Temporal fluctuations in retinal artery occlusions: an 11-year German cohort study

Abstract Purpose Cardiovascular events have been shown to follow seasonal and monthly distributions. It is unclear whether this applies to retinal vascular diseases. This study aims to determine the existence of seasonal variations in the onset of retinal artery occlusions (RAO) in a European population. Methods This retrospective, monocentric study included 646 eyes of 646 patients who were treated for RAO at the University Hospital Münster, Germany, between 2014 and 2024. Data on the exact diagnosis, day of presentation, intake of anticoagulation (AC) and general patient characteristics were collected. To determine seasonal variations in the presentation of RAO Chi-Square Test for specified proportions and Poisson regression were applied. Additional subgroup analyses further distinguished between central retinal artery occlusions (CRAO) and branch retinal artery occlusions (BRAO) and assessed whether pre-existing AC or antiplatelet (AP) medication status was associated with the temporal distribution of RAO presentations. Results No significant seasonal variation in the occurrence of RAO was observed (χ² p = 0.11; Poisson regression p = 0.24). Monthly analysis revealed significant variation according to the chi-square test ( p = 0.03), which was not confirmed by Poisson regression ( p = 0.07). In the CRAO subgroup, no significant seasonal variation was observed (χ² p = 0.22; Poisson regression p = 0.22), whereas monthly variation was significant in both the chi-square analysis ( p = 0.03) and Poisson regression ( p = 0.01). No significant seasonal or monthly variation was observed for BRAO. Pre-existing AC/AP medication status was not significantly associated with the seasonal distribution of RAO presentations in any of the analyzed groups. Conclusion This study characterizes temporal fluctuations in RAO presentations and highlights the necessity for further investigations into potential underlying pathophysiological mechanisms, in order to better understand patterns of RAO presentations and their potential clinical relevance.