Optic nerve changes detected with ocular ultrasonography during epiduroscopy: a narrative review

Background: Epiduroscopy has emerged as a transformative minimally invasive tool for the diagnosis and treatment of spinal diseases. However, the infusion of irrigation fluids and manipulation of epidural structures during the procedure may unintentionally alter intracranial dynamics, leading to transient increases in intracranial pressure (ICP). Objectives: This narrative review aims to evaluate the relationship between epiduroscopy and changes in optic nerve morphology, advocating for the use of ocular ultrasonography (OUS) as a non-invasive monitoring tool. Methods: We consolidated contemporary literature regarding the pathophysiological foundations of optic nerve sheath diameter (ONSD) changes and the clinical utility of OUS during spinal interventions. Results: Ocular ultrasonography allows for real-time, bedside measurement of ONSD, which serves as a reliable indirect indicator of ICP. The optic nerve sheath, being continuous with the subarachnoid space, dilates in response to pressure surges transmitted from the epidural compartment during fluid irrigation. Studies have shown that dynamic monitoring of ONSD can guide intraoperative decisions, such as adjusting irrigation pressure or volume. Conclusion and future directions: While OUS is currently subject to operator dependency, it provides a valuable non-invasive adjunct for identifying potential increases in ICP during epiduroscopy. Integrating ONSD evaluations into monitoring protocols may support clinical decision-making and enhance procedural vigilance. Future large-scale prospective studies are needed to establish standardized intervention thresholds and improve long-term patient outcomes.