Microvascular alterations detected by optical coherence tomography angiography in non‐arteritic anterior ischaemic optic neuropathy: a meta‐analysis

Abstract

Purpose: To evaluate microvascular alterations with optical coherence tomography angiography (OCTA) in eyes with non-arteritic anterior ischaemic optic neuropathy (NAION) and the unaffected fellow eyes. Design: Systematic review and meta-analysis. Methods: A comprehensive literature search was conducted in the PubMed and Embase databases through 6 September 2020, to identify the studies on NAION and the unaffected fellow eyes using OCTA. Eligible studies and data of interest were extracted and analysed by RevMan Software v. 5.4 and Stata Software v.14.0. The weighted mean differences and 95% confidence intervals were used to assess the strength of the association. Results: Seventeen observational comparative studies, including 379 eyes with NAION, 175 unaffected contralateral eyes and 470 eyes of healthy controls, were identified. Compared to those of the healthy controls, the perfusion density (PD) of radial peripapillary capillary (RPC) and peripapillary superficial capillary plexus (ppSCP) of NAION were significantly lower. Moreover, the PD of the macular SCP (mSCP) in NAION was significantly reduced in the whole image, superior quadrant and temporal quadrant, while the macular deep capillary plexus (mDCP) showed a decreasing PD only within the whole image. Between unaffected fellow eyes and healthy eyes, significant differences of PD were demonstrated in the whole image and some peripapillary regions of the RPC and ppSCP. Conclusion: Our results suggested that compared to those of healthy controls, the eyes affected by NAION and unaffected fellow eyes demonstrated significant microvascular impairments in different regions. Between acute and non-acute NAION, macular OCTA parameters showed different characteristic patterns.

Peripapillary and macular microvasculature features of non-arteritic anterior ischemic optic neuropathy

“…Our correlation matrices show that OCTA VAD and flux highly correlate in the superior sectors with the GCC sectoral OCT thickness. Of the limited OCTA studies that have analyzed the macular region, there is a lack of agreement in the characteristic pattern of regional changes in the microvasculature ( 43 , 48 – 51 ). For example, Liu et al ( 43 ) showed a lower SCP vessel density in the superior perifoveal region in NAION patients and Moon et al report that the SCP of nasal macular region is more affected and correlate significantly with a poor visual outcome ( 50 ).…”

Superficial capillary plexus vessel density/deep capillary plexus vessel density ratio in healthy eyes

“…Another study found that VD of the DCP (DVD) decreased in abnormal multifocal electroretinography patients using hydroxychloroquine for rheumatoid arthritis, but VD in the SCP (SVD) did not [6]. Meanwhile, Chou et al [7] reported a greater decrease in macular perfusion density of SCP than that of DCP in patients with non-arteritic anterior ischemic optic neuropathy. As such, the SCP and DCP can be differently affected by various conditions.…”