although basic research shows the strong therapeutic application prospects of extended-release drugs, its challenges mainly involve the discrepancy between the release rates in vitro and the efficiency of the drugs in vivo. Briefly, sustained release of anti-VEGF agents is an advantageous strategy for treating retinal angiogenesis.

An intelligent location method of key boundary points for assisting the diameter measurement of central serous chorioretinopathy lesion area

The diameter of central serous chorioretinopathy (CSCR) lesion is one of the important indicators to evaluate the severity of CSCR and the efficacy of corresponding treatment schemes. Traditional manual measurement by ophthalmologists is usually based on a single or a small number of optical coherence tomography (OCT) B-scan images. This measurement scheme may not be convincing, vulnerable to subjective factors and lower efficiency. To alleviate the above situation, this paper proposes an intelligent key boundary point location method for all B-scan images of a single patient to assist in the rapid and accurate diameter measurement of the CSCR lesion area. Firstly, an initial location module (ILM) based on the multi-task learning paradigm is appropriately adjusted and introduced into the key boundary point location task, which preliminarily realizes the rapid location of key boundary points. Secondly, to further ameliorate the ILM, a gradient based correction module (GBCM) is designed, followed by the construction of the cascade model (ILM-GBCM) which improves the location accuracy of key boundary points as a whole. Extensive experiments based on five different convolutional neural network (CNN) backbones are carried out, revealing the feasibility of ILM in this task and the effectiveness of ILM-GBCM. On 912 testing images, the maximum correction ratio reaches 83.66%, and the minimum location time at the image level is as low as 0.1754 s, which not only confirms the necessity of correction operation, but also greatly reduce the time cost of ophthalmologists' manual measurement operation in clinic.

Comparison of the efficiency of anti-VEGF drugs intravitreal injections treatment with or without retinal laser photocoagulation for macular edema secondary to retinal vein occlusion: A systematic review and meta-analysis

Objective: To compare the efficiency of anti-VEGF drugs intravitreal injections(IVI) treatment with or without retinal laser photocoagulation(LPC) for macular edema(ME) secondary to retinal vein occlusion(RVO).

Methods: The randomized controlled trials and retrospective studies including anti-VEGF drug IVI combined with retinal LPC and single IVI in the treatment of macular edema secondary to RVO were collected in PubMed, Medline, Embase, Cochrane Library, and Web of Science. We extracted the main outcome indicators including the best corrected visual acuity (BCVA), central macular thickness(CMT), the number of injections and the progress of retinal non-perfusion areas(NPAs) for systematic evaluation, to observe whether IVI + LPC could be more effective on the prognosis of RVO. We use Review Manager 5.4 statistical software to analyze the data

Results: 527 articles were initially retrieved. We included 20 studies, with a total of 1387 patients who were divided into the combination(IVI + LPC) treatment group and the single IVI group. All the patients completed the ocular examination including BCVA, slit-lamp test, fundus examination and Optical Coherence Tomography(OCT) test before and after each treatment. There was no statistical difference between the combination treatment group and single IVI group on BCVA(WMD = 0.12,95%CI = -3.54–3.78,p = 0.95),CMT(WMD = -4.40,95%CI = -21.33–12.53,p = 0.61) and NPAs(WMD = 0.01,95%CI = -0.28–0.30,p = 0.94).However, the number of IVI was decreased significantly in the combination treatment group in BRVO patients, compared to that in the single IVI group(WMD = -0.69,95%CI = -1.18∼-0.21,p = 0.005).

Conclusion: In the treatment of RVO patients with macular edema, the combination of IVI and retinal LPC neither improves BCVA nor reduces CMT significantly compared with the single IVI treatment. However, the combination treatment can decrease the number of intravitreal injections in patients with BRVO, while it is not observed in CRVO patients.

