Intrasession and intersession repeatability of a new PCT-200 corneal topographer on calibrated steel surfaces and healthy eyes
- Susana Ortí-Navarro
- Santiago García-Lázaro
- Teresa Ferrer-Blasco
- Rafael J. Perez-Cambrodí
- Lurdes Belda Salmeron
- David Madrid-Costa
ISSN: 2171-4703
Year of publication: 2010
Volume: 1
Issue: 4
Pages: 192-199
Type: Article
More publications in: Journal of Emmetropia: Journal of Cataract, Refractive and Corneal Surgery
Abstract
PURPOSE: To assess intrasession and intersession repeatability of a new tilted-cone, Placido-disc based corneal topographer (PCT-200, Optopol Tech., Poland) on calibrated steel surfaces and healthy human eyes. METHODS: Five repeated measures of surface topography were obtained on a set of four different calibrated steel spherical surfaces and on a sample 30 healthy human eyes in each of two sessions. Variance of apical radius, eccentricity and Fourier Indices was assessed both within and between sessions using analysis of variance (ANOVA), paired samples t-test and intraclass correlation coefficients (ICC). RESULTS: Repeated measurements on calibrated steel surfaces and human eye sample of all parameters were not significantly different within session (ANOVA) nor between sessions (paired samples t-test), p-values exceeded greatly 0.05 in all cases. ICCs were greater than 0.98 and 0.77 for steel surfaces and human eyes, respectively, for all parameters analysed. CONCLUSIONS: The new tilted-cone corneal topographer performs well in both spherical surfaces and healthy human eyes, providing with repeatable measures of corneal topography, comparable to other Placido-based devices currently in the market.