Risk of stroke development following retinal vein occlusion: A systematic review and meta-analysis.

Retinal vein occlusion (RVO) and cerebrovascular disease (CVD) share common risk factors and may be independently associated; however, the strength and nature of this association remain unclear. We conducted a systematic review and meta-analysis, informed by studies from PubMed, Scopus, EMBASE, Web of Science, and Google Scholar until January 6, 2024, aimed to clarify this relationship. Eligible studies included cohorts observing stroke incidence in RVO patients for over a year. Pooled effect estimates were calculated using random-effects models, with subgroup analyses evaluating associations between RVO types (central and branch) and stroke subtypes (ischemic and hemorrhagic). Ten cohort studies with a total of 428,650 participants (86,299 RVO patients) were included. Compared to controls, RVO patients exhibited a significantly increased risk of stroke (pooled risk ratio [RR]=1.38, 95% confidence interval (95%CI)=1.34-1.41). Subgroup analyses indicated elevated risk for both ischemic (RR=1.37, 95%CI=1.32-1.42) and hemorrhagic (RR=1.55, 95%CI=1.08-2.22) strokes in RVO patients. Additionally, both central (RR=1.50, 95%CI=1.27-1.78) and branch (RR=1.41, 95%CI=1.32-1.50) RVO were associated with stroke risk. Sensitivity analyses confirmed consistent results across various criteria, and funnel plots indicated no publication bias. RVO significantly increases the risk of both ischemic and hemorrhagic stroke, regardless of RVO type, suggesting a strong independent association between these conditions.

Do we miss rare adverse events induced by COVID-19 vaccination?

Although severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has caused many complications, the invention of coronavirus disease 2019 (COVID-19) vaccines has also brought about several adverse events, from common side effects to unexpected and rare ones. Common vaccine-related adverse reactions manifest locally or systematically following any vaccine, including COVID-19 vaccines. Specific side effects, known as adverse events of particular interest (AESI), are unusual and need more evaluation. Here, we discuss some of the most critical rare adverse events of COVID-19 vaccines.