Preoperative Brimonidine on IOP of Patients Undergoing RALP
Status:
Completed
Trial end date:
2017-08-07
Target enrollment:
Participant gender:
Summary
Patients with prostate cancer undergoing robot assisted radical laparoscopic prostatectomy
(RALP) in steep Trendelenburg position (sTBURG) are noted to have elevated intraocular
pressures (IOP) intraoperatively. One study showed an increase in IOP of 13 millimeters of
mercury (mmHg) from baseline IOP levels intraoperatively. Other studies have shown the IOP to
more than double intraoperatively during RALP in sTBURG. IOP is found to be directly related
to angle of inclination and increases time dependently with sTBURG. The IOP may remain
significantly elevated until the first postoperative day after RALP.
There are no previously published data concerning the safe threshold for IOP elevation and
the effects of this increased IOP on vision and on generalized eye health are still not
entirely known. One study showed postoperative visual field defects in 28% (7/25) of patients
who underwent RALP in sTBURG. It has been theorized that sTBURG and subsequent increased IOP
are risk factors for postoperative vision loss (PVL). It is believed that the increased IOP
decreases optic nerve perfusion pressure causing ischemic optic neuropathy. Some previously
recommended ways to reduce the intraoperative IOP spike during RALP include shorter operating
times, decreased angle of inclination, modified Trendelenburg position, use of Propofol for
maintenance anaesthesia and intraoperative topical hypotensive agents to reduce IOP. Given
the challenges with some of the above options, this study aims to evaluate the effect of
pre-operative treatment with topical Brimonidine Tartrate 0.2% on the IOP of patients
undergoing RALP with sTBURG. The goal is to prevent the anticipated IOP spike thereby
reducing risk of postoperative vision loss.