Purpose To characterise vascular changes in eyes with acute non-arteritic anterior ischaemic optic neuropathy (NAION), using optical coherence tomography angiography (OCT-A) imaging.
Methods 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.
Results 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%.
Conclusions 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.
- Optic Nerve
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Contributors SS collected, cleaned and analysed the data, drafted and revised the paper. MA contributed to the design and initiation of the project, designed data collection tools, monitored data collection, drafted and revised the paper. RPN contributed to the analysis and interpretation of data and drafted and revised the paper. CS and CC contributed to the interpretation of data, drafted and revised the paper. AVR analysed and revised the draft paper. LS contributed to the analysis and interpretation of data for the work and revised the draft paper. DM contributed to the design and initiation of the project, designed data collection tools, monitored data collection, contributed to the interpretation of data, drafted and revised the paper.
Competing interests None declared.
Patient consent Obtained.
Ethics approval Sing Health Institutional Review Board.
Provenance and peer review Not commissioned; externally peer reviewed.