title: Anterior chamber dimensions and posterior corneal arc length in Malay eyes: an anterior segment optical coherence tomography study.
abstract: OBJECTIVE
  We provided normative data of corneal and anterior segment dimensions, and a novel parameter, posterior corneal arc length (PCAL), in an adult Malay population.
  
  
  METHODS
  The current analysis is a substudy of the Singapore Malay Eye Study (SiMES), a population-based, cross-sectional study of urban Malay adults aged 40 to 80. Subjects underwent ophthalmic and systemic examination, including imaging with anterior segment optical coherence tomography (AS-OCT). Ocular parameters subsequently were measured with the Zhongshan Assessment Program (ZAP), and included anterior chamber depth (ACD), central corneal thickness (CCT), anterior and posterior corneal curvature (ACC and PCC, respectively), and PCAL, which is a novel parameter defined as the arc-distance of the posterior corneal border between the scleral spurs. Age- and sex-adjusted analyses, and multivariate analyses were performed to determine correlations of PCAL with other ocular and systemic components.
  
  
  RESULTS
  We studied 237 subjects, among whom the mean age was 56.6 ± 10.4 years and 50.2% were women. Ocular parameters (mean ± SD) included central ACD 2.78 ± 0.34 mm, CCT 550.23 ± 37.12 mm, ACC 7.43 ± 0.37 mm, PCC 6.75 ± 0.37 mm, and PCAL 13.95 ± 0.51 mm. There was moderate correlation between PCAL and ACD (r = 0.476, P < 0.001), but poor correlation with PCC (r = 0.243, P < 0.001), ACC (r = 0.251, P < 0.001), and systemic parameters, like age, body mass index (BMI), blood pressure, blood glucose levels, hemoglobin A1c (HbA1c), and refractive parameters. Multivariate analysis showed a significant association between PCAL and ACD (P < 0.001), PCC (P < 0.001), and height (P < 0.05).
  
  
  CONCLUSIONS
  Our study, to our knowledge, provides the largest baseline anterior segment parameters in an adult Asian Malay population. PCAL correlated moderately with ACD. These data are applicable clinically for assessment and surgical management of patients requiring anterior segment or corneal surgery.
authors: Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore.
authors: Deborah K L
authors: DK
authors: Tan
authors: Wesley
authors: W
authors: Chong
authors: Wan Ting
authors: WT
authors: Tay
authors: Leonard H
authors: LH
authors: Yuen
authors: Mingguang
authors: M
authors: He
authors: Tin
authors: T
authors: Aung
authors: Donald T H
authors: DT
authors: Tan
authors: Tien Yin
authors: TY
authors: Wong
authors: Jodhbir S
authors: JS
authors: Mehta
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000867:Anterior Chamber / Q000033:anatomy & histology*; D044466:Asian People / Q000208:ethnology; D001699:Biometry; D003315:Cornea / Q000033:anatomy & histology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012846:Singapore / Q000453:epidemiology; D041623:Tomography, Optical Coherence / Q000379:methods*; D014505:Urban Population