J Korean Ophthalmol Soc.  2019 Oct;60(10):922-928. 10.3341/jkos.2019.60.10.922.

Comparison of Corneal Astigmatism and Higher-order Aberrations between Color Light-emitting Diode Topographer and Scheimpflug Imager

• Kim DY
• Ha M
• Yi R
• Kim HW
• Chung SH

• KMID: 2460509
• DOI: http://doi.org/10.3341/jkos.2019.60.10.922

Abstract

PURPOSE
To compare corneal astigmatism, keratometry and corneal higher order aberrations between the light emitting diode corneal topography analyzer and Scheimpflug Imager.
METHODS
This prospective study involved 45 patients (45 eyes) who visited Seoul St. Mary's hospital before cataract surgery from June 7, 2017, to August 2, 2017. For each eye, keratometry, astigmatism and its axis of cornea, higher-order aberrations were evaluated with a Scheimpflug Imager (Pentacam HR®, Oculus, Wetzlar, Germany) and a color-LED corneal topographer (Cassini®, i-Optics, Den Haag, The Netherlands).
RESULTS
Astigmatism magnitude measured using Cassini® and Pentacam® showed no statistically differences but anterior and total astigmatic axes were significantly different, as measured by the two devices (p < 0.05). Anterior and total mean keratometry were statistically significantly different, as measured by the two devices (p < 0.05). J0 and J45 vectors of anterior and total cornea were statistically different (p < 0.05). In addition, Cassini® and Pentacam® showed discrepancies between total corneal astigmatism, total J0 and J45 vectors. Corneal anterior spherical aberration, vertical and horizontal coma, and oblique and horizontal trefoil aberrations were not statistically different between the two devices.
CONCLUSIONS
Astigmatic axes obtained from the two devices based on different principles showed statistically significant differences. Astigmatism magnitude was not statistically different but showed a discrepancy between the two devices.

Keyword

Astigmatism; Corneal topography; Corneal wavefront aberration

MeSH Terms

Astigmatism*
Cataract
Coma
Cornea
Corneal Topography
Corneal Wavefront Aberration
Humans
Lotus
Prospective Studies
Seoul

Figure

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  Figure 1. Bland-Altman plots showing the agreement between total astigmatism magnitude, J0 and, J45 obtained by the 2 devices (Cassini® and Pentacam®). (A-C) graphs plot the differences against the average of the two measurements, with 95% limits of agreement and mean difference. (A) Total astigmatism magnitude (B) Total J0 (C) Total J45. The dotted lines show the 95% LoA. The bold line shows the regression line. D = diopters.

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  Figure 2. Correlations of measurements of the (A) spherical aberration, (B) vertical coma, (C) horizontal coma between Pentacam® and Cassini®. SA = spherical aberration; r = Pearson correlation coefficient. * Statistically significant (p < 0.05, based on t-test).

Reference

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