title: Changes in anterior segment dimensions over 4 years in a cohort of Singaporean subjects with open angles.
abstract: OBJECTIVE
  To evaluate quantitative changes in anterior segment optical coherence tomography (AS-OCT) parameters at 4 years in subjects with open angles on gonioscopy at baseline.
  
  
  METHODS
  339 gonioscopically open-angle subjects aged >50 years underwent AS-OCT imaging (Visante, Carl Zeiss Meditec, Dublin, California, USA) at baseline and at 4 years. Customised software was used to analyse images. Linear regression was performed to assess baseline predictors of change in mean trabecular iris space area (TISA).
  
  
  RESULTS
  Of the 339 subjects, 204 (61%) had good images for analysis. The mean age at baseline was 60 (SD 6.42) years; 55.4% were women and 87.7% were Chinese. Overall, there was a decrease in anterior chamber depth (ACD), anterior chamber area (ACA), anterior chamber volume (ACV) and angle opening distance at 500/750 µm, TISA 500/750 µm, iris thickness at 2000 µm and iris area in both nasal and temporal quadrants (p<0.05) at 4 years. There was an increase in iris curvature (ICURV) and lens vault (LV) (p<0.05). With univariate analysis, shorter axial length (AxL), shallower ACD, greater LV, smaller ACA/ACV and larger mean ICURV at baseline were associated with less change in TISA750 at follow-up. On multivariate analysis, only baseline mean ICURV and shorter AxL were predictive of less change in TISA750 at 4 years.
  
  
  CONCLUSIONS
  Angle width significantly decreased; ICURV and LV increased in subjects with gonioscopically open angles followed at 4 years. Eyes with shorter AxL and greater ICURV at baseline had lesser decrease in angle width.
authors: Duke-NUS Graduate Medical School, Singapore, Singapore Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Singapore.
authors: Yingke
authors: Y
authors: He
authors: Duke-NUS Graduate Medical School, Singapore, Singapore Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Singapore Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
authors: Mani
authors: M
authors: Baskaran
authors: Duke-NUS Graduate Medical School, Singapore, Singapore Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Singapore.
authors: Arun K
authors: AK
authors: Narayanaswamy
authors: Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Singapore Federal University of Parana, Curitiba, Brazil.
authors: Lisandro M
authors: LM
authors: Sakata
authors: Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Singapore.
authors: Renyi
authors: R
authors: Wu
authors: Wilmer Eye Institute, Dana Center for Preventive Ophthalmology, Johns Hopkins University, Baltimore, Maryland, USA.
authors: Dianna
authors: D
authors: Liu
authors: Duke-NUS Graduate Medical School, Singapore, Singapore Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Singapore Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
authors: Monisha E
authors: ME
authors: Nongpiur
authors: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, China.
authors: Mingguang
authors: M
authors: He
authors: Wilmer Eye Institute, Dana Center for Preventive Ophthalmology, Johns Hopkins University, Baltimore, Maryland, USA.
authors: David S
authors: DS
authors: Friedman
authors: Duke-NUS Graduate Medical School, Singapore, Singapore Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Singapore Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
authors: Tin
authors: T
authors: Aung
mesh_terms: D000869:Anterior Eye Segment / Q000473:pathology; D044466:Asian People; D058452:Axial Length, Eye / Q000473:pathology; D001699:Biometry; D005260:Female; D005500:Follow-Up Studies; D006068:Gonioscopy; D006801:Humans; D007429:Intraocular Pressure; D007498:Iris / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D012846:Singapore; D041623:Tomography, Optical Coherence; D014065:Tonometry, Ocular; D014129:Trabecular Meshwork / Q000473:pathology*