Similarities and differences in systemic risk factors for retinal artery occlusion and stroke: A nationwide case-control study

LiViT-Net: A U-Net-like, lightweight Transformer network for retinal vessel segmentation

The intricate task of precisely segmenting retinal vessels from images, which is critical for diagnosing various eye diseases, presents significant challenges for models due to factors such as scale variation, complex anatomical patterns, low contrast, and limitations in training data. Building on these challenges, we offer novel contributions spanning model architecture, loss function design, robustness, and real-time efficacy. To comprehensively address these challenges, a new U-Net-like, lightweight Transformer network for retinal vessel segmentation is presented. By integrating MobileViT+ and a novel local representation in the encoder, our design emphasizes lightweight processing while capturing intricate image structures, enhancing vessel edge precision. A novel joint loss is designed, leveraging the characteristics of weighted cross-entropy and Dice loss to effectively guide the model through the task's challenges, such as foreground-background imbalance and intricate vascular structures. Exhaustive experiments were performed on three prominent retinal image databases. The results underscore the robustness and generalizability of the proposed LiViT-Net, which outperforms other methods in complex scenarios, especially in intricate environments with fine vessels or vessel edges. Importantly, optimized for efficiency, LiViT-Net excels on devices with constrained computational power, as evidenced by its fast performance. To demonstrate the model proposed in this study, a freely accessible and interactive website was established (https://hz-t3.matpool.com:28765?token=aQjYR4hqMI), revealing real-time performance with no login requirements.

Is retinal vein occlusion highly associated with an increased risk of myocardial infarction? A systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

Retinal vein occlusion (RVO) and acute myocardial infarction (MI) are significant vascular events that impact patient health and mortality. Both conditions share common risk factors, such as hypertension, diabetes, and atherosclerosis. This study investigated the potential connection between RVO and MI, particularly among younger individuals, to improve preventive measures and management protocols.

METHOD

A systematic review and meta-analysis were conducted, adhering to the PRISMA and MOOSE guidelines. Multiple databases, including PubMed, Scopus, MEDLINE, ScienceDirect, and ClinicalTrials.gov, were exhaustively searched until August 24, 2024. Studies were selected based on their reports of the association between RVO and MI risk. Quality assessment was performed using the Newcastle-Ottawa Quality Assessment Scale, and data were pooled using a random-effects model with hazard ratios and 95% confidence intervals.

RESULT

Twelve studies comprising 371,817 participants were included. Meta-analysis revealed a pooled hazard ratio of 1.324 (95% CI, 1.238-1.415), indicating a significant association between RVO and increased MI risk (p = 0.0001). Subgroup analysis for central retinal vein occlusion (CRVO) showed a hazard ratio of 1.691 (95% confidence interval [CI] 1.142, 2.502, p = 0.009) with moderate heterogeneity (I2 = 36%), whereas branch retinal vein occlusion (BRVO) yielded a non-significant hazard ratio of 1.167 (95% CI 0.843, 2.106, p = 0.444; I2 = 33%). Publication bias was identified (Egger's test, p = 0.036) and addressed through trim-and-fill adjustment, maintaining statistical significance.

CONCLUSION

Our meta-analysis shows a strong association between CRVO and a 69.1% increased risk of MI, while BRVO shows no significant correlation. Overall, RVO is linked to a 32.4% elevated risk of MI. Despite slight publication bias, adjusted analyses confirm reliability, indicating that improved cardiovascular monitoring for RVO patients, especially those with CRVO, is essential to mitigate MI risk.

CLINICAL TRIAL NUMBER

Not applicable.

