Isolated and combined unilateral central retinal artery and vein occlusions after vaccination. A review of the literature

Aetiology, Diagnosis and Treatment of Arterial Occlusions of the Retina-A Narrative Review

Arterial occlusions of the retina are potentially sight-threatening diseases which often result in profound visual loss. The aim of this narrative review is to provide an overview of the aetiology, discuss major risk factors, describe the management and systemic assessments and evaluate existing therapies. For this review, an extensive literature search in PubMed was performed. Emboli from the heart or the carotid arteries can cause ophthalmic artery occlusion (OAO), central retinal artery occlusion (CRAO) and branch retinal artery occlusion (BRAO). Most patients with arterial occlusions have vascular risk factors such as arterial hypertension, hyperhomocysteinaemia, carotid stenosis and atrial fibrillation, which also increase the risk of cerebral stroke and myocardial infarction. Therapies such as ocular massage, thrombolysis and anterior chamber paracentesis have been suggested but are still equivocal. However, it is evident that retinal artery occlusion should be immediately treated and accompanied by interdisciplinary collaboration, since early diagnosis and the proper treatment of possible risk factors are important to reduce the risk of further damage, recurrences, other vascular diseases and mortality.

Retinal Vein Occlusion after COVID-19 Vaccination-A Review

Background Retinal vein occlusion (RVO) occurring after COVID-19 vaccination has been reported worldwide. Such a sight-threatening condition occurring after COVID-19 vaccination is a menace to ophthalmic health. This article reviews current evidence related to post-COVID-19 vaccination RVO. Method A total of 29 relevant articles identified on PubMed in January 2023 were selected for review. Observation All cases presented to ophthalmologists with visual loss shortly after COVID-19 vaccination. Mean and median age were both 58. No sex predominance was observed. RVO was diagnosed from findings on dilated fundal examination and ophthalmic imaging. AstraZeneca and BNT vaccines accounted for most cases. Vascular risk factors, e.g., diabetes mellitus and hypertension, were common. Most laboratory tests requested came back unremarkable. Most patients responded well to standard treatment, except those with ophthalmic comorbidities. Visual prognosis was excellent on short-term follow-up. Discussion The causality between RVO and COVID-19 vaccination is undeterminable because of the nature of articles, heterogenous reporting styles, contradicting laboratory findings and co-existing vascular risk factors. Vaccine-induced immune thrombotic thrombocytopenia, retinal vasculitis and homocysteinaemia were proposed to explain post-vaccination RVO. Large-scale studies have demonstrated that the incidence of RVO following COVID vaccination is very low. Nevertheless, the effects of boosters on retinal vasculature and ophthalmic health are still unclear. Conclusions The benefits of COVID-19 vaccination are believed to outweigh its ophthalmic risks. To ensure safe vaccination, the prior optimisation of comorbidities and post-vaccination monitoring are important. COVID-19 vaccines (including boosters) should be offered with reasonable confidence. Further studies are warranted to elucidate the ophthalmic impact of vaccines.

Retinal vascular occlusion following SARS-CoV-2 vaccination: A VAERS database analysis

Purpose

To evaluate the cases of retinal vessel occlusion following COVID-19 vaccination and evaluate the onset interval and clinical presentations in patients diagnosed with vaccine associated retinal artery occlusion (RAO) and retinal vein occlusion (RVO).

Design

Retrospective study of the cases reported to the Centers for Disease Control and Prevention (CDC) Vaccine Adverse Events Reporting System (VAERS) between December 11, 2020 and July 1, 2022.

Participants

Patients diagnosed with retinal vessel occlusion following vaccination with BNT162b2, mRNA-1273, and Ad26.COV2.S globally.

Methods

We performed a descriptive analysis of the patient demographics and clinical presentation in patients with retinal vessel occlusion. The correlation between the vaccines and continuous and categorical variables were assessed. We performed the post-hoc analysis to evaluated the association between RAO and RVO onset post-vaccination, and vaccine and dosage. Finally, a 30-day reverse analysis for RAO and RVO onset following administration of vaccine. A major limitation in the methods of this study is the lack of control group for assessing the risk of retinal vessel occlusive disease in patients who received the vaccine compared to the patients who were unvaccinated.

Main Outcome Measures

The crude reporting rate of retinal vessel occlusion following SARS-CoV-2 vaccine. The ocular and systemic presentations, onset duration and short term risk of RAO and RVO following vaccination.

Results

During the study period, 1351 retinal vessel occlusion cases were reported globally. The crude reporting rates of retinal vessel occlusion for BNT162b2, mRNA-1273, and Ad26.COV2.S were 0.36, 0.41, and 0.69, respectively. The majority of the retinal vessel occlusion cases were reported following BNT162b2 (n=606, 74.17%). The mean age of patients with RVO and RAO was 58.54 ± 16.06 years and 64.63 ± 16.16 years, respectively. In the cohort, 817 and 433 patients were diagnosed with RVO and RAO, respectively. Most cases of RVO (41.12%) and RAO (48.27%) were reported within the first week post-vaccination. We observed that the mean onset interval for RVO was significantly longer in patients who received Ad26.Cov2.S (54.07 ± 88.98 days) compared to BNT162b2 (18.07 ± 28.66 days) and mRNA-1273 (22.85 ± 38.13 days) vaccines (p<0.0001). This was further confirmed by post-hoc analysis, which revealed a significantly longer onset duration for the Ad26.Cov2.S compared to BNT162b2 and mRNA 1273 vaccines (p<0.0001). The reverse Kaplan Meier 30-day risk analysis showed a significant a higher risk of RVO onset following BNT162b2 compared to other vaccines(p<0.0001).

