Comparing the Effect of Laryngeal Mask Airway And Endotracheal Tube Insertion on Intraocular Pressure in Cataract Surgery

Background and purpose: The method of anesthesia affects intraocular pressure (IOP), especially general anesthesia which is sometimes administered with endotracheal tube (ETT) insertion. The aim of this research was to compare the effect of laryngeal mask airway (LMA) and ETT on intraocular pressure in cataract surgery. Materials and methods: In a single blind randomized clinical trial, 61 patients were divided into two groups: ETT group (n=36) and LMA group (n=25). Induction of anesthesia was with midazolam, fentanyl, lidocaine, propofol, and atracurium in both groups. IOP was measured by Schiotz tonometer 5 minutes before and after induction of anesthesia in both groups. Results: IOP was found to decrease in both groups, but the decrease was significantly higher in LMA group (P<0.05). Heart rate did not show any significant changes in the two groups (P>0.05) Blood pressure decreased in both LMA and ETT groups but was not different between the two groups.  Conclusion: According to current study, IOP decreased after induction of general anesthesia and the decrease was higher in LMA group. Therefore, LMA can be used as an alternative in general surgery to reduce IOP.