Utility of the Anterior Segment Optical Coherence Tomography for Measurements of Central Corneal Thickness

ABSTRACT

PURPOSE: To demonstrate the capability of anterior segment optical coherence tomography (OCT), to evaluate central corneal thickness (CCT) and to compare the results with those by Orbscan II and standard ultrasound (US) pachymetry. METHODS: One examiner measured the CCT of 44 normal eyes of 22 subjects using anterior OCT, Orbscan II, and US pachymetry. Non-contact measurements by anterior segment OCT and Orbscan II were performed first, followed by contact measurements using US pachymetry. Three consecutive measurements were taken with each method and the mean values and correlations were analyzed. RESULTS: The mean value of the CCT was 531.45+/-32.90 micrometer with anterior OCT, 537.11+/-32.21 micrometer with Orbscan II, and 548.18+/-34.17 micrometer with US pachymetry. There was no statistically significant difference among the values obtained by the 3 instruments (P>0.05). CCT measurements by anterior segment OCT were highly correlated with Orbscan II and US pachymetry (P<0.001) measurements. CONCLUSION: CCT measurements by anterior segment OCT are highly correlated with Orbscan II or US pachymetry measurements. Using non-contact anterior segment OCT, a closer examination of the anterior segment including the cornea is possible. The measurement of the CCT using anterior segment OCT is applicable because result values are similar to measurements by Orbscan II or US pachymetry.