Clinical significance of subclinical atherosclerosis in retinal vein occlusion

[Retinal venous occlusion and its association with atherosclerotic vascular disease]

Retinal venous occlusion (RVO) is the second most frequent cause of decreased visual acuity due to retinal vascular, after diabetic retinopathy. Its etiology is not completely clear. Current scientific evidence suggests that it is related to the atherosclerotic process given the high number of cardiovascular risk factors and the higher incidence of cardiovascular events in these patients. In fact, RVO implies a 45% higher risk of stroke, 26% of acute myocardial infarction and peripheral vascular disease, 53% of heart failure and 36% of overall mortality, compared to the general population adjusted for age, sex and the different cardiovascular risk factors. However, no increase in cardiovascular mortality has been detected. Therefore, a multidisciplinary clinical approach to this pathology is essential.

The protective effect of anti-VEGF-A/Ang-2 bispecific antibody on retinal vein occlusion model mice

(233/250) Retinal vein occlusion (RVO) causes macular edema and retinal ischemia resulting in visual field and vision loss. A bispecific antibody that blocks VEGF-A and angiopoietin-2 (Ang-2) has been recently launched and applied clinically to treat macular edema, but the role of Ang-2 in the pathogenesis of RVO is still unclear. In this study, we investigated the effects of the anti-VEGF-A/anti-Ang-2 bispecific antibody (BsAb) in a murine RVO model. By using RVO model mice, the expression of Ang-2 gene and protein was examined in the retina through real-time qPCR and Western blotting, respectively. A significant increase in Ang-2 was detected 1 day after occlusion. Immediately after occlusion, control IgG 400 μg/mL, anti-VEGF-A antibody 200 μg/mL, anti-Ang-2 antibody 200 μg/mL, and BsAb 400 μg/mL were intravitreally administered at 2 μL. Visual function was examined using electroretinograms, and apoptosis was examined using TUNEL staining. Interestingly, BsAb partially suppressed the decrease in amplitude of a and b waves compared to control IgG. Anti-Ang-2 antibody and BsAb reduced apoptosis-positive cells 1 day after occlusion. Comprehensive gene expression profiles were also examined using RNA sequencing analysis. RNA sequencing analysis of the retinal tissues showed that BsAb suppressed expression of gene groups associated with inflammatory response and vascular development compared to anti-VEGF-A antibody. Taken together, higher expression of Ang-2 contributes to the pathophysiology of RVO, providing a possible mechanism for the efficacy of BsAb in suppressing retinal dysfunction in RVO.

Vitamin D deficiency in patients with retinal vein occlusion: a systematic review and meta-analysis

BACKGROUND

This review aims to substantiate the correlation between vitamin D and retinal vein occlusion (RVO) within the medical literature.

METHOD

A systematic review and meta-analysis were conducted in PubMed, SCOPUS, Web of Science, and Embase until December 10th, 2023. A meticulous literature search was undertaken to identify and analyze all observational-analytical papers reporting vitamin D levels in RVO patients. The principal outcome measures centered on the comparative assessment of vitamin D levels between patients with RVO (cases) and those devoid of RVO (controls). The protocol was registered in PROSPERO (code: CRD42024499853).

RESULTS

A total of six relevant studies consisting of 589 participants were included in this meta-analysis. The results indicated a significant association between vitamin D deficiency and increased risk of RVO (Odds ratio = 14.51; 95% CI: [1.71, 122.59], P = 0.014); and patients with RVO exhibited a significant decrease in serum vitamin D levels by 1.91ng/mL (95% CI: [-2.29, -1.54], P < 0.001). Moreover, there was no significant difference observed in vitamin D levels between central RVO (CRVO) and branch RVO (BRVO) subtypes (P = 0.63).

CONCLUSION

RVO patients have more vitamin D deficiency than healthy controls. These results contribute to the growing body of evidence highlighting the intricate role of vitamin D supplementation as both a prophylactic and a treatment strategy in RVO.

PROSPERO REGISTRATION IDENTIFIER

CRD42024499853.

