A Comparative Assessment of Intraocular Pressure in Prolonged Steep Trendelenburg Position Versus Level Supine Position Intervention

Abstract

Background: The purpose was to evaluate a level supine intervention (LSI) during laparoscopic surgery in steep Trendelenburg position (Lap ST). Increased intraocular pressure (IOP) and decreases in ocular perfusion pressure have been monitored during Lap ST procedures. Peri-orbital swelling and venous congestion in addition to IOP may produce a low perfusion state in the eye, via a compartment syndrome mechanism potentially exacerbated by trabecular meshwork dysregulated pressure dependent outflow. Research in rodent models has confirmed that in the ST position IOP can increase to critical thresholds of > 40 mmHg and studies have determined that even brief 30-40 minute episodes of acute IOP elevations can result in retinal cell ganglion (RCG) dysfunction. A LSI for one 5 minute interval at the 60 minute time point was introduced and was hypothesized to normalize IOP.

Repositioning during robotic procedures to prevent postoperative visual loss

“…11 IOP in patients without an LSI at 120 minutes ranged 25 to 54 mm Hg. 11 IOP in patients without an LSI at 120 minutes ranged 25 to 54 mm Hg.…”

“…11,12 Returning the patient to supine, or a position in which the ocular level is above the heart, will reduce IOP to below critical levels and facilitate an earlier return to baseline upon repositioning to level at the end of the case. 11,12 Returning the patient to supine, or a position in which the ocular level is above the heart, will reduce IOP to below critical levels and facilitate an earlier return to baseline upon repositioning to level at the end of the case.…”

“…11 Dorzolamide hydrochloride-timolol maleate ophthalmic solution should be administered by the anesthesia provider per the manufacturer's recommendations and at the physician's and anesthesia provider's discretion. Unlike an LSI, eye drops can be administered without surgical interruption.…”

Complications of robotic-assisted laparoscopic surgery distant from the surgical site

“…Ischaemic optic neuropathy (ION) ION has an estimated incidence across all procedures of 0.05% and is encountered with robotic abdominal and pelvic surgeries. 36 Posterior ION was reported in a case report involving two patients undergoing prostatectomy, with one using a robotic technique and the other laparoscopic. 37 The specifically reported cases described bilateral loss in visual acuity (as severe as complete blindness) and varied regarding the specific visual fields.…”

“…One small prospective trial demonstrated a significant decrease in intraocular pressure towards baseline when a five to seven-min break was taken at the 90 min or 120 min mark of surgery. 36 Increased awareness of ophthalmic complications relating to steep Trendelenburg, resulted in a report of two open-angle glaucoma patients having a robotic case rescheduled as open after ophthalmic consultation. 43…”