Retinal vein occlusion (RVO) guideline: executive summary

Artificial intelligence in managing retinal disease-current concepts and relevant aspects for health care providers

Given how the diagnosis and management of many ocular and, most specifically, retinal diseases heavily rely on various imaging modalities, the introduction of artificial intelligence (AI) into this field has been a logical, inevitable, and successful development in recent decades. The field of retinal diseases has practically become a showcase for the use of AI in medicine. In this article, after providing a short overview of the most relevant retinal diseases and their socioeconomic impact, we highlight various aspects of how AI can be applied in research, diagnosis, and disease management and how this is expected to alter patient flows, affecting also health care professionals beyond ophthalmologists.

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.

Ocular pharmacokinetics of intravitreal conbercept in a rabbit model following retinal scatter laser photocoagulation

Objective

The present study aims to evaluate the ocular pharmacokinetics of intravitreal conbercept after retinal scatter laser photocoagulation.

Methods

Thirty male Chinchilla rabbits (60 eyes) were used in this study. The control and photocoagulated animals received single bilateral intravitreal injections of conbercept, and the ocular tissues were collected and quantified for drug concentration using ELISA. Statistical analysis was then performed to compare the pharmacokinetic parameters between the control and photocoagulated eyes.

Results

The conbercept concentrations were higher in the control rabbits than the photocoagulated rabbits and reached peak values in all ocular tissues 1 d after intravitreal dosing. The terminal t1/2 values in the vitreous humor (4.36 d), aqueous humor (4.19 d), retina (3.94 d), and choroid-RPE (3.84 d) of the control eyes were longer than those in the photocoagulated eyes (3.82 d, 3.69 d, 3.65 d, and 3.58 d, respectively). Conbercept exposure assessed using AUC0-t was lower in the photocoagulated rabbits than control animals in all four ocular matrices (p < 0.01). The clearance and volume of distribution were greater in the photocoagulated eyes than the control eyes, while the mean residence times were shorter in all four matrices.

Conclusion

Retinal scatter laser photocoagulation shortly before single intravitreal injection of conbercept enabled higher drug clearance and shorter half-life values, resulting in lower exposure in the ocular tissues compared to non-photocoagulated conditions. The distinct ocular pharmacokinetics of intravitreal conbercept observed in a rabbit model through retinal scatter laser photocoagulation is expected to enlighten further studies on investigating the optimal order of the combination of photocoagulation and anti-VEGF agents.

Potential of Sulodexide in the Treatment of Diabetic Retinopathy and Retinal Vein Occlusion

Retinal vascular diseases, such as diabetic retinopathy or retinal vein occlusion, are common causes of severe vision loss. Central to the pathophysiology of these conditions are endothelial dysfunction, inflammation, capillary leakage, ischemia, and pathological neoangiogenesis. Capillary damage leads to leakage and the development of macular edema, which is associated with vision loss and requires complex treatment. Sulodexide, a glycosaminoglycan composed of heparan sulfate and dermatan sulfate with high oral bioavailability, exhibits several favorable pharmacologic properties, including antithrombotic, anti-inflammatory, and endothelium-protective effects. Additionally, treatment with sulodexide has been associated with the reduction of oxidative stress and decreased expression of angiogenic growth factors, such as vascular endothelial growth factor. This review aims to provide an overview of the pharmacological properties, mechanisms of action, and therapeutic effects of sulodexide. Furthermore, its potential for clinical application in venous and diabetic diseases, such as venous thromboembolism, chronic venous insufficiency, peripheral artery disease, or diabetic nephropathy, is summarized. We also present experimental and clinical studies evaluating the potential of sulodexide in ocular conditions and discuss its therapeutic implications for the treatment of retinal vascular diseases.

Efficacy of Ozurdex implants as second-line therapy for non-responders to anti-VEGF in retinal vein occlusion-associated macular edema: a retrospective cohort study

PURPOSE

Retinal vein occlusion (RVO) is a prevalent retinal vascular disorder characterized by retinal haemorrhage, neovascularization, and macular edema This study aimed to assess the structural and functional effects of intravitreal implant (Ozurdex) treatment as a second-line for RVO-associated macular edema in patients who did not respond to first-line anti-VEGF therapy.

MATERIALS AND METHODS

We conducted a retrospective observational cohort study using electronic health records of RVO patients at Salisbury District Hospital between January 2014 and December 2019. Inclusion criteria included patients diagnosed with central or branch RVO. Patients underwent ophthalmic evaluations at baseline, including central retinal thickness (CRT) and best-corrected visual acuity (BCVA) assessments. Statistical analysis was performed using IBM SPSS Statistics, employing various tests to determine significance.

RESULTS

Sixteen eyes of 16 White British patients were evaluated. Most patients had branch RVO (52.95%), and 47.05% had central RVO. While anti-VEGF treatment significantly improved BCVA (p = 0.0061), Ozurdex did not result in additional gain (p = 0.747). Both treatments significantly reduced CRT (p = 0.0055 for anti-VEGF; p = 0.0079 for Ozurdex). No significant differences were observed between diabetic and non-diabetic BCVA patients receiving either treatment.

CONCLUSION

Ozurdex emerges as a safe and effective option for persistent macular edema in RVO patients unresponsive to anti-VEGF therapy. Although structural improvements in CRT were observed following Ozurdex treatment, they did not correlate with additional gain in BCVA. Despite this, the reduced treatment frequency of Ozurdex compared to anti-VEGF injections may be advantageous, particularly for frail non-responding patients minimizing treatment burden.

Visual and anatomical failure of anti-VEGF therapy for retinal vascular diseases: a survival analysis of real-world data

IMPORTANCE

Predicting undesirable outcomes following anti-VEGF initiation in macular oedema is critical for effective clinical decision-making and optimised care.

OBJECTIVE

To estimate the time to undesirable events in diabetic macular oedema (DMO), central and branch vein occlusions (CRVO and BRVO) after appropriate loading doses with either ranibizumab or aflibercept and identified baseline predictors of negative outcome.

DESIGN, SETTING, PARTICIPANTS

A retrospective cohort study of 3277 patients (N = 2107 in DMO, N = 413 in CRVO and N = 757 in BRVO) collected over a 10-year period, in a large UK tertiary centre. Only one eye was included per patient. Inclusion criteria pre-specified a minimum of two clinic visits with one being at least 6 months post treatment.

MAIN OUTCOME AND MEASURES

The main outcome measure was absence of visual acuity (VA) improvement due to macular oedema failure of anti-VEGF therapy (defined as VA gain <5 ETDRS letters and CST increase of 50 µm or CST > 325 µm) modelled using time-event analyzes of appropriately loaded patients. Secondary outcomes included survival curves by individual condition (DMO, CRVO, BRVO) and factors associated with negative outcomes.

RESULTS

After starting anti-VEGF, there was a 50% chance of undesirable outcomes at 2.3, 5.24 and 6.16 years for DMO, CRVO and BRVO, respectively. Cox proportional hazards modelling identified presenting age, intraretinal (IRF) volume, presence of DMO and VA as predictors of negative outcomes, whilst South East Asian ethnicity conferred an independent protective effect.

CONCLUSION

Real-world data suggest that undesirable events following anti-VEGF injections is likely to in 50% of patients by the third year of treatment in spite of appropriate loading. The definition of undesirable treatment events captured nearly all patients who were escalated to another therapy, but this proportion represented a small percentage of our definition of failed response.

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.

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.

