The agreement between optical coherence tomography angiography and non-mydriatic retinal camera in estimating the optic nerve head parameters and relations with the peripapillary vessel density in primary open-angle glaucoma.

BACKGROUND/OBJECTIVES: To investigate the agreement between optical coherence tomography angiography (OCT-A) and non-mydriatic retinal camera (NMRC) in estimating the optic nerve head (ONH) parameters and evaluate the associations between peripapillary vessel density (VD) with ONH parameters assessed by both devices.

METHODS: The OCT-A and NMRC images of 262 participants (138 eyes were diagnosed with POAG, 63 were glaucoma suspect, and 61 were healthy subjects) were screened retrospectively. The vertical cup-to-disc ratio (VCDR), cup-to-disc area ratio (CDAR), rim area (RA), disc area (DA), and cup volume (CV) were recorded using both devices. Peripapillary VD data were also recorded using OCT-A. The intraclass correlation coefficient (ICC) and Bland-Altman plots were obtained to investigate the agreement between the devices. Age- and intraocular pressure (IOP)-corrected associations between the VD and ONH parameters measured by the two devices were analyzed using linear regression models.

RESULTS: ICC revealed excellent agreement for VCDR and CDAR, but poor agreement for RA, DA, and CV (ICC = 0.801, 0.793, 0.445, 0.298, and 0.527, respectively). The Bland-Altman plots showed poor agreement for VCDR and CDAR with a large span of limits of agreement (0.500 and 0.528, respectively) and significant proportional biases (P < 0.05). VD was found to be strongly associated with the VCDR and CDAR measurements of both devices (P < 0.001), but the associations were stronger for the measurements of NMRC.

CONCLUSIONS: The disagreement between the devices should be considered in clinical practice. The associations between the VD and ONH parameters proved once again the importance of the ONH parameters in terms of the management of glaucoma patients.