Branch retina vein occlusion combined with angle-closure glaucoma is associated with a mutation in BEST1: a case report

BACKGROUND

It is rare for a patient to be diagnosed with branch retina vein occlusion (BRVO), angle-closure glaucoma (ACG) and autosomal recessive bestrophinopathy (ARB). ARB is strongly associated with ACG. Although glaucoma is a significant risk factor for RVO, there is a plausible relationship between ACG and BRVO. To discuss correlation of these diseases is necessary.

CASE PRESENTATION

The genetic testing and medical treatment of a patient with ocular fundus diseases and ACG were recorded. We present a 47-year-old male patient with BRVO who was diagnosed with angle-closure glaucoma and a homozygous mutation of c.140G > A (p.R47H) in BEST1. Intravitreal ranibizumab was administered in combination with three antiglaucomatous eyedrops to lower intraocular pressure (IOP) in the right eye. One month later, BCVA improved to 0.3. IOP was controlled at 13 mmHg.

CONCLUSIONS

ACG was likely combined to ARB, while there's a plausible relationship between ACG and BRVO.

Review: The Development of Risk Factors and Cytokines in Retinal Vein Occlusion

Retinal vein occlusion (RVO) is the second most prevalent retinal disease. Despite this, the pathogenic mechanisms and risk factors are not entirely clear. In this article, we review recent publications on the classification, pathogenesis, risk factors, ischemic changes, cytokines, and vital complications of RVO. Risk factors and cytokines are important for exploring the mechanisms and new treatment targets. Furthermore, risk factors are interrelated, making RVO mechanisms more complex. Cytokines act as powerful mediators of pathological conditions, such as inflammation, neovascularization, and macular edema. This review aims to summarize the updated knowledge on risk factors, cytokines of RVO and signaling in order to provide valuable insight on managing the disease.

Retinal vein occlusion: drug targets and therapeutic implications

INTRODUCTION

The pathogenesis of retinal vein occlusion (RVO) is extremely complex and includes several mediators. These mediators represent potential drug targets that can be used in the development of intravitreal drugs.

AREAS COVERED

PubMed/MEDLINE databases were accessed between April-May 2021 to find the most relevant scientific papers regarding drug targets and therapeutic implications in RVO, focusing on current therapeutic options and potential cornerstones of future advances in treatment.

EXPERT OPINION

Before the introduction of intravitreal therapies, the visual outcome following a diagnosis of RVO was extremely poor. Anti-VEGF and corticosteroid treatments have radically changed RVO prognosis, helping to preserve patients' visual function and their quality of life. According to current clinical data, anti-VEGF and corticosteroid drugs are associated with both pros and cons; the present recommendation is to employ anti-VEGF molecules as a first-line treatment. Advances in our understanding of the biomolecular characteristics of RVO offer a solid basis for the development of new therapeutic targets and treatments.

Treatment of Macular Edema in Vascular Retinal Diseases: A 2021 Update

Macular edema (ME) is associated with various conditions; however, the main causes of ME are retinal vein occlusion (RVO) and diabetes. Laser photocoagulation, formerly the gold standard for the treatment of ME, has been replaced by anti-vascular endothelial growth factor (anti-VEGF) intravitreal injections. Despite its efficiency, this treatment requires frequent injections to preserve the outcomes of anti-VEGF therapy, and as many patients do not sufficiently respond to the treatment, ME is typically a chronic condition that can lead to permanent visual impairment. Generalized recommendations for the treatment of ME are lacking, which highlights the importance of reviewing treatment approaches, including recent anti-VEGFs, intravitreal steroid implants, and subthreshold micropulse lasers. We reviewed relevant studies, emphasizing the articles published between 2019 and 2021 and using the following keywords: macular edema, diabetic macular edema, retinal vein occlusion, laser photocoagulation, anti-VEGF, and intravitreal injections. Our results revealed that a combination of different treatment methods may be beneficial in resistant cases. Additionally, artificial intelligence (AI) is likely to help select the best treatment option for patients in the near future.