Comparison of the effect of ranibizumab in retinal vein occlusion and macular edema with different optical coherence tomographic patterns

AIM

To explore the morphological and functional parameters to evaluate the effectiveness of intravitreal injections of ranibizumab (IVR) in treating macular edema (ME) secondary to retinal vein occlusion (RVO).

METHODS

This retrospective study involved 65 RVO patients (65 eyes) who received IVR and were followed-up for more than 3mo. ME was categorized into cystoid macular edema (CME), diffuse retinal thickening (DRT), and serous retinal detachment (SRD) according to optical coherence tomography (OCT) images. The comparison of best corrected visual acuity (BCVA; logMAR) and central macular thickness (CMT) among different follow-up points and those among 3 groups were performed by Kruskal-Wallis test. The correlation between BCVA and baseline parameters during treatment was analyzed using Spearman correlation analysis.

RESULTS

BCVA tended to improve in all groups, with marked improvement in CME and DRT groups. CMT showed the greatest reduction after 1wk, and remained stable over the following 3mo. DRT patients had the worst BCVA and the highest CMT at baseline, but the differences became smaller after IVR treatment. CMT in SRD group was significantly better than in CME and DRT groups 3mo after IVR. Most patients of CME and SRD groups transitioned to a normal pattern at 3mo follow-up. DRT patients were most likely to transform into the other morphological groups, while SRD patients showed minimal transitions. BCVA at baseline was identified as the most important prognostic indicator in all 3 groups. Additionally, DRT patients with a longer clinical course, higher CMT and central retinal vein occlusion (CRVO) tend to exhibit worse BCVA after treatment. In addition, CRVO patients are more likely to have worse BCVA at 2 and 3mo follow-up compared with branch retinal vein occlusion (BRVO) patients in CME group. SRD patients with higher baseline CMT were prone to experiencing worse BCVA after treatment.

CONCLUSION

The effectiveness of IVR is strongly correlated with baseline BCVA in all 3 groups. Baseline parameters including clinical course, CMT, and RVO position are also useful in predicting the BCVA at different time points after treatment.

Deep Learning to Distinguish Edema Secondary to Retinal Vein Occlusion and Diabetic Macular Edema: A Multimodal Approach Using OCT and Infrared Imaging

Background: Retinal diseases are emerging as a significant health concern, making early detection and prompt treatment crucial to prevent visual impairment. Optical coherence tomography (OCT) is the preferred imaging modality for non-invasive diagnosis. Both diabetic macular edema (DME) and macular edema secondary to retinal vein occlusion (RVO) present an increase in retinal thickness, posing etiologic diagnostic challenges for non-specialists in retinal diseases. The lack of research on deep learning classification of macular edema secondary to RVO using OCT images motivated us to propose a convolutional neural network model for this task. Methods: The VGG-19 network was fine-tuned with a public dataset to classify OCT images. This network was then used to develop three models: unimodal-the input is only the OCT B-scan; multimodal-the inputs are the OCT B-scan and diabetes information, and multi-image-the inputs are the OCT B-scan, the infrared image, and the diabetes information. Seven hundred sixty-six patients from ULS São João were selected, comprising 208 healthy eyes, 207 with macular edema secondary to RVO, 218 with DME, and 200 with other pathologies. The performance metrics include accuracy, precision, recall, F0.5 score, and area under the receiver operating characteristic curve (AUROC). Results: The multi-image model achieved better results, with an accuracy of 95.20%, precision of 95.43%, recall of 95.20%, F0.5-score of 95.32%, F1-score of 95.21%, and AUROC of 99.59% on the classification task between four classes. Conclusions: This study presents a novel method to distinguish macular edema secondary to RVO and DME using diabetes diagnosis, OCT, and infrared images. This research aims to provide a reliable tool for ophthalmologists, improving the accuracy and speed of diagnoses.

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.

The Diagnosis and Treatment of Branch Retinal Vein Occlusions: An Update

Branch retinal vein occlusion (BRVO) is a common retinal vascular condition and a significant contributor to vision loss worldwide, particularly in middle-aged and elderly populations. This review synthesizes current knowledge on the epidemiology, pathogenesis, and clinical features of BRVO, alongside recent advancements in diagnostic and therapeutic strategies. BRVO is approximately four times more prevalent than central retinal vein occlusion (CRVO) and often leads to significant vision impairment. By focusing on BRVO, this review aims to address the specific challenges and advancements in its diagnosis and management. The pathophysiology of BRVO is complex, involving factors such as venous compression, inflammation, and increased levels of vascular endothelial growth factor (VEGF). Diagnostic approaches such as optical coherence tomography (OCT) and fluorescein angiography are highlighted for their roles in assessing disease severity and guiding treatment decisions. Therapeutic interventions, including laser photocoagulation, anti-VEGF therapy, and intravitreal corticosteroids, are critically evaluated, emphasizing emerging treatments such as gene therapy, peptide-based agents, and small-molecule inhibitors. Despite advancements in management strategies, the recurrence of macular edema and treatment resistance remain significant challenges. Continued research is essential to refine therapeutic protocols and improve long-term visual outcomes for patients with BRVO.

[Retinal Vein Occlusions]

As retinal vein occlusion is such a complex systemic disease, its underlying risk profile should be narrowed down individually. Ophthalmologists should always rule out glaucoma or ocular hypertension while also screening the patient for systemic vascular diseases or risk factors in particular. Intravitreally applied medication (VEGF inhibitors or steroids) and laser coagulation (focal or panretinal) or a combination thereof can be considered to treat such retinal anomalies.

Long term efficacy and safety profile of dexamethasone intravitreal implant in retinal vein occlusions: a systematic review

Background/objective

Retinal vein occlusion (RVO) is a common, sight-threatening vascular disorder affecting individuals of all ages, with incidence increasing with age. Due to its complex, multifactorial nature, treating RVO remains a clinical challenge. Currently, treatment strategies include laser photocoagulation (especially for branch RVO), anti-VEGF therapies, and intravitreal corticosteroids. This systematic review (without meta-analysis) aimed to update the evidence on the efficacy and safety of the sustained-release intravitreal dexamethasone implant (DEX-i) in managing macular edema (ME) secondary to central and branch RVO.

Methods

A systematic review was conducted to assess current literature on DEX-i for ME secondary to RVO. Relevant studies were analyzed for outcomes related to visual acuity, retinal thickness, and the safety profile of DEX-i in RVO treatment.

Results

Evidence indicates that DEX-i substantially improves best-corrected visual acuity (BCVA) and reduces central retinal thickness (CRT) in ME associated with both branch and central RVO, demonstrating rapid and sustained effects. Common adverse events associated with DEX-i included manageable complications, such as medically controlled intraocular pressure elevation and progression of cataracts.

Conclusion

DEX-i offers effective and sustained improvements in both visual and anatomical outcomes for patients with ME secondary to RVO. Individualized treatment selection is essential to optimize patient outcomes. Future directions include identifying predictive biomarkers and adopting patient-centered approaches based on individual clinical characteristics, which may enhance treatment success in RVO.

Intraocular complement activation is independent of systemic complement activation and is related to macular vascular remodelling in retinal vein occlusion

BACKGROUND

Retinal vein occlusion (RVO) is a major cause of vision loss. The pathogenesis remains poorly defined although inflammation is known to play a critical role. In this study, we investigated the levels of complement proteins in the aqueous humour and plasma of RVO participants and the relationship between complement levels and retinal pathologies.

METHODS

The plasma and aqueous humour were collected from 20 treatment-naive RVO and 20 cataract patients. Retinal lesions were examined by fundus stereoscopy and optical coherence tomography angiography. The levels of C1q, C2, C4, C4b, C3, C3b/iC3b, C5, C5a, CFB, CFD, CFI, CFH, and MBL in the plasma and aqueous humour were measured using the Luminex® x MAP® multiplex assay.

