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Purpose: To investigate the impact of anti-VEGF therapy on vascular metrics in eyes with macular edema secondary to central retinal vein occlusion (CRVO) using wider field swept-source OCT angiography (WF SS-OCTA)., Methods: We included 23 eyes with macular edema associated with non-ischemic CRVO from 22 patients treated with anti-VEGF therapy (median number of injections: 5 [2-9]). Changes in vessel density (VD), vessel skeletonized density (VSD), and foveal avascular zone (FAZ) parameters were measured using WF SS-OCTA. Visual acuity (VA) and central subfield thickness (CST) were also measured., Results: Median CST decreased significantly from 369 µm (305-531) to 267 µm (243-300, p < 0.001). VD and VSD parameters in 12 × 12 mm images showed significant reductions. For instance, VSD in the whole retina decreased from a median of 13.37 (11.22-13.74) to 11.29 (9.36-12.97, p = 0.013). Additionally, a significant increase in FAZ circularity was found, suggesting improved microvascular integrity. Significant inverse correlations were found between the number of anti-VEGF injections and all VSD and VD parameters on the 12 × 12 mm images (p < 0.05). Notably, the reductions in VSD and VD on 12 × 12 mm angiograms in the deep capillary plexus (DCP) after each injection significantly correlated with increased logMAR VA (worse VA)., Conclusion: Anti-VEGF therapy in CRVO patients not only mitigates macular edema but also alters the overall microvascular morphology and functionality as revealed by WF SS-OCTA., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: Coronavirus Disease 2019 (COVID-19) pneumonia may predispose to thromboembolic disease, including after the acute phase. We report on a unique case of central retinal vein occlusion (CRVO) occurring eight months after diagnosis of Coronavirus Disease 2019 (COVID-19) pneumonia in a likely case of post-COVID-19 syndrome., Case Report: A 42-year-old man developed blurred vision in his right eye eight months after symptoms of pneumonia. He had no underlying medical conditions, but experienced exertional chest pain since diagnosis of COVID-19 was confirmed by detection of SARS-CoV-2 on nasopharyngeal swab and was also seeing cardiology for management of myocarditis. His best-corrected visual acuity on snellen chart testing was reduced to 6/18 in the affected right eye, and dilated fundal examination revealed a non-ischaemic CRVO., Conclusion: The thromboembolic complications of COVID-19 may extend to CRVO, which in this case presented months after onset of symptoms of pneumonia, in association with myocarditis.

Purpose: The pathomechanism leading to retinal vein occlusion (RVO) is unclear. Mechanical compression, thrombosis, and functional contractions of veins are discussed as the reasons for the increased resistance of venous outflow. We evaluated changes in the retinal venous pressure (RVP) following intravitreal injection of anti-vascular endothelial growth factor (VEGF) agent to determine the effect on RVO-related macular edema., Methods: Twenty-six patients with RVO-related macular edema (16 branch RVOs [BRVOs] and 10 central RVOs [CRVOs], age 72.5 ± 8.8 years) who visited our hospital were included in this prospective study. Visual acuity (VA), intraocular pressure (IOP), central retinal thickness (CRT) determined by macular optical coherence tomography, and RVP measured using an ophthalmodynamometer were obtained before intravitreal injection of ranibizumab (IVR) and 1 month later., Results: Comparison of the BRVOs and CRVOs showed that VA was significantly improved by a single injection in BRVOs (P < 0.0001; P = 0.1087 for CRVOs), but CRT and RVP were significantly decreased without significant difference in IOP after the treatment in both groups (P < 0.0001)., Conclusion: The anti-VEGF treatment resulted in a significant decrease in the RVP, but the RVP remained significantly higher than the IOP. An increased RVP plays a decisive role in the formation of macula edema, and reducing it is desirable., (© 2021. The Author(s).)

