Keeping an eye on pressure: intraocular pressures during Trendelenburg position for pelvic surgery in patients with eye diseases - a systematic review.

Introduction & Objectives: With the widespread use of robot-assistance for pelvic surgeries including prostatectomies, urologists are increasingly aware of intra- and postoperative complications unique to these procedures, including rises in intraocular pressure. While the Trendelenburg positioning required to achieve operative field exposure has been shown to increase intraoperative pressures in people without eye diseases, the literature lacks comprehensive assessments of intraocular pressure in patients with eye diseases. Method(s): A search was conducted on OvidSP Medline and PubMed for studies exploring the effects of patient positioning on intraocular pressure. Search terms used included 'intraocular pressure', 'prostatectomy', 'urologic surgery procedure', 'hysterectomy', 'gynaecology', 'head-down', 'patient positioning' and 'Trendelenburg'. Result(s): A total of three studies satisfied the inclusion criteria. All studies were prospective and observational in design and demonstrated a significant increase in intraocular pressure after placement in Trendelenburg position compared to baseline. Intraocular pressures at 60min after placement into Trendelenburg ranged from 17.0 to 25.1 mmHg. All of these increased with duration in Trendelenburg position, with intraocular pressures ranging between 19.1 to 28.3 mmHg after 180 minutes. All studies examined functional outcomes of Trendelenburg positioning by testing patients' visual fields. Two studies demonstrated no defects in visual field testing. One study found visual field defects in patients with and without eye diseases, with some persisting at 3 months' follow up. Conclusion(s): From the currently available studies, urologists should consider using the least steep Trendelenburg position required to attenuate elevations in intraocular pressure during robot-assisted radical prostatectomies for all patients. However, it appears that visual field defects are minimal and transient, thus routine full ophthalmologis