RESULTS

RVO patients had significantly higher levels of C4, C4b, C3b/iC3b, CFB, and CFH in the plasma and aqueous humour compared to controls. The aqueous levels of C1q, C2, C5, C5a, and MBL were also significantly higher in RVO patients than in controls. CRVO patients had higher intraocular levels of C1q, C4, C5, CFI, CFH, and MBL than BRVO patients. C5a was below the detectable limit in the plasma in 18 cataracts and 16 RVO participants. The intraocular levels of C5a positively correlated with C1q, C2, C4, C3, C5, CFB, CFH, and MBL. The intraocular levels of CFD, CFI and MBL positively correlated with CRT, and the levels of C2, C3, C5, CFB, and MBL negatively correlated with the size of the foveal avascular zone. The plasma levels of C4b, C3b/iC3b, and CFD positively correlated with their counterparts in the aqueous humour in cataracts but not in RVO patients. The ratios of aqueous humour/plasma of C1q, C4, C4b, C3b/iC3b, C5, CFB, CFD, CFI, and CFH in the RVO patients were significantly higher than those in the cataract patients.

DISCUSSION AND CONCLUSIONS

The intraocular complement activation in RVO is mediated by the classical and the alternative pathways and is largely independent of systemic complement activation. Intraocular complement activation may be related to retinal oedema and vascular remodeling in RVO patients.

Insights to Ang/Tie signaling pathway: another rosy dawn for treating retinal and choroidal vascular diseases

Retinal neurovascular unit (NVU) is a multi-cellular structure that consists of the functional coupling between neural tissue and vascular system. Disrupted NVU will result in the occurrence of retinal and choroidal vascular diseases, which are characterized by the development of neovascularization, increased vascular permeability, and inflammation. This pathological entity mainly includes neovascular age-related macular degeneration (neovascular-AMD), diabetic retinopathy (DR) retinal vein occlusion (RVO), and retinopathy of prematurity (ROP). Emerging evidences suggest that the angopoietin/tyrosine kinase with immunoglobulin and epidermal growth factor homology domains (Ang/Tie) signaling pathway is essential for the development of retinal and choroidal vascular. Tie receptors and their downstream pathways play a key role in modulating the vascular development, vascular stability, remodeling and angiogenesis. Angiopoietin 1 (Ang1) is a natural agonist of Tie2 receptor, which can promote vascular stability. On the other hand, angiopoietin 2 (Ang2) is an antagonist of Tie2 receptor that causes vascular instability. Currently, agents targeting the Ang/Tie signaling pathway have been used to inhibit neovascularization and vascular leakage in neovascular-AMD and DR animal models. Particularly, the AKB-9778 and Faricimab have shown promising efficacy in improving visual acuity in patients with neovascular-AMD and DR. These experimental and clinical evidences suggest that activation of Ang/Tie signaling pathway can inhibit the vascular permeability, neovascularization, thereby maintaining the normal function and structure of NVU. This review seeks to introduce the versatile functions and elucidate the modulatory mechanisms of Ang/Tie signaling pathway. Recent pharmacologic therapies targeting this pathway are also elaborated and summarized. Further translation of these findings may afford a new therapeutic strategy from bench to bedside.

A Meta-Learning Approach for Classifying Multimodal Retinal Images of Retinal Vein Occlusion With Limited Data

Purpose

To propose and validate a meta-learning approach for detecting retinal vein occlusion (RVO) from multimodal images with only a few samples.

Methods

In this cross-sectional study, we formulate the problem as meta-learning. The meta-training dataset consists of 1254 color fundus (CF) images from 39 different fundus diseases. Two meta-testing datasets include a public domain dataset and an independent dataset from Kandze Prefecture People's Hospital. The proposed meta-learning models comprise two modules: the feature extraction networks and the prototypical networks (PNs). We use two deep learning models (the ResNet and the Contrastive Language-Image Pre-Training networks [CLIP]) for feature extraction. We evaluate the performance of the algorithms using accuracy, area under the receiver operating characteristic curve (AUCROC), F1-score, and recall.

Results

CLIP-based PNs outperform across all meta-testing datasets. For the public APTOS dataset, meta-learning algorithms achieve good results with an accuracy of 86.06% and an AUCROC of 0.87 with only 16 training images. In the hospital datasets, meta-learning algorithms show excellent diagnostic capability for detecting RVO with a very low number of shots (AUCROC above 0.99 for n = 4, 8, and 16, respectively). Notably, even though the meta-training dataset does not include fluorescein angiography (FA) images, meta-learning algorithms also have excellent diagnostic capability for detecting RVO from images with a different modality (AUCROC above 0.93 for n = 4, 8, and 16, respectively).

Conclusions

The proposed meta-learning models excel in detecting RVO, not only on CF images but also on FA images from a different imaging modality.

Translational Relevance

The proposed meta-learning models could be useful in automatically detecting RVO on CF and FA images.

Outcomes of anti-VEGF treatment for macular edema secondary to central retinal vein occlusion in patients with poor baseline visual acuity

OBJECTIVE

To report the visual outcomes of intravitreal anti-vascular endothelial growth factor (anti-VEGF) treatment for macular edema secondary to central retinal vein occlusion (CRVO) in patients with baseline visual acuity of ≤23 ETDRS letters vision.

DESIGN

Retrospective observational cohort study.

METHODS

This is a single-institution study. A total of 173 eyes from 173 patients who had completed 3 consecutive monthly anti-VEGF injections for macular edema secondary CRVO and best-corrected visual acuity (BCVA) ≤23 ETDRS letters were included. The main outcome measures were visual acuity at month 3 and month 12.

RESULTS

At month 3, BCVA increased to 34.1 ETDRS letters (95% CI, 30.7-37.5), with a gain of 25.0 letters (95% CI, 22.0-28.5; p < 0.001). The mean central subfield thickness decreased by 519 μm (95% CI, 475.5-567.0; p < 0.001). Most patients (67.6%) gained >15 ETDRS letters. A total of 160 patients were followed up for 12 months, and the mean BCVA was 31.2 ETDRS letters (95% CI, 27.5-34.9) at the end of this period. A third of eyes that did not respond (<5-letter gain) after a single injection experienced a 15-letter or more improvement after 3 consecutive injections.

CONCLUSIONS

Anti-VEGF treatment in eyes with CRVO and poor baseline visual acuity results in significant visual improvement, and moderate improvement is still noted despite a poor response after a single injection.

Time to initiate anti-vascular endothelial growth factor therapy and visual outcome in central retinal vein occlusion

This retrospective study aimed to investigate the progression of central retinal vein occlusion (CVO) prior to treatment initiation and its impact on prognosis. Of the 54 studied eyes with acute CVO, the average logMAR visual acuity (VA) at the initial visit was 0.65 ± 0.49 with an average time to treatment of 14.9 ± 14.5 days. VA at the initial treatment was identified as a stronger predictor of VA at the final visit compared to VA at the first visit or other factors. Patients who received treatment more than 28 days after the initial visit experienced a significant decline in VA compared to those treated within 28 days (0.21 ± 0.35 vs. 0.04 ± 0.13, p = 0.006). Additionally, patients who were treated between 15 and 28 days showed a greater decrease in VA compared to those treated within 14 days (0.12 ± 0.46 vs. 0.018 ± 0.02, p = 0.026). These findings from the current retrospective analysis suggesting that there is a possibility of VA decline at the initial treatment associating with worse prognosis even when treatment is administered within a month should be further investigated in the prospective study. Also, it may be crucial to consider frequent monitoring of acute CVO patients for initiating treatment at the optimal timing.