Quantitative analysis of aqueous humor (AH) was performed to investigate glucose metabolism in patients with central retinal vein occlusion (CRVO), and to explore metabolic changes after anti-vascular endothelial growth factor (VEGF) treatment. AH samples were collected from 35 patients. Participants diagnosed with CRVO (n = 15) were compared to participants who underwent cataract surgery (n = 20). Thirteen of the participants with CRVO received second-round anti-VEGF treatments. Ultra-high performance liquid chromatography tandem-mass spectrometry (UHPLC-MS/MS) was used to quantify metabolites of the AH. Central macular thickness (CMT) and retinal ganglion cell layer (RGC) thickness were measured using spectral-domain optical coherence tomography. Thirteen metabolites involved in glucose metabolism were identified. Among these metabolites, succinate, glutamate, and glutamine were significantly decreased for the CRVO group (p = 0.028, 0.009, and 0.017, respectively). The α-ketoglutarate/citrate (K/C) ratio had a significant positive correlation with glutamine levels for both control (r = 0.922, p < 0.001) and CRVO groups (r = 0.674, p = 0.006). A significant increase in lactate was observed after intravitreal anti-VEGF administration (t = 2.273, p = 0.045); the change in CMT was negatively correlated with this increase (r = -0.745, p = 0.003). The alteration of RGC thickness was negatively correlated with increases in both glutamine (r = -0.619, p = 0.024) and glucose (r = -0.754, p = 0.003). These results indicate that, compared to glucose metabolism, glutamine was significantly decreased in the AH of patients with CRVO, and may therefore serve as a potential target for CRVO therapy. The glycolytic pathway might be enhanced after intravitreal anti-VEGF injection, which is an important insight into CRVO pathophysiology., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Objectives: To evaluate the efficacy and safety of anti-vascular endothelial growth factor (VEGF) agents and corticosteroids for the treatment of macular oedema (ME) secondary to central retinal vein occlusion (CRVO)., Design: Systematic review and network meta-analysis., Participants: Patients from previously reported randomised controlled trials (RCTs) comparing anti-VEGF and corticosteroids for the treatment of ME secondary to CRVO., Methods: Literature searches were conducted using PubMed, Medline, Embase, Cochrane Library and clinicaltrials.gov until March 2017. Therapeutic effects were estimated using the proportions of patients gaining/losing ≥15 letters, best-corrected visual acuity (BCVA) and central retinal thickness (CRT). Treatment safety was estimated using the proportions of adverse events, namely increased intraocular pressure (IOP), cataracts, vitreous haemorrhage (VH) and retinal tear. The software ADDIS (V.1.16.8) was used for analysis. Treatment effect and safety of different drugs could be ranked based on simulation., Results: Eleven RCTs comprising 2060 patients were identified. Regarding patients gaining ≥15 letters, aflibercept and ranibizumab were significantly more effective than sham/placebo at 6 months. Regarding patients losing ≥15 letters at 6 months, ranibizumab showed significant improvement compared with dexamethasone. Aflibercept, bevacizumab or ranibizumab showed greater improvements in BCVA than sham/placebo at 6 months. Intravitreal ranibizumab injection demonstrated greater CRT reduction than both sham and dexamethasone did. Dexamethasone had a higher risk of increased IOP than aflibercept and ranibizumab. Ranibizumab demonstrated a greater risk of cataracts than dexamethasone. Aflibercept and ranibizumab demonstrated low incidence of VH and retinal tear, respectively. Aflibercept had a slight advantage over ranibizumab as assessed by benefit-risk analysis., Conclusions: Anti-VEGF agents have advantages in the treatment of ME secondary to CRVO. Aflibercept and ranibizumab showed marked BCVA improvement and CRT reduction. Aflibercept may have a slight advantage over ranibizumab. The results of this study can serve as a reference for clinicians to provide patient-tailored treatment., Prospero Registration Number: CRD42017064076., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2018. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: To report a case of central retinal vein occlusion (CRVO) seven days following the first dose of ChAdOx1 nCoV-19 vaccine and propose a hypothesis for the possible underlying pathogenesis. Observation: A 31-year-old male presented with CRVO with cystoid macular edema, one week after receiving his first ChAdOx1 nCoV-19 vaccine dose. Apart from mild hyperhomocysteinemia, no major thrombophilic or systemic risk factors were found. Anti-platelet factor 4 antibodies, specific for vaccine-induced immune thrombotic thrombocytopenia, were also negative. However, he tested strongly positive (> 250 U/mL) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG spike antibodies, 2 weeks post the first dose – suggestive of a prior subclinical infection. Conclusion: COVID-19 is known to be associated with an altered host one-carbon metabolism resulting in hyperhomocysteinemia. We hypothesize that a prior subclinical infection with COVID-19, the first hit, may have led to hyperhomocysteinemia in our patient and vaccination must have been the second hit that triggered the thrombotic event. Further studies, including correlation of thrombotic complications with IgG antibody titres post-vaccination, are essential in order to better understand the pathogenesis of such events. [ABSTRACT FROM AUTHOR]

