To evaluate the repeatability, reproducibility, and agreement in anterior, posterior, and in particular the total corneal power of 2 topography devices, rotating Scheimpflug photography and scanning-slit topography.
Department of Ophthalmology and Visual Science, Kitasato University Graduate School of Medical Sciences, Sagamihara, Japan.
Seventeen eyes of 17 subjects (mean age 24.7 years +/- 4.1 [SD]) were included in the study. The corneal shapes within the central 3.0 mm were measured with rotating Scheimpflug photography (Pentacam) and scanning-slit corneal topography (Orbscan II). The within-rater repeatability and reproducibility of 2 raters and the overall between-instrument agreement of the measurements were evaluated using intraclass correlation coefficients (ICCs) and the Bland-Altman method.
The repeatability of Scheimpflug photography and scanning-slit corneal topography was high (ICC, 0.70 to 0.99). Scheimpflug photography outperformed scanning-slit corneal topography for anterior power, posterior power, and total corneal power. The reproducibility results were similar, with limits of agreement (LoA) consistently narrower for Scheimpflug photography. The between-instrument agreement was moderate, with LoA around the mean value of total corneal power of 0.46 diopter ranging from 0.032 to 0.889.
The results suggest that repeatability and reproducibility are higher in Scheimpflug photography than in scanning-slit topography. The agreement between rotating Scheimpflug photography and scanning-slit topography for total corneal power was moderate.
Journal of Cataract and Refractive Surgery 02/2009; 35(1):127-33. DOI:10.1016/j.jcrs.2008.10.019 · 2.55 Impact Factor