Optical coherence tomography angiography in acute non-arteritic anterior ischaemic optic neuropathy

PurposeTo characterise vascular changes in eyes with acute non-arteritic anterior ischaemic optic neuropathy (NAION), using optical coherence tomography angiography (OCT-A) imaging.MethodsThis hospital-based observational case-control study included included five patients with acute NAION (6 eyes), within 7 days after onset of symptoms and 19 age-matched healthy controls (19 eyes). OCT-A (RTVue XR 100; Optovue, Fremont, California, USA), covering a 4.5×4.5 mm scan area, was used to evaluate peripapillary blood flow in cases and controls. The flow densities at the retinal and choroidal level were measured using the split-spectrum amplitude-decorrelation angiography algorithm.ResultsThe mean age of the NAION and normal subjects was 69 (61–82) and 68 (58–82) years, respectively (p=0.3). At the acute stage, OCT-A disclosed global reduction of the mean peripapillary flow density in eyes with NAION (53.5±3.7%) compared with normal eyes (64.3±2.4%) (p