Comparative estimation of anterior chamber depth by ultrasonography, Orbscan II, and IOLMaster

J Cataract Refract Surg. 2004 Jun;30(6):1268-71. doi: 10.1016/j.jcrs.2003.11.053.


Purpose: To assess the degree of agreement of anterior chamber depth (ACD) measurements by 2 optical devices (Orbscan II and IOLMaster) and compare them with contact ultrasound A-scan.

Setting: Department of Ophthalmology at Hull Royal Infirmary, England. methods: In this prospective study of 81 eyes of 41 consecutive patients, ACD estimation was done by 3 methods-scanning slit topography (Orbscan II), partial coherence interferometry (IOLMaster), and contact ultrasound A-scan in that order. The same observer performed all measurements. Repeated measures Analysis of Variance (ANOVA) was used to analyze difference between ACD measurements by the 3 methods. Difference in measurements between methods was assessed using the paired t test.

Results: The mean ACD (+/-SD) by the 3 methods was 3.32 mm (0.60), 3.33 mm (0.61), and 2.87 mm (0.55), respectively. There was a statistically significant difference between measurements recorded by the 3 methods (P<.01). Mean contact A-scan measurements were 0.40 mm and 0.43 mm lower than by Orbscan II and IOLMaster respectively (P<.01).

Conclusion: Applanation ultrasound gives consistently lower measurements for ACD compared to Orbscan II and IOLMaster. Although a high degree of agreement between Orbscan II and IOLMaster was noted, further studies are needed to assess the interchangeability of measurements in clinical practice.

Publication types

  • Comparative Study

MeSH terms

  • Aged
  • Aged, 80 and over
  • Anterior Chamber / diagnostic imaging*
  • Biometry / instrumentation*
  • Body Weights and Measures*
  • Cataract / complications
  • Cataract Extraction
  • Diagnostic Techniques, Ophthalmological*
  • Humans
  • Middle Aged
  • Prospective Studies
  • Reproducibility of Results
  • Ultrasonography