Posters

Comparison of CCT measurement in corneal edema using ultrasound pachymetry, anterior segment OCT, spectral domain OCT and corneal topography

Poster Details

First Author: P. Tanthuvanit THAILAND

Co Author(s):    A. Metheetrairat   N. Wongchaisuwat   P. Chonpimai   W. Nujoi           

Abstract Details

Purpose:

To compare central corneal thickness(CCT) measurement in corneal edema by using ultrasound pachymetry, anterior segment Optical Coherence Tomography (OCT), spectral domain OCT and corneal topography

Setting:

This prospective cross sectional study was conducted at Siriraj hospital, Mahidol university since 2013 to 2014. Participants were patients with corneal edema detected by slit lamp examination or previous pachymetry with high CCT(>550µm).

Methods:

Sixty one eyes of 42 patients were evaluated for CCT by ultrasound pachymetry, visante anterior segment OCT , cirrus spectral domain OCT and pentacam corneal topography by 2 observers. Each observer is acquired to complete two measurements. Intraobserver reproducibility and interobserver reliability were determined while intraclass correlation coefficients(ICC) between devices were also calculated.

Results:

Sixty one eyes of 42 patients completed the CCT measurement. In mild degree of corneal edema with CCT less than 650 µm, CCT by 4 devices were indifferent and reliable. In moderate to severe corneal edema cases, visante and cirrus OCT were considered as good candidate devices. Reasonably high correlation in CCT measurement between visante and cirrus OCT (ICC = 0.992) was observed. Interobserver and intraobserver reliabilities were high in both groups and could be interchangeable in CCT which was less than 750 µm. Pentacam exhibited overestimated results and significant error reading while ultrasound pachymetry displayed undetectable in 8 cases (13%), especially in severe corneal edema and opacity cases.

Conclusions:

Visante OCT is the most accurate device for CCT measurement in any degree of corneal edema, while cirrus OCT ,ultrasound pachymetry and pentacam topography are also reliable in less than 650 µm CCT.

Financial Disclosure:

NONE