title: Comparison of anterior segment optical coherence tomography and ultrasound biomicroscopy for assessment of the anterior segment.
abstract: OBJECTIVE
  To compare anterior segment parameters using quantitative imaging by anterior segment optical coherence tomography (AS-OCT) and ultrasound biomicroscopy (UBM).
  
  
  METHODS
  Tertiary-care glaucoma research center.
  
  
  METHODS
  Sixty-three eyes of 63 subjects had anterior segment evaluation by AS-OCT (Visante-Zeiss) and UBM (Paradigm). Central corneal thickness (CCT), anterior chamber depth (ACD) (measured from the central corneal endothelium to the anterior lens capsule), and the peripheral iridocorneal angles (temporal and nasal) were assessed and compared.
  
  
  RESULTS
  There was an excellent correlation between AS-OCT and UBM measurements for the nasal angle (r = 0.84; P<.0001), temporal angle (r = 0.86; P<.0001), ACD (r = 0.97; P<.0001), and CCT (r = 0.91; P<.0001). There was no significant difference (paired t test) between the mean ACD, CCT, and angle parameters measured by AS-OCT or UBM. The mean values of the parameters measured by AS-OCT and UBM were, respectively, as follows: nasal angle, 26.25 degrees +/- 11.0 (SD) and 28.27 +/- 11.3 degrees (P = .3); temporal angle, 25.1 +/- 11.4 degrees and 28.3 +/- 13.5 degrees (P = .15); ACD, 2.85 +/- 0.5 mm and 2.78 +/- 0.5 mm (P = .2); and CCT, 512 +/- 46 microm and 502 +/- 46 microm (P = .25). The AS-OCT images showed sharper definition of the scleral spur than the UBM images.
  
  
  CONCLUSIONS
  Anterior segment optical coherence tomography and UBM can both be used for anterior segment measurements and yielded comparable results.
authors.affiliation: Glaucoma Research Laboratory, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India. tanujdada@hotmail.com
authors.forename: Tanuj
authors.initials: T
authors.lastname: Dada
authors.forename: Ramanjit
authors.initials: R
authors.lastname: Sihota
authors.forename: Ritu
authors.initials: R
authors.lastname: Gadia
authors.forename: Anand
authors.initials: A
authors.lastname: Aggarwal
authors.forename: Subrata
authors.initials: S
authors.lastname: Mandal
authors.forename: Viney
authors.initials: V
authors.lastname: Gupta
mesh_terms: D000328:Adult; D000867:Anterior Chamber / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D000869:Anterior Eye Segment / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D003315:Cornea / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D003941:Diagnostic Techniques, Ophthalmological; D005260:Female; D006801:Humans; D007498:Iris / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D008297:Male; D033401:Microscopy, Acoustic; D015203:Reproducibility of Results; D041623:Tomography, Optical Coherence