Agreement Between Angle-to-Angle Distance and Aqueous Depth Obtained With Two Different Optical Coherence Tomographers and a Scheimpflug Camera.

Abstract

To compare angle-to-angle (ATA) distance and aqueous depth (AQD) readings produced by two different optical coherence tomography (OCT) devices and a Scheimpflug camera. ATA distance and AQD were measured in 60 eyes using the Visante time-domain OCT (TD-OCT) (Carl Zeiss Meditec AG), the Anterion swept-source OCT (SS-OCT) (Heidelberg Engineering GmbH), and the Pentacam HR Scheimpflug camera (Oculus Optikgeräte GmbH). Moreover, ATA distance was measured along the horizontal and vertical meridians. Bland-Altman analysis was used to assess the agreement between devices. All three devices did not yield similar horizontal ATA distance: 11.96 ± 0.47 mm (TD-OCT), 11.96 ± 0.42 mm (SS-OCT), and 11.05 ± 0.52 mm (Pentacam). More specifically, the Pentacam yielded significantly smaller values (approximately 0.9 mm, P < .001). Mean vertical ATA distance was 12.61 ± 0.65 and 12 ± 0.65 mm for the TD-OCT and SS-OCT, respectively (P = .983). Vertical ATA distance was significantly larger than horizontal ATA distance for both OCT devices (approximately 0.6 mm, P < .001). The lowest mean difference was found between both OCT devices (0.0068 and -0.0415 mm, for horizontal and vertical meridians, respectively) and the highest between the Pentacam and the two OCT devices (approximately 0.9 mm). As for AQD, inter-device mean values were also statistically significant: 2.89 ± 0.48, 2.82 ± 0.49, and 2.79 ± 0.50 mm, for the TD-OCT, SS-OCT, and Pentacam, respectively (P < .001). Mean differences were similar for the TD-OCT versus SS-OCT and SS-OCT versus Pentacam (approximately 0.02 mm), and larger between the TD-OCT and Pentacam (approximately 0.05 mm). The results show that the TD-OCT and SS-OCT are interchangeable instruments for ATA distance measurement but the Pentacam is not with either of the two OCT devices. A clinical criterion should assess whether these three devices could be used interchangeably for AQD measurement. [J Refract Surg. 2021;37(2):133-140.].