Analysis of the current research status and trends in retinal vein occlusion based on bibliometrics

To investigate the effectiveness of repeated injections of intravitreal triamcinolone acetonide (IVTA) in the treatment of macular oedema caused by central retinal vein occlusion (CRVO). Seventeen pseudophakic or aphakic eyes of 17 patients (10 male, seven female) with macular oedema caused by CRVO received a repeat injection of 4 mg IVTA, 16 weeks after the first injection of the same dose. The examination included measurements of best-corrected visual acuity (BCVA) for distance and central foveal thickness (CFT) by optical coherence tomography (OCT), preoperatively and 1, 2, 3 and 4 months postoperatively. The values were compared by paired-t test. Side-effects were monitored. BCVA and CFT were not significantly different before initial and repeat injections. Transient improvements of BCVA and CFT were achieved after both injections. At the end of follow-up, BCVA and CFT were significantly different compared to pre-injection values in the same group (P = 0.032, 0.049 in the initial-injection group and P = 0.001, 0.008 in the repeat-injection group, respectively). However, compared to the initial injection, BCVA measurements were significantly worse at each time-point (P = 0.043, 0.011, 0.010 and 0.012, respectively) after the repeat injection, as were CFT at 1, 2 and 3 months post-injection (P = 0.040, 0.015 and 0.025, respectively). The achieved maximum mean intraocular pressures were 20.00 [standard deviation (SD) 2.06] mmHg and 18.56 (SD 3.65) mmHg after the first and repeat injections, respectively. These values were not significantly different (P = 0.467). No other significant adverse events were noted during the study. A repeat injection of 4 mg IVTA may not be as effective as an initial injection for the treatment of macular oedema caused by CRVO.

The use of intravitreal corticosteroids in the management of macular oedema has recently gained widespread acceptance. New long-acting steroid preparations and methods of delivery have facilitated the use of these new modalities. This review describes the various types of macular oedema for which this therapeutic option is used and the results.

Objectives:To detect the expressions of hypoxia-inducible factor 1α (HIF-1α) and microRNA-210 (miR-210) in the aqueous humor of patients with central retinal vein occlusion (CRVO) combined with macular edema, and explore their correlations with CRVO combined with macular edema.Methods:A total of 65 patients (65 eyes) with CRVO combined with macular edema who were treated in the Lixiang Eye Hospital of Soochow University from April 2018 to March 2020 were selected as subjects (CRVO combined with macular edema group). Additionally, 74 patients (74 eyes) with cataract were selected during the same period as cataract control group. The expressions of HIF-1α mRNA and miR-210 in the aqueous humor were detected by quantitative real-time PCR (qRT-PCR). The levels of monocyte chemoattractant protein-1 (MCP-1), interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) in the aqueous humor were measured using enzyme-linked immunosorbent assay (ELISA). The correlations of HIF-1α mRNA and miR-210 in the aqueous humor of patients with CRVO combined with macular edema with vasoactive molecule levels, the diagnostic value of HIF-1α mRNA and miR-210 levels in the aqueous humor in CRVO combined with macular edema, as well as the factors influencing the occurrence of CRVO combined with macular edema were analyzed.Results:The levels of HIF-1α mRNA, miR-210, MCP-1, VEGF and IL-6 in the aqueous humor of the CRVO combined with macular edema group were higher than those of the cataract control group (P < 0.05). In the CRVO combined with macular edema group, HIF-1α mRNA and miR-210 levels in the aqueous humor were positively correlated (r = 0.522, P < 0.05), and they were positively correlated with MCP-1, VEGF and IL-6 levels (P < 0.05). The area under the curve (AUC) of HIF-1α mRNA and miR-210 in the aqueous humor in diagnosing CRVO combined with macular edema was 0.888 and 0.866, the specificity was 95.9% and 85.1%, and the sensitivity was 76.9% and 80.0%, respectively. The AUC of their combination was 0.937, with the specificity of 93.2% and the sensitivity of 86.2%. HIF-1α, miR-210 and VEGF were the independent risk factors affecting the occurrence of CRVO combined with macular edema (P < 0.05).Conclusion:In patients with CRVO combined with macular edema, HIF-1α mRNA and miR-210 were highly expressed in the aqueous humor, which may play an important role in the occurrence and development of the disease.

