Disagreement of Radial Peripapillary Capillary Density Among Four Optical Coherence Tomography Angiography Devices.

PURPOSE: This prospective study evaluated the agreement among four optical coherence tomography angiography (OCTA) devices in the assessment of radial peripapillary capillary (RPC) density.

METHODS

The study included 48 eyes of 48 subjects (14 healthy, 19 glaucomatous, and 15 non-glaucomatous optic neuropathy). Each participant was scanned using four OCTA devices in a random sequence: RTVue XR Avanti (RTVue), DRI OCT Triton (Triton), Revo NX 130 (Revo), and PLEX Elite 9000 (PlexE). All 6 × 6-mm grayscale OCTA images from each device were analyzed for RPC density using a customized algorithm. Agreement between each pair of devices was assessed using intraclass correlation coefficients (ICCs) and Bland-Altman plots.

RESULTS

There was a poor correlation between devices in all comparisons (RTVue-Triton, ICC = 0.34; RTVue-Revo, ICC = 0.31; RTVue-PlexE, ICC = 0.28; Triton-Revo, ICC = 0.31; Triton-PlexE, ICC = 0.17; Revo-PlexE, ICC = 0.34). Significant proportional biases (P < 0.05) and wide limits of agreement with apparent constant biases were identified in all comparisons. The mean difference was greatest for the RTVue-Revo pair (-49.3%; 95% confidence interval [CI], -52.9 to -45.8) and smallest for the Triton-PlexE pair (-7.7%; 95% CI, -10.1 to -5.3).

CONCLUSIONS

The RPC densities obtained from each device had poor inter-device agreement and significant biases and cannot be used interchangeably.

TRANSLATIONAL RELEVANCE: RPC density obtained from different OCTA devices is not interchangeable; thus, the progression of optic neuropathy should be monitored using the same OCTA device.