J Korean Ophthalmol Soc.  2013 Aug;54(8):1219-1226.

Comparison of Anterior Chamber Depth Obtained from Applanation and Optical Principle Devices

• Park Y
• Hwang HB
• Chung SK

Abstract

PURPOSE
To assess the reproducibility and reliability of applanation A-scan ultrasonography (Pacscan 300A, Sonomed Inc., Chicago, IL, USA) and optical measurements with IOL Master(R) (Carl Zeiss Meditec, Germany), Pentacam(R) (Oculus, Wetzlar, Germany), and Orbscan II(R) (Orbtek Inc., Laredo, TX, USA) when measuring anterior chamber depth (ACD).
METHODS
In this study of 188 eyes of 94 patients, ACD estimation prior to cataract surgery was preformed by the applanation A-scan method and IOL Master(R), Pentacam(R), and Orbscan II(R) optical methods. Repeatability from each device was evaluated by coefficient of variation, standard deviation, and intraclass correlation coefficient. RM-ANOVA on Ranks was used to compare the differences in ACD among the devices. The Bland-Altman plot was performed to assess agreement in measurements between the devices.
RESULTS
The mean ACD according to the applanation A-scan method and IOL Master(R), Pentacam(R), and Orbscan II(R) optical methods were 2.89 +/- 0.49 mm, 3.25 +/- 0.45 mm, 3.21 +/- 0.46 mm, and 3.19 +/- 0.47 mm, respectively, and the differences were statistically significant (p < 0.01). The coefficient of variation for the 4 methods was 2.50% in the A-scan, 0.87% in the IOL Master(R), 1.25% in the Pentacam(R), and 1.04% with Orbscan II(R), and reproducibility was higher with the optical principle devices. The correlation coefficient between A-scan and IOL Master(R) was 0.65, between IOL Master(R) and Pentacam(R) 0.91, between IOL Master(R) and Orbscan II(R) 0.90, between A-scan and Pentacam(R) 0.69, between A-scan and Orbscan II(R) 0.71, and between Pentacam(R) and Orbscan II(R) 0.93.
CONCLUSIONS
Applanation A-scan provided lower measurements for ACD compared with IOL Master(R), Pentacam(R) and Orbscan II(R). There was good agreement between results obtained with the latter 3 methods, and reproducibility was high with optical measurements. The coefficient of variation was low for IOL Master(R).

Keyword

Anterior chamber depth; A-scan; IOL Master(R); Orbscan II(R); Pentacam(R)

MeSH Terms

Anterior Chamber
Cataract
Chicago
Eye
Humans

Figure

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  Figure 1. Correlation plot of anterior chamber depth measured by each device. (A) Correlation plot of anterior chamber depth measured by A scan and IOL MasterⓇ. (B) Correlation plot of anterior chamber depth measured by A scan and PentacamⓇ. (C) Correlation plot of anterior chamber depth measured by A scan and Orbscan IIⓇ. (D) Correlation plot of anterior chamber depth measured by IOL MasterⓇ and PentacamⓇ. (E) Correlation plot of anterior chamber depth measured by IOL MasterⓇ and Orbscan IIⓇ. (F) Correlation plot of anterior chamber depth measured by Orbscan IIⓇ and pentacam.

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  Figure 2. Bland-Altman plots showing differences in anterior chamber depth measurements between devices. The upper and lower dashed lines indicate 95% limits of agreement, and the solid line indicates the mean.

Reference

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