Abstract
Purpose :
To examine the foveal vasculature in patients with age-related macular degeneration-associated geographic atrophy (GA) using optical coherence tomography (OCT) angiography, a non-invasive technique that allows segmented analysis of the retinal and choroidal vessels.
Methods :
Observational, cross-sectional study of 11 eyes from 7 patients with GA and 14 control eyes from 7 healthy individuals. 5 patients had bilateral GA and 4 of these were fovea-sparing. All patients with GA were examined by OCT angiography, en face OCT and blue-light fundus autofluorescence. Segmented OCT angiographic flow patterns were collected from the superficial retinal vascular layer and the choriocapillaris (CC). The foveal avascular zone (FAZ) was measured on superficial scans of control and GA eyes.
Results :
FAZ was significantly larger in GA eyes (0.47 mm2 [Symbol] 0.18 mm2) compared to control eyes (0.28 mm2 [Symbol] 0.08 mm2) (p<0.05). Absent or impaired CC flow was observed within all GA lesions and to a lesser degree beyond lesion margins. In patients with bilateral GA, a high degree of symmetry was observed in CC flow between fellow eyes. In 3 patients with foveal-sparing GA CC flow was detected within the foveal avascular zone.
Conclusions :
In this cohort of patients with GA, OCT angiography demonstrated enlarged FAZ and impaired CC flow. Moreover, CC flow in bilateral GA were symmetrical within and beyond lesion margins and within the foveal avascular zone. These findings may impact the design and outcome of interventional GA trials where contralateral eyes are used as controls.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.