Posters

Repeatability and agreement of corneal thickness measurements by three methods of pachymetry in small incision lenticule extraction eyes

Poster Details

First Author: J.Huang CHINA

Co Author(s):    L. Hu   Z. Hu   G. Savini   J. Yu           

Abstract Details

Purpose:

To evaluate repeatability and concordance of corneal thickness (CT) measurements using Scheimpflug imaging (Pentacam HR, Oculus) and anterior segment swept-source optical coherence tomography (AS-SS-OCT, CASIA 1000, Tomey) compared with ultrasound pachymetry (USP, SP-3000, Tomey) in eyes after small incision lenticule extraction (SMILE).

Setting:

Eye Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China.

Methods:

This study involved ninety-one eyes from 91 patients. Three measurements by each device, the repeatability and concordance of central corneal thickness (CCT), thinnest corneal thickness (TCT), and mid-peripheral corneal thickness (MPCT) measurements were analyzed. Within-subject standard deviation (Sw), test-retest repeatability (TRT), intraclass correlation coefficient (ICC), and coefficient of variation (CoV) were calculated. Measurement differences and agreements were assessed by repeat-measurement analysis of variance and Bland-Altman analysis.

Results:

Scheimpflug imaging, AS-SS-OCT and USP revealed that Sw was <5.91 µm, CoV was <1.08 %, TRT was <16.38 µm, and ICC was >0.94. The repeatability of Scheimpflug imaging measurements was lower with respect to that of AS-SS-OCT. The mean CT values were ranked from the thickest to the thinnest in the following order: Scheimpflug imaging, USP and AS-SS-OCT. The 95% limits of agreement were relatively narrow and the Bland-Altman plots were more concentrated at the CCT, the TCT and at the CT2mm. However, it was shown to be wide at the CT5mm.

Conclusions:

In eyes after SMILE, the repeatability of CT measurements with Scheimpflug imaging, AS-SS-OCT and USP were high. Concordance between measurements at the CCT, TCT and CT2mm was high, but measurement agreements among CT5mm revealed poor concordance.

Financial Disclosure:

None