The Effect of Steep Trendelenburg Positioning on Retinal Structure and Function during Robotic-Assisted Laparoscopic Procedures

Abstract

Purpose. Robotic-assisted laparoscopic radical prostatectomy (RALP) has become a standard treatment choice for localized prostate cancer. RALP requires a steep Trendelenburg position, which leads to a significant increase in intraocular pressure (IOP). This study evaluated the effect on the retinal structure and function in patients undergoing RALP. Methods. Standard automated perimetry (SAP) and optical coherence tomography (OCT) were performed in 20 males scheduled for RALP at 1 month and 1 day before the operation and at 1 and 3 months after the operation. IOP measurements were made in the supine position at 5 min after intubation under general anesthesia (T1), at 6 discrete time points (5, 30, 60, 120, 180, and 240 min; T2-7), and at 5 min after returning to a horizontal supine position (T8). Serial retinal nerve fiber layer (RNFL) thicknesses and visual field progression were assessed using the guided progression analysis software program. RNFL thickness progression and visual field progression were evaluated by event analysis. Results. Average IOP (mmHg) for each time point was as follows: T1 = 12.3 ± 2.6, T2 = 20.4 ± 4.2, T3 = 23.3 ± 3.8, T4 = 24.0 ± 3.2, T5 = 24.3 ± 3.4, T6 = 27.1 ± 7.2, T7 = 29.8 ± 8.7, and T8 = 20.1 ± 4.4. During RALP, IOP significantly increased. There was no progression of the visual field and RNFL thickness after surgery or any other ocular complications found. Conclusions. Although IOP significantly increased during RALP, there were no significant changes in the retinal structure and function between the pre- and postoperation observations.