Abstract
Purpose :
To compare indocyanine green angiography (ICGA) and 4 different optical coherence tomography angiography (OCTA) devices and to test their reproducibility in the evaluation of choroidal neovascularization (CNV).
Methods :
Observational case series of Type 1 and Type 2 CNV presenting at the Eye Clinic, Department of Biomedical and Clinical Sciences, Luigi Sacco Hospital, University of Milan imaged with ICGA and 4 different OCTA: prototype PlexElite (Carl Zeiss Meditec), prototype Spectralis OCTA (Spectralis; Heidelberg Engineering, Heidelberg, Germany), Optovue RTVue XR Avanti (Optovue, Inc, Fremont, California, USA) and AngioPlex (Cirrus 5000 HD-OCT; Carl Zeiss Meditec, Inc, Dublin, California, USA). OCTA examinations were performed using a 3 x 3 mm or 6 x 6 mm volume scan pattern in order to capture the full lesion. The mean area of CNV, vessel density (VD) and fractal dimension (FD) were compared between devices.
Results :
A total of 17 eyes of 17 patients with CNV were enrolled in this study. The mean age was 74.7 ± 13.7 years with 13 male and 4 female patients. The mean BCVA was 20/70 (range, 20/200-20/20) with 13 eyes treatment naïve and 4 eyes had received prior intravitreal therapy with VEGF inhibitors. Nine eyes presented a type 1 CNV and 8 eyes a type 2 CNV. The CNV area was significantly larger in ICGA then OCTA devices. Moreover, the 4 different instruments produced measurements with different mean values of CNV area, VD and FD. Bland-Altman analysis revealed that the limits of agreement for the comparisons were not acceptable.
Conclusions :
CNV area is larger when imaged with standard ICGA compared to different OCTA devices with different algorithm, wavelength and scan pattern. The differences between several OCTA devices in the evaluation of quantitative parameters of CNV, as CNV area, VD and FD, suggests the necessity to standardize OCTA measurements for research and clinical practice
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.