Conclusions

The low crude reporting rate highlights a low safety concern for retinal vessel occlusion following SARS-CoV-2 vaccination. This study provides insights into possible temporal association between reported retinal vessel occlusion events with SARS-CoV-2 vaccines, however further insights are needed to understand the underlying immunopathological mechanisms that promote thrombosis of retinal vasculature on vaccine administration.

Risk assessment of retinal vascular occlusion after COVID-19 vaccination

Coronavirus disease 2019 (COVID-19) vaccines are associated with several ocular manifestations. Emerging evidence has been reported; however, the causality between the two is debatable. We aimed to investigate the risk of retinal vascular occlusion after COVID-19 vaccination. This retrospective cohort study used the TriNetX global network and included individuals vaccinated with COVID-19 vaccines between January 2020 and December 2022. We excluded individuals with a history of retinal vascular occlusion or those who used any systemic medication that could potentially affect blood coagulation prior to vaccination. To compare the risk of retinal vascular occlusion, we employed multivariable-adjusted Cox proportional hazards models after performing a 1:1 propensity score matching between the vaccinated and unvaccinated cohorts. Individuals with COVID-19 vaccination had a higher risk of all forms of retinal vascular occlusion in 2 years after vaccination, with an overall hazard ratio of 2.19 (95% confidence interval 2.00-2.39). The cumulative incidence of retinal vascular occlusion was significantly higher in the vaccinated cohort compared to the unvaccinated cohort, 2 years and 12 weeks after vaccination. The risk of retinal vascular occlusion significantly increased during the first 2 weeks after vaccination and persisted for 12 weeks. Additionally, individuals with first and second dose of BNT162b2 and mRNA-1273 had significantly increased risk of retinal vascular occlusion 2 years following vaccination, while no disparity was detected between brand and dose of vaccines. This large multicenter study strengthens the findings of previous cases. Retinal vascular occlusion may not be a coincidental finding after COVID-19 vaccination.

Risk of New Retinal Vascular Occlusion After mRNA COVID-19 Vaccination Within Aggregated Electronic Health Record Data

Importance

New-onset retinal vascular occlusion (RVO) occurring acutely after messenger RNA (mRNA) COVID-19 vaccination has been described in recent literature. Because RVO can cause vision loss or blindness, an epidemiologic investigation evaluating this potential association is of great importance to public health.

Objective

To investigate how often patients are diagnosed with new RVO acutely after the mRNA COVID-19 vaccine compared with influenza and tetanus, diphtheria, pertussis (Tdap) vaccines.

Design, Setting, and Participants

A retrospective population-based cohort design using the TriNetX Analytics platform, a federated, aggregated electronic health record (EHR) research network containing the deidentified EHR data of more than 103 million patients, was used to examine aggregate EHR data. Data were collected and analyzed on October 20, 2022. Data on patients within the TriNetX Analytics platform were searched for the presence of vaccination Common Procedural Technology codes, and instances of newly diagnosed RVO within 21 days of vaccination were recorded and reported. Propensity score matching based on demographic characteristics (age, sex, race and ethnicity) and comorbidities (diabetes, hypertension, and hyperlipidemia) was performed between vaccination groups for evaluation of relative risks (RRs).

Main Outcomes and Measures

The appearance of a new-encounter diagnosis of RVO within 21 days of the mRNA COVID-19 vaccination was the primary outcome. Historical comparison cohorts of patients receiving influenza and Tdap vaccinations allowed for evaluation of the RRs for RVO.

Results

Of 3 108 829 patients (mean [SD] age at vaccination, 50.7 [20.4] years; 56.4% women) who received the mRNA COVID-19 vaccine, 104 (0.003%; 95% CI, 0.003%-0.004%) patients had a new diagnosis of RVO within 21 days of vaccination. After propensity score matching, the RR for new RVO diagnosis after the first dose of COVID-19 vaccination was not significantly different from that after influenza (RR, 0.74; 95% CI, 0.54-1.01) or Tdap (RR, 0.78; 95% CI, 0.44-1.38) vaccinations, but was greater when compared with the second dose of the COVID-19 vaccination (RR, 2.25; 95% CI, 1.33-3.81).

Conclusions and Relevance

The findings of this study suggest that RVO diagnosed acutely after mRNA COVID-19 vaccination occurs extremely rarely at rates similar to those of 2 different historically used vaccinations, the influenza and Tdap vaccines. No evidence suggesting an association between the mRNA COVID-19 vaccination and newly diagnosed RVO was found.