Abstract
Purpose: To compare and determine the repeatability of central corneal thickness (CCT) measurements using four noncontact pachymetry instruments in eyes with keratoconus. Materials and Methods: The CCT of consecutive patients with keratoconus was measured during a single visit using the swept source optical coherence tomography (SS-OCT, Casia SS-1000°CT, Tomey, Nagoya, Japan), a rotating Scheimpflug camera system (Pentacam, Oculus Optikgerate GmbH, Wetzlar, Germany), scanning slit topographer (Orbscan IIz topography, Baush and Lomb Surgical Inc., San Dimas, CA, USA), and a hand-held spectral domain OCT (HHSD-OCT, Bioptigen Inc., Durham, North Carolina, USA). Test-retest variability, correlation between measurements and interdevice agreement were analyzed. Results: Fifty eyes of 25 participants were analyzed in this study. All measurement methods correlated well with each other (r > 0.9, P < 0.001). Mean ± standard deviation CCT measured by HHSD-OCT, Orbscan IIz, SS-OCT, and Pentacam was 462 ± 41 mm, 458 ± 41 mm, 454 ± 40 mm, and 447 ± 42 mm, respectively. While the HHSD-OCT over-estimated the CCT (P < 0.001), there was a good correlation between the measurements obtained from the other three devices. However, the numerical difference was high and this trend was seen in all the paired comparisons.Conclusions: Though the measurements by different devices correlated well, the numerical agreement may be inadequate for their interchangeable use in clinical practice.
Original language | English |
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Pages (from-to) | 722-727 |
Number of pages | 6 |
Journal | Indian journal of ophthalmology |
Volume | 63 |
Issue number | 9 |
DOIs | |
Publication status | Published - 3 Dec 2015 |
Bibliographical note
Creative Commons Attribution Non-Commercial Share Alike License. Kumar M, Shetty R, Jayadev C, Dutta D. Comparability andrepeatability of pachymetry in keratoconus using four noncontact techniques.
Indian J Ophthalmol 2015;63:722-7.
Keywords
- Central corneal thickness
- hand-held spectral domain optical coherence tomography
- ultrasound pachymetry