Artificial intelligence-based extraction of quantitative ultra-widefield fluorescein angiography parameters in retinal vein occlusion

OBJECTIVE: To examine the association between quantitative vascular parameters extracted from intravenous fluorescein angiography (IVFA) and baseline clinical characteristics of patients with retinal vein occlusion (RVO). METHODS: Our prospective single-centre study in Toronto, Canada, recruited patients with a diagnosis of macular edema secondary to RVO presenting with a central macular thickness (CMT) ≥310 μm from 2017 to 2023. IVFA images were captured using an ultra-widefield scanning laser ophthalmoscope and processed using the artificial intelligence-based RETICAD system to extract quantitative measurements of blood flow, perfusion, and blood-retinal barrier (BRB) permeability. Univariable and multivariable regression models were used to investigate associations between quantitative IVFA parameters and baseline best-corrected visual acuity (BCVA), CMT, and macular volume. RESULTS: The study included 41 eyes from 41 RVO patients. In the multivariable analysis, BRB permeability was significantly associated with both CMT (p < 0.001) and macular volume (p = 0.005). Subgroup analyses revealed that in central RVO patients, central BRB permeability remained significantly associated with CMT (p = 0.022) and macular volume (p = 0.010); however, there was no association with BCVA (p = 0.921). In branch RVO patients, central BRB permeability was significantly associated with BCVA (p = 0.006) and CMT (p = 0.009), but not with macular volume (p = 0.723). Additionally, both central and peripheral BRB permeability were significantly higher in patients with RVO compared to healthy controls (p < 0.001). CONCLUSIONS: Our investigation reveals novel associations between baseline clinical characteristics and quantitative IVFA parameters in RVO patients, which may serve as clinically relevant biomarkers. Future studies should explore these associations in diverse RVO patient populations with extended follow-up.