Retina-Brain Homology: The Correlation Between Ophthalmic or Retinal Artery Occlusion and Ischemic Stroke

The retina's similar structure and function to the brain make it a unique visual "window" for studying cerebral disorders. Ophthalmic artery occlusion (OAO) or retinal artery occlusion (RAO) is a severe ophthalmic emergency that significantly affects visual acuity. Studies have demonstrated that patients with OAO or RAO face a notably higher risk of future acute ischemic stroke (AIS). However, ophthalmologists often overlook multidisciplinary approach involving the neurologist, to evaluate the risk of AIS and devise clinical treatment strategies for patients with OAO or RAO. Unlike the successful use of thrombolysis in AIS, the application of thrombolysis for OAO or RAO remains limited and controversial due to insufficient reliable evidence. In this review, we aim to summarize the anatomical and functional connections between the retina and the brain, and the clinical connection between OAO or RAO and AIS, compare and review recent advances in the effectiveness and safety of intravenous and intra-arterial thrombolysis therapy in patients with OAO or RAO, and discuss future research directions for OAO or RAO. Our goal is to advance the development of multidisciplinary diagnosis and treatment strategies for the disease, as well as to establish expedited pathways or thrombolysis guidelines for vascular intervention.

Genetically predicted retinal vascular occlusion in relation to cardiovascular diseases: A bidirectional two-sample Mendelian randomization analysis

INTRODUCTION

Increasing evidence implicates retinal vascular occlusions as a susceptibility factor for cardiovascular diseases (CVDs), whereas inconsistent results on the relationship were reported in previous observational studies. This research using a bidirectional two-sample Mendelian randomization (MR) analysis aimed to investigate the potential association between genetically determined central/branch retinal artery and retinal vein occlusions (CRAO/BRAO/RVO) and the risk of CVD.

METHODS

Summary statistics of retinal vascular occlusions from the largest available genome-wide association study of European descent were used to investigate their relationship with CVDs, and vice versa. Primary analyses were conducted using the common inverse-variance weighted approach. Several complementary sensitivity analyses were performed to verify the reliability of our results.

RESULTS

Inverse variance weighted method showed suggestive effects of genetically determined RVO on ischemic stroke (IS) (odds ratio [OR] = 1.021, 95% confidence [CI] = 1.004-1.037, p = 0.012), a genetic liability to CRAO increased the risk of myocardial infarction (MI) (OR = 1.014, 95% CI = 1.006-1.023, p = 7.0 × 10-4). In addition, genetic predisposition to BRAO had a positive effect on stroke (OR = 1.008, 95% CI = 1.002-1.013, p = 0.011), IS (OR = 1.007, 95% CI = 1.001-1.014, p = 0.022), and cardioembolic stroke (CES) (OR = 1.018, 95% CI = 1.006-1.031, p = 0.004). The point estimates from sensitivity analyses were in the same direction. Reverse MR analyses found no significant evidence for the effect of CVDs on retinal vascular occlusions.

CONCLUSION

Our MR study provides potential evidence that retinal vascular occlusions are causally linked to increased risk of CVDs including IS, MI, stroke, and CES. This supports the need for clinical CVD screening in individuals with retinal vascular occlusions. Further investigations are warranted to clarify the effects of CVDs on ocular comorbidities.

Positive Prediction Value of Retinal Artery Occlusion Diagnoses in the Danish National Patient Registry: A Validation Study

PURPOSE

The hospital registration of retinal artery occlusions in the Danish National Patient Registry has not previously been validated. In this study, the diagnosis codes were validated to ensure the diagnoses had an acceptable validity for research. The validation was performed both for the overall diagnosis population and at the subtype diagnosis level.

METHODS

The medical records for all patients with retinal artery occlusion with an incident hospital record in the years 2017-2019 in Northern Jutland (Denmark) were assessed in this population-based validation study. Furthermore, fundus images and two-person verification were assessed for the included patients when available. The positive prediction values for the overall diagnosis of retinal artery occlusion, as well as for the central or branch subtypes, were calculated.

RESULTS

A total of 102 medical records were available for review. The overall positive prediction value for a retinal artery occlusion diagnosis was 79.4% (95% CI: 70.6-86.1%), while the overall positive prediction value at the subtype diagnosis level was 69.6% (95% CI: 60.1-77.7%), with 73.3% (95% CI: 58.1-85.4%) for branch retinal artery occlusion and 71.2% (95% CI: 56.9-82.9%) for central retinal artery occlusion. For the stratified analyses at the subtype diagnosis, age, sex, diagnosis year, and primary or secondary diagnosis, the positive prediction values ranged from 73.5 to 91.7%. In the stratified analyses at the subtype level, the positive prediction values ranged from 63.3 to 83.3%. The differences among the positive prediction values of the individual strata of both analyses were not statistically significant.

