title: Trends in rates of primary angle closure glaucoma and cataract surgery in England from 1968 to 2004.
abstract: OBJECTIVE
  Eyes that are predisposed to primary angle closure usually have a shallow anterior chamber secondary to a relatively forward position of the lens and progressive lens thickening with ageing. The aim of this study was to examine trends over time in rates of primary angle closure glaucoma (PACG) in England, and to compare these rates with rates of cataract surgery.
  
  
  METHODS
  Hospital episode statistics and the hospital inpatient inquiry were analyzed for PACG as the main diagnosis between the years 1968 and 2004, and for cataract surgery over the same period. Age-specific and sex-specific rates of PACG and cataract surgery were calculated over 3 representative time periods.
  
  
  RESULTS
  Annual rates of patients with PACG did not change significantly from the late 1960s to the mid-1980s and then increased until the early 1990s before reaching a plateau; from 1999 to 2004, rates of patients with PACG declined significantly. From the 1980s to 2004, annual rates of patients undergoing cataract surgery increased significantly and substantially. In the recent period of decline in PACG, the decline was greatest in older age groups, whereas rates of cataract surgery increased significantly in all age groups for both men and women throughout the whole time period.
  
  
  CONCLUSIONS
  Rates of patients with PACG have started to decline in recent years, after a long period of increases in rates of patients undergoing cataract surgery. Although other explanations are possible, this lends support to the hypothesis that cataract surgery may reduce the likelihood of acute angle closure.
authors.affiliation: Ophthalmology Department, Oxford Eye Hospital, Oxford University, UK. tiarnan.keenan@doctors.org.uk
authors.forename: Tiarnan D L
authors.initials: TD
authors.lastname: Keenan
authors.forename: John F
authors.initials: JF
authors.lastname: Salmon
authors.forename: David
authors.initials: D
authors.lastname: Yeates
authors.forename: Michael
authors.initials: M
authors.lastname: Goldacre
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D002386:Cataract / Q000453:epidemiology*; D002387:Cataract Extraction / Q000639:trends*; D004739:England / Q000453:epidemiology; D005260:Female; D015812:Glaucoma, Angle-Closure / Q000453:epidemiology*; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D017678:Sex Distribution