ASSESSMENT OF CENTRAL CORNEAL THICKNESS AND CORNEAL ENDOTHELIAL MORPHOLOGY USING ULTRASOUND PACHYMETRY,SPECULAR MICROSCOPY, AND CONFOSCAN 4.

Title ASSESSMENT OF CENTRAL CORNEAL THICKNESS AND CORNEAL ENDOTHELIAL MORPHOLOGY USING ULTRASOUND PACHYMETRY,SPECULAR MICROSCOPY, AND CONFOSCAN 4.
Author, Co-Author Haya AL Farhan, WafaAl Otaibi MSc Al Otaibi, Hanouf Al Razqan, Alanoud Al Harqan.
Topic
Year
2013
Day
Program Number
135984
Room
Room 6C
Affiliation
Abstract PURPOSE:
The aim was to compare the precision of ultrasound pachymetry (USP), non-contact specular microscopy (SP-2000P) and confocal microscopy (z-ring CS4) in measuring endothelial cell density (ECD), coefficient variation of cell size (CV), and central corneal thickness (CCT).

METHODS:
We randomly selected one eye from each of 30 normal subjects in this study. Two subjects dropped out of the study; their associated data were excluded from analysis. ECD, CV and CCT measurements were obtained using USP, SP-2000P and z-ring CS4. The results were analyzed by repeated–measures ANOVA for intra-observer repeatability, inter-observer reproducibility, unpaired t-test, paired t-test, ANOVA and limits of agreement.

RESULTS:
The average ECD values for the SP-2000P and the z-ring CS4 were 3115.50 ± 279.70 and 3167.50 ± 264.75 cells/mm2, respectively. The average CV values were 27.12 ± 2.51% and 27.10 ± 2.41%. The average CCT values for USP, SP-2000P and the z-ring CS4  were 555.11 ± 35.83, 535.82 ± 41.10 and 552.57 ± 36.83 µm. The intra-observer repeatability ANOVA P-values for ECD and CV measurements using SP-2000P were 0.22 and 0.75, respectively. For the z-ring CS4, the respective values were 0.99 and 0.34.

The intra-observer repeatability ANOVA P-values for CCT measurements using USP, SP-2000P and the z-ring CS4 were 0.56, 0.20 and 0.45, respectively. The inter-observer reproducibility paired t-test P-values for CCT measurements using USP, SP-2000P and the z-ring CS4 were 0.30, 0.30 and 0.16, respectively.

The difference in ECD measurements was not statistically significant (t = 0.74; P = 0.45), and neither was the difference in CV values (t = 0.26; P = 79). The mean ECD difference was 52.10 ± 97.90 cells/mm2, and the limits of agreement were +139.80° to −243.90 cells/mm2. The mean CV difference was 0.20 ± 1.45 mm, and the limits of agreement ranged from 3.00 to −2.70%. The ANOVA P-value for CCT measurements using USP, SP-2000P and the z-ring CS4 was (P = 0.10).

CONCLUSIONS:
The SP-2000P and the z-ring CS4 can be used interchangeably to measure ECD and CV. The USP produce comparable measurements of the CCT with SP-2000P and the z-ring CS4 and can be used interchangeably.

Affiliation of Co-Authors
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