TY - JOUR
T1 - Comparison of Central Corneal Thickness using Anterior Segment Optical Coherence Tomography vs Ultrasound Pachymetry
AU - Kim, Hanna Y.
AU - Budenz, Donald L.
AU - Lee, Pak S.
AU - Feuer, William J.
AU - Barton, Keith
N1 - Funding Information:
This study was supported by International Aid, an unrestricted grant from Pfizer Inc, New York, New York, NEI Core Grant EY014801, Bethesda, Maryland, and an unrestricted grant from Research to Prevent Blindness, New York, New York. Dr Lee has received travel expenses from Heidelberg Engineering. Involved in design of study (H.Y.K., D.L.B.); collection, management, analysis and interpretation of data (H.Y.K., D.L.B., P.S.L., W.J.F., K.B.); and preparation, review, or approval of manuscript (H.Y.K., D.L.B., P.S.L., W.J.F., K.B.). The Tema Eye Survey project was approved by the Human Subjects Committee of Stanford Medical School, the Ethics Committee of the Ministry of Health of Ghana, the Human Subjects Research Office of the University of Miami Miller School of Medicine, and the Research Governance Committee of Moorfields Eye Hospital.
PY - 2008/2
Y1 - 2008/2
N2 - Purpose: To determine if there is a systematic difference in central corneal thickness (CCT) measured using anterior segment optical coherence tomography (AS-OCT) as compared with ultrasound pachymetry. Design: Prospective observational study. Methods: Consecutive subjects with clinically normal corneas underwent CCT measurement by both ultrasound and AS-OCT while participating in a population-based study in Ghana, West Africa. One eye of each subject was randomly selected for analysis. Two measurements were taken and averaged. Agreement and interobserver variability were also analyzed. Results: One hundred and fifty-five subjects of African ethnicity and average age 57 years (standard deviation [SD] 12; range, 40 to 98 years) were included. Measurements by AS-OCT and US were taken a mean of 15 days (maximum, six weeks) apart. The mean (SD) [range] US CCT was 525.3 μm (33.5) [422, 653] and 499.0 μm (32.0) [428, 613] with AS-OCT. Measurements by the two modalities were strongly correlated (r2 = 0.82; P < .001), and a significant difference was observed between mean US and AS-OCT CCT (SD) [range] of 26.3 μm (14.2) [-63, 12] (P < .001). The width of the limits of agreement was 28 μm, about 6% of the average pachymetry reading. In 50 eyes randomly remeasured with OCT by a second observer, the intraclass correlation coefficient was 0.91. There was a small but significant systematic difference between observers (mean 6.9 μm, SD 10.9 μm), or 1.4% (P < .001), increasing the difference noted above. Conclusion: There is a reproducible systematic difference between CCT measurements taken with ultrasound and OCT. It is important to note in clinical practice, that measurements acquired by these two modalities are not directly interchangeable.
AB - Purpose: To determine if there is a systematic difference in central corneal thickness (CCT) measured using anterior segment optical coherence tomography (AS-OCT) as compared with ultrasound pachymetry. Design: Prospective observational study. Methods: Consecutive subjects with clinically normal corneas underwent CCT measurement by both ultrasound and AS-OCT while participating in a population-based study in Ghana, West Africa. One eye of each subject was randomly selected for analysis. Two measurements were taken and averaged. Agreement and interobserver variability were also analyzed. Results: One hundred and fifty-five subjects of African ethnicity and average age 57 years (standard deviation [SD] 12; range, 40 to 98 years) were included. Measurements by AS-OCT and US were taken a mean of 15 days (maximum, six weeks) apart. The mean (SD) [range] US CCT was 525.3 μm (33.5) [422, 653] and 499.0 μm (32.0) [428, 613] with AS-OCT. Measurements by the two modalities were strongly correlated (r2 = 0.82; P < .001), and a significant difference was observed between mean US and AS-OCT CCT (SD) [range] of 26.3 μm (14.2) [-63, 12] (P < .001). The width of the limits of agreement was 28 μm, about 6% of the average pachymetry reading. In 50 eyes randomly remeasured with OCT by a second observer, the intraclass correlation coefficient was 0.91. There was a small but significant systematic difference between observers (mean 6.9 μm, SD 10.9 μm), or 1.4% (P < .001), increasing the difference noted above. Conclusion: There is a reproducible systematic difference between CCT measurements taken with ultrasound and OCT. It is important to note in clinical practice, that measurements acquired by these two modalities are not directly interchangeable.
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U2 - 10.1016/j.ajo.2007.09.030
DO - 10.1016/j.ajo.2007.09.030
M3 - Article
C2 - 18054888
AN - SCOPUS:38349182519
VL - 145
SP - 228-232.e1
JO - American Journal of Ophthalmology
JF - American Journal of Ophthalmology
SN - 0002-9394
IS - 2
ER -