The effects of prone position on optic nerve sheath diameter and intraocular pressure in elective lumbar disc surgery.

BACKGROUND: The objective of this study was to determine the efficacy of intraocular pressure (IOP) measurements in diagnosing elevated increased intracranial pressure (ICP) by examining the correlation between optic nerve sheath diameter (ONSD) and IOP in the prone position. METHODS: This prospective observational study included patients in the American Society of Anesthesiologists (ASA) 1–2 risk group, aged 18–65 years, who were scheduled for elective surgery. ONSD and IOP measurements were performed with ultrasound and Tonopen XL. RESULTS: Data from 59 patients were analysed. Spearman’s correlation analysis was used to determine the relationship between quantitative data. Significance was considered at p < 0.05. ONSD and IOP measurements were significantly higher in the prone position (p = 0.001). However, no correlation was found between ONSD and IOP measurements. CONCLUSION: We found that ONSD and IOP measurements increased in the prone position, but these two measurements were not correlated. ONSD can be used in the diagnosis and follow-up of elevated ICP. Since there are many factors affecting IOP values, we concluded that IOP would not be effective in the diagnosis and follow-up of ICP.