1. Impact of quality indicators on variability of keratometry measurements using a SS-OCT–based optical biometer.
- Author
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Cannon, Nathan T., Cooke, David L., Wendelstein, Jascha A., Lehman, Erik, and Pantanelli, Seth M.
- Subjects
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UNITS of measurement , *ASTIGMATISM , *STATISTICAL reliability , *PRIVATE investigators , *MEDICAL personnel - Abstract
TK has less variability than standard K when image QIs suggest a poor-quality measurement. The SD of Kmean/TKmean may be used to estimate measurement variability. Purpose: To characterize the variability of keratometry measurements on the IOLMaster 700 and relate it to device image quality indicators (QIs). Setting: 2 academic centers and 1 private practice. Design: Multicenter, retrospective consecutive case series. Methods: Measurements from 3 sites, obtained between December 2015 and July 2023, were included. Surgery-naïve phakic eyes with same-day sequential measurements on the same eye were identified. Repeat measurement pairs were grouped by IOLMaster QIs (success vs warning), and changes in mean standard keratometry (∆Kmean) and total keratometry (∆TKmean) as well as standard astigmatism (∆Kastig) and total astigmatism (∆TKastig) vectors were calculated. Results: Analysis was performed on 3222 eyes of 1890 patients. Measurement "success" was associated with a smaller ΔKmean (0.09 ± 0.14 diopters [D]) and ΔTKmean (0.11 ± 0.16 D) when compared with pairs in which both measurements had a "warning" (0.25 ± 0.32 D and 0.14 ± 0.17 D, respectively; P <.0001). A similarly smaller ∆Kastig (0.26 ± 0.28 D) and ∆TKastig (0.28 ± 0.30 D) were observed with measurement "success" vs "warning" (0.77 ± 0.79 D and 0.42 ± 0.41 D, respectively; P <.0001). Even when both measurements were successful, the proportion of measurement pairs that had a ∆Kastig >0.50 D increased from 14% to 24% to 32% when Kmean SD was ≥0.01, 0.05, and 0.10 D, respectively. Conclusions: When measurement quality is poor, TK varies less than standard K measurements. Clinicians may use the SD of Kmean/TKmean to estimate the repeatability of measurements and balance this against their tolerance for performing repeat measurements. [ABSTRACT FROM AUTHOR]
- Published
- 2025
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