Associations between the Vessel Density in Deep Vascular Plexus and Macular Edema Recurrences in Patients with Retinal Vein Occlusion.

Introduction: The aim of this study was to study the relationships between vessel density (VD) in different retinal vascular plexus and retinal vein occlusion-macular edema (RVO-ME) recurrence using wide-field swept source optical coherence tomography angiography (OCTA).

Methods: Patients with a history of central retinal vein occlusion (CRVO) or branch retinal vein occlusion (BRVO) with macular edema in the Department of Ophthalmology, Shanghai General Hospital, from May 25, 2020, to January 12, 2023, were retrospectively reviewed and recruited. All patients were followed up for at least 6 months and divided in the release group and the recurrence group. The optical coherence tomography and OCTA examination were performed. Demographics, retinal structural, and angiographic data were collected and compared between two groups. The ordinal logistic regression was performed to assess the risk factors for RVO-ME.

Results: A total of 85 patients were enrolled in this study. Among them, 30 patients had CRVO, while 55 had BRVO. The VD in the 6-9 mm ring in deep vascular plexus (DVP) was significantly higher in the recurrence group (25.414 ± 6.068% in the release group vs. 27.574 ± 7.767% in the recurrence group, p = 0.036). More patients with mean VD of the 6-9 mm ring in DVP no less than 30% were observed in the recurrence group (observed n = 20, expected n = 14.4, p = 0.043). The ordinal logistic regression reported that patients with mean VD of the 6-9 mm ring in DVP ≥30% had risk of RVO-ME increased to 11.508 (95% CI: 1.745-75.944, p = 0.011), when compared to the patients with mean VD of the 6-9 mm ring in DVP <20%, even with RVO type, baseline central macular thickness weighed.

Conclusion: High vessel density of the 6-9 mm ring in DVP, especially those ≥30%, was associated with macular edema recurrences in patients with retinal vein occlusion.