Comparison of AO-SLO and OCT angiography in imaging of the hierarchical structure of retinal vessels

Abstract

Purpose : Retinal vascular network shows layered structure in ganglion cell layer and inner plexiform layer of retina. The layered structure of vascular network cannot be imaged using the existing examination such as fluorescein angiography. The purpose of this study was to evaluate the usefulness of adaptive optics scanning laser ophthalmoscopy (AO-SLO) and OCT angiography in imaging of the layered retinal vascular networks.

Methods : This study included seven healthy eyes of seven cases. 2.8mm and 3.0mm square area on the fovea were imaged using AO-SLO and OCT angiography, respectively. The vascular area of superficial or deep layer as well as FAZ area was measured using Image J.

Results : AO-SLO imaging showed the superficial layer vessel area, deep layer vessel area and FAZ area are 1.2±0.2mm², 1.4±0.3mm² and 0.4±0.1mm², respectively. In These areas of OCT angiography were 2.1±0.4mm², 3.0±0.3mm² and 0.3±0.1mm², respectively. The superficial as well as deep vessel area in OCT angiography was significantly greater than the area in AO-SLO (p=2x10^-5, 3x10^-7). The significant difference between the two imaging instruments could not be observed in FAZ area (p=0.3).

Conclusions : AO-SLO as well as OCT angiography could be useful to image the layered structure of retinal vessel. However, the imaged layer could be different due to the difference of the imaging system as well as the imaging resolution.

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