Purpose: The pathomechanism leading to retinal vein occlusion (RVO) is unclear. Mechanical compression, thrombosis, and functional contractions of veins are discussed as the reasons for the increased resistance of venous outflow. We evaluated changes in the retinal venous pressure (RVP) following intravitreal injection of anti-vascular endothelial growth factor (VEGF) agent to determine the effect on RVO-related macular edema. Methods: Twenty-six patients with RVO-related macular edema (16 branch RVOs [BRVOs] and 10 central RVOs [CRVOs], age 72.5 ± 8.8 years) who visited our hospital were included in this prospective study. Visual acuity (VA), intraocular pressure (IOP), central retinal thickness (CRT) determined by macular optical coherence tomography, and RVP measured using an ophthalmodynamometer were obtained before intravitreal injection of ranibizumab (IVR) and 1 month later. Results: Comparison of the BRVOs and CRVOs showed that VA was significantly improved by a single injection in BRVOs (P < 0.0001; P = 0.1087 for CRVOs), but CRT and RVP were significantly decreased without significant difference in IOP after the treatment in both groups (P < 0.0001). Conclusion: The anti-VEGF treatment resulted in a significant decrease in the RVP, but the RVP remained significantly higher than the IOP. An increased RVP plays a decisive role in the formation of macula edema, and reducing it is desirable. [ABSTRACT FROM AUTHOR]

Purpose: To study the different patterns of retinal veins occlusion (RVO) on fundus fluorescein angiography (FFA). Materials & Methods: It is a hospital based descriptive study of 33 patients, conducted in Akhtar Saeed Trust Hospital, Ophthalmology Department from February 2014 to October 2016. These patients were selected from outpatient department (OPD) and diagnosed as cases of vein occlusions clinically. Presenting features were sudden painless visual loss, visual field defects, floaters if neovascularization has occurred, flame shaped retinal hemorrhages, dilated tortuous veins in all four quadrants or segmental depending upon it is central or branch vein occlusion. Patients with cataract, vitreous hemorrhage, proliferative diabetic retinopathy and media opacities which impair fundus view were excluded. After informed consent all selected patients were sent for fundus fluorescein angiography (FFA) with intravenous injections of 3ml of 25% and multiple photographs were taken for 20-25 minutes with Topcon digital fundus camera. The pattern of vein occlusions were observed and noted. Results: In this hospital based study 33 patients of vein occlusions, 21 males and 11 females, all with unilateral involvement were included. The age range was 50-75 years with mean age 62.50 years. The duration of visual disturbances on presentation was 2 to 4 weeks from onset of visual symptoms. After clearance of hemorrhages fundus fluorescein angiography (FFA) was performed. Most common site for venous occlusion was superotemporal quadrant seen in 39.40 % cases and non ischemic variety of vein occlusion was more common than ischemic variety. Conclusion: Based on FFA findings non ischemic CRVO was more common as compare to ischemic CRVO. Temporal BRVO's were seen more commonly as compared to nasal BRVO. Macular edema and leakage was seen in all cases of retinal vein occlusion (RVO). [ABSTRACT FROM AUTHOR]

Abstract: Retinal vein occlusion is a major cause of vision loss. We provide an overview of the clinical features, pathogenesis, natural history, and management of both branch retinal vein occlusion and central retinal vein occlusion. Several recent multicenter randomized clinical trials have been completed which have changed the approach to this disorder. Management of retinal vein occlusions can be directed at the underlying etiology or the resulting sequelae. Options include surgical intervention, laser photocoagulation, intravitreal pharmacotherapy, and sustained drug delivery devices. [Copyright &y& Elsevier]

Introduction: Moderate hyperhomocysteinemia is considered a risk factor for both venous and arterial thrombosis. A prevalence of up to 30% of fasting hyperhomocysteinemia has been recently reported in patients with retinal vein occlusion (RVO) whereas conflicting data exist on the role of C677T polymorphism of the methylenetetrahydrofolate reductase (MTHFR) gene as a risk factor for RVO. No report has been published on cystathionine beta-synthase (CBS) 844ins68 polymorphism (another genetic determinant of blood Hcy levels) in RVO patients. Moreover, scarce information is available on the usefulness of measuring homocysteine also after methionine loading to increase the diagnostic efficacy of hyperhomocysteinemia in RVO patients. Materials and methods: In 55 consecutive patients with diagnosis of RVO and 65 matched controls, plasma fasting total homocysteine (Hcy) levels and CBS and MTHFR polymorphisms were evaluated. In patients with normal fasting Hcy levels, post-methionine Hcy levels were determined. Results: Moderate fasting hyperhomocysteinemia was detected in 18/55 patients (32.7%). In the remaining 37 patients, Hcy was measured again post-methionine loading (PML). Only 3/37 (8.1%) patients had PML hyperhomocysteinemia. Thus, the total prevalence of moderate hyperhomocysteinemia in this cohort of RVO patients was 21/55 (38.2%). The prevalence of homozygosity for C677T MTHFR genotype, but not that of heterozygosity for CBS844ins68, was significantly higher in RVO patients than in controls. Conclusions: Differently from what has been reported for arterial and/or venous thrombosis, a single fasting Hcy measurement is able to detect most of RVO patients (85.7%) with moderate hyperhomocysteinemia. C677T MTHFR, but not CBS 844ins68, genotype may play a role as risk factor for RVO. [Copyright &y& Elsevier]