title: Comparison of axial lengths in occludable angle and angle-closure glaucoma--the Bhaktapur Glaucoma Study.
abstract: OBJECTIVE
  To compare the anterior chamber depth (ACD) and axial length of eyes in a population-based sample among normal, occludable angle, and primary angle-closure glaucoma (PACG) groups.
  
  
  METHODS
  Totally, 3979 subjects from a population-based glaucoma prevalence study underwent complete ocular examination including four mirror gonioscopy. An angle in which >270 degrees of the posterior trabecular meshwork could not be seen was considered occludable. PACG was considered when there were features of primary angle closure (eye with an occludable angle, peripheral anterior synechiae, increased intraocular pressure, iris whorling, lens opacities, or excessive pigment deposition on the trabecular surface) and optic disc with glaucomatous damage. A handheld ultrasonic biometer was used to measure the ACD and the axial length of subjects. The ACD and axial length were measured on all subjects with occludable angles (n = 86), PACG (n = 17) and a random subgroup of normal subjects (n = 685). The measurements were compared among the groups and statistically analyzed using independent t-test, one-way analysis of variance, χ2 test, and logistic regression.
  
  
  RESULTS
  The mean age among occludable angle and angle-closure glaucoma groups was 59.64 ± 9.70 and 71.23 ± 8.5 years, respectively, which was significantly higher (p < 0.001) than the mean of 54.03 ± 10.90 years among normal subjects. In the occludable angle group, the ACD (2.55 ± 0.69) was significantly different (p < 0.001) than the normal group (2.85 ± 0.39). The axial length (22.08 ± 0.83) in the occludable angle group was also considerably different (p < 0.001) when compared with the normal group (22.62 ± 0.90). In PACG group, the ACD and axial length were 2.48 ± 0.22 and 22.02 ± 0.59, respectively. The risk of having an occludable angle decreased with per unit millimeter increase in ACD (odds ratio, 0.24; 95% confidence intervals, 0.12-0.50) and axial length (odds ratio, 0.49; 95% confidence intervals, 0.36-0.67) after adjusting the effect of age and sex.
  
  
  CONCLUSIONS
  The eyes in Nepalese population with occludable angle and angle-closure glaucoma appear to have significantly shallower anterior chambers and shorter axial lengths when compared with the normal group.
authors.affiliation: Nepal Glaucoma Eye Clinic, Tilganga Institute of Ophthalmology, Kathmandu, Nepal. ssthapa@tilganga.com.np
authors.forename: Suman S
authors.initials: SS
authors.lastname: Thapa
authors.forename: Indira
authors.initials: I
authors.lastname: Paudyal
authors.forename: Shankar
authors.initials: S
authors.lastname: Khanal
authors.forename: Nabin
authors.initials: N
authors.lastname: Paudel
authors.forename: Ger H M B
authors.initials: GH
authors.lastname: van Rens
mesh_terms: D000328:Adult; D000368:Aged; D000867:Anterior Chamber / Q000000981:diagnostic imaging*; D001699:Biometry / Q000379:methods; D005260:Female; D005901:Glaucoma / Q000175:diagnosis*; D015812:Glaucoma, Angle-Closure / Q000175:diagnosis*; D006068:Gonioscopy; D006801:Humans; D008297:Male; D008875:Middle Aged; D009390:Nepal; D016017:Odds Ratio; D014129:Trabecular Meshwork / Q000473:pathology*; D014463:Ultrasonography