Comparative features on same-day optical coherence tomography angiography (OCTA) and fluorescein angiography (FA) in diabetic macular edema (DME)

Abstract

Purpose : To compare visualization of microaneurysms (MA) and the foveal avascular zone (FAZ) area using OCTA and FA in patients with DME.

Methods : Patients with DME were prospectively recruited for same-day imaging on spectral-domain OCTA (Avanti; Optovue) and FA (HRA; Heidelberg Engineering). OCT angiograms were automatically segmented into superficial (OCTAs) and deep (OCTAd) capillary plexuses, and early-phase FA was used. A quantitative analysis was performed comparing the number of visible MAs and the FAZ area between the two imaging modalities using Image J. MA counts and FAZ area were performed by two masked readers, and intraclass correlation coefficient (ICC) was calculated. A paired Student T-test was used to compare the mean FAZ area and the mean MA count between FA and the two OCTA vascular plexuses.

Results : Nineteen eyes from 10 patients were included in this study. A strong ICC was established for MA count and FAZ area between the two readers (Range 0.91–0.99). The mean MA count on the FA, OCTAs and OCTAd were 18.4 ± 13.5, 12.5 ± 9.8, 24.9 ± 12.2, respectively. There was a statistically significant difference between FA vs. OCTAd (p=0.03), which was not found between FA vs. OCTAs (p=0.09). The OCTAd identified a greater number of MAs compared to OCTAs (p<0.001). The mean FAZ area measured on the FA, OCTAs and OCTAd were 0.39 ± 0.17mm², 0.28 ± 0.23mm², and 0.39 ± 0.23mm², respectively. There was no statistically significant difference between FA vs. OCTAs (p=0.08), and FA vs. OCTAd (p=0.94). However, the OCTAd demarcated a greater FAZ area compared to the OCTAs (p=0.005).

Conclusions : OCTA is a noninvasive, dye-less, fast acquisition imaging technique that enables visualization of MA and the FAZ as an alternative to traditional dye-based.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.

 

Multimodal imaging of patient with DME. (A) FA with corresponding OCTA 3x3mm area centered in the fovea. (B) FA 3x3mm area showing FAZ area outlined in blue (0.539 mm²), and 21 MA circled in blue. (C) OCTA of superficial capillary plexus showing FAZ area outlined in red (0.794mm²), and 25 MA circled in red. (D) OCTA of deep capillary plexus showing FAZ area outlined in yellow (0.943mm²), and 44 MA circled in yellow.