Reproducibility of macular perfusion parameters in non-proliferative diabetic retinopathy patients by two different OCTA sweep modes

Aim: To assess the reproducibility of macular perfusion parameters in non-proliferative diabetic retinopathy (NPDR) patients measured by different examiners and two different sweep modes of optical coherence tomography angiography (OCTA).

Methods: Ninety-eight (98 eyes) patients with NPDR were included in this study. All participates were performed three times using Cirrus OCTA with Angiography 3×3 mm² and 6×6 mm² sweep mode by two examiners. The macular foveal avascular zone (FAZ) and vessel density (VD) in the superficial retinal layer (SRL) were measured. The reproducibility of the measurements was evaluated with intraclass correlation coefficients (ICC) and coefficient of variation (CoV).

Results: The intra-mode ICCs of Angiography 3×3 mm² and 6×6 mm² sweep mode were 0.957 to 0.959 and 0.964 to 0.977, respectively; and the inter-mode ICCs were 0.962 to 0.970. The intra-examiner ICCs of macular perfusion parameters were >0.950; and the inter-examiner ICCs were 0.928 to 0.969. All CoVs were <1.0%.

Conclusion: Cirrus OCTA can measure macular perfusion parameters in NPDR patients with excellent reproducibility. The measurements of FAZ and VD in the SRL determined by Angiography 3×3 mm² and 6×6 mm² sweep mode are highly consistent and both sweep modes are suitable for macular perfusion parameters measurement.