Sang Moon Youn; Sung Hyup Lim; Ho Young Lee

doi:10.3341/jkos.2014.55.6.801

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Youn, Lim, and Lee: Measurement Comparison of Anterior Segment Parameters between AL-Scan® and Pentacam®

Original Article

J Korean Ophthalmol Soc 2014;55(6):801-808.

Published online: 30 August 2014

DOI: https://doi.org/10.3341/jkos.2014.55.6.801

Measurement Comparison of Anterior Segment Parameters between AL-Scan® and Pentacam®

Sang Moon Youn, MD¹, Sung Hyup Lim, MD¹, Ho Young Lee, MD²

¹Department of Ophthalmology, Inje University Busan Paik Hospital, Inje University College of Medicine, Busan, Korea

²Shinsegae Eye Clinic, Busan, Korea

Address reprint requests to Ho Young Lee, MD, Shinsegae Eye Clinic, #783-1 Gaya-daero, Busanjin-gu, Busan, 614-849, Korea, Tel: 82-51-818-8288, Fax: 82-51-808-8238, E-mail: happytriad@gmail.com

Received 13 December 2013 Revised 20 January 2014 Accepted 22 May 2014

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Purpose

To investigate the clinical availability of AL-Scan® (Nidek, GAMAGORI, Japan) by comparing anterior segment param-eters measured with AL-Scan® and Pentacam® (Oculus, Wetzlar, Germany).

Methods

Seventy-three patients (117 eyes) who received refractive surgery at our hospital were tested with AL-Scan® and Pentacam®. We compared measurements including anterior chamber depth, central corneal thickness, white-to-white, and cor-neal curvature.

Results

When comparing measurements obtained with AL-Scan® and Pentacam®, the anterior chamber depth (p < 0.001), cen-tral corneal thickness (p < 0.001) and 2.4 mm zone K value (p = 0.038) showed significant differences; the white-to-white (p =0.348) and 3.3 mm zone K value (p = 0.429) showed no significant differences. All AL-Scan® and Pentacam® parameters had a strong positive linear correlation (p < 0.001). The Bland-Altman plots showed a high degree of agreement between AL-Scan® and Pentacam® in all parameters except for anterior chamber depth.

Conclusions

AL-Scan® is convenient to use clinically because simultaneous measurements of ocular biometry including axial length, intraocular lens power, and topography are possible. However, because differences in some anterior segment parame-ters exist when compared with Pentacam®, measurements with AL-Scan® may require comparisons with other instruments.

Keywords: AL-Scan®, Anterior chamber depth, Central corneal thickness, Corneal refractive power, Pentacam®

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Figure 1.

Pearson correlation of AL-Scan® and Pentcam® in anterior segment parameters. ACD = anterior chamber depth; CCT = central corneal thickness; WTW = white-to-white; K = keratometric diopter.

Figure 2.

Bland-Altman plots of AL-Scan® and Pentacam® in anterior segment parameters. ACD = anterior chamber depth; CCT = central corneal thickness; WTW= white-to-white; K = keratometric diopter.

Table 1.

Comparison of AL-Scan® and Pentacam® in anterior segment parameters

	AL-Scan®	Pentacam®	p-value
Anterior chamber depth (mm)	3.77 ± 0.30	3.18 ± 0.29	<0.001^*
Anatomical anterior chamber depth (mm)	3.22 ± 0.29	3.18 ± 0.29	<0.001^*
Central corneal thickness (μm)	548.74 ± 33.41	543.38 ± 32.49	<0.001^*
White-to-white (mm)	11.81 ± 0.32	11.77 ± 0.34	0.348^*
K1 (2.4 mm zone) (diopter)	42.68 ± 1.24	42.61 ± 1.30^†	0.004^*
K2 (2.4 mm zone) (diopter)	44.03 ± 1.55	44.03 ± 1.60^†	0.876^*
Kmean (2.4 mm zone) (diopter)	43.36 ± 1.35	43.32 ± 1.40^†	0.038^*
K1 (3.3 mm zone) (diopter)	42.67 ± 1.25	42.61 ± 1.30^†	0.005^*
K2 (3.3 mm zone) (diopter)	43.99 ± 1.54	44.03 ± 1.60^†	0.177^*
Kmean (3.3 mm zone) (diopter)	43.33 ± 1.35	43.32 ± 1.40^†	0.429^*

Values are presented as mean ± SD.

K = keratometric diopter.

^* Paired-t test;

^† Corneal refractive power with Pentacam® was measured only 3.0 mm zone.

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