Automated interpretation of retinal vein occlusion based on fundus fluorescein angiography images using deep learning: A retrospective, multi-center study

Purpose

Fundus fluorescein angiography (FFA) is the gold standard for retinal vein occlusion (RVO) diagnosis. This study aims to develop a deep learning-based system to diagnose and classify RVO using FFA images, addressing the challenges of time-consuming and variable interpretations by ophthalmologists.

Methods

4028 FFA images of 467 eyes from 463 patients were collected and annotated. Three convolutional neural networks (CNN) models (ResNet50, VGG19, InceptionV3) were trained to generate the label of image quality, eye, location, phase, lesions, diagnosis, and macular involvement. The performance of the models was evaluated by accuracy, precision, recall, F-1 score, the area under the curve, confusion matrix, human-machine comparison, and Clinical validation on three external data sets.

Results

The InceptionV3 model outperformed ResNet50 and VGG19 in labeling and interpreting FFA images for RVO diagnosis, achieving 77.63%-96.45% accuracy for basic information labels and 81.72%-96.45% for RVO-relevant labels. The comparison between the best CNN and ophthalmologists showed up to 19% accuracy improvement with the inceptionV3.

Conclusion

This study developed a deep learning model capable of automatically multi-label and multi-classification of FFA images for RVO diagnosis. The proposed system is anticipated to serve as a new tool for diagnosing RVO in places short of medical resources.

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.

Association of triglyceride‑glucose index in branch retinal vein occlusion

BACKGROUND

To investigate the association between the triglyceride-glucose (TyG) index and newly diagnosed branch retinal vein occlusion (BRVO) in patients.

METHODS

The study included 57 individuals with BRVO and a control group comprising 50 healthy volunteers matched for age and gender. Detailed eye examinations were conducted, and various blood biochemistry and hematological parameters were recorded. The TyG index was calculated using fasting plasma glucose and triglyceride values.

RESULTS

The mean age was 61.4 ± 9.6 years for the BRVO group and 60.6 ± 10.3 years for the control group. The TyG values were significantly higher in the BRVO group when compared to the control group (8.84 ± 0.41 vs. 8.52 ± 0.29, p < 0.001). Multivariate analysis revealed that the TyG index independently predicted BRVO (odds ratio = 2.58, 95% confidence interval = 1.69-3.93; p < 0.001). In receiver operating characteristics analysis, the TyG index had an area under the curve of 0.749, and a TyG index higher than 8.52 predicted BRVO with 83% sensitivity and 70% specificity.

CONCLUSIONS

This study establishes a significant association between an elevated TyG index and BRVO. Consequently, the TyG index could serve as a valuable predictive tool for identifying individuals at risk for BRVO.

Prevalence and risk factors of retinal vein occlusion in individuals with diabetes: The kailuan eye study

PURPOSE

The aim of this study was to analyze the incidence of retinal vein occlusion (RVO) in patients with and without diabetes in the population and compare the influencing factors.

METHOD

The community-based Kailuan Eye Study included 14,440 participants (9835 male, 4605 female) with a mean age of 54.0 ± 13.3 years (range, 20-110 years). They underwent a systemic and ophthalmologic examination. RVO were diagnosed on fundus photographs.

RESULT

By matching for age and gender, we included a total of 2767 patients each with diabetes and non-diabetes. The prevalence of RVO among patients with and without diabetes was 1.5% and 0.8%, respectively. The prevalence of RVO was higher in patients with diabetes than in patients without diabetes in all age groups. Multifactorial regression analysis showed that only fasting blood glucose levels were significantly different between patients with RVO with or without DM. The occurrence of RVO in the group with diabetes was mainly associated with higher fasting glucose and systolic blood pressure; in the group without diabetes, RVO was mainly associated with higher diastolic blood pressure, Body Mass Index, and lower low-density lipoprotein cholesterol levels.

CONCLUSION

We found that patients with diabetes have increased risks of RVO. In addition to blood pressure control, we recommend educating patients with diabetes about RVO, to prevent its subsequent occurrence.

Potential Mechanism of Platelet GPIIb/IIIa and Fibrinogen on Retinal Vein Occlusion

PURPOSE

To explore the role of coagulation and fibrinolytic factors, and the potential mechanism of platelet aggregation in the pathogenesis of retinal vein occlusion.

METHODS

Coagulation and fibrinolytic parameters in patients with retinal vein occlusion were determined using hemagglutinin and HISCL-5000. Relationships between these elevated parameters and factors representing typical clinical manifestations of retinal vein occlusion were examined, and these parameters were analyzed using a STRING database to indicate the potential role of platelet aggregation. Platelet glycoprotein IIb/IIIa (GPIIb/IIIa) levels were evaluated by flow cytometry after antiplatelet treatment in patients and mouse models. Furthermore, the GPIIb/IIIa ligand fibrinogen in peripheral blood and retina of mouse models was assessed by the turbidimetric method and real-time PCR, respectively.

RESULTS

In patients, significant increases in peripheral blood fibrinogen and GPIIb/IIIa levels were observed (p = 0.0040, p < 0.0001, respectively). A positive correlation was observed between macular thickness (MT) and both fibrinogen and GPIIb/IIIa (r = 0.4528, p = 0.0063; r = 0.3789, p = 0.0427, respectively). After intravitreal injections of anti-vascular endothelial growth factor drugs, a significant reduction in fibrinogen levels was observed (p = 0.0072). In addition, the use of antiplatelet drugs resulted in a significant decrease in GPIIb/IIIa (p < 0.0001). In a mouse model, antiplatelet therapy significantly reduced both peripheral blood and retina fibrinogen levels and the overall rate of vein occlusion 3 days after occlusion (p < 0.0005). In addition, the reduction in GPIIb/IIIa levels after antiplatelet therapy was remarkable.

CONCLUSION

Fibrinogen and GPIIb/IIIa may be involved in retinal vein occlusion and blocking platelet aggregation may be a new therapeutic approach for retinal vein occlusion.

Could Triglyceride-Glucose Index, a Predictor of Atherosclerosis, Be Associated with Retinal Vein Occlusion?

Objectives

The triglyceride-glucose (TyG) index is a sign of atherosclerosis in cardiovascular diseases. The TyG index is thought to have clinical significance for the assessment of vascular damage. In this study we aimed to demonstrate the connection between the TyG index and retinal vein occlusion (RVO).

Materials and Methods

This case-control observational study involved 492 participants aged 40-90, admitted to the ophthalmology outpatient clinic of our hospital. TyG index was calculated using the formula: ln(fasting TG [mg/dL] × fasting plasma glucose [mg/dL]/2).

Results

The RVO group included 387 patients (181 women and 206 men) and the control group included 115 patients (61 women and 54 men). The average patient age was 62.9±11.1 years in the RVO group and 56.7±8.7 years in the control group. The TyG index was higher in the RVO group (8.9±0.7) than in the control group (8.8±0.6). This difference was statistically significant (p=0.04). The correlation was statistically significant when evaluated according to age and sex by multivariate logistic regression analysis (odds ratio: 1.45, confidence interval: 1.03- 2.02, p=0.03).

Conclusion

The TyG index is a novel atherogenicity index that is derived from routine blood tests and can be used to determine the risk of RVO in at-risk individuals with a simple calculation. Therefore, the TyG index could help as a reliable guide to identify individuals at RVO with high risk and initiate early intervention.