CONCLUSIONS

the validities of the retinal artery occlusion and subtype level diagnoses are comparable to other validated diagnoses and considered acceptable for use in research.

Incidence of Retinal Artery Occlusion and Related Mortality in Korea, 2005 to 2018

IMPORTANCE

It remains unclear whether comorbidities in patients with retinal artery occlusion (RAO), a rare retinal vascular disorder, differ by subtype and whether mortality is higher.

OBJECTIVE

To examine the nationwide incidence of clinically diagnosed, nonarteritic RAO, causes of death, and mortality rate in patients with RAO compared with that in the general population in Korea.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective, population-based cohort study examined National Health Insurance Service claims data from 2002 to 2018. The population of South Korea was 49 705 663, according to the 2015 census. Data were analyzed from February 9, 2021, to July 30, 2022.

MAIN OUTCOMES AND MEASURES

The nationwide incidence of any RAO, including central RAO (CRAO; International Statistical Classification of Diseases and Related Health Problems, Tenth Revision [ICD-10] code, H34.1) and noncentral RAO (other RAO; ICD-10 code, H34.2) was estimated using National Health Insurance Service claims data from 2002 to 2018, with 2002 to 2004 as the washout period. Furthermore, the causes of death were evaluated and the standardized mortality ratio was estimated. The primary outcomes were the incidence of RAO per 100 000 person-years and the standardized mortality ratio (SMR).

RESULTS

A total of 51 326 patients with RAO were identified (28 857 [56.2%] men; mean [SD] age at index date: 63.6 [14.1] years). The nationwide incidence of any RAO was 7.38 (95% CI, 7.32-7.44) per 100 000 person-years. The incidence rate of noncentral RAO was 5.12 (95% CI, 5.07-5.18), more than twice that of CRAO (2.25 [95% CI, 2.22-2.29]). Mortality was higher in patients with any RAO than in the general population (SMR, 7.33 [95% CI, 7.15-7.50]). The SMR for CRAO (9.95 [95% CI, 9.61-10.29]) and for noncentral RAO (5.97 [95% CI, 5.78-6.16]) showed a tendency toward a gradual decrease with increasing age. The top 3 causes of death in patients with RAO were diseases of the circulatory system (28.8%), neoplasms (25.1%), and diseases of the respiratory system (10.2%).

CONCLUSIONS AND RELEVANCE

This cohort study found that the incidence rate of noncentral RAO was higher than that of CRAO, whereas SMR was higher for CRAO than noncentral RAO. Patients with RAO show higher mortality than the general population, with circulatory system disease as the leading cause of death. These findings suggest that it is necessary to investigate the risk of cardiovascular or cerebrovascular disease in patients newly diagnosed with RAO.

Risk Factors and Treatment Strategy for Retinal Vascular Occlusive Diseases

Retinal occlusive diseases are common diseases that can lead to visual impairment. Retinal artery occlusion and retinal vein occlusion are included in the clinical entity, but they have quite different pathophysiologies. Retinal artery occlusion is an emergent eye disorder. Retinal artery occlusion is mainly caused by thromboembolism, which frequently occurs in conjunction with life-threatening stroke and cardiovascular diseases. Therefore, prompt examinations and interventions for systemic vascular diseases are often necessary for these patients. Retinal vein occlusion is characterized by retinal hemorrhage and ischemia, which may impair visual function via several complications such as macular edema, macular ischemia, vitreous hemorrhage, and neovascular glaucoma. Even though anti-vascular endothelial growth factor therapy is the current established first-line of treatment for retinal vein occlusion, several clinical studies have been performed to identify better treatment protocols and new therapeutic options. In this review, we summarize the current findings and advances in knowledge regarding retinal occlusive diseases, particularly focusing on recent studies, in order to provide an update for a better understanding of its pathogenesis.