Technical Optimization and Clinical Utility of Intraoperative Visual Evoked Potentials During Transsphenoidal Surgery for Pituitary Adenomas

PURPOSE: To evaluate clinical and technical factors associated with successful intraoperative visual evoked potential (VEP) acquisition during transsphenoidal surgery (TSS) for pituitary adenomas, and to assess the prognostic value of intraoperative VEP changes on postoperative visual outcomes. METHODS: A total of 163 patients who underwent primary TSS with intraoperative VEP monitoring between January 2016 and December 2024 were analyzed. Baseline signal acquisition and visual outcomes at 1 month postsurgery were assessed in relation to tumor characteristics, preoperative visual function, stimulation modality (goggle-mounted vs. high-luminance light-emitting diode [LED]), and use of concurrent electroretinography (ERG). Multivariable logistic regression identified independent predictors of successful VEP acquisition. RESULTS: Visual evoked potentials were successfully obtained in 78.8% of eyes. Higher acquisition rates were observed in patients with tumors <10 mm, intrasellar location, and preserved visual function (all P < 0.05). The high-luminance LED system with ERG significantly improved signal acquisition (89.0 vs. 64.3%, P < 0.001). Among patients monitored with this optimized approach, irreversible intraoperative VEP loss strongly predicted postoperative visual deterioration (70.8 vs. 8.2%, P < 0.001). No such association was observed with the goggle-based system. CONCLUSIONS: Technically optimized VEP monitoring using high-luminance stimulation and ERG validation improves signal reliability and prognostic value for visual outcomes in pituitary surgery. Broader adoption may be supported by standardized protocols and careful patient selection.