Retinal Vein Occlusion in a Multi-Ethnic Asian Population: The Singapore Epidemiology of Eye Disease Study

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.

Chinese Herbal Medicine Combined with Intravitreal Antivascular Growth Factor Agents in Treatment of Macular Edema Secondary to Retinal Vein Occlusion: A Systematic Review and Meta-Analysis

Background. Retinal vein occlusion (RVO) is the second most common retinal vascular disease in the world after diabetic retinopathy. Moreover, macular edema (ME) is the main cause of visual impairment in RVO patients. Intravitreal injection of antivascular endothelial growth factor (VEGF) agents is recommended for RVO-ME. However, repeated injections severely limit their efficacy. Chinese herbal medicine (CHM) is widely used in RVO-ME as adjuvant therapy in China. Objective. The study aims to evaluate the efficacy and safety of anti-VEGF combined with CHM for RVO-ME and to provide reliable evidence for clinical application. Methods. Seven databases were searched without language or publication status restrictions. Randomized controlled trials (RCTs) comparing anti-VEGF combined with CHM (anti-VEGF + CHM) versus anti-VEGF in participants with RVO-ME were included in this study. The “risk of bias assessment tool” of the Cochrane Handbook was applied to assess the quality of included trials, and RevMan 5.3 software was used for data analysis. Results. A total of 10 relevant trials with 743 patients were identified. The results showed that BCVA of the anti-VEGF + CHM group significantly improved at 3 months ( $P<0.00001$ ), 6 months ( $P=0.008$ ), and 12 months ( $P=0.01$ ), and CMT significantly reduced at 1 month ( $P=0.02$ ), 2 months ( $P=0.0009$ ), 3 months ( $P<0.05$ ), 6 months ( $P<0.0001$ ), and 12 months ( $P<0.00001$ ) compared with the anti-VEGF group alone. At the same time, the anti-VEGF + CHM group has a better performance in reducing the number of injections ( $P<0.05$ ) and improving the total effective rate ( $P<0.0001$ ). However, regarding adverse events, there was no statistical difference between the two groups ( $P=0.09$ ). Conclusions. Our results provide promising evidence that anti-VEGF therapy combined with CHM may be more beneficial to patients than anti-VEGF therapy alone. However, because of the low quality and small sample size of the included studies, more rigorous and larger-scale trials were necessary to validate our results. Registration Number. CRD42021270262.

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

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

Clinical implications of retinal oximetry in retinal vein occlusion: a review

PURPOSE

To review retinal vein occlusion (RVO) and its relationship with retinal oxygen saturation via automated retinal oximetry in eyes with RVO.

METHODS

A literature review was performed in PubMed and Medline until October 2021 utilizing specific keywords and cross-matched reference lists.

RESULTS

This review found RVO to be associated with risk factors including age, hypertension, cardiovascular and metabolic conditions, male gender, and glaucoma. These may be attributed to a breakdown of regulatory processes in the retina. Retinal venous oxygen saturation (SvO₂ ) and arteriovenous difference in eyes with central RVO have been found to be reduced and elevated, respectively. The literature indicates variable and contradictory findings in regard to branch RVO and retinal oxygenation. Additionally, ischaemic eyes have been found to have elevated retinal arterial oxygen saturation; however, the literature reports variable results regarding SvO₂ levels. Medications have been suggested to increase SvO₂ in RVO eyes, which may represent an important mechanism for disease management. Ranibizumab is currently the most studied drug for retinal oxygenation in RVO and has been suggested to increase SvO₂ in RVO eyes. In comparison, dexamethasone was found to decrease SvO₂ .

CONCLUSION

The current literature on retinal oxygenation in ischaemic subtypes of RVO and in drug therapies is minimal, and further work is required to expand upon our understanding of how ischaemia and drugs influence retinal oxygenation and clinical outcomes.

