title: Prevalence and characteristics of plateau iris configuration among American Caucasian, American Chinese and mainland Chinese subjects.
abstract: BACKGROUND
  To investigate the prevalence, risk factors and characteristics of plateau iris configuration (PIC) among American Caucasian, American Chinese and mainland Chinese.
  
  
  METHODS
  This multicentre, cross-sectional study of non-glaucomatous subjects (40-80 years) included 111 American Caucasian, 116 American Chinese and 110 mainland Chinese. Prevalence of PIC based on ultrasound biomicroscopy imaging was compared among the different ethnic groups. Risk factors and anterior segment optical coherence tomography-measured iris and angle parameters in eyes with PIC were compared.
  
  
  RESULTS
  The prevalence of PIC was 25.2% in American Caucasian, 24.1% in American Chinese and 20.9% in mainland Chinese (p=0.73). The presence of PIC was associated with more positive spherical equivalence (OR=1.31, p=0.002) and shorter axial length (OR=0.75, p=0.04). There were significant differences in angle recess area (ARA) (p=0.04), IT750 (p=0.007) and IT2000 (p<0.001) between Chinese and Caucasians who have PIC.
  
  
  CONCLUSIONS
  The prevalence of PIC did not differ among American Caucasian, American Chinese and mainland Chinese. PIC was associated with non-myopia and shorter axial length. Chinese eyes with PIC had smaller ARA and thicker irides than Caucasian ones. PIC might be a physiological variation of the iris and ciliary body that exists in normal eyes, both in Chinese and Caucasians.
authors.affiliation: University of California, , San Francisco, California, USA.
authors.forename: Yingjie
authors.initials: Y
authors.lastname: Li
authors.forename: Ye Elaine
authors.initials: YE
authors.lastname: Wang
authors.forename: Guofu
authors.initials: G
authors.lastname: Huang
authors.forename: Dandan
authors.initials: D
authors.lastname: Wang
authors.forename: Mingguang
authors.initials: M
authors.lastname: He
authors.forename: Mary
authors.initials: M
authors.lastname: Qiu
authors.forename: Shan
authors.initials: S
authors.lastname: Lin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000869:Anterior Eye Segment / Q000000981:diagnostic imaging; D001213:Asian / Q000208:ethnology*; D002681:China / Q000208:ethnology; D003430:Cross-Sectional Studies; D006068:Gonioscopy; D006801:Humans; D007429:Intraocular Pressure; D007498:Iris / Q000000981:diagnostic imaging / Q000473:pathology*; D007499:Iris Diseases / Q000175:diagnosis / Q000208:ethnology*; D033401:Microscopy, Acoustic; D008875:Middle Aged; D015588:Observer Variation; D015995:Prevalence; D015203:Reproducibility of Results; D012307:Risk Factors; D041623:Tomography, Optical Coherence; D014481:United States / Q000208:ethnology; D044465:White People / Q000208:ethnology*
keywords: Anatomy; Glaucoma; Iris