title: Visual sensation during phacoemulsification and intraocular lens implantation using topical and regional anesthesia.
abstract: OBJECTIVE
  To evaluate patients' visual sensations at different stages of phacoemulsification and posterior chamber intraocular lens (PC IOL) implantation under topical and regional anesthesia.
  
  
  METHODS
  Department of Ophthalmology, United Christian Hospital and Tseung Kwan O Hospital, Kowloon, Hong Kong, China.
  
  
  METHODS
  Seventy-six consecutive patients having phacoemulsification were randomized to a topical anesthesia group (n = 35) or regional anesthesia group (n = 41). The topical anesthesia group received lidocaine hydrochloride 2% gel (Xylocaine) and the regional anesthesia group, a peribulbar or retrobulbar injection of lignocaine 2%. The patients' visual sensations, including light and color sensations, shape of objects, and visual patterns, were evaluated at different stages of surgery.
  
  
  RESULTS
  Two patients (4.9%) in the regional anesthesia group and none in the topical anesthesia group experienced total loss of light sensation throughout surgery (P =.50). There was a significant association between color perception and the type of anesthesia at stages 1 and 2 (P<.05) but not at stages 3, 4, and 5 (P>.05). The perception of objects and visual patterns had no association with the type of anesthesia at any stage (P>.05). Of all patients in the study, 56 (73.7%) reported color changes as surgery proceeded. Both groups saw waves, defined as curves with periodic fluctuations in amplitude, at all stages. The perception of some colors and a rectangular moving object was significantly associated with the type of anesthesia at some or all stages (P<.05).
  
  
  CONCLUSIONS
  Patients having phacoemulsification and PC IOL implantation under topical or regional anesthesia had a wide spectrum of visual sensations that were similar at most stages of surgery. Patients in the topical anesthesia group perceived more colors at the early stages and more blue throughout surgery than patients in the regional anesthesia group.
authors.affiliation: Department of Ophthalmology, United Christian Hospital, Kowloon, Hong Kong, China.
authors.forename: Chong Fai
authors.initials: CF
authors.lastname: Chung
authors.forename: Jimmy S M
authors.initials: JS
authors.lastname: Lai
authors.forename: Dennis S C
authors.initials: DS
authors.lastname: Lam
mesh_terms: D000368:Aged; D000765:Anesthesia, Conduction / Q000379:methods*; D000772:Anesthesia, Local / Q000379:methods*; D000779:Anesthetics, Local / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D019654:Lens Implantation, Intraocular; D008012:Lidocaine / Q000008:administration & dosage; D008297:Male; D018918:Phacoemulsification; D012677:Sensation / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*
chemical_list: D000779:Anesthetics, Local; D008012:Lidocaine