Exploration on OCT biomarker candidate related to macular edema caused by diabetic retinopathy and retinal vein occlusion in SD-OCT images

To improve the understanding of potential pathological mechanisms of macular edema (ME), we try to discover biomarker candidates related to ME caused by diabetic retinopathy (DR) and retinal vein occlusion (RVO) in spectral-domain optical coherence tomography images by means of deep learning (DL). 32 eyes of 26 subjects with non-proliferative DR (NPDR), 77 eyes of 61 subjects with proliferative DR (PDR), 120 eyes of 116 subjects with branch RVO (BRVO), and 17 eyes of 15 subjects with central RVO (CRVO) were collected. A DL model was implemented to guide biomarker candidate discovery. The disorganization of the retinal outer layers (DROL), i.e., the gray value of the retinal tissues between the external limiting membrane (ELM) and retinal pigment epithelium (RPE), the disrupted and obscured rate of the ELM, ellipsoid zone (EZ), and RPE, was measured. In addition, the occurrence, number, volume, and projected area of hyperreflective foci (HRF) were recorded. ELM, EZ, and RPE are more likely to be obscured in RVO group and HRFs are observed more frequently in DR group (all P ≤ 0.001). In conclusion, the features of DROL and HRF can be possible biomarkers related to ME caused by DR and RVO in OCT modality.

Central retinal vein occlusion in patients with metastatic solid tumors on tyrosine kinase inhibitors: a report of case series and literature review

Background

Central retinal vein occlusion (CRVO) is a rare adverse effect related to the use of tyrosine kinase inhibitors (TKIs) in patients with metastatic malignancies, which has only been reported in several case reports.

Case presentation

We reported the case series of three CRVO patients on regular regimens of TKIs as part of targeted therapies for metastatic malignancies, all of whom were otherwise healthy with no or well-controlled systemic conditions. All these patients received injections of intravitreal dexamethasone implant (IDI) and achieved a fluid-free macula at the end of the visit. In addition, we reviewed the existing literature on this subject and present here an updated analysis of the related TKIs, ocular presentation, treatment, and prognosis.

Conclusion

All patients diagnosed with CRVO on TKIs received dexamethasone implant treatment and obtained a fluid-free macula. We would like to raise awareness among our colleague oncologists about the possibility of CRVO related to TKI use and the necessity for patients to be screened regularly by a retinal specialist.

Cumulative effect of metabolic syndrome on the risk of retinal vein occlusion in young patients: A nationwide population-based study

This study aimed to investigate the impact of the cumulative burden of metabolic syndrome (MetS) on the incidence of retinal vein occlusion (RVO) in young adults. We included 1,408,093 subjects aged ≥20 and <40 years without a history of RVO who underwent four consecutive annual health examinations during 2009-2012 from the database of the Korean National Health Insurance Service. The metabolic burden was evaluated based on the cumulative number of MetS diagnoses at each health examination (0-4 times) and the cumulative number of each MetS component diagnosed at each health examination (0-4 times per MetS component). Cox proportional hazards models were used to estimate the risk of RVO according to metabolic burden. The risk of RVO was positively correlated with the cumulative number of MetS diagnoses over the four health examinations. All five MetS components were independently associated with an increased risk of RVO. Subgroup analysis for the impact of MetS on RVO occurrence revealed that MetS had a greater impact on female subjects (P <0.001). Prompt detection of metabolic derangements and their treatment might be important to decrease the risk of RVO in young adults, especially women.

Prognostic modelling of number of patients with retinal vein occlusion in anti-VEGF therapy

PURPOSE

The purpose of the study was to evaluate temporal changes in age- and sex-stratified incidence rates of retinal vein occlusion (RVO) commenced in anti-vascular endothelial growth factor (anti-VEGF) treatment, proportion of patients remaining in active anti-VEGF therapy over time, and to develop a forecasting model for future number of patients with RVO in active anti-VEGF therapy.

METHODS

This was a registry-based study of patients with RVO in the Capital Region of Denmark from commenced in anti-VEGF therapy from 1 January 2007 to 30 June 2022. Census data were extracted from Statistics Denmark for incidence rate analyses and forecasting data of future demographics.

RESULTS

A total of 2641 patients with RVO were commenced in anti-VEGF therapy, of which 2192 were later discontinued. Number of patients rose dramatically during the first years of introduction of anti-VEGF therapy, after which growth was slower and followed the demographic changes. Trend analyses revealed that the COVID-19 epidemics impacted with fewer referrals and more aggressive discontinuation practices. Annual incidence of RVO in 2012-2021 was 13.1 per 100 000 (95% CI: 12.6-13.6 per 100 000). Proportion of patients with RVO remaining in active anti-VEGF treatment was 55.0%, 40.1%, 30.8% and 12.1% after Years 1, 2, 3 and 8, respectively. According to our forecast, number of patients with RVO in active anti-VEGF therapy will grow slowly but continually at least until year 2035.

CONCLUSION

Our study reports incidence rates and provides prognostic modelling of number of patients with RVO in anti-VEGF therapy.

Efficacy, Safety, and Treatment Burden of Aflibercept 2 mg and Ranibizumab in Retinal Vein Occlusion: A Systematic Review and Meta-analysis

INTRODUCTION

This systematic review and meta-analysis aimed to provide an updated evidence base for clinical decision-making by comparing the efficacy and safety of aflibercept 2 mg and ranibizumab in treating retinal vein occlusion (RVO).

METHODS

A systematic search was conducted using eight databases up to December 2021. Randomized controlled trials (RCTs) and real-world studies (RWSs) comparing aflibercept and ranibizumab in patients with RVO were evaluated. The primary outcomes assessed were efficacy, number of injections administered, and adverse events.

RESULTS

Three RCTs (424 patients) and 11 RWSs (1415 patients) were included. For central RVO (CRVO), RCTs demonstrated a comparable efficacy, whereas RWSs showed that mean changes from baseline in best-corrected visual acuity (BCVA) and central retinal thickness (CRT) were significantly greater with aflibercept compared to ranibizumab; the number of injections of aflibercept was fewer than that of ranibizumab in RCTs, but similar in RWSs. For branch RVO (BRVO), no statistically significant difference in efficacy between the two drugs in RCTs/RWSs was observed, with fewer injections of aflibercept at 12 months in RWSs. The safety profiles of both drugs were similar for both CRVO and BRVO.

CONCLUSIONS

For CRVO, aflibercept had similar efficacy and safety profile but with fewer injections versus ranibizumab in RCTs; RWSs showed greater BCVA improvement and CRT reduction with aflibercept than ranibizumab. For BRVO, RCTs showed similar in efficacy, safety, and injection numbers for both drugs, while RWSs demonstrated that aflibercept required fewer injections at 12 months of follow-up. Overall, this study provides updated evidence for clinical decision-making in the treatment of RVO.

Ophthalmic vascular manifestations in eosinophil-associated diseases: a comprehensive analysis of 57 patients from the CEREO and EESG networks and a literature review

Introduction

Eosinophils have widespread procoagulant effects. In daily practice, eosinophil-related cardiovascular toxicity consists of endomyocardial damage, eosinophilic vasculitis and arterial or venous thrombosis. Here we aim to report on the clinical features and treatment outcomes of patients with unexplained ophthalmic vascular manifestations and eosinophilia.

Methods

We conducted a retrospective, multicenter, observational study and a literature review of patients with eosinophilia (≥0.5 x109/L) and concomitant ophthalmic vascular manifestations independent of the underlying eosinophilic disease but with no alternative cause for ophthalmic manifestations.