Prevalence of Retinal Vein Occlusions and Estimated Cerebrospinal Fluid Pressure: The Kailuan Eye Study

Purpose

To investigate the prevalence of retinal vein occlusions (RVOs) and associated factors in a Chinese population.

Patients and Methods

The cross-sectional community-based Kailuan Eye Study included individuals who participated in the Kailuan Study. RVOs were diagnosed on the fundus photographs. Estimated cerebrospinal fluid pressure (eCSFP) was calculated as “eCSFP=0.44*Body Mass Index+0.16*Diastolic Blood Pressure-0.18*Age”.

Results

The study included 12,499 participants with a mean age of 52.9±13.1 years. The overall prevalence of RVO was 120/12,499 or 0.96%, with branch RVOs observed in 116/12,499 individuals and central RVOs in 4/12,499 individuals. RVOs started at the optic disc in 19 participants (15.8% of all RVOs), and in 101 (84.2%) individuals arterio-venous crossings outside the optic disc. In multivariable analysis, a higher RVO prevalence was associated with older age (P<0.001), higher eCSFP (P<0.001), and higher fasting serum glucose concentration (P<0.001). Differentiating between RVOs at arterio-venous crossings and RVOs at the optic disc revealed that the prevalence of both RVO types was associated with higher eCSFP (P<0.001 and P=0.004, respectively) after adjusting for age and fasting serum glucose concentration.

Conclusion

In this adult Chinese population recruited on a community basis, the prevalence of any RVO (mean: 0.96) was associated with older age, higher eCSFP and higher fasting serum glucose concentration. Higher eCSFP may play an etiologic role in RVOs.

Retinal vascular occlusions

Acute retinal vascular occlusions are common causes of visual impairment. Although both retinal artery occlusions and retinal vein occlusions are associated with increased age and cardiovascular risk factors, their pathophysiology, systemic implications, and management differ substantially. Acute management of retinal artery occlusions involves a multidisciplinary approach including neurologists with stroke expertise, whereas treatment of retinal vein occlusions is provided by ophthalmologists. Optimisation of systemic risk factors by patients' primary care providers is an important component of the management of these two disorders.

Comparative efficacy of intravitreal pharmacotherapy for macular edema secondary to retinal vein occlusion: A protocol for the systematic review and network meta-analysis

BACKGROUND

Multiple intravitreal pharmacotherapies including different anti-vascular endothelial growth factors (VEGF), intravitreal steroids, and combined therapy with anti-VEGF and steroids are available for patients with macular edema secondary to retinal vein occlusion (RVO). However, the recommendation of multiple therapies remains unknown. This study aims to evaluate the efficacy and safety of multiple intravitreal pharmacotherapies in patients with macular edema secondary to RVO.

METHODS

We will systematically search the PubMed, Embase, and the Cochrane library for eligible studies. Randomized controlled trials (RCTs) with intravitreal pharmacotherapies for patients with macular edema secondary to RVO will be included. The Cochrane Collaboration's tool will be used to assess the risk of bias in the randomized trial. The primary outcome is the mean change in BCVA from baseline. The secondary outcomes are the proportion of patients who gained ≥15 letters in BCVA from baseline, the mean change in central retinal thickness from baseline and the number of serious adverse events.

RESULTS

The result will obtain a comprehensive treatment recommendation for macular edema secondary to RVO.

CONCLUSION

The results of the network meta-analysis will be submitted in a peer-reviewed journal for publication.

ETHICAL STATEMENT

This article does not contain any studies with human or animal subjects performed by any of the authors.

Retinal vein occlusion and chronic kidney disease: A meta-analysis

OBJECTIVES

We performed this meta-analysis to assess the correlation of retinal vein occlusion (RVO) and chronic kidney disease (CKD).

METHODS

We searched PubMed, Embase, Web of Science and Cochrane Library for population-based studies reporting the CKD as associated factor to RVO, central retinal vein occlusion (CRVO) or branch retinal vein occlusion (BRVO). Then we pooled the data for analysis.

