Agreement of corneal astigmatism measurements obtained with three devices

Session Details

Session Title: Presented Poster Session: Infection & Imaging

Venue: Poster Village: Pod 2

First Author: : X.Wang CHINA

Co Author(s): :    J. Dong   Y. Zhang   S. Zhang   B. Sun              

Abstract Details

Purpose:

To investigate inter-instrument agreement among corneal topography/ray-tracing aberrometry (iTrace), partial coherence interferometry (IOLMaster), and Scheimpflug imaging (Pentacam) for the measurements of corneal astigmatism.

Setting:

A prospective observational case series study

Methods:

A total of 90 eyes from 90 subjects without ocular disease were included in the final analysis. Main outcome measures were corneal cylinder power and axis of astigmatism. All corneal astigmatism were converted to two perpendicular components using vector analysis. The inter-device agreement was assessed by Bland-Altman analysis, paired sample t test, and one-way ANOVA.

Results:

No significant inter-instrument difference exist in astigmatism magnitude, cardinal component, oblique component (all P > 0.05). For iTrace wavefront astigmatism and Simk astigmatism comparison, there were significant difference in astigmatism magnitude, and oblique component (both < 0.01) but not the cardinal component (P = 0.687). For Pentacam pupil 3mm axial astigmatism and apex 3mm axial astigmatism comparison, there was significant difference in astigmatism magnitude (P < 0.001), but not the cardinal component and oblique component (both P > 0.05).

Conclusions:

These three instruments (iTrace, IOLMaster, Pentacam) could be used interchangeably for corneal astigmatism measurement. However, the measurement difference of iTrace wavefront astigmatism and Simk astigmatism, and Pentacam pupil 3mm and apex 3mm axial astigmatism should be noticed in clinic practice.

Financial Disclosure:

None