Results

Fifty-seven patients were included (20 from the observational study and 37 from the literature review). Ophthalmic vascular features were the initial manifestation of eosinophil-related disease in 34 (59%) patients and consisted of 29 central retinal artery occlusions, six branch retinal artery occlusions, five central retinal vein occlusions, two branch retinal vein occlusions, seven retinal vasculitides, two retinal vasospasms, 12 Purtscher's retinopathies, 13 anterior ischemic optic neuropathies and two posterior ischemic optic neuropathies. The median [IQR] absolute eosinophil count at onset of ophthalmic vascular manifestations was 3.5 [1.7-7.8] x109/L. Underlying eosinophil-related diseases included eosinophilic granulomatosis with polyangiitis (n=32), clonal hypereosinophilic syndrome (HES) (n=1), idiopathic HES (n=13), lymphocytic HES (n=2), adverse drug reactions (n=3), parasitosis (n=2), polyarteritis nodosa (n=1), IgG4-related disease (n=1), eosinophilic fasciitis (n=1) and primary sclerosing cholangitis (n=1). Other extra-ophthalmologic arterial or venous thromboses related to eosinophilia were reported in four (7%) and nine (16%) patients, respectively. Visual prognosis was poor: only eight (10%) patients achieved full recovery of ophthalmologic symptoms. After a median follow-up of 10.5 [1-18] months, one patient (3%) had a recurrence of an ophthalmic vascular manifestation, and three patients (10%) had a recurrence of other vascular symptoms (deep vein thrombosis in two and pulmonary embolism in one patient). At the time of recurrence, absolute eosinophil counts were above 0.5 x109/L in all cases (n=4).

Discussion

This study broadens the spectrum of vascular manifestations associated with hypereosinophilia by adding ophthalmic vascular manifestations. In patients with ophthalmological vascular manifestations and hypereosinophilia, aggressive treatment of the underlying pathology (and normalization of blood count) should be implemented.

Prevalence of retinal pathologies in people over 60 years: the Tehran Geriatrics Eye Study

AIM

To determine the prevalence of some retinal pathologies in people over 60y and their association with demographic and ocular factors.

METHODS

A cross-sectional study was conducted in Tehran using multistage cluster sampling. After selecting subjects aged 60 and over, optometric, and ophthalmic examinations were done. For retinal examination, a 90 D lens was used and indirect ophthalmoscopy was performed after instilling tropicamide drops. Biometry was done using the IOL Master for all participants.

RESULTS

Of 3791 people that were invited through cluster sampling, 3310 participated in the study (response rate=82%). The prevalence of retinal pigmented epithelium (RPE) change, drusen, geographic atrophy (GA), hypertensive retinopathy (HTR), nonproliferative diabetic retinopathy (NPDR), proliferative diabetic retinopathy (PDR), choroidal neovascularization (CNV), central retinal artery occlusion (CRAO), myopic retinopathy (MR), branch retinal vein occlusion (BRVO), and central retinal vein occlusion (CRVO) was 27.42%, 11.08%, 4.52%, 3.03%, 4.05%, 0.54%, 0.82%, 0.39%, 0.20%, 0.49%, and 0.19%, respectively. After removing the effect of age, the odds of NPDR were 1.68 times higher in women compared to men (P=0.014). After removing the effect of sex, the odds of drusen, RPE change, GA, CNV, BRVO, and CRVO increased with age.

CONCLUSION

There is a higher prevalence of RPE change, drusen, GA, CNV and a lower prevalence of MR and CRAO in the elderly population of Tehran aged over 60y compared to global average values. Considering the correlation of most of the diseases with age and their effects on vision, attention should be paid to these diseases and the related screening programs to prevent vision impairment.

Computational Retinal Microvascular Biomarkers from an OCTA Image in Clinical Investigation

Retinal structural and functional changes in humans can be manifestations of different physiological or pathological conditions. Retinal imaging is the only way to directly inspect blood vessels and their pathological changes throughout the whole body non-invasively. Various quantitative analysis metrics have been used to measure the abnormalities of retinal microvasculature in the context of different retinal, cerebral and systemic disorders. Recently developed optical coherence tomography angiography (OCTA) is a non-invasive imaging tool that allows high-resolution three-dimensional mapping of the retinal microvasculature. The identification of retinal biomarkers from OCTA images could facilitate clinical investigation in various scenarios. We provide a framework for extracting computational retinal microvasculature biomarkers (CRMBs) from OCTA images through a knowledge-driven computerized automatic analytical system. Our method allows for improved identification of the foveal avascular zone (FAZ) and introduces a novel definition of vessel dispersion in the macular region. Furthermore, retinal large vessels and capillaries of the superficial and deep plexus can be differentiated, correlating with retinal pathology. The diagnostic value of OCTA CRMBs was demonstrated by a cross-sectional study with 30 healthy subjects and 43 retinal vein occlusion (RVO) patients, which identified strong correlations between OCTA CRMBs and retinal function in RVO patients. These OCTA CRMBs generated through this "all-in-one" pipeline may provide clinicians with insights about disease severity, treatment response and prognosis, aiding in the management and early detection of various disorders.

Initial response and 12-month outcomes after commencing dexamethasone or vascular endothelial growth factor inhibitors for retinal vein occlusion in the FRB registry

To compare baseline characteristics, initial response and 12-month efficacy and safety outcomes in eyes with branch and central retinal vein occlusion (BRVO and CRVO) treated with dexamethasone implants (DEX) or anti-vascular endothelial growth factor (anti-VEGF) we performed a multi-centre, retrospective and observational study using Fight Retinal Blindness! Registry. Of 725 eligible eyes, 10% received DEX initially with very frequent adjunctive anti-VEGF (BRVO-DEX 49%, CRVO-DEX 60%). The primary outcome of mean adjusted change in VA at 12 months with DEX and anti-VEGF initiated groups were not statistically significantly different (BRVO: DEX + 6.7, anti-VEGF + 10.6 letters; CRVO: DEX + 2.8, anti-VEGF + 6.8 letters). DEX initiated eyes had fewer injections and visits than anti-VEGF initiated eyes. The BRVO-DEX eyes had greater initial mean changes in VA and central subfield thickness (CST) and achieved inactivity sooner than BRVO-anti-VEGF eyes. The mean CST after the first three months was above 350 μm in all but the BRVO-anti-VEGF group, suggesting undertreatment. In routine care DEX is uncommonly used when available as initial treatment of BRVO and CRVO requiring supplemental anti-VEGF within the first year. The 12-month outcomes were similar, but DEX initiated eyes had fewer injections and visits but more episodes of raised IOP Vs those starting anti-VEGF.

