Comparison of Propofol and Isoflurane Effects on Intraocular Pressure among Patients Undergoing Lumbar Disc Surgery

Abstract

Purpose: Blindness is a catastrophic complication of surgeries performed in prone position which occurs mainly due to hemodynamic alterations and the relevant effects on optic nerve perfusion. In this study, we compared the effects of Propofol and Isoflurane on intraocular pressure among patients undergoing lumbar disk surgery. Patients and Methods: In this randomized clinical trial, 60 patients who were candidates for lumbar disk surgery were randomly assigned into two groups: Propofol and Isoflurane groups. Intraocular Pressure was measured before and after induction of anesthesia in supine position, immediately after prone positioning of the patient and at the end of operation in prone position and also after turning the patients back to supine position. Mean arterial pressure, systolic and diastolic blood pressure and heart rates were also assessed. Result: The baseline Mean Intraocular Pressure among awake patients in supine position in Isoflurane and Propofol groups were 15.8 ± 3.1 and 18.2 ± 5.4 mmHg respectively. At the end of operation intraocular pressure in prone position in these two groups of patients changed to 18 ± 5.8 and 17.2 ± 4.9 mmHg respectively (P = 0.024) indicating a statistically significant difference in change. According to mixed analysis, mean arterial pressure, systolic blood pressure, diastolic blood pressure, end tidal Co2 and heart rate did not show statistically significant difference between the two groups (P < 0.05). Conclusion: Propofol better controls the intraocular pressure compared to Isoflurane in prone position among patients undergoing lumbar disk surgery with no significant difference in hemodynamic responses. Keywords: Intraocular pressure; prone; position; surgery; Propofol; Isoflurane.