title: Anterior chamber and aqueous depth measurement in pseudophakic eyes: agreement between ultrasound biometry and scheimpflug imaging.
abstract: OBJECTIVE
  To compare anterior chamber depth (ACD) and aqueous depth (AQD) measurements provided by a Scheimpflug camera combined with corneal topography to those obtained by immersion ultrasound (US) biometry when assessing the distance between the cornea and intraocular lens (IOL) in pseudophakic patients.
  
  
  METHODS
  In a sample of 40 consecutive patients, each patient underwent measurements of ACD and AQD by means of the two techniques. Scheimpflug (Sirius; C.S.O., Firenze, Italy) measurements were obtained by manually tracing a line between the anterior surface of the IOL and the central cornea. Results were compared by t test. Agreement was evaluated by Bland-Altman plots with 95% limits of agreement (LoA).
  
  
  RESULTS
  There was no statistically significant difference between the AQD as measured by US (3.95 ± 0.34 mm; range: 3.39 to 4.74 mm) and the AQD as measured by Scheimpflug photography (3.96 ± 0.34 mm; range: 3.41 to 4.77 mm; P = .3187). The statistically (but not clinically) significant difference between the ACD as measured by US (4.54 ± 0.37 mm; range: 3.93 to 5.35 mm) and Scheimpflug photography (4.58 ± 0.34 mm; range: 4.03 to 5.36 mm; P = .0024) disappeared after setting the US speed for ACD at 1,545 m/sec (mean ACD: 4.58 ± 0.37 mm; range: 3.96 to 5.39 mm). The 95% LoA ranged between -0.15 and +0.18 mm for AQD and between -0.12 and +0.21 mm for ACD.
  
  
  CONCLUSIONS
  In pseudophakic eyes, the manual ACD and AQD measurements obtained from the Scheimpflug camera combined with corneal topography are not significantly different compared to those provided by US and therefore can be considered interchangeable with the latter.
authors: Bietti Eye Doundation, Rome, Italy. giacomo.savini@alice.it
authors: Giacomo
authors: G
authors: Savini
authors: Kenneth J
authors: KJ
authors: Hoffer
authors: Michele
authors: M
authors: Carbonelli
mesh_terms: D000368:Aged; D000867:Anterior Chamber / Q000473:pathology*; D001082:Aqueous Humor; D001699:Biometry / Q000295:instrumentation; D003315:Cornea / Q000473:pathology; D019781:Corneal Topography; D005260:Female; D006801:Humans; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular; D008297:Male; D033401:Microscopy, Acoustic / Q000379:methods*; D018918:Phacoemulsification; D010781:Photography / Q000379:methods*; D019591:Pseudophakia / Q000150:complications; D015203:Reproducibility of Results