Journal List > J Korean Ophthalmol Soc > v.50(12) > 1008440

Yum, Choi, Kim, and Lee: Comparison of Aberrations in Korean Normal Eyes Measured With Two Different Aberrometers

Abstract

Purpose

To compare ocular higher order aberrations measured by two different aberrometers in a sample of normal eyes.

Methods

We included 41 normal eyes of Koreans in this study. Ocular aberration data were obtained through three measurements per eye using Zywave and OPD-Scan devices. Spherical equivalent and higher order aberrations calculated in the central 6 mm zone and expressed as root mean square (RMS) values were analyzed.

Results

A comparison of measurements between the Zywave and OPD-Scan devices demonstrated no statistically significant differences in the RMS values of total higher order aberration (p=0.11), but significant differences were detected in the RMS values of total spherical aberration, total coma and total trefoil (p<0.01).

Conclusions

The two different aberrometers that we tested are suitable for taking repeated measurements and are internally consistent, but not interchangeable.

References

1. Born M. Principles of optics. New York: Pergamon Press;1975. p. 464–6.
2. Rozema JJ, Van Dyck DE, Tassignon MJ. Clinical comparison of 6 aberrometers. Part 1: Technical specifications. J Cataract Refract Surg. 2005; 31:1114–27.
crossref
3. Rozema JJ, Van Dyck DE, Tassignon MJ. Clinical comparison of 6 aberrometers. Part 2: statistical comparison in a test group. J Cataract Refract Surg. 2006; 32:33–44.
crossref
4. Liang J, Grimm B, Goelz S, Bille JF. Objective measurement of wave aberrations of the human eye with the use of a Hartmann-Shack wavefront sensor. J Opt Soc Am A Opt Image Sci Vis. 1994; 11:1949–57.
crossref
5. Thibos LN. Principles of Hartmann-Shack aberrometry. J Refract Surg. 2000; 16:563–5.
crossref
6. MacRae S, Fujieda M. Slit Skiascopic-guided ablation using the Nidek Laser. J Refract Surg. 2000; 16:576–80.
crossref
7. Molebny V, Pallikaris IG, Naoumidis LP, et al. Retina ray-tracing technique for eye refraction mapping. SPIE Proc. 1997; 2971:175–83.
8. Navarro R, Moreno-Barriuso E. Laser ray-tracing method for optical testing. Opt Lett. 1999; 24:951–3.
crossref
9. Mrochen M, Kaemmerer M, Mierdel P, et al. Principles of Tscherning aberrometry. J Refract Surg. 2000; 16:570–1.
crossref
10. Mirshahi A, Buhren J, Gerhardt D, Kohnen T. In vivo and in vitro repeatability of Hartmann-Shack aberrometry. J Cataract Refract Surg. 2003; 29:2295–301.
crossref
11. Hament WJ, Nabar VA, Nuijts RM. Repeatability and validity of Zywave aberrometer measurements. J Cataract Refract Surg. 2002; 28:2135–41.
crossref
12. Durrie DS, Stahl ED. Comparing wavefront devices. Krueger RR, Applegate RA, MacRae SM, editors. Wavefront Customized Visual Correction: The Quest for Super Vision II. Thorofare, NJ: SLACK Inc;2004. 1:chap. 21.
13. Jeong JH, Kim MJ, Tchah HW. Clinical Comparison of Laser Ray Tracing Aberrometer and Shack-Hartmann Aberrometer. J Korean Ophthalmol Soc. 2006; 47:1911–9.
14. Altman DG, Bland JM. Measurements in medicine: the analysis of method comparison studies. Statistician. 1983; 32:307.
15. Bland JM, Altman DG. Statistical methods for assessing agreement between two methods of clinical measurements. Lancet. 1986; 1:307–10.
16. Bailey MD, Mitchell GL, Dhaliwal DK, et al. Patient satisfaction and visual symptoms after laser in situ keratomileusis. Ophthalmology. 2003; 110:1371–8.
crossref
17. Marcos S. Aberrations and visual performance following standard laser vision correction. J Refract Surg. 2001; 17:596–601.
crossref
18. Burakgazi AZ, Tinio B, Bababyan A, et al. Higher order aberrations in normal eyes measured with three different aberrometers. J Refract Surg. 2006; 22:898–903.
crossref
19. Rodriguez P, Navarro R, Gonzalez L, Hernández JL. Accuracy and reproducibility of Zywave, Tracey and experimental aberrometers. J Refract Surg. 2004; 20:810–7.
crossref
20. Cerviño A, Hosking SL, Montés-Micó R. Comparison of higher order aberrations measured by NIDEK OPD-Scan dynamic skiascopy and Zeiss WASCA Hartmann-Shack aberrometers. J Refract Surg. 2008; 24:790–6.
crossref
21. Kim DS, Narváez J, Krassin J, Bahjri K. Comparison of the VISX wavescan and NIDEK OPD-scan aberrometers. J Refract Surg. 2009; 25:429–34.
crossref
22. Liang CL, Juo SH, Chang CJ. Comparison of higher-order wavefront aberrations with 3 aberrometers. J Cataract Refract Surg. 2005; 31:2153–6.
crossref

Figure 1.
Repeatability Coefficient (μm)* of OPD-Scan TM and Zywave TM. This graphs show the distribution of the differences between each total higher order aberration measurement and the mean of three consecutive measurements in each of the 41 eyes. (Repeatibility coefficient: OPD-ScanTM=0.11 μm and ZywaveTM=0.06 μm)* Repeatability Coefficient (μm)=95% confidence interval for repeated measurements; HOA=higher order aberration.
jkos-50-1789f1.tif
Figure 2.
Correlations of OPD-ScanTM and Zywave TM. HOA=higher order aberration; SA=spherical aberration; r=Pearson correlation coefficient (p<0.01).
jkos-50-1789f2.tif
Table 1.
Comparisons of spherical equivalent of manifest refraction, OPD-Scan TM and Zywave TM
  MR* OPD scan TM Zywave TM OPD scan TM-MR*(pair t-test) Zywave TM-MR*(pair t-test) OPDscan TM-Zywave TM (pair t-test)
Spherical equivalent (Diopters) −0.26±0.75 −0.21±0.85 +0.11±0.83 0.05±0.36(p=0.11) 0.37±0.33(p<0.01) −0.31±0.15(p<0.01)

* MR=manifest refraction.

Table 2.
Repeatability Coefficient (μm)* of OPD-Scan TM and Zywave TM
  OPD scan TM ZywaveTM
Total higher order aberration (μm) 0.11 0.06
Total Spherical aberration (μm) 0.12 0.05
Total Coma (μm) 0.13 0.06
Total Trefoil (μm) 0.13 0.08

* Repeatability Coefficient (μm)=95% confidence interval for repeated measurements.

Table 3.
Comparisons of higher order aberrations between OPD-Scan TM and Zywave TM
  OPD scan TM Zywave TM OPD scan TM-Zywave TM (paired t-test)
Total higher order aberration (μm) 0.436±0.143 0.409±0.144 0.027±0.097
      (p=0.11)
Total Spherical aberration (μm) 0.133±0.126 0.168±0.128 −0.335±0.097
      (p<0.01)
Total Coma (μm) 0.199±0.123 0.233±0.129 −0.034±0.113
      (p<0.01)
Total Trefoil (μm) 0.306±0.131 0.217±0.096 0.089±0.120
      (p<0.01)

Root mean square value (μm) of aberration from 3 rd to 5 th order in the central 6-mm area was calculated.

TOOLS
Similar articles