title: Lens opacity, thickness, and position in subjects with acute primary angle closure.
abstract: OBJECTIVE
  To compare lens thickness (LT), lens position (LP), relative lens position (RLP), and degree and type of lens opacity between affected and fellow eyes of subjects with acute primary angle closure (APAC) to identify any differences in lens characteristics that may be contributory to the acute episode. In addition, axial length (AL) and anterior chamber depth (ACD) measurements were evaluated.
  
  
  METHODS
  Seventy-three study subjects with unilateral APAC were treated with sequential laser iridotomy (LI) in both eyes. Two weeks after LI, ACD, LT, and AL measurements were made in both eyes using ultrasound pachymetry. LP was defined as ACD+1/2LT and RLP as LP/AL. The Lens Opacity Classification III (LOCS III) System was used for grading lens opacity.
  
  
  RESULTS
  The subjects were 90% Chinese and 63% female. Mean age was 61.0+/-10.9 years. Significant differences between the affected and fellow eyes were found in the ACD (2.11+/-0.35 vs 2.18+/-0.23; P=0.02) and LP (4.61+/-0.47 vs 4.75+/-0.29; P=0.02). Cortical opacity was greater in fellow eyes (0.32+/-0.72 vs 0.53+/-0.95; P=0.02). There was no difference in LT, RLP, or degree of lens opacity in the nuclear and posterior subcapsular regions.
  
  
  CONCLUSIONS
  Compared with fellow eyes, APAC-affected eyes have shallower ACD, more anterior LP, and less cortical opacity. These differences may be contributory to APAC.
authors.affiliation: Singapore National Eye Centre, Singapore.
authors.forename: Marcus C C
authors.initials: MC
authors.lastname: Lim
authors.forename: Laurence S
authors.initials: LS
authors.lastname: Lim
authors.forename: Gus
authors.initials: G
authors.lastname: Gazzard
authors.forename: Rahat
authors.initials: R
authors.lastname: Husain
authors.forename: Yiong-Huak
authors.initials: YH
authors.lastname: Chan
authors.forename: Steve K L
authors.initials: SK
authors.lastname: Seah
authors.forename: Tin
authors.initials: T
authors.lastname: Aung
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000867:Anterior Chamber / Q000000981:diagnostic imaging / Q000473:pathology; D001699:Biometry; D001837:Body Weights and Measures; D002386:Cataract / Q000145:classification / Q000150:complications*; D005260:Female; D015812:Glaucoma, Angle-Closure / Q000150:complications* / Q000601:surgery; D006801:Humans; D032801:Iridectomy; D007908:Lens, Crystalline / Q000000981:diagnostic imaging / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014463:Ultrasonography