Quantification of peripapillary vessel density in non-arteritic anterior ischemic optic neuropathy patients with optical coherence tomography angiography

Abstract

Background: Quantitative assessments based on optical coherence tomographic angiography (OCTA) may have potential promising value in the early detection of non-arteritic anterior ischemic optic neuropathy (NA-AION), but there is limited information on the ability of OCTA to distinguish eyes with NA-AION. This study was conducted to evaluate the ability of measurements of peripapillary perfusion using OCTA to distinguish healthy eyes from eyes with NA-AION. Methods: In this retrospective case-control study, newly diagnosed NA-AION patients and healthy controls matched at a ratio of 1:3 by gender and age (±5 years) were enrolled from 1 September 2020 to 30 June 2021. Peripapillary vessel density (pVD) was examined based on the area of vessels by means of a 4.5 mm OCTA scan. In addition, peripapillary retinal nerve fiber layer (pRNFL) thickness was obtained from structural optical coherence tomography (OCT), as was the area under the receiver operating characteristic (ROC) curve (AUC). Results: A total of 29 eyes from 28 cases with NA-AION and 99 healthy eyes from 68 participants were imaged. All participants were Chinese. The NA-AION group showed a significant reduction of the pVD (P<0.001), while all subregions of pRNFL thickness were prominent in all 8 quadrants (P>0.05). The pVD of the optic disc in the superior temporal (ST) region showed better diagnostic accuracy (AUC =0.86) in discriminating the NA-AION group from healthy controls. After adjusting for confounders, ST was independently associated with the presence of NA-AION [odds ratio (OR) =0.971, 95% confidence interval (CI): 0.943–0.990, P=0.048]. Conclusions: Decreased pVD was detected by non-invasive measurements of OCTA in the eyes of NA-AION patients. This finding may reveal an association between the ST region and the presence of NA-AION. The pVD may have potential diagnostic ability and may serve as an additional biomarker in the management of the disease.