title: Transient but significant visual field defects after robot-assisted laparoscopic radical prostatectomy in deep tRendelenburg position.
abstract: BACKGROUND
  Robot-assisted laparoscopic radical prostatectomy (RALP) is a minimally invasive surgical procedure for prostate cancer. During RALP, the patient must be in a steep Trendelenburg (head-down) position, which leads to a significant increase in intraocular pressure (IOP). The association of RALP with visual field sensitivity, however, has not been prospectively studied. The purpose of this study was to evaluate prospectively the visual field, retinal nerve fiber layer (RNFL) thickness, and optic disc morphology in 50 normal eyes of 25 male patients that underwent RALP.
  
  
  METHODS
  The subjects were 25 males among 33 consecutive patients who underwent uneventful RALP under general anesthesia in our hospital. Visual field tests using the Humphrey visual field analyzer 30-2 SITA-standard program were performed before, 7 days after, and 1-3 months after RALP. IOP was measured before, during, and after RALP; and ophthalmologic examinations, including slit-lamp, fundus examination, and optical coherence tomography (OCT), were scheduled before and 7 days after surgery.
  
  
  RESULTS
  IOP was significantly increased during RALP up to 29.4 mmHg (P<0.01). Postoperative local visual field defects were detected in 7 eyes of 7 subjects dominantly in the lower hemifield without abnormal findings in the optic nerve head or retina, and the visual field recovered to normal within 3 months after surgery. General factors associated with RALP, IOP, RNFL thickness, or optic disc parameters did not differ significantly between eyes with and without postoperative visual field defects, and parameters of OCT measurements were not altered after surgery.
  
  
  CONCLUSIONS
  Transient but significant unilateral visual field defects were found in 28% of the subjects examined. The probable cause are the increased IOP and altered perfusion during surgery and ophthalmologic examinations are therefore suggested before and after RALP.
authors.affiliation: Department of Ophthalmology, The University of Tokyo Graduate School of Medicine, Tokyo, Japan; Department of Ophthalmology, Asahi General Hospital, Chiba, Japan.
authors.forename: Yukako
authors.initials: Y
authors.lastname: Taketani
authors.affiliation: Department of Ophthalmology, The University of Tokyo Graduate School of Medicine, Tokyo, Japan.
authors.forename: Chihiro
authors.initials: C
authors.lastname: Mayama
authors.affiliation: Department of Urology, Asahi General Hospital, Chiba, Japan.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Suzuki
authors.affiliation: Department of Anesthesiology, Asahi General Hospital, Chiba, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Wada
authors.affiliation: Department of Anesthesiology, Asahi General Hospital, Chiba, Japan.
authors.forename: Tatsuhiro
authors.initials: T
authors.lastname: Oka
authors.affiliation: Department of Ophthalmology, Asahi General Hospital, Chiba, Japan; Department of Ophthalmology, Tokyo Metropolitan Police Hospital, Tokyo, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Inamochi
authors.affiliation: Department of Ophthalmology, Asahi General Hospital, Chiba, Japan.
authors.forename: Yohei
authors.initials: Y
authors.lastname: Nomoto
mesh_terms: D006801:Humans; D056888:Patient Positioning; D011446:Prospective Studies; D011468:Prostatectomy / Q000009:adverse effects / Q000379:methods*; D012371:Robotics; D014794:Visual Fields