title: Visual experiences during vitreous surgery under regional anesthesia: a multicenter study.
abstract: OBJECTIVE
  To investigate patients' subjective intraoperative visual experiences during vitreous surgery performed under regional anesthesia, to ascertain if patients were frightened by their visual experiences, and to determine the risk factors associated with a frightening visual experience.
  
  
  METHODS
  Multicenter, prospective study.
  
  
  METHODS
  Sixty-five patients who had vitreous surgery under regional (retrobulbar or peribulbar) anesthesia in five centers in Ireland, Singapore, and Hong Kong were interviewed within 2 hours of their operation using a standardized questionnaire.
  
  
  RESULTS
  Thirty patients (46.2%) perceived light perception throughout the entire operation, 19 patients (29.2%) experienced transient loss of light perception, and 16 patients (24.6%) experienced no light perception throughout the entire duration of the surgery. Nine patients (13.8%) were frightened by their intraoperative visual experiences. Patients who were frightened by their visual experiences were more likely to see color (100%) than those who were not frightened (55.4%) (P = .010). The mean age of the patients who were frightened was lower (51.8 years) compared with those who were not frightened (64.6 years) (P = .003). The mean duration of surgery was longer for patients who were frightened (118.9 minutes) compared with those who were not frightened (91.2 minutes) (P = .047).
  
  
  CONCLUSIONS
  Most patients undergoing vitreous surgery under regional anesthesia retained at least light perception intraoperatively. Importantly, 13.8% of patients were frightened by their visual experiences. A younger age, longer duration of surgery, and perception of color were risk factors for a frightening visual experience.
authors.affiliation: The Eye Institute at Tan Tock Seng Hospital, National Healthcare Group, Singapore.
authors.forename: Colin S H
authors.initials: CS
authors.lastname: Tan
authors.forename: Usman
authors.initials: U
authors.lastname: Mahmood
authors.forename: Paul D
authors.initials: PD
authors.lastname: O'Brien
authors.forename: Stephen
authors.initials: S
authors.lastname: Beatty
authors.forename: Alvin K H
authors.initials: AK
authors.lastname: Kwok
authors.forename: Vincent Y W
authors.initials: VY
authors.lastname: Lee
authors.forename: Kah-Guan
authors.initials: KG
authors.lastname: Au Eong
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000772:Anesthesia, Local / Q000379:methods / Q000523:psychology*; D001007:Anxiety / Q000523:psychology; D005239:Fear / Q000523:psychology; D005260:Female; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D010361:Patients / Q000523:psychology*; D011446:Prospective Studies; D012164:Retinal Diseases / Q000601:surgery; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014796:Visual Perception / Q000502:physiology*; D014821:Vitrectomy / Q000523:psychology*