Clinical effects of atorvastatin combined with conbercept in the treatment of patients with macular edema secondary to retinal vein occlusion and carotid plaque: study protocol for a prospective randomized controlled trial

INTRODUCTION

Intravitreal injections of anti-vascular endothelial growth factor (anti-VEGF) drugs have been widely used in patients with macular edema (ME) secondary to retinal vein occlusion (RVO); however, recurrence is a major concern. This study aims to observe the clinical effects of atorvastatin and intravitreal therapy in the treatment of patients with branch or central RVO-ME and coexistent carotid plaques (CP).

METHODS AND ANALYSIS

A prospective randomized controlled clinical trial will be conducted. Sixty-four patients diagnosed with branch or central RVO-ME and coexistent CP will be enrolled and randomly allocated in a 1:1 ratio to the control and experimental groups. The control group will be treated with intravitreal conbercept monthly for 3 months, followed by monthly evaluation and injection of pro re nata (PRN) for 12 months, while the experimental group will be treated with oral atorvastatin 20 mg daily combined with the control group treatment. If a drop of best-corrected visual acuity (BCVA) is more than five Early Treatment Diabetic Retinopathy Study (ETDRS) letters (one line) or an increment in central subfield thickness (CSFT) of 100 μm (or a 10% increment from the previous visit), intravitreal re-treatment will be performed. Outcome measurements include CSFT, BCVA, number of injections, and incidence of adverse events during the 12-month follow-up period. Differences between groups will be evaluated using Student's t-test, and comparisons between groups will be evaluated using repeated-measures analysis of variance.

ETHICS AND DISSEMINATION

The study has been approved by the Institutional Review Board of Nanjing Lishui People's Hospital, Nanjing, China (approval number 2023KY0418-12, dated 18 April 2023), and has been registered on chictr.org.cn. Written informed consent will be collected from each patient and the results of this trial will be submitted to a peer-reviewed journal.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2300071359. Registered on 12 May 2023.

Maximum carotid intima-media thickness and NT-pro BNP in association with retinal vein occlusion

The purpose is to clarify the relationship between patients with retinal vein occlusion (RVO), maximal intima-media complex thickness (Max IMT), and N-terminal pro-brain natriuretic peptide (NT-proBNP), which is useful in assessing atherosclerosis. This was a retrospective observation, single center study. The patients were 86 RVO patients (male: female = 43:43, mean age 63.3 years), 25 with central retinal vein occlusion (CRVO) and 61 with branch retinal vein occlusion (BRVO), classified as ≧50 years old and <50 years old, Max IMT≧1.1 and less, NT-pro BNP≧55 and less. Results showed that Max IMT ≧1.1 was significantly more common in both the CRVO and BRVO groups at ≧50 years, and NT-pro BNP ≧55 was significantly more common in the CRVO group. Max IMT≧1.1 was seen in 80% of the BRVO group and in 85% of patients aged ≧50 years. Sixty-eight percent of patients in the CRVO group had Max IMT≧1.1, but none of those < 50 years had Max IMT≧1.1. Forty-eight percent of RVO patients had NT-pro BNP≧55, and significantly more patients had Max IMT≧1.1 than those who did not have NT-pro BNP more than 55 (p = 0.02). Multiple regression analysis with Max IMT as the dependent variable showed that age and NT-pro BNP were significantly associated with RVO (p = 0.015, 0.022). RVO patients were more likely to have a Max IMT≧1.1, which was associated with atherosclerosis. Max IMT and NT-pro BNP were also associated with RVO patients, so NT-pro BNP may be a marker of RVO.

The Incidence, Time to Development, and Risk Factors for Fellow Eye Retinal Vein Occlusions

BACKGROUND AND OBJECTIVE

Little is known about factors affecting risk or time to development of fellow eye retinal vein occlusion (RVO). The purpose of this study was to examine the incidence and risk factors for fellow eye RVO.

PATIENTS AND METHODS

This was a retrospective case-control study comparing unilateral and fellow eye RVO patients. This study was exempt by the Cleveland Clinic Institutional Review Board.