Background:Central retinal vein occlusion (CRVO) is one of the most common retinal vascular diseases, which is closely related to systemic diseases like hypertension, diabetes and arteriosclerosis. Due of its blinding, it will seriously reduce the quality of life. Macular edema (ME) caused by CRVO is one of the serious complications of visual impairment. We found that the severity of ME in CRVO was positively associated with vascular endothelial growth factor (VEGF) in the anterior chamber. With the accelerated pace of modern life and the changed dietary structure, the incidence of this disease will continue to rise. Therefore, it is of great practical significance to seek effective treatment methods. Intraocular injection of anti-VEGF can effectively alleviate ME and improve visual acuity, showing excellent clinical application prospects. In recent years, there have been some new understandings and advances on the etiology and treatment methods of the present disease, such as the deepening into the molecular biology and gene level. Clinical studies on the efficacy of the disease have emerging. Therefore, a network meta-analysis (NMA) of anti-VEGF treatment for CRVO is particularly necessary to systematically compare its efficacy.Methods:The two reviewers will comprehensively retrieved electronic databases such as PubMed, The Cochrane Library, Wanfang database, Web of Science, Chinese Scientifific Journals Database, EMBASE, China National Knowledge Infrastructure, and China BioMedical Literature. A randomized controlled trial for CRVO against VEGF between January 2010 and June 2021 was included according to the relevant content of the study. In addition, 2 researchers will screen the literature to assess the risk bias for the included articles. We will evaluate the collected evidence and data using a Bayesian NMA method, and analyzed it with STATA and WinBUGS software.Results:Anti-VEGF is one of the effective methods for ME in CRVO patients, accordingly, this study will evaluate its efficacy and safety using a Bayesian NMA system.Conclusion:This study can provide an effective rationale for the clinical application of anti-VEGF for CRVO, contribute to the treatment of CRVO and patient condition rehabilitation in clinical work.Ethics and dissemination:Do not require.INPLASY registration number:INPLASY2021110073.

Objective To observe the levels of vascular endothelial growth factor (VEGF),interleukin-6 (IL-6) and monocyte chemotactic protein-1 (MCP-1) in aqueous humor of patients with macular edema secondary to central retinal vein occlusion (CRVO).Methods Forty eyes of 40 consecutive patients with macular edema secondary to CRVO (CRVO group) were enrolled in this study.The patients included 25 males and 15 females.The patient age ranged from 38 to 76 years.The control group was 20 patients with senile cataract who underwent phacoemulsification,including 10 males and 10 females.The levels of VEGF165,VEGF165 b,IL-6 and MCP-1 in aqueous humor were determined by enzyme-linked immunosorbent assay.The correlation of VEGF,and IL-6,and MCP-1 were analyzed.Results The median aqueous level of VEGF165,IL-6 and MCP-1 were 1089.0,165.6,1253.0 pg/ml respectively in CRVO group,which were higher than the control group's results (168.2,4.7,216.4 pg/ml respectively),the differences were statistically significant (Z=-4.549,-6.008,-5.343; P＜0.001).The VEGF165b in CRVO group and control group were 834.0,915.9 pg/ml respectively,the difference was not statistically significant (Z=-0.207,P＞0.05).The ratio of VEGF165 b to VEGF165 in CRVO group and control group were 2.71,7.28 respectively,the difference was statistically significant (t=-3.007,P＜0.05).There was a highly positive correlation between IL-6 and VEGF in CRVO group (r=0.526,P=0.001) and also mild positive correlation in control group (r=0.425,P=0.070).No correlation between MCP-1 and VEGF was observed in both groups (CRVO group:r=0.211,P＞0.05.Control group:r=-0.019,P＞0.05).Conclusions VEGF165,IL-6 and MCP-1 levels were increased in CRVO patients while the VEGF165 b was normal.The ratio between VEGF165 b and VEGF165 in aqueous humor of patients with macular edema secondary to CRVO was decreased. Key words: Retinal vein occlusion/complications; Macular edema; Aqueous humor; Vascular endothelial growth factor A; Interleukin-6; Chemokine CCL2

Vitreous Levels of Interleukin-6 and Vascular Endothelial Growth Factor in Macular Edema with Central Retinal Vein Occlusion

Purpose: To investigate whether pigment epithelium-derived factor (PEDF) or vascular endothelial growth factor (VEGF) influences macular edema in patients with central retinal vein occlusion (CRVO).Materials and Methods: In 27 patients who had CRVO with macular edema and 21 patients with nonischemic ocular diseases (control group), retinal ischemia was evaluated by measuring the area of capillary nonperfusion on fluorescein angiography and macular edema was examined by optical coherence tomography. Vitreous fluid samples were obtained during pars plana vitrectomy.Results: The vitreous level of VEGF was significantly higher in the CRVO patients than in the controls (median: 366 vs. 15.6 pg/ml, P < 0.0001), while the vitreous level of PEDF was significantly lower in the patients than in the controls (median: 17.5 vs. 28.4 ng/ml, P = 0.0298). Vitreous levels of VEGF were significantly higher in CRVO patients with retinal ischemia than in those without ischemia (P < 0.0001), while PEDF levels did not show a significant difference. Vitreous levels of VEGF and PEDF were related to the retinal thickness at the central fovea (P = 0.0059 and P = 0.0308, respectively).Conclusions: VEGF and PEDF may independently influence retinal vascular permeability in CRVO patients with macular edema.

