Journal List > J Korean Ophthalmol Soc > v.55(12) > 1009855

Shin, Lee, and Chung: Comparison of Keratometry and Corneal Higher Order Aberrations between Scout Videokeratoscope and Pentacam Scheimpflug Camera

Abstract

Purpose

To investigate the correlations of keratometry and corneal high order aberrations (HOAs) between the Keratron Scout videokeratoscope and the Pentacam HR Scheimpflug camera.

Methods

From December 2012 to February 2013, keratometry and corneal HOAs were determined using the Keratron Scout videokeratoscope and Pentacam HR Scheimpflug camera in 23 healthy individuals (46 eyes).

Results

Average keratometry showed high correlation with 95% confidence interval −0.155 ± 0.37 between the Keratron Scout and Pentacam HR. When comparing HOAs of the Keratron Scout and total corneal HOAs of Pentacam HR, total root-meansquare (RMS), and spherical aberration were positively correlated between the 2 devices (r = 0.67, p < 0.001 and r = 0.74, p < 0.001, respectively). When comparing HOAs of Keratron Scout and anterior corneal HOAs of Pentacam HR, total RMS, spherical aberration and coma were positively correlated between the 2 devices (r = 0.62, p < 0.001, r = 0.81, p < 0.001, and r = 0.52, p = 0.047, respectively).

Conclusions

Although the 2 devices are based upon different principles, the Keratron Scout videokeratoscope and Pentacam HR Scheimpflug camera showed positive correlations in keratometry, total RMS, spherical aberration, and coma. Both devices may be useful for clinical applications.

References

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Figure 1.
The comparison of average keratometry (K) between the Keratron Scout videokeratoscopy and Pentacam HR Scheimpflug Camera. The solid line represents ±0.37 standard deviation confidence interval (CI) (i.e. 95% of the points should fall within these lines).
jkos-55-1758f1.tif
Figure 2.
The correlation between corneal higher order aberrations (HOAs) of the Keratron Scout videokeratoscopy and total corneal HOAs of Pentacam HR Scheimpflug Camera. RMS = root-mean-square; SA = spherical aberration.
jkos-55-1758f2.tif
Figure 3.
The correlation between corneal higher order aberrations (HOAs) of Keratron Scout videokeratoscopy and anterior corneal HOAs of Pentacam HR Scheimpflug Camera. RMS = root-mean-square; SA = spherical aberration.
jkos-55-1758f3.tif
Table 1.
Demographics of 23 patients (M:F = 8:15)
Values
Age (years) 24.4 ± 4.24
UCVA (log MAR) 0.16 ± 0.08
BCVA (log MAR) 0.92 ± 0.09
Sphere (diopter) −3.76 ± 1.54
Cylinder (diopter) −1.48 ± 0.86

Values are presented as mean ± SD.

UCVA = uncorrected visual acuity; BCVA = best corrected visual acuity.

Table 2.
The comparison of cornea higher order aberrations (HOAs) between the Keratron Scout videokeratoscopy and Pentacam HR Scheimpflug Camera
Scout (corneal HOAs) Pentacam (corneal HOAs) p-value
Total RMS 0.41 ± 0.06 0.37 ± 0.05 0.054
Spherical aberration 0.24 ± 0.07 0.22 ± 0.08 0.061
Coma 0.20 ± 0.07 0.18 ± 0.05 0.005
Trefoil 0.16 ± 0.01 0.10 ± 0.01 <0.001
Scout (corneal HOAs) Pentacam (anterior corneal HOAs) p-value
Total RMS 0.41 ± 0.06 0.40 ± 0.07 0.31
Spherical aberration 0.26 ± 0.06 0.27 ± 0.08 0.153
Coma 0.20 ± 0.07 0.20 ± 0.07 0.173
Trefoil 0.18 ± 0.06 0.10 ± 0.01 <0.001

Values are presented as mean ± SD.

RMS = root-mean-square.

Table 3.
The correlation of cornea higher order aberrations (HOAs) between the Keratron Scout videokeratoscopy and Pentacam HR Scheimpflug Camera
Scout (corneal HOAs) Pentacam (corneal HOAs) Differences Correlation coefficient p-value
Total RMS 0.41 ± 0.06 0.37 ± 0.05 0.04 ± 0.05 0.67 <0.001
Spherical aberration 0.24 ± 0.07 0.22 ± 0.08 0.02 ± 0.05 0.74 <0.001
Coma 0.20 ± 0.07 0.18 ± 0.05 0.03 ± 0.09 0.32 0.189
Trefoil 0.16 ± 0.01 0.10 ± 0.01 0.07 ± 0.06 0.45 0.105
Scout (corneal HOAs) Pentacam (anterior corneal HOAs) Differences Correlation coefficient p-value
Total RMS 0.41 ± 0.06 0.40 ± 0.07 0.01 ± 0.06 0.62 <0.001
Spherical aberration 0.26 ± 0.06 0.27 ± 0.08 0.03 ± 0.05 0.81 <0.001
Coma 0.20 ± 0.07 0.20 ± 0.07 0.02 ± 0.09 0.52 0.047
Trefoil 0.18 ± 0.06 0.10 ± 0.01 0.07 ± 0.07 0.43 0.094

Values are presented as mean ± SD.

RMS = root-mean-square.

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