Comparison of corneal thickness measurements using the Sirius topographer system and the Pentacam camera

Poster Details

First Author: A.Mohamed Sherif EGYPT

Co Author(s):    A. Abd El Latif Osman              

Abstract Details

Purpose:

To compare and correlate the central corneal thickness CCT and the thinnest location measurement of the cornea measured by two modern imaging systems: Sirius topographer( Costruzioni Strumenti Oftalmici ,Florence, Italy) and the Oculus Pentacam (Oculus Optikgeräte GmbH, Wetzlar, Germany) .

Setting:

Rowad Cornea Center (RCC), Giza ,Egypt

Methods:

34 eyes of 19 patients presenting for refractive surgery were imaged using the Sirius Topographer and the Pentacam . The CCT and thinnest corneal location values were recorded and analysed Exclusion criteria: Previous refractive surgery Corneal opacities Keratoconus Statistical analysis was performed using the Statistical Program for Social Science (SPSS) ver¬sion 13.0 for Windows. (SPSS, Inc., Chicago, IL). Correlation between measurements obtained with both instruments was determined using Spearman correlation coefficient " r" . The 95% limits of agreement LoA (= mean of the difference ± 1.96SD ) between both instruments were also calculated.

Results:

Mean CCT measured by the Sirius system was 552.12 ± 62.6 µm while the mean CCT measured by the Pentacam was 532.82 ± 48.9 µm. A significant correlation was found between both instruments (r=0.85) The 95%LoA between both instruments in CCT measurement was 67.34 and -25.58 µm. The mean difference between CCT measurement by both machines was 20.88 ± 29.04 µm. The difference was not statistically significant (p=0.081) The mean thinnest location measured by Sirius was 526.24 ± 49.66 µm while the mean thinnest location measured by Pentacam was 529.32 ± 50.51 µm. The mean difference between measurements of both machines was -3.85 ± 9.03 µm. The difference was not statistically significant (p=0.40) There was significant correlation between both instruments (r=0.92) The 95%LoA between both instruments in measuring the thinnest location of the cornea was 13.85 and -21.55 µm.

Conclusions:

Significant correlation between both instruments in CCT and thinnest location measurement in normal corneas was found.No statistically significant difference between the values obtained by both devices were found. Further studies are needed to assess the correlation and agreement of both devices in cases of previous refractive surgery and opacities. FINANCIAL DISCLOSURE?: No