title: Chronic angle-closure with glaucomatous damage: long-term clinical course in a North American population and comparison with an Asian population.
abstract: OBJECTIVE
  To study the long-term clinical course of North American chronic angle-closure glaucoma (CACG) patients with optic disc damage and visual field loss in the presence of an angle closed at least partially by peripheral anterior synechiae and to compare it with a similar group of Singaporean patients.
  
  
  METHODS
  A retrospective, interventional case-control study series.
  
  
  METHODS
  Fifty-one patients (80 eyes) diagnosed with CACG with glaucomatous optic nerve head and visual field damage at a New York hospital from January 1990 through December 1994. All study eyes underwent laser peripheral iridotomy (LPI).
  
  
  METHODS
  The presenting features, management, and subsequent long-term intraocular pressure (IOP) outcome were analyzed and compared with 65 Asian patients (83 eyes) from a Singapore hospital who were similarly diagnosed during the same period.
  
  
  METHODS
  The long-term outcome after LPI was assessed in terms of IOP and the requirement for additional therapy.
  
  
  RESULTS
  The mean presenting IOP was higher in the Singapore eyes (40 +/- 15 mmHg) compared with the New York eyes (31 +/- 12.5 mmHg). All 80 New York eyes (100%) and 78 of 83 Singapore eyes (94%) required further treatment to control IOP during follow-up. Of the eyes with a subsequent rise in IOP, 33 of 80 eyes (41.3%) compared with 34 of 83 eyes (41.0%) of the Singapore patients were controlled with additional topical medication. Of the New York eyes, 25 of 80 (31.3%) eventually underwent filtering surgery, compared with 44 of 83 (53.0%) in the Singapore study. The other 22 eyes (27.5%) in the New York group went on to additional laser procedures, peripheral iridoplasty, laser trabeculoplasty, or a combination thereof, after which IOPs were controlled and no surgery was required. There was no similar comparison for the Singapore group, because these eyes went directly on to surgery.
  
  
  CONCLUSIONS
  Despite the presence of a patent LPI, most eyes with CACG presenting with elevated IOP and having both optic disc and visual field damage in both populations required further treatment to control IOP. Results in the American population are similar to that reported in Asian patients.
authors.affiliation: Singapore National Eye Centre, Singapore, Republic of Singapore.
authors.forename: Mohamad
authors.initials: M
authors.lastname: Rosman
authors.forename: Tin
authors.initials: T
authors.lastname: Aung
authors.forename: Leonard P K
authors.initials: LP
authors.lastname: Ang
authors.forename: Paul T K
authors.initials: PT
authors.lastname: Chew
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Liebmann
authors.forename: Robert
authors.initials: R
authors.lastname: Ritch
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D002908:Chronic Disease; D005260:Female; D005500:Follow-Up Studies; D015812:Glaucoma, Angle-Closure / Q000150:complications* / Q000175:diagnosis / Q000208:ethnology / Q000601:surgery; D006801:Humans; D007429:Intraocular Pressure; D007498:Iris / Q000601:surgery; D053685:Laser Therapy; D008297:Male; D008875:Middle Aged; D009519:New York City / Q000453:epidemiology; D009898:Optic Disk / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000150:complications* / Q000175:diagnosis / Q000208:ethnology; D012189:Retrospective Studies; D012846:Singapore / Q000453:epidemiology; D014786:Vision Disorders / Q000150:complications* / Q000175:diagnosis / Q000208:ethnology; D014794:Visual Fields