title: Qualitative evaluation of the iris and ciliary body by ultrasound biomicroscopy in subjects with angle closure.
abstract: OBJECTIVE
  To qualitatively analyze anterior chamber structures imaged by ultrasound biomicroscopy (UBM) in primary angle-closure patients.
  
  
  METHODS
  Subjects diagnosed as primary angle-closure suspect (PACS), primary angle-closure glaucoma (PACG), and previous acute primary angle closure (APAC) were recruited prospectively along with a group of normal controls. UBM was performed under standardized dark room conditions and qualitative assessment was carried out using a set of reference photographs of standard UBM images to categorize the various anatomic features related to angle configuration. These included overall and basal iris thicknesses, iris convexity, iris angulation, ciliary body size, and ciliary sulcus.
  
  
  RESULTS
  A total of 60 PACS, 114 PACG, 41 APAC, and 33 normal controls were included. Patients were predominantly older Chinese females. After controlling the confounding effect of age and sex, eyes with overall thicker irides [medium odds ratio (OR) 3.58, thick OR 2.84] when compared with thin irides have a significantly higher likelihood of having PACS/PACG/APAC versus controls. Thicker basal iris component (medium OR 4.13, thick OR 3.39) also have higher likelihood of having angle closure when compared with thin basal iris thickness. Subjects with basal iris insertion, mild iris angulation, and large ciliary body have a higher OR of having angle closure. In contrast, the presence/absence of a ciliary sulcus did not influence the likelihood of angle closure.
  
  
  CONCLUSIONS
  Eyes with thicker overall and basal iris thicknesses are more likely to have angle closure than controls. Other features that increase the likelihood of angle closure include basal iris insertion, mild iris angulation, and large ciliary body.
authors: *Singapore National Eye Centre & Singapore Eye Research Institute ‡Yong Loo Lin School of Medicine, National University of Singapore, Singapore †Narayana Nethralaya, Bangalore, India.
authors: Judy Y
authors: JY
authors: Ku
authors: Monisha E
authors: ME
authors: Nongpiur
authors: Judy
authors: J
authors: Park
authors: Arun K
authors: AK
authors: Narayanaswamy
authors: Shamira A
authors: SA
authors: Perera
authors: Tin A
authors: TA
authors: Tun
authors: Rajesh S
authors: RS
authors: Kumar
authors: Mani
authors: M
authors: Baskaran
authors: Tin
authors: T
authors: Aung
mesh_terms: D000368:Aged; D000867:Anterior Chamber / Q000000981:diagnostic imaging; D044466:Asian People; D002924:Ciliary Body / Q000000981:diagnostic imaging*; D005260:Female; D015812:Glaucoma, Angle-Closure / Q000000981:diagnostic imaging*; D006801:Humans; D007429:Intraocular Pressure; D007498:Iris / Q000000981:diagnostic imaging*; D008297:Male; D033401:Microscopy, Acoustic; D008875:Middle Aged; D011446:Prospective Studies