Comparison of Corneal Higher-Order Aberrations Measured with Two Instruments Using Scheimpflug Camera System

Yeon Jung Choi; Na Hee Kang; Roo Min Jun

doi:10.3341/jkos.2015.56.10.1497

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Choi, Kang, and Jun: Comparison of Corneal Higher-Order Aberrations Measured with Two Instruments Using Scheimpflug Camera System

Original Article

J Korean Ophthalmol Soc 2015;56(10):1497-1504.

Published online: 29 August 2015

DOI: https://doi.org/10.3341/jkos.2015.56.10.1497

Comparison of Corneal Higher-Order Aberrations Measured with Two Instruments Using Scheimpflug Camera System

Yeon Jung Choi, M.D¹, Na Hee Kang, M.D, PhD², Roo Min Jun, M.D, PhD¹

¹Department of Ophthalmology, Ewha Womans University School of Medicine, Seoul, Korea

²BE Woorieyes Clinic, Chuncheon, Korea

Address reprint requests to Roo Min Jun, MD, PhD Department of Ophthalmology, Ewha Womans University Mokdong Hospital, #1071 Anyangcheon-ro, Yangcheon-gu, Seoul 07985, Korea Tel: 82-2-2650-5154, Fax: 82-2-2650-4334 E-mail: jrmoph@ewha.ac.kr

‗ This study was presented as a narration at the 113th Annual Meeting of the Korean Ophthalmological Society 2015.

Received 17 April 20155 June 2015 Accepted 14 August 2015

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 compare the corneal higher-order aberrations (HOAs) of normal young subjects using Galilei ^TM G4 (Zeimer, Port, Switzerland) and Pentacam^® (Oculus Inc., Wetzlar, Germany).

Methods

Corneal HOAs were measured using Galilei ^TM G4 and Pentacam^® in 41 healthy individuals (41 eyes). Intraclass corre-lation coefficients (ICCs) were obtained to evaluate the repeatability of the 2 devices. Differences in HOAs between the 2 instru-ments were analyzed with a paired t-test and correlations evaluated.

Results

All ICCs measured using Galilei ^TM G4 and Pentacam^® showed more than moderate repeatability (>0.81) except trefoil, tetrafoil, 4th and 5th HOAs. When comparing the measurements obtained with Galilei ^TM G4 and Pentacam^®, total HOAs, spher-ical aberration (SA), secondary astigmatism and 5th total HOAs were statistically significantly different between the 2 device (all p ≤ 0.001). In addition, Galilei ^TM G4 and Pentacam^® showed discrepancy among all corneal HOAs items. Although the total cor-neal HOAs and the SA were significantly correlated, other HOA measurements generally exhibited a low correlation.

Conclusions

Corneal HOAs obtained by the 2 instruments cannot be used interchangeably due to their differences and discrep-ancy although corneal HOAs measured using Galilei ^TM G4 and Pentacam^® showed relatively high repeatability.

Keywords: Corneal higher-order aberrations, Galilei ^TM G4, Pentacam

References

1. Lombardo M, Lombardo G. Wave aberration of human eyes and new descriptors of image optical quality and visual performance. J Cataract Refract Surg. 2010; 36:313–31.

2. Artal P, Guirao A, Berrio E, Williams DR. Compensation of cor-neal aberrations by the internal optics in the human eye. J Vis. 2001; 1:1–8.

3. Campbell CE. A new method for describing the aberrations of the eye using Zernike polynomials. Optom Vis Sci. 2003; 80:79–83.

4. Barkana Y, Gerber Y, Elbaz U. . Central corneal thickness measurement with the Pentacam Scheimpflug system, optical low- coherence reflectometry pachymeter, and ultrasound pachymetry. J Cataract Refract Surg. 2005; 31:1729–35.

5. Lee YE, Jun RM. The intra and inter-examiner repeatability of cor-neal parameters obtained by GALILEI(TM) in normal subjects. J Korean Ophthalmol Soc. 2009; 50:1611–16.

6. Burakgazi AZ, Tinio B, Bababyan A. . Higher order aberra-tions in normal eyes measured with three different aberrometers. J Refract Surg. 2006; 22:898–903.

7. Yum JH, Choi SK, Kim JH, Lee DH. Comparison of aberrations in Korean normal eyes measured with two different aberrometers. J Korean Ophthalmol Soc. 2009; 50:1789–94.

8. Knapp S, Awwad ST, Ghali C, McCulley JP. Ocular aberrations measured by the Fourier-based WaveScan and Zernike-based LADARWave Hartmann-Shack aberrometers. J Refract Surg. 2009; 25:201–9.

9. Shin JY, Lee MY, Chung SH. Comparison of keratometry and cor-neal higher order aberrations between Scout videokeratoscope and Pentacam Scheimpflug camera. J Korean Ophthalmol Soc. 2014; 55:1758–64.

10. McGraw KO, Wong SP. Forming inferences about some intraclass correlation coefficients. Psychological Methods. 1996; 1:30.

11. Williams D, Yoon GY, Porter J. . Visual benefit of correcting higher order aberrations of the eye. J Refract Surg. 2000; 16:S554–9.

12. Artal P, Berrio E, Guirao A, Piers P. Contribution of the cornea and internal surfaces to the change of ocular aberrations with age. J Opt Soc Am A Opt Image Sci Vis. 2002; 19:137–43.

13. López-Miguel A, Maldonado MJ, Belzunce A. . Precision of a commercial hartmann-shack aberrometer: limits of total wavefront laser vision correction. Am J Ophthalmol. 2012; 154:799–807.e5.

14. Aramberri J, Araiz L, Garcia A. . Dual versus single Scheimpflug camera for anterior segment analysis: precision and agreement. J Cataract Refract Surg. 2012; 38:1934–49.

