Comparison of placido-dual rotating Scheimpflug, swept source optical coherence tomography, and placido-slit scanning systems

Session Details

Session Title: Imaging

Session Date/Time: Tuesday 16/09/2014 | 08:00-10:30

Paper Time: 08:29

Venue: Capital Hall B

First Author: : C.Choi SOUTH KOREA

Co Author(s): :    H. Chin              

Abstract Details

Purpose:

To compare measurements of corneal indices using Placido-dual rotating Scheimpflug (PDRS), swept source optical coherence tomography (SS-OCT), and Placido-slit scanning (PSS) systems in normal and post-refractive surgery eyes.

Setting:

Department of Ophthalmology, Kangbuk Samsung Medical Center

Methods:

Sixty-one normal eyes (normal group) and 57 post-refractive surgery eyes (refractive group) from 59 healthy participants were included. Corneal topography measurements were performed using PDRS (Galilei), SS-OCT (Casia SS-1000), and PSS (Orbscan IIz). The intraclass correlation coefficients (ICC) between devices were calculated.

Results:

The agreement among the three devices in terms of anterior keratometry and pachymetry was high (ICC>0.900). Posterior average keratometry and eccentricity had high ICC values between PDRS and SS-OCT (>0.900), but not PSS when compared with the other two devices. PSS exhibited much steeper values for posterior keratometry (P<0.001). The ICC values for posterior corneal elevation were low among all three devices (≤0.900 for all). Maximum posterior elevation measurements were highest for PSS (38.77±9.38㎛ in the normal group, 43.84±11.20㎛ in the refractive group), followed by SS-OCT (10.89±3.55㎛ in the normal group, 10.72±3.89㎛ in the refractive group), and PDRS (9.20±4.43㎛ in the normal group, 9.32±3.35㎛ in the refractive group).

Conclusions:

The anterior keratometry and pachymetry obtained using three different devices showed high degrees of agreement. Posterior keratometry, elevation, and eccentricity showed greater agreement between PDRS and SS-OCT than with the PSS system. PDRS and SS-OCT were equivalent in detecting the shape of the posterior cornea and could be considered interchangeable.

Financial Interest:

NONE