The effect of steep Trendelenburg positioning on intraocular pressure and visual function during robotic-assisted radical prostatectomy

Background To evaluate intraocular pressure (IOP) changes in patients undergoing robotic-assisted radical prostatectomy and to evaluate complications from increased IOP. Methods Thirty-one eyes scheduled for robotic prostatectomy were included. Perioperative IOP measurements were performed as follows: prior to induction of anaesthesia while supine and awake (T1); immediately post-induction while supine (T2); every hour from 0 to 5 h while anaesthetised in a steep Trendelenburg position (T3-T8); prior to awakening while supine (T9); and 30 min after awakening while supine (T10). A complete ophthalmic examination including visual acuity and retinal nerve fibre layer thickness (RNFL) was performed at enrolment and 1 month postoperatively. Results Average IOP (mm Hg) for each time point was as follows: T1=18.0, T2=9.8, T3=18.9, T4=21.6, T5=22.5, T6=22.3, T7=24.2, T8=24.0, T9=15.7 and T10=17.9. The proportion of eyes with intraoperative IOP. 30 mm Hg were as follows: T3=0%, T4=3.23%, T5=9.68%, T6=6.45%, T7=22.22%, and T8=25%. Maximum IOP was 36 mm Hg. Mean visual acuity (logarithm of the minimal angle of resolution) and RNFL showed no statistically significant difference before and after operation and no other ocular complications were found at final examination. Conclusions While IOP increased in a time-dependent fashion in anesthaetised patients undergoing robotic-assisted radical prostatectomy in a steep Trendelenburg position, visual function showed no significant change postoperatively and no complications were seen. Steep Trendelenburg positioning during time-limited procedures appears to pose little or no risk from IOP increases in patients without pre-existing ocular disease.