title: Charles Bonnet syndrome in Asian patients in a tertiary ophthalmic centre.
abstract: OBJECTIVE
  To describe the epidemiology of Charles Bonnet syndrome (CBS) among patients in an Asian tertiary ophthalmic centre and to describe the characteristics of the hallucinations experienced.
  
  
  METHODS
  1077 consecutive patients aged 50 years and above were asked a standardised question to determine if they had ever experienced formed visual hallucinations. All patients who experienced these symptoms were further interviewed using a detailed, standardised questionnaire to ascertain if they met the diagnostic criteria established for CBS.
  
  
  RESULTS
  There were 491 men (45.6%) and 586 women (54.4%). The best corrected visual acuity ranged from 20/20 to light perception in the better seeing eye and from 20/20 to no light perception in the worse seeing eye. Four patients (0.4%) were diagnosed with CBS; two men and two women. There were two Chinese and two Indians. The average age of the CBS patients was 76.3 years (range 65-90 years). Two patients had cataracts, one had glaucoma, and one had both cataracts and glaucoma. A wide variety of visual hallucinations were reported. Three out of four patients experienced a negative reaction to their hallucinations. Only one patient had discussed his symptoms with a doctor.
  
  
  CONCLUSIONS
  This is the first report on the epidemiology of CBS in Asian patients. The prevalence rate of CBS (0.4%) is slightly lower than in comparable studies in non-Asian populations. The nature of the hallucinations experienced were similar to those previously reported.
authors.affiliation: The Eye Institute at Tan Tock Seng Hospital, National Healthcare Group, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore 308433, Singapore. Colintan_eye@yahoo.com.sg
authors.forename: C S H
authors.initials: CS
authors.lastname: Tan
authors.forename: V S Y
authors.initials: VS
authors.lastname: Lim
authors.forename: D Y M
authors.initials: DY
authors.lastname: Ho
authors.forename: E
authors.initials: E
authors.lastname: Yeo
authors.forename: B Y
authors.initials: BY
authors.lastname: Ng
authors.forename: K G
authors.initials: KG
authors.lastname: Au Eong
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001294:Attitude to Health; D003142:Communication; D003430:Cross-Sectional Studies; D005260:Female; D006212:Hallucinations / Q000208:ethnology* / Q000523:psychology; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012846:Singapore / Q000453:epidemiology; D013577:Syndrome; D014796:Visual Perception