Comparison of keratometric corneal power and keratometric astigmatism measurements obtained by a swept-source optical coherence tomography, a rotating Scheimpflug-based corneal tomography and a placido-based corneal topography

Session Details

Session Title: Imaging Anterior Segment

Session Date/Time: Sunday 08/10/2017 | 16:00-18:00

Paper Time: 16:42

Venue: Meeting Center Room I

First Author: : S.Koh JAPAN

Co Author(s): :    N. Maeda   K. Okamoto   K. Nishida              

Abstract Details

Purpose:

To evaluate and compare the agreement and repeatability in measuring keratometric corneal power and keratometric astigmatism among a swept-source optical coherence tomography (OCT), a rotating Scheimpflug-based corneal tomography and a Placido-based corneal topography.

Setting:

Osaka University Hospital, Osaka, Japan

Methods:

Two consecutive series of anterior segment images were obtained from 22 normal eyes and 21 keratoconic eyes with swept-source OCT (Casia 2, Tomey), rotating Scheimpflug-based corneal tomography (Pentacam HR, Oculus) and Placido-based corneal topography (KR-1W, Topcon). The main outcome measures were keratometric corneal power and keratometric astigmatism. Repeated-measures analysis of variance, Bland-Altman plots and the within-subjects SD were used to evaluate the agreement and repeatability between the measurements.

Results:

Keratometric corneal power measured with OCT was significantly greater than those with other 2 devices in normal group. (P<0.05) Keratometric astigmatism measured with OCT was significantly greater than those with Placido-based corneal topography in both groups. (P<0.05) The agreement of both keratometric corneal power and keratometric astigmatism among the 3 devices was high in both groups. Repeatability of both parameters were better with OCT than with other 2 devices in both groups. In keratoconus group, the repeatability difference between OCT and Placido-based corneal topography were remarkably greater than that between OCT and rotating Scheimpflug-based corneal tomography.

Conclusions:

Significant differences in keratometry results were found between OCT and rotating Scheimpflug-based corneal tomography or Placido-based corneal topography, however, Bland-Altman plots showed good agreement among the measurements of the 3 devices. The repeatability of the measurements of keratometric corneal power and keratometric astigmatism were better with OCT than those with other 2 devices. Particularly, in keratoconic eyes, the difference between repeated measurements was remarkably less with OCT than with Placido-based corneal topography.

Financial Disclosure:

is employed by a forNONEprofit company with an interest in the subject of the presentation, research is funded, fully or partially, by a company producing, developing or supplying the product or procedure presented