Abstract
Purpose :
To explore the association between pachydrusen location and regional variations in choroidal structure and choriocapillaris (CC) blood flow.
Methods :
7 eyes with pachydrusen from 7 patients with pachychoroid disease lacking subretinal fluid were identified based upon previously described color fundus photography and optical coherence tomography (OCT) findings. The University of Washington CC flow deficit quantification algorithm was applied to 6x6 mm en face Swept-Source OCT angiography volumes acquired on the PLEX Elite 9000 (Carl Zeiss Meditec, Dublin, CA) in order to analyze choroidal structure and to automatically segment and quantify choriocapillaris flow deficits within a 20um thick slab 10um under the retinal pigment epithelium. The en face CC slabs underwent structural compensation and projection artifact removal prior to quantification. Flow deficits smaller than 452 um*um (24 um diameter) were removed. Structural OCT B-scans and en face choroidal slabs were used to assess inner choroidal thickness (full choroidal thickness – Haller’s layer thickness) and the location of pachyvessels.
Results :
Choriocapillaris flow was reduced in areas occupied by pachydrusen compared to areas lacking these lesions as demonstrated by flow deficit area and flow density maps. Inner choroidal thickness was significantly decreased in areas with pachydrusen (-80.14 mm, Z=-2.36, P=0.018) which were characteristically found overlying pachyvessels. This finding was supported by the strong negative correlation between inner choroidal thickness and pachyvessel area (r=-0.87, P<0.001).
Conclusions :
In eyes with pachychoroid disease, pachydrusen are found overlying pachyvessels in areas where inner choroid attenuation is associated with reduced CC blood flow.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.