Comparison of WaveScan Aberrometer Refraction to Subjective Manifest Refraction and Autorefractor

Sang Jun Park; Won Ryang Wee; Jin Hak Lee; Mee Kum Kim

doi:10.3341/jkos.2009.50.5.684

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Park, Wee, Lee, and Kim: Comparison of WaveScan Aberrometer Refraction to Subjective Manifest Refraction and Autorefractor

Original Article

J Korean Ophthalmol Soc 2009;50(5):684-690.

Published online: 7 September 2009

DOI: https://doi.org/10.3341/jkos.2009.50.5.684

Comparison of WaveScan Aberrometer Refraction to Subjective Manifest Refraction and Autorefractor

Sang Jun Park, MD¹, Won Ryang Wee, MD^1,², Jin Hak Lee, MD^1,^2,³, Mee Kum Kim, MD^1,²

¹Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea

²Seoul Artificial Eye Center, Seoul National University Hospital Clinical Research Institute, Seoul, Korea

³Department of Ophthalmology, Seoul National University Bundang Hospital, Sungnam, Korea

Address reprint requests to Mee Kum Kim, MD Department of Ophthalmology, Seoul National University College of Medicine #28 Yeongeon-dong, Jongno-gu, Seoul 110-744, Korea Tel: 82-2-2072-2662, Fax: 82-2-741-3187, E-mail: kmk9@snu.ac.kr

Received 1 September 2008 Accepted 14 January 2008

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 accuracy of myopic refraction using an aberrometer (WaveScan, Visx, Santa Clara, CA, USA) with manifest refraction using retinoscopy and an autorefractor.

Methods

The medical records of 200 eyes in 100 patients who visited our clinic from February 2005 to February 2007 for refractive surgery were reviewed retrospectively. We compared the refractive errors obtained using an aberrometer, retinoscopy, and an autorefractor (KR-7100, Topcon, Tokyo, Japan). All of the measured refractive errors were converted to power vectors for statistical analysis. The power vectors consisted of the M vector (M), J₀ vector (J₀), and J₄₅ vector (J₄₅).

Results

The mean sphere was −4.75 diopters (D) and the mean cylinder was −0.66D with retinoscopy. Power vectors of the aberrometer (PVw) were highly correlated with power vectors of retinoscopy (PVr) and the autrorefractor (PVa). The correlation coefficients (R₂) between PVw and PVr were 0.960 (M), 0.852 (J₀), and 0.679 (J₄₅) and the correlation coefficients between PVw and PVr were 0.963 (M), 0.685 (J₀), and 0.516 (J₄₅). Mean differences were −0.247±0.412D (M), 0.034±0.120D (J₀), and −0.017±1.07D (J₄₅) between PVw and PVr, and were –0.068±0.403D (M), −0.055±0.194D (J₀), and −0.052±0.165D (J₄₅) between PVw and PVa.

Conclusions

The measurement of refractive errors using a WaveScan aberrometer seems to be reliable and accurate, although some myopic shift was observed.

Keywords: Aberrometer, Autorefractor, Manifest refraction, Refraction

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Figure 1.

Correlation graphs and correlation coefficients.

Table 1.

Best corrected visual acuity of patients

Visual acuity	Number	Percent	Cumulative percent
20/12.5	30	15%	14%
20/16	141	70.5%	85.5%
20/20	29	14.5%	100%

Table 2.!

Descriptive statistics of vector analysis

	WaveScan (D)	Manifest refraction (D)	Autorefraction (D)
M vector	−5.00±2.07	−4.75±2.04	−4.93±2.11
J₀ vector	0.266±0.310	0.232±0.297	0.320±0.343
J₄₅ vector	−0.028±0.190	−0.012±0.165	0.024±0.237

D=diopter.

Table 3.

Linear regression statistics with the vectors of the WaveScan

		Pearson correlation	R²	p Value
WaveSacn	M vector	0.980	0.960	<0.001
− Manifest refraction	J₀ vector	0.923	0.852	<0.001
	J₄₅ vector	0.825	0.679	<0.001
WaveSacn	M vector	0.982	0.963	<0.001
− Autorefractor	J₀ vector	0.829	0.685	<0.001
	J₄₅ vector	0.720	0.516	<0.001

Table 4.

Difference of the vectors between the instruments

		Difference (Mean±SD)	95% Confidence Interval	p Value
WaveSacn	M vector	−0.247±0.412	−0.305, −0.189	<0.001
− Manifest refraction	J₀ vector	0.034±0.120	0.017, 0.050	<0.001
	J45 vector	−0.017±0.107	−0.031, −0.002	0.031
WaveSacn	M vector	−0.068±0.403	−0.124, −0.012	0.018
− Autorefractor	J₀ vector	−0.055±0.194	−0.082, −0.028	<0.001
	J₄₅ vector	−0.052±0.166	−0.075, −0.029	<0.001

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