Article for CME creditCorneal thickness indices discriminate between keratoconus and contact lens-induced corneal thinning☆
Section snippets
Patients and methods
This investigation was performed in two phases: an initial model-building study, and a subsequent validation study. The model-building study evaluated 1 eye of 23 patients (11 male, 12 female) with keratoconus, 31 contact lens wearers (16 male, 15 female), and 43 normal subjects (14 male, 29 female). The mean (± standard deviation) age was 37 ± 10 years (range, 22–57 years) in the keratoconus patients, 36 ± 10 years (range, 21–51 years) in the contact lens wearers, and 46 ± 14 years (range,
Results
Both maximum keratometry (Max K) and minimum keratometry (Min K) readings were significantly greater in patients with keratoconus compared with normal and contact lens-wearing eyes (P < 0.001 for both Max K and Min K) in the model-building study. No significant differences in Max K and Min K readings were observed between normal and contact lens-wearing eyes. The mean astigmatism was significantly greater (P < 0.001) in eyes with keratoconus compared with normal and contact lens-wearing eyes.
Discussion
This study shows that indices generated from corneal thickness measurements (CTI) or corneal thickness and central keratometry measurements (DF1) obtained from the Orbscan CTS are very effective in distinguishing keratoconus from normal eyes, contact lens-wearing eyes, and keratoconus suspects. An important difference between these two indices and previously reported indices to diagnose keratoconus is that these used corneal thickness measurements alone (CTI) or in combination with curvature
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Manuscript no. 210292
The authors have no proprietary interest in the products or devices mentioned herein.