title: Five-year incidence of angle closure among glaucoma health examination participants.
abstract: OBJECTIVE
  To investigate incidence of angle closure (AC) and its associated factors through a community-based longitudinal study over a 5-year period.
  
  
  METHODS
  Japanese residents aged 40 years or over who underwent two glaucoma health examinations held in 2005 and 2010 were enrolled. Of the participants of the first glaucoma health examination (first examination), those who satisfied exclusion criteria such as having eyes with angle closure, glaucoma, incisional ocular surgery, or other conditions that could influence the results were eliminated from the second glaucoma health examination (second examination). In addition to routine ophthalmic examination, a scanning peripheral anterior chamber depth analyzer (SPAC) was employed to investigate the anterior chamber configuration. The incidence of angle closure over the 5-year period and its associated factors were investigated.
  
  
  RESULTS
  Of the 754 participants of the first examination, 569 participants were invited for the second examination and 331 participants (87 males and 244 females, age: 62.6 ± 12.7 years), or 619 eyes, were analyzed after eliminating eyes matching exclusion criteria. In the 5-year period, the incidence of AC was 5.4 % (95 % CI: 3.5-8.4 %) of participants or 5.5 % (95 % CI: 4.0-7.6 %) of eyes, including eight eyes (1.3 %) with primary angle-closure glaucoma. Eyes that developed AC had a much smaller SPAC grade at the first examination and a greater decrease in SPAC grade than those that did not develop AC, whereas age and sex were not associated.
  
  
  CONCLUSIONS
  AC was developed by 5.4 % of senior Japanese residents over the 5-year period. The shallow anterior chamber and the marked decrease in anterior chamber depth were associated with AC development.
authors.affiliation: Department of Ophthalmology, University of Yamanashi, Faculty of Medicine, Chuo, Yamanashi, Japan. kenjik@yamanashi.ac.jp
authors.forename: Kenji
authors.initials: K
authors.lastname: Kashiwagi
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Chiba
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Mabuchi
authors.forename: Toshie
authors.initials: T
authors.lastname: Furuya
authors.forename: Shigeo
authors.initials: S
authors.lastname: Tsukahara
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000867:Anterior Chamber / Q000473:pathology; D019058:Community Networks; D018450:Disease Progression; D005260:Female; D015812:Glaucoma, Angle-Closure / Q000175:diagnosis / Q000453:epidemiology*; D006068:Gonioscopy; D006801:Humans; D015994:Incidence; D007429:Intraocular Pressure; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009896:Optic Atrophy / Q000175:diagnosis; D009898:Optic Disk / Q000473:pathology; D012307:Risk Factors; D014065:Tonometry, Ocular; D014786:Vision Disorders / Q000175:diagnosis; D014794:Visual Fields