RESULTS

Out of 1,083 patients, fellow eye RVO had a cumulative incidence of 3.6% (95% CI 2.61, 4.94) with a median time to development of 18 months (95% CI 6.0, 28.0). Fellow eye disease was associated with multiple characteristics including chronic kidney disease (odds ratio [OR] 3.78, 95% CI 1.89 to 7.55) and diabetic retinopathy (3.18, 1.57 to 6.44).

CONCLUSION

While fellow eye RVO is relatively rare, it typically occurs within the first few years following initial diagnosis. Multiple characteristics were associated with fellow eye disease and time to onset. [Ophthalmic Surg Lasers Imaging Retina 2023;54:471-476.].

Alteration of plasma von Willebrand factor in the treatment of retinal vein occlusion with cystoid macular edema

Retinal vein occlusion (RVO) is a major retinal disease caused by venous thrombosis. Although several studies have proposed an association between venous thrombosis and von Willebrand factor (VWF), the association between RVO and VWF remains unclear. We aimed to investigate the association between RVO and VWF and the alteration of VWF levels under anti-vascular endothelial growth factor (VEGF) treatment. We enrolled 55 patients with RVO involved cystoid macular edema. They received intravitreal injection of anti-VEGF drugs, either ranibizumab or aflibercept. We examined the clinical data and measured plasma VWF antigen and a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13) activity to identify variabilities during treatment. At baseline, there was no significant difference between the RVO group and age-matched controls in both VWF antigen and ADAMTS13 activity levels, but ADAMTS13 activity was significantly lower in central RVO than in branch RVO (P = 0.015). In branch RVO, VWF antigen was negatively correlated with central choroidal thickness (r = −0.51, P < 0.001). In branch RVO after anti-VEGF treatment, VWF antigen levels decreased significantly from 134% at baseline to 109% at 1 day (P = 0.002) and 107% at 1 month (P = 0.030) after treatment. In contrast, ADAMTS13 activity showed no significant difference during this period. In branch RVO at 1 month after treatment, VWF antigen was negatively correlated with central choroidal thickness (r = −0.47, P = 0.001). Our findings suggest an association between VWF and central choroidal thickness in patients with branch RVO, thus the measurement of VWF may be useful for evaluating disease activity and prognosis.

The Long-term Outcomes of Central Retinal Vein Occlusion and Factors Associated with Resolution of Macular Edema

Purpose: To report the long-term outcomes of patients with macular edema (ME) secondary to central retinal vein occlusion (CRVO) and to explore the ME incidence and factors associated with ME resolution.Methods: We retrospectively studied patients with ME secondary to CRVO. The visual acuity at baseline was compared to that at the final visit. The incidence and timing of ME resolution during treatment were evaluated and the visual outcomes of patients who did and did not experience ME resolution were compared. We also identified factors predictive of ME resolution.Results: We included 79 patients; the mean follow-up time was 50.1 ± 14.3 months. The mean logarithm of the minimal angle of resolution (logMAR) of visual acuity was 0.94 ± 0.75 at diagnosis and 1.00 ± 0.84 at the final visit (p = 1.000). A logMAR visual loss of 0.3 or greater was noted in 28 patients (35.4%). During follow-up, ME resolution was evident in 40 eyes (50.6%) at a mean of 16.9 ± 17.4 months. Visual improvement was greater in patients who evidenced ME resolution than in those who did not (p < 0.001). The ME resolution rate was higher in patients younger than 60 years (p = 0.039) and in those who lacked subretinal fluid at diagnosis (p < 0.001).Conclusions: In patients with ME secondary to CRVO, the risk of long-term recurrent ME was higher in older patients and those evidencing subretinal fluid at diagnosis indicating that such patients require close follow-up and aggressive treatment.

