Reliability of optical coherence tomography angiography measurements following intravenous sodium fluorescein...

To validate the short-term reliability of optical coherence tomography angiography (OCT-A) metrics obtained after intravenous sodium fluorescein administration, and to determine whether fluorescein interferes with quantitative chorioretinal and peripapillary microvascular measurements in patients with mild nonproliferative diabetic retinopathy (NPDR).

This cross-sectional study included 47 eyes of 47 patients with mild NPDR undergoing fundus fluorescein angiography (FFA). OCT-A imaging was performed immediately before and 15 minutes after intravenous injection of 5 mL of 10% sodium fluorescein. Quantitative OCT-A parameters included the foveal avascular zone (FAZ) area, superficial and deep capillary plexus vessel densities (SCP and DCP VDs), choriocapillaris blood flow area (CBFA), retinal nerve fiber layer (RNFL) thickness, and radial peripapillary capillary vessel density (RPCVD). Pre- and post-FFA measurements were compared using paired-sample t-tests. Intraclass correlation coefficient (ICC) and Bland-Altman analyses were additionally performed to evaluate agreement and repeatability between measurements.

The study population consisted of 23 female and 24 male patients (mean age: 45.08 ± 15.10 years). No statistically significant differences were observed in FAZ area, SCP or DCP vessel densities, CBFA, RNFL thickness, or RPCVD following fluorescein administration (p > 0.05 for all parameters). ICC analyses demonstrated good-to-excellent repeatability across representative OCT-A parameters, while Bland-Altman analyses confirmed good agreement without evidence of systematic proportional bias between measurements obtained before and after FFA.

OCT-A-derived retinal, choroidal, and peripapillary microvascular parameters remain stable following intravenous sodium fluorescein administration. These findings support the methodological robustness and reliability of OCT-A measurements obtained shortly after FFA, allowing OCT-A to be safely integrated into routine multimodal retinal imaging protocols without concern for fluorescein-related measurement interference.