BackgroundThe association of inflammatory factors and the aqueous flare value with macular edema in central retinal vein occlusion (CRVO) patients remains unclear. We investigated the relations between the aqueous flare value and vitreous levels of vascular endothelial growth factor (VEGF), soluble intercellular adhesion molecule-1 (sICAM-1), and interleukin-6 (IL-6) in patients with CRVO and macular edema or patients with idiopathic macular hole (MH).MethodsIn 38 patients who underwent unilateral vitrectomy (21 CRVO patients and 17 MH patients), vitreous samples were obtained during vitrectomy to measure VEGF, sICAM-1, and IL-6. Retinal ischemia was evaluated from capillary non-perfusion on fluorescein angiography, and the CRVO patients were classified into nonischemic or ischemic groups. Aqueous flare values were measured with a laser flare meter and macular edema was examined by optical coherence tomography.ResultsThe median aqueous flare value increased significantly across the three groups (MH group < nonischemic CRVO group < ischemic CRVO group). There was a significant correlation between the flare value and vitreous levels of VEGF, sICAM-1, and IL-6 in the CRVO group. The flare value was also significantly correlated with the severity of macular edema in the CRVO group.ConclusionsInflammation and/or ischemia may increase vascular permeability and disrupt the blood-aqueous barrier by increasing levels of inflammatory factors in patients with CRVO and macular edema.

Objective: To review the studies related to keratoconus in China, investigate research hotspots and development trends in this field, and provide reference for future research. Methods: This is a bibliometrics study. The relevant literature written in Chinese was retrieved from the WanFang DATA and the China National Knowledge Infrastructure, English articles were collected from the Web of Science Core Collection database. Searched for journal articles related to keratoconus VOSviewer software, CiteSpace, and Bibliometrix in the R language were employed to create the knowledge map. The analysis encompassed the distribution of published journals, research collaboration networks of countries/regions, institutions, and authors. Additionally, core authors, high-frequency keyword co-occurrence, keyword topic maps, and keyword emergence time ranking were examined. Results: The study ultimately included 1 100 Chinese articles and 668 English articles. Chinese literature and English literature began to increase in 1997 and 2009, respectively, indicating that the field is currently in a developmental stage. The publications involved 244 Chinese journals and 150 English journals, predominantly in the field of ophthalmology. The United States collaborated the most with China, contributing to 123 articles, followed by other countries such as the United Kingdom and Switzerland. Chinese literature and English literature involved 552 and 883 institutions, respectively. The institution with the highest number of Chinese literature publications was the Eye Institute of Shandong First Medical University (63 papers), while Wenzhou Medical University had the highest number of English literature publications (91 papers). Chinese literature involved 2 435 authors, and English literature involved 2 073 authors. The largest collaboration cluster in Chinese literature was formed by the teams of Xie Lixin and Shi Weiyun, while the Gao Hua team formed the largest cluster in English literature. However, collaboration between authors was primarily limited to within each team. A total of 622 and 1 611 keywords were extracted from Chinese and English literature, respectively. The node centrality of the four Chinese keywords, "keratoconus", "cornea", "corneal transplantation" and "myopia" as well as the three English keywords, "keratoconus", "collagen cross-linking" and "penetrating keratoplasty" was greater than 0.1. "Collagen", "riboflavin", "corneal transplantation" and "ultraviolet A" were identified as common core hotspots and important research topics in Chinese and English literature on keratoconus. Keyword emergence analysis indicated that the keywords with the highest intensity of emergence in Chinese and English literature were "myopia" (13.54) and "penetrating keratoplasty" (9.99), respectively. The longest emergence time was observed for "contact lenses" (1995-2006) and "penetrating keratoplasty" (2003-2014). Conclusions: At present, research on keratoconus in China is on the rise, with research hotspots including pathogenesis, various new surgical methods, and improvement in quality of life. The future research trend mainly focuses on early diagnosis and screening methods, artificial intelligence, biomechanical examination, subclinical keratoconus, and small incision lenticule extraction.

Background and aimsTo measure soluble vascular endothelial growth factor receptor-2 (sVEGFR-2) in the vitreous fluid of patients with central retinal vein occlusion (CRVO) and macular oedema or patients with idiopathic...

