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Comparability of epithelial and corneal thickness measurements between a novel spectral-domain optical coherence tomography system and Spectralis SD-OCT

Session Details

Session Title: Cornea
Session Date/Time: Sunday 22/02/2015 | 08:30-11:00
Paper Time: 09:09
Venue: Hall 2
First Author: : N.Luft AUSTRIA
Co Author(s): :    M. Bolz   M. Dirisamer   J. Pretzl   E. Wimmer   T. Kreutzer   S. Priglinger

Abstract Details

Purpose:

To assess, if corneal epithelial and total corneal thickness measurements obtained with two different SD-OCT machines for anterior segment imaging could be used interchangeably.

Setting:

AO – Ars Ophthalmica Study Center, Department of Ophthalmology, General Hospital Linz, Medical Faculty of Johannes Keppler University

Methods:

This prospective study included volunteers with healthy corneas, patients with corneal dystrophies (e.g. Fuchs endothelial dystrophy), patients that had undergone Descemet membrane endothelial keratoplasty (DMEK) and eyes after small incision lenticule extraction (SMILE) refractive surgery. Three consecutive measurements of corneal epithelial thickness (CET) and total corneal thickness (TCT) were performed at 5 points 1.25mm apart in the horizontal meridian across the corneal apex using a novel SD-OCT system (RS-3000 Advance; NIDEK Co. Ltd., Aichi, Japan) and Spectralis SD-OCT (Heidelberg Engineering GmbH, Heidelberg, Germany). Axial resolution of the two instruments was similar with 4.0µm and 3.9µm, respectively.

Results:

Mean age was 49±22 years. With RS-300 Advance mean CET and TCT was 56±8µm and 533±94 µm, respectively. When assessed with Spectralis, mean CET and TCT was 57±6 and 549±90 µm. Mean CET of healthy corneas was 57±2µm with the RS-3000 Advance and 52±2 µm with Spectralis. In eyes with DMEK grafts, CET was 58±18 µm measured with the former instrument and 56±13 µm with the latter. Eyes after SMILE showed a CET of 54±4 µm with the former device and of 58±3 µm with the latter.

Conclusions:

Preliminary results showed good agreement of CET readings between the two SD-OCT machines in a heterogeneous sample of eyes. Measurements of TCT with the two instruments were less comparable. This can partly be explained by alignment errors between scans. However, care must be taken when measuring TCT using the caliper function that is provided in both devices. The Bland-Altman method will be used to analyze inter-device agreement in defined subgroups of eyes.

Financial Disclosure:

NONE

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