Comparing Change in Anterior Curvature After Corneal Cross-linking Using Scanning-slit and Scheimpflug Technology
To evaluate the correlation between anterior axial curvature difference maps following corneal cross-linking (CXL) for progressive keratoconus obtained from Scheimpflug-based tomography and Placido-based topography. Between-devices reliability analysis of randomized clinical trial data. Corneal imag...
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Published in | American journal of ophthalmology Vol. 191; pp. 129 - 134 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
United States
Elsevier Inc
01.07.2018
Elsevier Limited |
Subjects | |
Online Access | Get full text |
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Summary: | To evaluate the correlation between anterior axial curvature difference maps following corneal cross-linking (CXL) for progressive keratoconus obtained from Scheimpflug-based tomography and Placido-based topography.
Between-devices reliability analysis of randomized clinical trial data.
Corneal imaging was collected at a single-center institution preoperatively and at 3, 6, and 12 months postoperatively using Scheimpflug-based tomography (Pentacam; Oculus Inc, Lynnwood, Washington, USA) and scanning-slit, Placido-based topography (Orbscan II; Bausch & Lomb, Rochester, New York, USA) in patients with progressive keratoconus receiving standard protocol CXL (3 mW/cm2 for 30 minutes). Regularization index (RI), absolute maximum keratometry (K Max), and change in K Max (ΔK Max) were compared between the 2 devices at each time point.
Fifty-one eyes from 36 patients were evaluated at all time points. Values were significantly different at all time points (56.01 ± 5.3 diopters [D] Scheimpflug vs 55.04 ± 5.1 D scanning-slit preoperatively [P = .003]; 54.58 ± 5.3 D Scheimpflug vs 53.12 ± 4.9 D scanning-slit at 12 months [P < .0001]) but strongly correlated between devices (r = 0.90–0.93) at all time points. The devices were not significantly different at any time point for either ΔK Max or RI but were poorly correlated at all time points (r = 0.41–0.53 for ΔK Max, r = 0.29–0.48 for RI). At 12 months, 95% limits of agreement were 7.51 D for absolute K Max, 8.61 D for ΔK Max, and 19.86 D for RI.
Measurements using Scheimpflug and scanning-slit Placido-based technology are correlated but not interchangeable. Both devices appear reasonable for separately monitoring the cornea's response to CXL; however, caution should be used when comparing results obtained with one measuring technology to the other. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-News-1 ObjectType-Feature-3 content type line 23 |
ISSN: | 0002-9394 1879-1891 |
DOI: | 10.1016/j.ajo.2018.04.018 |