Interpretable Detection of Diabetic Retinopathy, Retinal Vein Occlusion, Age-Related Macular Degeneration, and Other Fundus Conditions

Diabetic retinopathy (DR), retinal vein occlusion (RVO), and age-related macular degeneration (AMD) pose significant global health challenges, often resulting in vision impairment and blindness. Automatic detection of these conditions is crucial, particularly in underserved rural areas with limited access to ophthalmic services. Despite remarkable advancements in artificial intelligence, especially convolutional neural networks (CNNs), their complexity can make interpretation difficult. In this study, we curated a dataset consisting of 15,089 color fundus photographs (CFPs) obtained from 8110 patients who underwent fundus fluorescein angiography (FFA) examination. The primary objective was to construct integrated models that merge CNNs with an attention mechanism. These models were designed for a hierarchical multilabel classification task, focusing on the detection of DR, RVO, AMD, and other fundus conditions. Furthermore, our approach extended to the detailed classification of DR, RVO, and AMD according to their respective subclasses. We employed a methodology that entails the translation of diagnostic information obtained from FFA results into CFPs. Our investigation focused on evaluating the models' ability to achieve precise diagnoses solely based on CFPs. Remarkably, our models showcased improvements across diverse fundus conditions, with the ConvNeXt-base + attention model standing out for its exceptional performance. The ConvNeXt-base + attention model achieved remarkable metrics, including an area under the receiver operating characteristic curve (AUC) of 0.943, a referable F1 score of 0.870, and a Cohen's kappa of 0.778 for DR detection. For RVO, it attained an AUC of 0.960, a referable F1 score of 0.854, and a Cohen's kappa of 0.819. Furthermore, in AMD detection, the model achieved an AUC of 0.959, an F1 score of 0.727, and a Cohen's kappa of 0.686. Impressively, the model demonstrated proficiency in subclassifying RVO and AMD, showcasing commendable sensitivity and specificity. Moreover, our models enhanced interpretability by visualizing attention weights on fundus images, aiding in the identification of disease findings. These outcomes underscore the substantial impact of our models in advancing the detection of DR, RVO, and AMD, offering the potential for improved patient outcomes and positively influencing the healthcare landscape.

Do we need more guidance on thrombophilia testing? Challenges and special considerations

INTRODUCTION

Thrombophilia testing (TT) is a laboratory procedure designed to detect the risk factors involved in the pathogenesis of vascular occlusions. The role of TT is also controversial because it has a limited impact on the choice and duration of antithrombotic treatments.

AREAS COVERED

We reviewed, by examining MEDLINE up to October 2023. Accepted and not accepted thrombophilia markers are discussed along with the appropriateness or not of prescribing TT in several conditions such as: provoked and unprovoked venous thromboembolism (VTE), women who are planning a pregnancy whose relatives had VTE or have a hereditary thrombophilia, before assumption of estro-progestins, after multiple pregnant loss, arterial thrombosis, retinal vein occlusion, and splanchnic vein thrombosis.

EXPERT OPINION

TT is not essential in the management of VTE, but it may be useful for limiting adverse events in case of thrombophilia. We expose our criticism of items afforded by other guidelines by presenting our opinion based on both the scientific evidence and clinical practice. We also deal with common mistakes in prescribing and interpretations of TT hoping to purpose an educational approach on this topic. Finally, we emphasize the creation of the expert in hemostasis and thrombosis who should be present in every hospital.

Oxidative stress in the eye and its role in the pathophysiology of ocular diseases

Oxidative stress occurs through an imbalance between the generation of reactive oxygen species (ROS) and the antioxidant defense mechanisms of cells. The eye is particularly exposed to oxidative stress because of its permanent exposure to light and due to several structures having high metabolic activities. The anterior part of the eye is highly exposed to ultraviolet (UV) radiation and possesses a complex antioxidant defense system to protect the retina from UV radiation. The posterior part of the eye exhibits high metabolic rates and oxygen consumption leading subsequently to a high production rate of ROS. Furthermore, inflammation, aging, genetic factors, and environmental pollution, are all elements promoting ROS generation and impairing antioxidant defense mechanisms and thereby representing risk factors leading to oxidative stress. An abnormal redox status was shown to be involved in the pathophysiology of various ocular diseases in the anterior and posterior segment of the eye. In this review, we aim to summarize the mechanisms of oxidative stress in ocular diseases to provide an updated understanding on the pathogenesis of common diseases affecting the ocular surface, the lens, the retina, and the optic nerve. Moreover, we discuss potential therapeutic approaches aimed at reducing oxidative stress in this context.

Changes in foveal avascular zone area and retinal vein diameter in patients with retinal vein occlusion detected by fundus fluorescein angiography

Purpose

To investigate changes in foveal avascular area (FAZ) and retinal vein diameter in patients with retinal vein occlusion (RVO) after intravitreal ranibizumab, and to analyze the correlation between ranibizumab therapy and visual gain.

Methods

This retrospective study enrolled 95 eyes of 95 patients who had accepted three consecutive monthly ranibizumab injections, including 50 branch RVOs (BRVOs) and 45 central RVOs (CRVOs). BRVOs were divided into ischemia group (n = 32) and non-ischemia group (n = 18), and CRVOs also had ischemia group (n = 28) and non-ischemia group (n = 17). Comprehensive ophthalmic examinations were performed before the first injection and after 6, 12, and 24 months. The FAZ was manually circumscribed on early-phase images of fundus fluorescein angiography. Retinal vein diameters were measured on fundus photographs.

Results

After three injections, the FAZ area was significantly enlarged firstly and then reduced in all ischemic RVOs and the non-ischemic BRVOs (p < 0.05), while the retinal vein diameter was significantly reduced firstly and then increased in all groups except for unobstructed branch veins of non-ischemic BRVOs (p < 0.05). The correlation between the FAZ area and best corrected visual acuity was statistically significant in all CRVOs (non-ischemic, r = 0.372; ischemic, r = 0.286; p < 0.01) and ischemic BRVOs (r = 0.180, p < 0.05). Spearman's correlation analysis revealed that the retinal vein diameter was significantly correlated to the larger FAZ area in obstructed branch veins of ischemic BRVOs (r = -0.31, p < 0.01), inferior temporal branch veins of non-ischemic CRVOs (r = -0.461, p < 0.01) and ischemia CRVO groups (superior temporal branch vein, r = -0.226, p < 0.05; inferior temporal branch vein, r = -0.259, p < 0.01).

Conclusion

After three consecutive monthly ranibizumab injections, the FAZ area was enlarged and retinal vein diameter reduced with gradual recovery to near baseline from 12 months. These results suggest that ranibizumab therapy can worsen macular ischemia and prevent visual gain in the short term. It has important significance for the treatment and prognosis of RVO, although the natural course of RVO may also affect ischemia and visual gain.

Intravitreal Anti-Vascular Endothelial Growth Factor Therapies for Retinal Disorders

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

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.

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.

Antithrombotic treatment for retinal vein occlusion: a systematic review and meta-analysis

BACKGROUND

Retinal vein occlusion (RVO) represents a common thrombotic disorder.

OBJECTIVES

In this meta-analysis, we evaluated the efficacy and safety of anticoagulant and antiplatelet therapy in RVO.

METHODS

MEDLINE and EMBASE were searched up to December 2021 for observational studies and randomized controlled trials including patients with RVO. Efficacy outcomes were best-corrected visual acuity improvement, recurrent RVO, fluorescein angiography improvement, cardiovascular events, and safety outcomes were major bleeding and intraocular bleeding.

RESULTS

A total of 1422 patients (15 studies) were included. Antiplatelet therapy was administered to 477 patients (13 studies), anticoagulant therapy to 312 patients (12 studies), and 609 (7 studies) patients received no antithrombotic treatment. The treatment duration ranged between 0.5 and 3 months. The median follow-up duration was 12 months. Best-corrected visual acuity improvement was reported in 58% of the patients (95% confidence interval [CI], 45%-69%) overall, 64% (95% CI, 58%-71%) in those on anticoagulant therapy, and 33% (95% CI, 21%-47%) in those on antiplatelet therapy. The rates of recurrent RVO was 11% (95% CI, 7%-17%), 7% (95% CI, 2%-19%), and 15% (95% CI, 8%-28%), respectively. The rate of recurrent RVO in untreated patients was 9% (95% CI, 6%-14%). The rate of major bleeding was 5% (95% CI, 3%-9%) overall, 4% (95% CI, 2%-9%) in those on anticoagulant therapy, and 7% (95% CI, 2%-23%) in those on antiplatelet therapy.

