The Impact of Abdominal Insufflation on the Intraocular Pressure During Robot-Assisted Radical Prostatectomy

Increased intraocular pressure (IOP) during robot-assisted radical prostatectomy (RARP) is known to occur and may cause in rare cases anterior ischemic optic neuropathy. In this study, we evaluated the impact of abdominal insufflation pressures on IOP during RARP in a cohort of patients undergoing RARP.

Patients undergoing RARP were recruited for this Institutional Review Board-approved study from January 2019 to October 2022 at our Center. IOP was measured for both eyes using a Tonopen (Reichert, Buffalo, NY) at six time points (T1-T6); preoperatively, in the operating room in supine position under anesthesia without insufflation, at 30^ο Trendelenburg position (T position) without insufflation, at Trendelenburg position with abdominal insufflation at 10 mm Hg, 15 mm Hg, and 20 mm Hg. A mixed effects model was applied to analyze changes in IOP with changes in insufflation pressure, while controlling for age, body mass index (BMI), and systolic blood pressure.

For a total of 28 patients, the mean age and BMI were 61.2 ± 7.4 (SD) years, and 29.0 ± 4.6 kg/m², respectively, while the mean systolic blood pressure was 128.1 mm Hg ± 17.0 mm Hg. The mean IOP at six time points increased from 13.6 mm Hg to 26.8 mm Hg, whereas the mean systolic blood pressure ranged from 132.1 (±17) mm Hg to 130.9 (±18) mm Hg from time points 1-6. On a mixed-effects model, a change in 1 mm Hg of abdominal insufflation pressures was associated with a 0.35 mm Hg increase in IOP (95% confidence interval [CI] = 0.29-0.4) holding all other variables constant. Furthermore, a 1 mm Hg change in systolic blood pressure was associated with a 0.06 mm Hg increase in IOP (95% CI = 0.03-0.09).

Our findings suggest that intra-abdominal insufflation pressure and systolic blood pressure are significantly associated with IOP during RARP after accounting for the correlation of the repeated measures and controlling for age and BMI.