This is a pilot study to assess the clinical safety and efficacy of recording real-time flash visual evoked potentials (VEPs) using the SightSaver TM Visual Stimulator mask during prone spine surgery. A prospective, observational pilot study. Twenty patients presenting for spine surgery (microdiscectomy, 1–2 level lumbar fusion, or > 2 levels thoraco-lumbar fusion) were enrolled. The SightSaver™ Visual Stimulator™ was used to elicit VEPs throughout surgery. Somatosensory evoked potentials (SSEPs) were simultaneously recorded. All patients underwent general anesthesia with a combination of intravenous and inhaled agents. The presence, absence, and changes in VEP were qualitatively analyzed. Reproducible VEPs were elicited in 18/20 patients (36/40 eyes). VEPs were exquisitely sensitive to changes in anesthesia and decayed with rising MAC of isoflurane and/or N2O. Decrements in VEPs were observed without concomitant changes in SSEPs. The mask was simple to apply and use and was not associated with adverse effects. The SightSaver™ mask represents an emerging technology for monitoring developing visual insults during surgery. The definitive applications remain to be determined, but likely include use in select patients and/or surgeries. Here, we have validated the device as safe and effective, and show that VEPs can be recorded in real time under general anesthesia in the prone position. Future studies should be directed towards understanding the ideal anesthetic regimen to facilitate stable VEP recording during prone spine surgery.
Flash visual evoked potential Visual evoked potential Visual loss spine surgery Perioperative visual loss
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Compliance with ethical standards
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
Informed consent was obtained from all individual participants included in the study.
Lee LA, Roth S, Posner KL, et al. The American Society of Anesthesiologists Postoperative Visual Loss Registry: analysis of 93 spine surgery cases with postoperative visual loss. Anesthesiology 2006;105(4):652–9.CrossRefPubMedGoogle Scholar
Chung S-B, Park C-W, Seo D-W, et al. Intraoperative visual evoked potential has no association with postoperative visual outcomes in transsphenoidal surgery. Acta Neurochir. 2012;154:1505–10.CrossRefPubMedGoogle Scholar
Uribe AA, Mendel E, peters ZA, Shneker BF, et al. Comparison of visual evoked potential monitoring during spine surgeries under total intravenous anesthesia versus balanced general anesthesia. Clin Neurophysiol. 2017;128(10):2006–13.CrossRefPubMedGoogle Scholar
Odom JV, Bach M, Brigell M, et al. ISCEV standard for clinical visual evoked potentials: (2016 update). Doc Ophthalmol. 2016;133(1):1–9.CrossRefPubMedGoogle Scholar
Harris PA, Taylor R, Thielke R, Payne J, et al. Research electronic data capture (REDCap)—a metadata-driven methodology and workflow process for providing translational research informatics support. J Biomed Inform. 2009;42(2):377–81.CrossRefPubMedGoogle Scholar
Banoub M, Tetzlaff JE, Schubert A. Pharmacologic and physiologic influences affecting sensory evoked potentials: implications for perioperative monitoring. Anesthesiology 2003;99(3):716–37.CrossRefPubMedGoogle Scholar
Uribe AA, Baig MN, Puente EG, et al. Current intraoperative devices to reduce visual loss after spine surgery. Neurosurg Focus. 2012;33(2):E14.CrossRefPubMedGoogle Scholar
Creel D. Visually evoked potentials. In: Kolb H, Fernandez E, Nelson R, editors. Webvision: the organization of the retina and visual system. Salt Lake City: University of Utah Health Sciences Center; 2015.Google Scholar
Van Der Marel EH, Dagnelie G, Spekreijse H. Subdurally recorded pattern and luminance EPs in the alert rhesus monkey. Electroencephalogr Clin Neurophysiol. 1984;57:354–68.CrossRefPubMedGoogle Scholar
Kraut MA, Arezzo JC, Vaughan JG. Intracortical generators of the flash VEP in monkeys. Electroencephalogr Clin Neurophysiol. 1985;62:300–12.CrossRefPubMedGoogle Scholar
Ducati A, Fava E, Motti EDF. Neuronal generators of the visual evoked potentials: intracerebral recording in awake humans. Electroencephalogr Clin Neurophysiol. 1988;71:89–99.CrossRefPubMedGoogle Scholar
Pawela CP, Hudetz AG, Ward BD, et al. Modeling of region-specific fMRI BOLD neurovascular response functions in rat brain reveals residual differences that correlate with the differences in regional evoked potentials. Neuroimage 2008;41(2):525–34.CrossRefPubMedPubMedCentralGoogle Scholar
Kumar A, Bhattacharya A, Makhija N. Evoked potential monitoring in anaesthesia and analgesia. Anaesthesia 2000;55(3):225–41.CrossRefPubMedGoogle Scholar
Goto T, Tanaka Y, Kodama K, et al. Loss of visual evoked potential following temporary occlusion of the superior hypophyseal artery during aneurysm clip placement surgery. Case report. J Neurosurg. 2007;107(4):865–7.CrossRefPubMedGoogle Scholar
Curatolo JM, Macdonnell RA, Berkovic SF, et al. Intraoperative monitoring to preserve central visual fields during occipital corticectomy for epilepsy. J Clin Neurosci. 2000;7(3):234–7.CrossRefPubMedGoogle Scholar
San-Juan, D., de Dios Del Castillo Calcaneo, J., Villegas, T.G. et al. Visual intraoperative monitoring of occipital arteriovenous malformation surgery. Clin Neurol Neurosurg. 2011;113(8):680–2.CrossRefPubMedGoogle Scholar