To present a bibliometric analysis of global scientific publications on the nondrug and nonsedative hypnotic treatment of insomnia with regard to influential institutions, publications, countries, research hotspots, trends, and frontiers. A literature review was conducted by searching the Web of Science Core Collection (WoSCC) and China National Knowledge Infrastructure (CNKI) databases to identify all publications related to the nondrug and nonsedative hypnotic treatment of insomnia from 2000 to 2021. Eligible publications were reviewed, including annual publication increments, citation analyses, international collaborations, and keyword analyses. The data were analysed using CiteSpace (vers5.8.R3, 6.1.R2 and 6.1.6, College of Computing and Informatics, Philadelphia, PA, USA) and virtualized by knowledge maps. RESULTS：In total, 9832 publications were included in this analysis. The results from the WoSCC showed that the United States of America (Count = 2268, 40.33%), Stanford University (Count = 141, 2.51%), and the United States Department of Health and Human Services were the leading country, institute, and funding agency regarding the number of publications, respectively. 'Cognitive-behavioural therapy" was the most popular research topic generated from the cocited reference. The most frequently co-occurring keywords were insomnia, cognitive behavioural therapy, disorder, depression, quality of life, Meta-analysis, older adult, sleep, prevalence and efficacy, while keywords including clinical practice guideline, guideline, and Tai Chi remained popular after 2021. Circadian rhythm was the strongest research frontier for 2000-2021. In China, Chengdu University of Traditional Chinese Medicine (Count = 69, 4.79%) was the most productive institute in this field. The most frequently co-occurring keywords from Chinese literature were sleep disorder, sleep quality, acupuncture and moxibustion, Parkinson's disease, transcranial magnetic stimulation, health education, music therapy, chronic insomnia, quality of life, and nonmotor symptoms. Traditional Chinese medicine was the strongest research frontier for 2019-2021. This bibliometric study provides an exhaustive mapping encompassing pertinent institute, publications, influential articles, researchers and topics of the global trend of nondrug and nonsedative hypnotic treatment for insomnia. The results show that the research trend has shifted from primary studies on the efficacy and safety of nondrug and nonsedative hypnotic treatment for insomnia to comorbidity studies. Clinical practice guidelines will potentially become the research frontier for this field post-2021. The findings are important for researchers, clinicians, journal editors, and policy-makers working in the field of nondrug and nonsedative hypnotic treatment for insomnia to understand the strengths and potentials in the current studies and guide future clinical practice, research, and science policy.

To describe two cases of strictly unilateral diabetic retinopathy with macular edema where the precipitating factor appears to have been retinal venous congestion. Retrospective interventional case study. Examination of fundus photographic records demonstrated generalized venous dilation in the affected eyes years in advance of the development of unilateral diabetic macular edema. Relentless progression of edema and visual loss followed despite retinal photocoagulation treatment and ultimately the affected eyes in both patients developed central retinal vein occlusion. The fellow eyes in both patients remained without retinopathy throughout the period of observation. The sequential and strictly unilateral appearance of retinal venous dilation, diabetic macular edema, and central retinal vein occlusion in diabetic patients without fellow-eye retinopathy suggests that venous congestion induced the progression from hyperglycemic insult to vascular injury in the affected eyes. Presumably, diabetes may cause retinal vascular dysfunction that results in little or no vascular damage unless venous congestion is present. This supports that venous congestion and increased sensitivity to congestion are important components of the pathogenesis of diabetic macular edema.

This Issue At A Glance

Vitreous inflammatory factors in macular edema with central retinal vein occlusion

ObjectivesTo map publication trends and explore research hotspots of retinal vein occlusion (RVO) study.MethodsBased on Web of Science Core Collection (WoSCC), a bibliometric analysis was carried out. The knowledge map was constructed by VOSviewer v.1.6.10 to visualize the annual publication number, the distribution of countries, international collaborations, author productivity, source journals, cited reference and keywords in this field.ResultsA total of 2,135 peer-reviewed papers were retrieved on RVO from 2009 to 2018. The United States ranks highest among countries with the most publications and the most active institution was Kyoto University. Noma H contributed the most publications in this field. Retina—The Journal of Retinal and Vitreous Disease was the most prolific journal in RVO research. The top cited references mainly presented anti-VEGF medications on the management of RVO. The keywords formed six clusters: (1) Risk factors and pathogenesis of RVO; (2) Metabolismof RVO; (3) Therapeutic use of corticosteroids on RVO; (4) Diagnostic methodsof RVO; (5) Management of macular edema secondary to RVO (6) Anti-VEGFtreatment of RVO.ConclusionsThe six major research hotspots could provide an insight into RVO research and valuable information for researchers to identify potential collaborators and partner institutions.