title: Visual perception during phacoemulsification cataract surgery under topical and regional anaesthesia.
abstract: OBJECTIVE
  To compare the subjective visual experiences of patients during phacoemulsification and intraocular lens (IOL) implantation using regional and topical anaesthesia.
  
  
  METHODS
  A prospective, cohort, questionnaire-based study.
  
  
  METHODS
  The study cohort consisted of 247 patients without pre-existing ocular pathology who underwent routine phacoemulsification and IOL implantation. The mean age of the subjects was 75.4 +/- 9.4 years and 34.5% of them had a history of cataract surgery. Three different methods of local anaesthesia were used: 66 (26.7%) of the patients were given topical anaesthesia (TA); 74 (30.0%) were given sub-Tenon's anaesthesia (SA), and 107(43.3%) were given peribulbar anaesthesia (PA). The patients were interviewed immediately after surgery by theatre staff using a standardized questionnaire that investigated their intraoperative visual experiences.
  
  
  RESULTS
  There was no significant difference between the three methods of anaesthesia regarding light perception during the surgery. However, patients undergoing surgery under TA experienced brighter light intensity levels (78.3%) than those given SA (50.0%) and PA (55.7%) (p = 0.02). A total of 69.6% of subjects who received TA reported visual perception of colours during surgery, as opposed to 56.8% of SA recipients and 49.0% of PA recipients (p = 0.02). In addition, patients under TA were more aware of surgical instruments (26.1%) than those under SA (10.8%) and PA (15.9%) (p = 0.08). The vast majority of patients in all three groups found the visual experience to be non-frightening. There were no associations between intraoperative visual impression and age or sex. Although not statistically significant (p = 0.06), prior cataract surgery appeared to alleviate some of the anxiety associated with the visual experience.
  
  
  CONCLUSIONS
  Patients undergoing regional and topical anaesthesia experience a wide variety of visual sensations during surgery. The differences in visual impressions between the groups may reflect the varying degrees of optic nerve blockade that result from the different anaesthetics.
authors.affiliation: Department of Ophthalmology, Royal Free Hampstead NHS Trust, London, UK. ptranos@hotmail.com
authors.forename: Paris G
authors.initials: PG
authors.lastname: Tranos
authors.forename: Sanjeewa S
authors.initials: SS
authors.lastname: Wickremasinghe
authors.forename: Neil
authors.initials: N
authors.lastname: Sinclair
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Foster
authors.forename: Riaz
authors.initials: R
authors.lastname: Asaria
authors.forename: Martin L
authors.initials: ML
authors.lastname: Harris
authors.forename: Brian C
authors.initials: BC
authors.lastname: Little
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000765:Anesthesia, Conduction; D000772:Anesthesia, Local; D001007:Anxiety / Q000209:etiology / Q000523:psychology; D002387:Cataract Extraction / Q000523:psychology; D015331:Cohort Studies; D003118:Color Perception; D005260:Female; D006801:Humans; D007432:Intraoperative Period; D007910:Lenses, Intraocular; D008027:Light; D008297:Male; D008875:Middle Aged; D018918:Phacoemulsification / Q000523:psychology; D011446:Prospective Studies; D012086:Reoperation; D011795:Surveys and Questionnaires; D014785:Vision, Ocular