RESULTS

After screening potential literature, 12 eligible studies with 23,656,214 individuals were finally included in quantitative synthesis. The pooled prevalence (95% confidence interval [CI]) of CKD in RVO group was 10.9% (95% CI: 6.6%, 15.1%). The pooled prevalence of any RVO in end stage renal disease (ESRD) group was 1.8% (95% CI: 1.6%, 2.1%). The prevalence of CKD was significantly higher in subjects diagnosed with RVO than non-RVO participants (odds ratio [OR]: 3.30; 95% CI: 2.28, 4.76; p < 0.001). CRVO subjects had a higher prevalence of CKD than BRVO patients (OR: 2.17; 95% CI: 1.28, 4.66; p = 0.004). In a similar manner, compared to non-ESRD subjects, ESRD patients had significantly higher prevalence of RVO (OR: 2.19; 95% CI: 1.97, 2.43; p < 0.001), CRVO (OR: 2.61; 95% CI: 2.17, 3.15; p < 0.001) and BRVO (OR: 2.01; 95% CI: 1.76, 2.30; p < 0.001).

CONCLUSION

The prevalence of CKD increases in RVO patients, especially in CRVO. And in turn, the prevalence of RVO also increases in ESRD patients. The data support a correlation of RVO and CKD.

Comparison of systemic conditions at diagnosis between central retinal vein occlusion and branch retinal vein occlusion

Objective

To compare systemic conditions at the time of diagnosis between patients with central retinal vein occlusion (CRVO) and branch retinal vein occlusion (BRVO).

Design

This study included patients diagnosed with CRVO or BRVO between February 2009 and August 2017 at three branch hospitals of Hallym University Medical Center. Demographic and anthropometric variables, systemic comorbidity profiles, and laboratory findings at diagnosis were collected from a clinical data warehouse system, and were compared between the CRVO and BRVO groups.

Result

Four hundred and seventeen patients with CRVO and 1,511 patients with BRVO were included. The mean age was 61.8 ± 13.9 years, which was comparable between two groups (P = .332). Female proportion was higher in the BRVO group (55.0%) than in the CRVO group (48.0%; P = .013). Diabetes mellitus (P = .017) and chronic kidney disease (P = .004) were more prevalent in the CRVO group. Serum homocysteine level was abnormally high in 23.5% of CRVO patients and in 8.4% of BRVO patients (P < .001). Blood urea nitrogen and serum creatinine levels were abnormally elevated in more subjects with CRVO (P = .002).

Conclusion

CRVO is associated with higher prevalence of diabetes mellitus and chronic kidney disease, as well as with elevated serum homocysteine level. These results might suggest a difference between the pathophysiologies of CRVO and BRVO.

10-year fundus tessellation progression and retinal vein occlusion

AIM

To access the 10-year fundus tessellation progression in patients with retinal vein occlusion.

METHODS

The Beijing Eye Study 2001/2011 is a population-based longitudinal study. The study participants underwent a detailed physical and ophthalmic examination. Degree of fundus tessellation was graded by using fundus photographs of the macula and optic disc. Progression of fundus tessellation was calculated by fundus tessellation degree of 2011 minus degree of 2001. Fundus photographs were used for assessment of retinal vein occlusion.

RESULTS

The Beijing Eye Study included 4403 subjects in 2001, 3468 subjects was repeated in 2011. Assessment of retinal vein obstruction and fundus tessellation progression were available for 2462 subjects (71.0%), with 66 subjects fulfilled the diagnosis of retinal vein occlusion. Of the 66 participants, 59 participants with unilateral branch retinal vein occlusion, 5 participants with unilateral central retinal vein occlusion, 1 participant with bilateral branch retinal vein occlusion, and 1 participant with branch retinal vein occlusion in one eye and central retinal vein occlusion in the other eye. Mean degree of peripapillary fundus tessellation progression were significantly higher in the whole retinal vein occlusion group (0.33±0.39, P<0.001), central retinal vein occlusion group (0.71±0.8, P=0.025) and branch retinal vein occlusion group (0.29±0.34, P=0.006) than the control group (0.20±0.26). After adjustment for age, prevalence of tilted disc, change of best corrected visual acuity, axial length, progression of peripapillary fundus tessellation was associated with the presence of retinal vein occlusion (P=0.004; regression coefficient B, 0.094; 95%CI, 0.029, 0.158; standardized coefficient B, 0.056). As a corollary, after adjusting for smoking duration, systolic blood pressure, anterior corneal curvature, prevalence of RVO was associated with more peripapillary fundus tessellation progression (P<0.001; regression coefficient B: 1.257; OR: 3.517; 95%CI: 1.777, 6.958).

