J Korean Ophthalmol Soc.  2006 Aug;47(8):1287-1291.

Comparison of A-scan, Scheimpflug Camera, and Orbscan for Measurement of Anterior Chamber Depth

• Ryu HW
• Kim KR
• Chung SK

Abstract

PURPOSE: To assess the reproducibility and reliability of the A-scan, Scheimpflug camera and Orbscan Topography system in measuring anterior chamber depth (ACD)
METHODS
In this prospective study of 207 eyes of 150 patients, ACD estimation prior to cataract surgery was done by three METHODS: A-scan, Scheimpflug camera, and Orbscan (in that order). One observer performed all measurements three times for each test. ACD was defined as the length between the center of anteror surface of cornea and the center of anterior lens surface.
RESULTS
The mean ACD by the three methods were 2.86+/-0.46 mm, 3.22+/-0.46 mm, and 3.13+/-0.44 mm, respectively: the differences were statistically significant (P<0.01). The correlation coefficient between Scheimpflug camera and Orbscan was 0.93. The coefficient of variation for the three methods were 3.20% in the A-scan, 1.34% in the Scheimpflug camera, and 0.84% with Orbscan.
CONCLUSIONS
Applanation A-scan gives lower measurements for ACD compared with Scheimpflug and Orbscan. There was good agreement between results obtained with the latter 2 methods based on optical principles. Orbscan had the best reproducibility of results among the three methods.

Keyword

Anterior chamber depth; A-scan; Orbscan; Scheimpflug camera

MeSH Terms

Anterior Chamber*
Cataract
Cornea
Humans
Prospective Studies
Reproducibility of Results