Abstract
Purpose :
This prospective, observational case series of patients with primary open angle glaucoma (POAG) and non-glaucomatous optic neuropathy (NGON) characterized qualitative anatomic correlations between optical coherence tomography angiography (OCTA) macular perfusion defects and OCT ganglion cell analysis (GCA) thinning.
Methods :
11 eyes of 7 patients with POAG and 6 eyes from 4 patients with NGON underwent 3x3mm and 6x6mm macular scans by a spectral-domain OCTA prototype device and GCA (ganglion cell layer + inner plexiform layer) macula scans by Cirrus SD-OCT (both Carl Zeiss Meditec, Dublin, CA, USA). Areas of impaired perfusion on OCTA were compared to areas of GCA thinning on OCT.
Results :
All images used were good quality scans. Mean age of POAG patients was 66 years, and mean GCA thickness was 71 μm. 4 eyes had superior thinning, 1 had inferior thinning, 1 had superior and inferior thinning, 2 had global thinning, and 3 had non-specific defects on GCA thickness map. OCTA macular microvasculature defects were correlated with GCA thinning in 3 POAG eyes that had the most severe GCA thinning (1 had focal and 2 had global defects). (Fig 1)
Mean age of NGON patients was 53 years, and mean GCA thickness was 61.5 μm. 3 eyes had focal GCA thinning, and 3 had global GCA thinning. Qualitative anatomic correlations between OCTA macular microvasculature defects and GCA thinning were correlated in the 3 NGON eyes with focal defects - 2 of which had ischemic ON and 1 with inflammatory ON. (Fig 2)
Conclusions :
OCTA macular perfusion defects showed visually apparent anatomic correlations with GCA thinning in the POAG eyes with advanced GCA thinning. In NGON, these correlations were seen in eyes with focal defects, which included both of the only two ischemic ON cases. OCTA perfusion defects are most apparent in eyes with severely thinned GCA and focal GCA thinning. The correlations were more pronounced in NGON compared to POAG. Larger quantitative studies are needed to determine how well OCTA microvasculature defects correlate with GCA thinning.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.