CONCLUSION

Anticoagulant therapy was associated with higher visual acuity improvement and fewer recurrent RVO events than antiplatelet therapy, at the cost of an acceptable proportion of bleeding complications.

Laser-Induced Porcine Model of Experimental Retinal Vein Occlusion: An Optimized Reproducible Approach

Retinal vein occlusion (RVO) is a frequent visually disabling condition. The management of RVO continues to challenge clinicians. Macular edema secondary to RVO is often recurrent, and patients typically require intravitreal injections for several years. Understanding molecular mechanisms in RVO is a key element in improving the treatment of the condition. Studying the molecular mechanisms in RVO at the retinal level is possible using animal models of experimental RVO. Most studies of experimental RVO have been sporadic, using only a few animals per experiment. Here, we report on 10 years of experience of the use of argon laser-induced experimental RVO in 108 porcine eyes from 65 animals, including 65 eyes with experimental branch retinal vein occlusion (BRVO) and 43 eyes with experimental central retinal vein occlusion (CRVO). Reproducibility and methods for evaluating and controlling ischemia in experimental RVO are reviewed. Methods for studying protein changes in RVO are discussed in detail, including proteomic analysis, Western blotting, and immunohistochemistry. Experimental RVO has brought significant insights into molecular changes in RVO. Testing intravitreal interventions in experimental RVO may be a significant step in developing personalized therapeutic approaches for patients with RVO.

Hypermixed Convolutional Neural Network for Retinal Vein Occlusion Classification

Retinal vein occlusion (RVO) is one of the most common retinal vascular diseases leading to vision loss if not diagnosed and treated in time. RVO can be classified into two types: CRVO (blockage of the main retinal veins) and BRVO (blockage of one of the smaller branch veins). Automated diagnosis of RVO can improve clinical workflow and optimize treatment strategies. However, to the best of our knowledge, there are few reported methods for automated identification of different RVO types. In this study, we propose a new hypermixed convolutional neural network (CNN) model, namely, the VGG-CAM network, that can classify the two types of RVOs based on retinal fundus images and detect lesion areas using an unsupervised learning method. The image data used in this study is collected and labeled by three senior ophthalmologists in Shanxi Eye Hospital, China. The proposed network is validated to accurately classify RVO diseases and detect lesions. It can potentially assist in further investigating the association between RVO and brain vascular diseases and evaluating the optimal treatments for RVO.

[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.

A narrative review on the association of high intraocular pressure and glaucoma in patients with retinal vein occlusion

BACKGROUND AND OBJECTIVE

Retinal vein occlusion (RVO) is a major cause of vision loss and elevated intraocular pressure (IOP), high ocular perfusion pressure, and glaucoma are known ophthalmic risk factors for RVO. The aim of this paper is to provide the update on the association and management of high IOP/glaucoma and RVO.

METHODS

A literature review was performed in PubMed and Medline until May 2022 utilizing specific keywords and cross-matched reference lists.

KEY CONTENT AND FINDINGS

The association of RVO with high IOP/glaucoma may be attributed to retinal ganglion cell loss due to retinal ischemia in high IOP and glaucoma. As new modalities showed, decreased optic disc perfusion, reduced density of blood vessels in the optic nerve head of glaucoma patients, changes in the peripapillary microvascular parameters, and decreased retinal nerve fiber layer (RNFL) thickness of the optic nerve head of eyes with RVO suggest a common pathway between RVO and glaucoma. Literature suggests the close follow up for glaucoma development among patients with non-arteriovenous (AV) crossing (optic cup or optic nerve sited) RVO in fellow eye and management of elevated IOP among RVO cases treated with anti-vascular endothelial growth factor (VEGF) antibodies/corticosteroids and those with preexisting primary open angle glaucoma (POAG).

CONCLUSIONS

Determining potential patient responses to treatment and considering therapeutic options are challenging among patients with RVO and glaucoma. However, IOP lowering managements in preventing IOP spikes in patients with preexisting glaucoma and early treatment of macular edema in eyes with RVO is recommended.

Increased Macrophage-like Cell Density in Retinal Vein Occlusion as Characterized by en Face Optical Coherence Tomography

Objectives: to quantitatively analyze macrophage-like cells (MLCs) at the vitreoretinal interface in retinal vein occlusion (RVO) using swept-source optical coherence tomography angiography (SS-OCTA) and en face optical coherence tomography (OCT). Methods: The study included 72 RVO patients, with 43 acute patients and 29 chronic patients. For a normal control, 64 fellow eyes were included. MLCs were visualized in a 5 μm en face OCT slab above the vitreoretinal interface centered on the fovea. After semi-automatic binarization and quantification, we evaluated the MLC count and density among groups. We also investigated the MLC density and distribution relative to retinal edema. Results: Morphological changes and congregation of MLCs appeared in RVO eyes. The MLC density of both the acute and chronic groups was significantly higher than that of the control eyes (p < 0.001). In the acute group, the MLC density of the edematous region was lower than both the non-edematous region (p < 0.001) and the whole image (p < 0.01). The MLC density in acute eyes was negatively correlated to central fovea thickness (CFT) (r = −0.352, p < 0.05). The MLC density in chronic eyes was positively correlated to CFT and mean retina thickness (MRT) (r = 0.406, p < 0.05; r = 0.412, p < 0.05, respectively). Conclusions: SS-OCTA is a viable and simple method for the characterization of MLCs at the vitreoretinal interface. A significant increase in the MLC density in both acute and chronic eyes implicates the activation and recruitment of MLCs in RVO and that the MLC density and distribution can be affected by retinal edema.

The Efficacy and Safety of Dexamethasone Intravitreal Implant for Diabetic Macular Edema and Macular Edema Secondary to Retinal Vein Occlusion: A Meta-Analysis of Randomized Controlled Trials

Purpose

The purpose of this meta-analysis was to evaluate the efficacy and safety of dexamethasone intravitreal implant (DEX) for the treatment of diabetic macular edema (DME) with retinal vein occlusion secondary to macular edema (RVO-ME).

Materials and Methods

Relevant databases were searched to include randomized controlled trials (RCTs) evaluating DEX for DME and RVO-ME. The search was conducted until March 2022. Meta-analysis was performed using Rev Man 5.4.1 software after screening the literature by inclusion and exclusion criteria, extracting information, and evaluating the methodological quality of the included studies.

Results

The study showed that DEX treatment of RVO-ME was associated with an improvement in best corrected visual acuity (BCVA) (MD = −9.08, 95% CI: −10.89–7.27, P < 0.00001) and central retinal thickness (CRT) (MD = 93.47, 95% CI: 28.55–159.39, P=0.005). DEX treatment of DME was significantly better than anti-VEGF treatment in terms of CRT reduction (MD = −72.35, 95% CI: −115.0–29.69, P=0.0009). The safety study showed that the risk of cataract from RVO-ME (OR = 5.06, 95% CI: 1.96 to 13.06, P=0.0008) and the incidence of high intraocular pressure (OR = 6.67, 95% CI: 3.46 to 12.86, P < 0.00001) were significantly higher with DEX than with anti-VEGF therapy. The risk of cataract from DME (OR = 4.70, 95% CI: 2.10 to 10.54, P=0.00022) was significantly higher with DEX than with anti-VEGF therapy (OR = 4.70, 95% CI: 2.10 to 10.54, P=0.0002). The incidence of high IOP (OR = 13.77, 95% CI: 4.96 to 38.18, P < 0.00001) was significantly higher with DEX than with anti-VEGF therapy.

Conclusions

In patients with DME and RVO-ME, DEX was more efficacious but slightly less safe than anti-VEGF therapy.