Evaluation of biometric methods for measuring the anterior chamber depth in the non-contact mode

• Published in: Graefe's archive for clinical and experimental ophthalmology 2006-05, Vol.244 (5), p.559-564
• Main Authors: Meinhardt, B, Stachs, O, Stave, J, Beck, R, Guthoff, R
• Format: Article
• Language: English
• Subjects: Adult; Anterior Chamber - anatomy & histology; Biometry - methods; Body Weights and Measures; Diagnostic Techniques, Ophthalmological; Humans; Lens, Crystalline - physiology; Middle Aged; Ophthalmology; Prospective Studies
• ISSN: 0721-832X; 1435-702X
• DOI: 10.1007/s00417-005-0103-7

High-resolution biometry of the anterior ocular segment is now becoming more and more important against a background of refractive surgery and the evaluation of potentially accommodative lens replacement materials. The aim of this study was a systematic investigation of the currently available non-contact methods for measuring the anterior chamber depth (ACD). The ACDs of 50 phakic eyes of 27 patients aged between 19 and 59 years were measured with the IOL-Master (Zeiss), the AC-Master (Zeiss), the Pentacam (Oculus) and slit-lamp pachymetry by Jaeger (Haag-Streit). The median anterior chamber depth in the investigated eyes was 3.63 mm for the IOL-Master (minimum 2.88 mm, maximum 4.22 mm), 3.802 mm for the AC-Master (2.816 mm-4.373 mm), 3.915 mm for the Pentacam (minimum 2.994 mm, maximum 4.614 mm) and 3.75 mm for Jaeger (2.887 mm-4.29 mm). With a probability of error of alpha=0.05 there were no significant differences concerning the ACD between the methods of Jaeger and AC-Master, Jaeger and IOL-Master, or Pentacam and AC-Master (Wilcoxon and Wilcox). The intra-individual variability was +/-5.4 microm for AC-Master, +/-12.7 microm for Pentacam, +/-24.5 microm for IOL-Master and +/-41.2 microm for Jaeger. The maximum method-dependent difference in ACD determination was 285 microm. All the methods allow non-contact biometry, but the results might differ due to measuring principles inherent to the system, experience of the examiner and compliance of the patient. Partial coherence interferometry with the AC-Master offers the advantage of measurement exactly along the optical axis with the highest reproducibility and patient compliance.