Peripapillary Microvascularization Analysis Using Swept-Source Optical Coherence Tomography Angiography in Optic Chiasmal Compression.

Inès Ben Ghezala,François Borsotti,Cyril Meillon,Alain M Bron,Julie Blanc,Déa Haddad,Rachid Madkouri,Catherine Creuzot-Garcher

doi:10.1155/2021/5531959

Abstract

Purpose To evaluate the vessel density (VD) of the radial peripapillary capillary (RPC) network using swept-source optical coherence tomography angiography (SS-OCTA) “en face” images of eyes with chiasmal compression caused by brain tumors before and after decompressive surgery compared with healthy controls. Methods A cross-sectional study was conducted in 12 patients with chiasmal compression confirmed by neuroimaging. Sixteen healthy participants were also included. All patients with chiasmal compression underwent a neuro-ophthalmological examination one week before and 6 months after brain surgery, including static automated perimetry as well as measurement of the thickness of the retinal nerve fiber layer (RNFL) and the ganglion cell complex (GCC) with spectral-domain optical coherence tomography (SD-OCT). Based on this neuro-ophthalmological examination, the presence of an optic neuropathy (ON) was evaluated. Peripapillary VD was obtained in four sectors on a 6 × 6 mm SS-OCTA image using the Cirrus Plex Elite 9000. Results Baseline average VD was significantly lower in patients with chiasmal compression and ON than in controls (median: 55.62; interquartile range (IQR): 2.96 vs. 58.53; IQR: 2.02; p=0.003). This decrease was also found in the temporal, superior, and nasal sectors. Average postoperative VD was decreased in patients with chiasmal compression compared with average preoperative VD (median: 56.16; IQR: 4.07 vs. 57.48; IQR: 3.83; p=0.004). Preoperative VD was significantly correlated with RNFL, GCC thickness, and visual field defects. Conclusions The VD of the RPC network was decreased in chiasmal compressive ON, and it was further decreased at 6 months after decompressive surgery.

Highlights

Various brain tumors can cause chiasmal compression: adenomas of the pituitary gland, craniopharyngiomas, pinealomas, Rathke cleft cysts, and meningiomas
Chiasmal compression predominantly affects the crossed nerve fibers associated with the nasal hemiretina, leaving uncrossed nerve fibers relatively well-preserved [1, 2]. is compression increases the risk of damage to the axons of retinal ganglion cells, leading to deterioration of visual function, of the visual field (VF)
Two patients with chiasmal compression were excluded owing to coexisting diabetes and multiple sclerosis

Summary

Introduction

Various brain tumors can cause chiasmal compression: adenomas of the pituitary gland, craniopharyngiomas, pinealomas, Rathke cleft cysts, and meningiomas. Is compression increases the risk of damage to the axons of retinal ganglion cells, leading to deterioration of visual function, of the visual field (VF). It is traditionally diagnosed by the presence of a characteristic bitemporal hemianopsia on the VF [3]. Previous studies have documented that peripapillary and macular retinal thickness, RNFL, ganglion cell layer, and inner plexiform layer, were correlated with the location and the severity of the VF defects [4,5,6,7]. Nasal retinal thickness is especially strongly correlated with temporal VF [7]

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Conclusion