J Korean Ophthalmol Soc.  2013 Nov;54(11):1688-1693. 10.3341/jkos.2013.54.11.1688.

Accuracy of Ocular Biometry and Postoperative Refraction in Cataract Patients with AL-Scan(R)

• Kim SI
• Kang SJ
• Oh TH
• Choi JS
• Baek NH

• KMID: 2217915
• DOI: http://doi.org/10.3341/jkos.2013.54.11.1688

Abstract

PURPOSE
To compare the axial lengths, anterior chamber depths, and keratometric measurements and to predict postoperative refractions of AL-Scan(R), IOL master(R), and ultrasound.
METHODS
A total of 40 eyes in 30 patients who received cataract surgery were included in the present study. The axial length, anterior chamber depth, and keratometry were measured by 2 types of partial coherence interferometry (AL-Scan(R) and IOL master(R)) and ultrasound. The SRK/T formula was used to calculate IOL power, and the predictive error which subtracts predictive refraction from postoperative refraction was compared among the ocular biometry devices.
RESULTS
Axial lengths were 23.08 +/- 0.62 mm, 23.09 +/- 0.62 mm, and 22.99 +/- 0.62 mm measured by AL scan(R), IOL master(R), and ultrasound, respectively. Axial length measured by ultrasound was statistically significantly shorter than AL scan(R) and IOL master(R) (p < 0.001, p < 0.001, respectively). The anterior chamber depth and keratometry were 3.11 +/- 0.06 mm and 44.82 +/- 1.34 D measured by AL scan(R), and 3.13 +/- 0.06 mm and 44.85 +/- 1.26 D measured by IOL master(R), respectively. The differences of anterior chamber depth and keratometry between the 2 devices were not statistically significant (p = 0.226, p = 0.331, respectively). The mean absolute prediction errors were 0.44 +/- 0.35 D, 0.40 +/- 0.34 D, and 0.39 +/- 0.30 D in AL-Scan(R), IOL master(R) and ultrasound, respectively, and were not statistically significantly different (p = 0.843, p = 0.847, p = 1.000, respectively).
CONCLUSIONS
The ocular biometric measurements and prediction of postoperative refraction using AL-Scan(R) were as accurate as IOL master(R) and ultrasound.

Keyword

AL-Scan(R); Axial length; IOL master(R); Partial coherence interferometry

MeSH Terms

Anterior Chamber
Biometry*
Cataract*
General Surgery
Humans
Interferometry
Ultrasonography

Figure

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  Figure 1. Bland-Altman plot of axial length between AL scan® and IOL master® (A), and A-scan (B) (95% limits of agreement for axial length difference: AL scan® -IOL master® [-0.049, 0.036]; AL scan® - A-scan [0.048, 0.141]).

• 

  Figure 2. Bland-Altman plot of anterior chamber depth between AL scan® and IOL master® (95% limits of agreement for axial length difference: AL scan® - IOL master® [-0.34, 0.28]).

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  Figure 3. Bland-Altman plot of keratometry between AL scan® and IOL master® (A), and Auto refractive keratometry (ARK) (B) (95% limits of agreement for axial length difference: AL scan® -IOL master® [-0.49, 0.41]; AL scan® - ARK [-0.44, 0.38]).

Reference

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