The effects of sevoflurane and ketamine on intraocular pressure in children during examination under anesthesia

PURPOSE: We studied the effects on intraocular pressure (IOP) of anesthesia administered during examination under anesthesia (EUA) in children. DESIGN: Randomized clinical trial. METHODS: This randomized trial compared IOP after inhaled sevoflurane gas to that after intramuscular ketamine hydrochloride in children undergoing EUA. IOP was measured in 30 eyes with TonoPen XL (Mentor, Inc, Norwell, Massachusetts, USA) as soon as possible after anesthesia induction (T1) and two, four, six, and eight minutes thereafter. At the same times, we recorded systolic and diastolic blood pressure (SBP, DBP) and heart rate (HR). RESULTS: Compared with the mean IOP at T1, IOP in the sevoflurane group was significantly lower for all measurements from two to eight minutes thereafter (mean decrease in IOP: two minutes = 12%, four minutes = 19%; six minutes = 19%; eight minutes = 17%, all P < or = .01). In the ketamine group, mean IOP was not significantly changed from T1 through six minutes, whereas at eight minutes, it was 7% lower (P = .03). SBP and DBP were significantly lower for sevoflurane than for ketamine at all measurements from two minutes onward, and HR was lower for sevoflurane than for ketamine at two, four, and six minutes. CONCLUSIONS: IOP measured after ketamine sedation is more likely to represent the awake IOP than that after sevoflurane anesthesia. Changes in SBP, DBP, and HR caused by sevoflurane suggest that hemodynamic alterations may underlie its effects on IOP.