Optical coherence tomography (OCT) angiography (OCTA) is a novel technology for imaging the retinal vasculature. The real-life applicability of OCTA was assessed in a busy outpatient eye clinic using the same hardware (Triton, TOPCON, Tokyo, Japan) but different software versions 1 year apart. The influence of various parameters on OCTA performance was assessed.
Materials and methods
Two groups of 100 patients with intravitreal injections for maculopathy were evaluated with OCTA. Demographic characteristics did not differ significantly. Group A was assessed in February 2016, group B in February 2017. Recording time, scan quality, visual acuity, patient age, diagnosis, and lens status were recorded for statistical evaluation.
The time taken for examination differed significantly between the two groups. In group A, average recording time was 44.7 s (standard deviation, SD, 26.9 s; range 10–103 s), in group B 17.1 s (SD 9.0 s, range 7–53 s; P = 0.001). Image quality was higher in group B (P = 0.03). In bivariate analysis, recording time, age, and visual acuity correlated with image quality. In univariate regression analysis, recording duration and visual acuity were associated with a higher risk of poor OCTA quality. In multivariate regression analysis, scan duration was the sole predictor of a higher risk for poor OCTA quality (group A: odds ratio, OR, 5.9; confidence interval, CI, 2.0–17.5; P = 0.001; group B: OR 3.9, CI 1.3–11.9, P = 0.01).
Advances in software-based artefact correction reduce recording time and improve SS-OCTA quality significantly. Although SS-OCTA is still more time consuming than conventional SS-OCT, current performance enables routine application even in a busy retina outpatient clinic. Further hardware and software improvements should focus on recording time.