Predicting CT-Based Coronary Artery Disease Using Vascular Biomarkers Derived from Fundus Photographs with a Graph Convolutional Neural Network

The study population contains 145 patients who were prospectively recruited for coronary CT angiography (CCTA) and fundoscopy. This study first examined the association between retinal vascular changes and the Coronary Artery Disease Reporting and Data System (CAD-RADS) as assessed on CCTA. Then, we developed a graph neural network (GNN) model for predicting the CAD-RADS as a proxy for coronary artery disease. The CCTA scans were stratified by CAD-RADS scores by expert readers, and the vascular biomarkers were extracted from their fundus images. Association analyses of CAD-RADS scores were performed with patient characteristics, retinal diseases, and quantitative vascular biomarkers. Finally, a GNN model was constructed for the task of predicting the CAD-RADS score compared to traditional machine learning (ML) models. The experimental results showed that a few retinal vascular biomarkers were significantly associated with adverse CAD-RADS scores, which were mainly pertaining to arterial width, arterial angle, venous angle, and fractal dimensions. Additionally, the GNN model achieved a sensitivity, specificity, accuracy and area under the curve of 0.711, 0.697, 0.704 and 0.739, respectively. This performance outperformed the same evaluation metrics obtained from the traditional ML models (p < 0.05). The data suggested that retinal vasculature could be a potential biomarker for atherosclerosis in the coronary artery and that the GNN model could be utilized for accurate prediction.

Plasma lipid levels and risk of retinal vascular occlusion: A genetic study using Mendelian randomization

The causal effects of plasma lipid levels and the risk of retinal vascular occlusion (RVO) have not been clearly identified, especially for high-density lipoprotein-cholesterol (HDL-C) and low-density lipoprotein-cholesterol (LDL-C). Here, we try to identify these causal risk factors using a two-sample Mendelian randomization (MR) analysis. Single nucleotide polymorphisms (SNPs) were chosen as instrumental variables (IVs). We obtained genetic variants associated with lipid exposure at the genome-wide significance (P<5×10^-8) level from a meta-analysis of GWAS from the Global Lipids Genetics Consortium (GLGC) based on 188,577 individuals of mostly European ancestry for MR analyses. Meanwhile, we used lipid GWAS from UK Biobank (UKB) with a sample size of 115,078 individuals as a supplement. We obtained genetic predictors of RVO from a FinnGen biobank study. We conducted both univariable and multivariable MR (MVMR) analyses to identify the causal effects of RVO. Although inverse variance weighted (IVW) was the primary method used for MR analyses, MR-Egger and weighted-median methods were used as supplements to IVW. We determined the heterogeneity of IVs using Cochrane's Q test and I² , and used the MR-Egger intercept and MR-PRESSO Global test to detect horizontal pleiotropy. A leave-one-out sensitivity analysis was conducted by removing a single variant from the analysis. Genetically predicted increased HDL-C level was associated with decreased risk of RVO from GLGC [OR=0.806; 95% CI=(0.659, 0.986); P=0.036], which was consistent with UKB results [OR=0.766; 95% CI=(0.635, 0.925); P=0.005]. MVMR analysis for plasma lipids [adjusted OR=0.639; 95% CI=(0.411, 0.992); P=0.046] or diabetes [adjusted OR=0.81; 95% CI=(0.67, 0.979); P=0.029] suggested that low HDL-C may be an independent risk factor for RVO. However, there was no evidence to support a causal association between LDL-C {GLGC [adjusted OR=1.015; 95% CI=(0.408, 2.523); P=0.975], UKB [OR=1.115; 95% CI=(0.884, 1.407); P=0.359]}, total cholesterol {GLGC [adjusted OR=0.904; 95% CI=(0.307, 2.659); P=0.854], UKB [OR=1.047; 95% CI=(0.816, 1.344); P=0.716]} or triglycerides {GLGC [OR=1.103; 95% CI=(0.883, 1.378); P=0.385], UKB [OR=1.003; 95% CI=(0.827, 1.217); P=0.098]} and RVO. Using two-sample MR analysis, our study suggested that dyslipidemia was a risk factor for RVO. Furthermore, our results indicated that a low HDL-C level may be an independent risk factor for RVO, suggesting that controlling HDL-C level may be effective in RVO development.