Optical coherence tomography and visual evoked potentials in evaluation of optic chiasm decompression

Pavel Poczos,Tomáš Česák,Petr Čelakovský,Filip Gabalec,Jaroslav Adamkov,Jan Kremláček,Jiří Soukup,Naďa Jirásková,Markéta Macháčková

doi:10.1038/s41598-022-06097-8

Pavel Poczos, Tomáš Česák + Show 7 more

Open Access

https://doi.org/10.1038/s41598-022-06097-8

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Abstract

Chiasmal compression is a known cause of visual impairment, often leading to surgical decompression of the optic chiasm (OC). A prospective study was held at University Hospital in Hradec Králové to explore sensitivity of optical coherence tomography (OCT) and visual evoked potentials (VEPs) to OC compression and eventual changes after a decompression. 16 patients with OC compression, caused by different sellar pathologies, were included. The main inclusion criterion was the indication for decompressive surgery. Visual acuity (VA), visual field (VF), retinal nerve fibre layer (RNFL) and ganglion cell layer (GCL) thickness, and peak time and amplitude of pattern-reversal (P-VEPs) and motion-onset VEPs (M-VEPs) were measured pre- and postoperatively. The degree of OC compression was determined on preoperative magnetic resonance imaging. For M-VEPs, there was a significant postoperative shortening of the peak time (N160) (p < 0.05). P100 peak time and its amplitude did not change significantly. The M-VEPs N160 amplitude showed a close relationship to the VF improvement. Thinner preoperative RNFL does not present a statistically important limiting factor for better functional outcomes. The morphological status of the sellar region should be taken into consideration when one evaluates the chiasmal syndrome. M-VEPs enable detection of functional changes in the visual pathway better than P-VEPs.

Highlights

Chiasmal compression is a known cause of visual impairment, often leading to surgical decompression of the optic chiasm (OC)
The results clearly indicate a tendency of continuous improvement in Visual acuity (VA) and visual field (VF) in the postoperative period
Our results show that the mean thickness of the retinal nerve fibre layer (RNFL) (Fig. 1b) as well as of the ganglion cell layer (GCL) (Fig. 2b) was statistically significantly greater in grade 0–1 than in grade 2–4

Summary

Introduction

Chiasmal compression is a known cause of visual impairment, often leading to surgical decompression of the optic chiasm (OC). Visual acuity (VA), visual field (VF), retinal nerve fibre layer (RNFL) and ganglion cell layer (GCL) thickness, and peak time and amplitude of pattern-reversal (P-VEPs) and motion-onset VEPs (M-VEPs) were measured pre- and postoperatively. M-VEPs enable detection of functional changes in the visual pathway better than P-VEPs. Decompression of the optic chiasm (OC) with subsequent improvement of visual complaints represents one of the main goals of neurosurgical procedures in the treatment of pathologies of the sellar r egion[1,2,3,4,5]. Standard automatic perimetry results do not always offer enough information for a surgery indication[10,11,12] Another tool has been sought to evaluate the functional condition of the visual pathway. The receptive fields of the retina for magnocellular inputs are located mainly in the extrafoveal part of the retina

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