Comparison Between Automated and Manual Measurement of Foveal Avascular Zone Retinopathy in Optical Coherence Tomography

Objective A comparison between automated and manual measurements of a foveal avascular zone in optical coherence tomography angiography (OCTA) in patients with diabetic retinopathy (DR). Material and Methods Consecutive patients with non-proliferative DR were included in this study. All patients received an OCTA, with a 3 x 3 mm scan of the macular region taken with the Zeiss OCT CIRRUS 5000 with the AngioPlex module. The size of the foveal avascular zone (FAZ) was determined both manually and with the help of the automated measurement metrics. Next, the measurements obtained using manual and automated methods were compared. In addition, the circularity index determined in metrics was examined for correlations with the size and area of the FAZ. Results Thirty-four eyes from 28 patients with non-proliferative diabetic retinopathy with a mean age of 63 years were included. The mean size of the foveal avascular zone was 0.34 +/- 0.12 mm(2) (0.08-0.65 mm(2)) for manual evaluation and 0.23 +/- 0.11 mm(2) (range 0.03-0.49 mm(2)) in metrics. The circularity index in metrics averaged 0.58 and showed a statistically significant correlation with the size of the manually measured FAZ. Conclusion There was a comparable result for the size of the FAZ in both measurement methods. Automated measurements with metrics can reliably represent changes in the FAZ for most patients, based on the calculated area, as well as on the circumference and the circularity index.