Optical Coherence Tomographic Angiography of the Temporal Retina in Glaucoma

Abstract

Purpose : To detect temporal retina perfusion defects in glaucoma using OCT angiography (OCTA).

Methods : AngioVue 6x6-mm OCTA scans were performed on the macula (centered on fovea) and temporal retina (5.7 mm temporal to foveal center) in one eye of each participant. Flow signal was calculated using the split-spectrum amplitude-decorrelation angiography algorithm. The superficial vascular complex (SVC) vessel density (VD) was measured using a custom software with automatic shadow removal and reflectance compensation. The temporal and macular retina images were combined using an automated software with approximately 0.3mm overlap. The macular and temporal retinal SVC VD, ganglion cell complex (GCC) thickness, and visual field (VF) were measured.

Results : Forty glaucoma participants (20 perimetric and 20 pre-perimetric) and 24 age-matched normal participants were included. The VF parameters (Table 1) indicated the glaucoma patients ranged from early to severe, with the average having early defects. The overall mean SVC VD and GCC thickness was significantly lower in the glaucoma group compared to control both in macular and temporal regions (Table 1). The or-logic combination of overall average, superior hemisphere and inferior hemisphere SVC VD demonstrated AROC 0.785, 0.873 and 0.858 for temporal, macular and combination of two scans (Figure 1). The corresponding sensitivity at 95% specificity was 50%, 62.5% and 60% respectively. The or-logic combination of overall average, superior hemisphere and inferior hemisphere GCC thickness demonstrated AROC 0.822, 0.884 and 0.839 for temporal, macular and combination of two scans. The corresponding sensitivity at 95% specificity was 62.5%, 70% and 57.5% respectively. There is no significant difference between AROCs of SVC VD and AROCs of GCC thickness (all P>0.05). Among the glaucoma participants, the macular and combined temporal and macular retina overall average SVC VD values were significantly correlated with the corresponding VF sensitivity (Pearson r=0.573, P<0.001; r=0.52, P=0.001, respectively), but the overall temporal retinal SVC VD was not significantly correlated with the corresponding VF sensitivity (r=0.311, P=0.051).

Conclusions : The OCTA measured temporal retina SVC VD significantly decreased in glaucomatous eyes. However, adding the temporal retina OCTA scans did not improve the diagnostic accuracy to macular scan for glaucoma.

This is a 2020 ARVO Annual Meeting abstract.