CONCLUSION

Peripapillary fundus tessellation progresses faster in individuals with retinal vein occlusion. This may reflect the thinning and hypoperfusion of choroid in patients with retinal vein occlusion.

Review of the association between retinal microvascular characteristics and eye disease

Computerized retinal imaging technologies enable the static and dynamic measurement of a range of retinal microvascular parameters. Large population-based studies have reported associations between these microvascular indices and various ophthalmic diseases including diabetes, age-related macular degeneration, retinal artery embolism, retinal vein occlusion, glaucoma and non-glaucomatous optic neuropathies. Increasingly, sophisticated imaging and analysis techniques have the potential to provide relevant clinical information regarding disease risk and progression; however, further studies are required to verify associations and strengthen the predictive power of these techniques. We summarize the current state of knowledge regarding retinal microvascular characteristics and eye disease.

Protective effect of metformin against retinal vein occlusions in diabetes mellitus - A nationwide population-based study

Previous studies have found that metformin can reduce cardiovascular risk, but its association with retinal vein occlusion (RVO) is unknown. In this population-based cohort study using the Taiwan National Health Insurance Research Database (NHIRD), we demonstrated the protective effect of metformin against RVO in diabetes mellitus (DM) and explored the incidence rate and factors associated with RVO development in general and diabetic populations. One million patients were randomly selected from the registry files of the NHIRD, and all their claims data were collected for the 1996–2011 period. Patients with a new diagnosis of central or branch RVO were identified using International Classification of Disease codes. DM was defined for patients with diagnoses and treatments. Factors associated with RVO development in the non-DM and DM cohorts were explored using Cox proportional regression models. In total, 1,018 RVO patients were identified from the database. The average incidence of RVO was 9.93 and 53.5 cases per 100,000 person-years in the non-DM and DM cohorts, respectively. Older age, DM, hypertension, and glaucoma were significant risk factors for RVO, whereas the prescription of anticoagulants was a significant protective factor. In the DM cohort, older age, hypertension, and diabetic retinopathy were significant risk factors for RVO, whereas metformin treatment was a significant protective factor. These results confirmed the risk factors for RVO and demonstrated the protective effect of metformin against RVO in DM patients. Prescribing metformin for DM patients may be beneficial for reducing the incidence of RVO, along with its hypoglycemic action.

Suprachoroidal Triamcinolone Acetonide for Retinal Vein Occlusion: Results of the Tanzanite Study

PURPOSE

To compare the safety and efficacy of treatment with suprachoroidal triamcinolone acetonide (CLS-TA) plus intravitreal aflibercept vs. treatment with aflibercept alone in patients with macular edema due to retinal vein occlusion (RVO).

DESIGN

Randomized masked controlled clinical trial.

SUBJECTS

Forty-six patients with RVO.

METHODS

Subjects were randomized 1:1 to suprachoroidal injection of CLS-TA plus intravitreal aflibercept (combination arm) or sham suprachoroidal injection plus aflibercept (aflibercept arm), followed by aflibercept as needed at months 1, 2, and 3 in each arm.

MAIN OUTCOME MEASURES

The primary efficacy end point was the number of protocol-required aflibercept re-treatments through month 3. Secondary outcomes included mean improvement from baseline best-corrected visual acuity (BCVA), central subfield thickness (CST), and the percentage of participants with CST ≤310 μm at each time point.

