title: Optical coherence tomography angiography in acute non-arteritic anterior ischaemic optic neuropathy.
abstract: To characterise vascular changes in eyes with acute non-arteritic anterior ischaemic optic neuropathy (NAION), using optical coherence tomography angiography (OCT-A) imaging.
  
  
  
  This 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.
  
  
  
  The 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<0.001). The mean vascular flow density was also reduced in the peripapillary choroid layer of eyes with NAION (53.2±7.8%) compared with controls (69.5±3.0%) (p<0.001). In patients (3 eyes) with resolution of optic disc oedema, a repeated OCT-A analysis (at 4-22 weeks) of the full segment (including retina and choroid) revealed spontaneous improvement of the average total peripapillary flow density by 8.1±2.7%.
  
  
  
  Using OCT-A, we revealed a global and sectorial reduction of retinal and choroidal peripapillary flow densities at the acute stage of NAION, followed by partial subsequent spontaneous recovery. Further studies are needed to establish the potential value of OCT-A for evaluating NAION and other optic neuropathies.
authors.affiliation: Singapore National Eye Center, Singapore, Singapore.|Singapore Eye Research Institute, Singapore, Singapore.
authors.forename: Sourabh
authors.initials: S
authors.lastname: Sharma
authors.affiliation: Singapore National Eye Center, Singapore, Singapore.|Singapore Eye Research Institute, Singapore, Singapore.|Department of Ophthalmology and Visual Sciences, Duke-NUS Graduate Medical School, Singapore, Singapore.
authors.forename: Marcus
authors.initials: M
authors.lastname: Ang
authors.affiliation: Singapore Eye Research Institute, Singapore, Singapore.|Department of Ophthalmology and Visual Sciences, Duke-NUS Graduate Medical School, Singapore, Singapore.
authors.forename: Raymond P
authors.initials: RP
authors.lastname: Najjar
authors.affiliation: Department of Ophthalmology and Visual Sciences, Duke-NUS Graduate Medical School, Singapore, Singapore.
authors.forename: Chelvin
authors.initials: C
authors.lastname: Sng
authors.affiliation: Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, New Territories, Hong Kong.
authors.forename: Carol Y
authors.initials: CY
authors.lastname: Cheung
authors.affiliation: Singapore Eye Research Institute, Singapore, Singapore.
authors.forename: Annadata V
authors.initials: AV
authors.lastname: Rukmini
authors.affiliation: Singapore Eye Research Institute, Singapore, Singapore.|Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore.|Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.|Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
authors.forename: Leopold
authors.initials: L
authors.lastname: Schmetterer
authors.affiliation: Singapore National Eye Center, Singapore, Singapore.|Singapore Eye Research Institute, Singapore, Singapore.|Neuroscience and Behavioral Disorders, Duke-NUS, Singapore, Singapore.
authors.forename: Dan
authors.initials: D
authors.lastname: Milea
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D000072226:Computed Tomography Angiography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D018917:Optic Neuropathy, Ischemic / Q000000981:diagnostic imaging*; D010865:Pilot Projects; D011446:Prospective Studies; D041623:Tomography, Optical Coherence / Q000379:methods
keywords: Optic Nerve