Anzeige
Erschienen in:
01.05.2006 | Clinical Investigation
Evaluation of biometric methods for measuring the anterior chamber depth in the non-contact mode
Erschienen in: Graefe's Archive for Clinical and Experimental Ophthalmology | Ausgabe 5/2006
Einloggen, um Zugang zu erhaltenAbstract
Purpose
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).
Methods
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).
Results
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 α=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 μm for AC-Master, ±12.7 μm for Pentacam, ±24.5 μm for IOL-Master and ±41.2 μm for Jaeger. The maximum method-dependent difference in ACD determination was 285 μm.
Conclusions
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.