RESULTS

The number of re-treatments were reduced in the combination arm compared with that in the aflibercept arm (23 vs. 9; -61%; P = 0.013) and the percentage of participants requiring no re-treatments was increased (78% vs. 30%; P = 0.003). The mean improvement from baseline BCVA letter score in combination vs. that in the aflibercept arms was 16.1 vs. 11.4 (P = 0.20) at month 1, 20.4 vs. 11.9 (P = 0.04) at month 2, and 18.9 vs. 11.3 (P = 0.09) at month 3. The mean baseline CST in the combination arm (731.1 μm) decreased into the normal range at month 1 (284.7 μm) and remained there at months 2 and 3 (272.4 μm and 285.4 μm). The mean baseline CST (727.5 μm) in the aflibercept arm decreased to 322.8 μm at month 1 and increased at months 2 and 3 (383.4 μm and 384.6 μm). Edema resolution (CST ≤ 310 μm) occurred in 87.0%, 87.0%, and 78.3% of participants in the combination arm at months 1, 2, and 3, respectively, vs. 56.5%, 47.8%, and 47.8% of participants in the aflibercept arm. In the combination arm, 1 participant had cataract progression and 4 (2 with preexistent glaucoma) had increased intraocular pressure that was controlled with topical medication.

CONCLUSIONS

Combination intravitreal aflibercept and suprachoroidal CLS-TA is well tolerated and significantly reduces the need for additional intravitreal aflibercept injections over a 3-month period in patients with RVO. Preliminary evidence suggests that combination therapy may sustain edema resolution and improve visual outcomes.

Prevalence and associated factors of retinal vein occlusion in the Korean National Health and Nutritional Examination Survey, 2008-2012: A cross-sectional observational study

Retinal vein occlusion (RVO) is the second most common retinal vascular diseases and there are only a few Asian population-based studies with small samples. Hypertension is one of a modifiable risk factor of RVO, but no recent studies have shown the relationship between RVO and hypertension control status. We aimed to investigate the prevalence of RVO and its associated factors in an adult Korean population.A nationwide population-based, cross-sectional study. We enrolled 37,982 participants from the Korea National Health and Nutrition Examination Survey who were 19 years or older and who had undergone ophthalmologic exams from 2008 through 2012. All participants underwent a comprehensive ophthalmic examination, standardized ophthalmic and health interviews, and laboratory investigations. Digital fundus photographs were interpreted by retinal specialists who investigated for the presence of RVO. The prevalence of RVO was then estimated. RVO-associated factors were determined using step-wise logistic regression analyses. We also performed a subgroup analysis to evaluate the association between hypertension and RVO according to hypertension control status and antihypertensive medication use.Of those enrolled participants, 25,765 participants met our study criteria and were included in the analyses. The overall RVO prevalence (n = 205) was 0.6 ± 0.1% (0.6 ± 0.1% for branch RVO and <0.1% for central RVO), and no sex differences were observed. In multivariate logistic regression analyses after adjusting for all potential risk factors, we found the following factors to be significantly associated with RVO: old age (odds ratio (OR) = 1.72, 95% CI: 1.27-2.34), hypertension (OR = 2.56, 95% CI: 1.31-5.08), history of stroke (OR = 2.08, 95% CI: 1.01-4.45), and hypercholesterolemia (OR = 1.84, 95% CI: 1.01-3.35). In a subset of participants with hypertension, participants with uncontrolled hypertension (OR = 3.46, 95% CI: 1.72-6.94) and unmedicated hypertension (OR = 4.12, 95% CI: 2.01-8.46) were more significantly associated with RVO than participants without hypertension.RVO prevalence in Korea was moderate relative to that in the rest of the world, and RVO-associated factors were similar to those identified in other population-based studies. Well-controlled hypertension and antihypertensive medication showed inverse association with RVO.