Comparison of the visualization and measurement of choroidal neovascularization using fluorescein angiography and two spectral domain optical coherence tomography angiography devices

Abstract

Purpose : Detection of choroidal neovascularization (CNV) has important diagnostic and prognostic implications in the management of various retinal diseases. Advances in OCTA technology allow non-invasive analysis of the retinal vasculature, with the potential to replace traditional invasive angiography. Our study aims to compare the sensitivity of detection and measured size of CNV between fluorescein angiography (FA) and two spectral domain optical coherence tomography angiography (OCTA) devices, the Optovue RTVue XR Avanti and the Heidelberg Spectralis OCTA module.

Methods : Twelve patients with CNV lesions were imaged consecutively using FA, OCT and on both OCTA devices on the same day. Corresponding 3 × 3 mm and 6 × 6 mm OCTA scans centered at the CNV lesion were obtained. Two independent masked readers evaluated the FA and OCTA images for CNV characteristics and its area measurements.

Results : All instances of CNV were identified on FA with assistance of the structural OCT, whilst either OCTA platform identified 11/12 of lesions, with a sensitivity of 92%. 9 eyes and 2 eyes were identified as type 1 and type 2 NV, respectively. The sensitivity of FA data alone was 83.3%. Mean overall CNV area (CNVA) was 8.6 ± 8.2 mm² on FA, 4.1 ± 2.5 mm² on Optovue OCTA, and 4.0 ± 2.4 mm² on Heidelberg OCTA. There were no significant differences in CNVA between the 2 OCTA devices (p=0.94) and the measurements demonstrated strong correlation (r=0.99). Though not statistically significant (p=0.13) given our small sample size, CNVA was on average 2.1 times larger on FA compared with either OCTA reading. Bland-Altman plot revealed a mean difference (bias) between OCTA and FA CNVA of 4.5 ± 6.5 mm².

Conclusions : Sensitivity of detection of CNV was 92% on both the Optovue and Heidelberg OCTA platforms. FA with structural OCT identified all lesions, but was only 83.3% sensitive with FA data alone. There were no statistically significant differences in CNVA between the Optovue and Heidelberg OCTA, and the corresponding measurements demonstrated strong correlation. CNVA was on average 2.1 times larger on FA than OCTA. Our study suggests that OCTA may be a viable non-invasive alternative to FA in the detection of CNV. Larger studies are needed to fully elucidate this, which can be of substantial clinical relevance.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.