15. Cerviño A, Dominguez-Vicent A, Ferrer-Blasco Blasco. . Intrasubject repeatability of corneal power, thickness, and wavefront aberra-tions with a new version of a dual rotating Scheimpflug-Placido system. J Cataract Refract Surg. 2015; 41:186–92.

16. Wang L, Shirayama M, Koch DD. Repeatability of corneal power and wavefront aberration measurements with a dual-Scheimpflug Placido corneal topographer. J Cataract Refract Surg. 2010; 36:425–30.

17. Netto MV, Ambrósio R Jr, Shen TT, Wilson SE. Wavefront analy-sis in normal refractive surgery candidates. J Refract Surg. 2005; 21:332–8.

18. Yoon G, Macrae S, Williams DR, Cox IG. Causes of spherical aberration induced by laser refractive surgery. J Cataract Refract Surg. 2005; 31:127–35.

19. Domínguez-Vicent A, Monsálvez-Romín D, Aguila-Carrasco Carrasco. . Measurements of anterior chamber depth, white-to-white dis-tance, anterior chamber angle, and pupil diameter using two Scheimpflug imaging devices. Arq Bras Oftalmol. 2014; 77:233–7.

20. Al-Sayyari TM, Fawzy SM, Al-Saleh AA. Corneal spherical aber-ration in Saudi population. Saudi J Ophthalmol. 2014; 28:207–13.

Figure 1.

Bland-Altman plots showing the agreement between mean corneal aberrometers (μ m) obtained by the 2 tomography de-vices: Galilei ^TM G4 and Pentacam®. (A-F) graphs plot the difference against the average of two measurements of corneal HOAs, with 95% limits of agreement (broken lines) and the mean difference (black line). (A) Total corneal HOAs, (B) Coma, (C) Trefoil, (D) Spherical aberration, (E) Secondary astigmatism, (F) Tetrafoil. HOAs = higher-order aberrations; SA = spherical aberration; 2° astig = secondary astigmatism.

Figure 2.

Correlations of measurements of corneal aberration using Galilei ^TM G4 and Pentacam®. (A-F) Shows measurements of total corneal HOAs using Galilei ^TM G4 against Pentacam® measurements. (A) Total corneal HOAs, (B) Coma, (C) Trefoil, (D) Spherical aberration, (E) Secondary astigmatism, (F) Tetrafoil. HOAs = higher-order aberrations; SA = spherical aberration; 2° astig = sec-ondary astigmatism; r = Pearson correlation coefficient. ^* Statistically significant ( p-value < 0.05, based on t-test).

Table 1.

Demographics of subjects

	Data
No. of subjects (eyes)	41 (41)
Age (years)	27.76 ± 4.04 (19-35)
Male:female	14:27
SE (diopter)	-1.87 ± 2.33 (-6.0 ± 5.0)

Values are presented as mean ± SD unless otherwise indicated. SE = spherical equivalent.

Table 2.

Intra-examiner ICC of corneal HOAs using Galilei ^TM G4 and Pentacam®

	Pentacam®		Galilei ^TM G4
	ICC	95% CI	ICC	95% CI
Total corneal HOAs (μ m)	0.885	0.762-0.950	0.970	0.949-0.984
3° total HOA (μ m)	0.877	0.751-0.945	0.816	0.684-0.898
Coma Z (3, 1) (μ m)	0.924	0.845-0.967	0.951	0.916-0.973
Trefoil Z (3, 3) (μ m)	0.532	0.039-0.795	0.433	0.018-0.688
4° total HOA (μ m)	0.644	0.271-0.842	0.675	0.443-0.821
SA Z (4, 0) (μ m)	0.896	0.784-0.955	0.933	0.886-0.963
2° astig Z (4, 2) (μ m)	0.907	0.808-0.959	0.842	0.730-0.913
Tetrafoil Z (4, 4) (μ m)	0.692	0.372-0.864	0.430	0.029-0.683
5° total HOA (μ m)	0.761	0.521-0.892	0.612	0.331-0.787

ICC = intraclass correlation coefficient; CI = confidence interval; HOA = higher-order aberration; SA = spherical aberration; 2° astig = secondary astigmatism.

Table 3.

The comparison of corneal HOAs between the Galilei ^TM G4 and Pentacam®

	Pentacam®	Galilei ^TM G4	p-value^*	Mean difference
Total corneal HOAs (μ m)	0.490 ± 0.175	0.638 ± 0.200	<0.001	0.148 ± 0.366
3rd order HOA (μ m)	0.114 ± 0.047	0.131 ± 0.052	0.141	0.016 ± 0.129
Coma Z (3, 1) (μ m)	-0.022 ± 0.063	0.002 ± 0.068	0.141	-0.024 ± 0.190
Trefoil Z (3, 3) (μ m)	-0.027 ± 0.063	-0.039 ± 0.036	0.272	-0.012 ± 0.128
4th order HOA (μ m)	0.074 ± 0.026	0.083 ± 0.027	0.170	-0.009 ± 0.073
SA Z (4, 0) (μ m)	0.032 ± 0.024	0.045 ± 0.016	0.001	-0.014 ± 0.048
2° astig Z (4, 2) (μ m)	-0.004 ± 0.026	-0.003 ± 0.025	0.219	-0.007 ± 0.068
Tetrafoil Z (4, 4) (μ m)	-0.029 ± 0.028	-0.004 ± 0.033	0.872	-0.001 ± 0.094
5th order HOA (μ m)	0.025 ± 0.012	0.037 ± 0.018	<0.001	-0.013 ± 0.037

^* Values are presented as mean ± SD unless otherwise indicated. HOA = higher-order aberration; SA = spherical aberration; 2° astig = secondary astigmatism.

^* p-value based on t-test.

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