English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Purpose: To calculate and compare cone location and magnitude index (CLMI ), Kmax and other corneal measures derived from three different technologies, Placido, Scheimpflug, and a combination dual Scheimpflug-Placido device, from the same group of eyes with keratoconus and postrefractive surgery corneal ectasia. Methods: Keratoconus (n = 26) eyes of (n = 19) subjects and postrefractive surgery ectasia (n = 5) eyes of (n = 5) subjects were selected to have measurements performed using the Keratron Scout, Pentacam HR and Galilei Dual Scheimpflug Analyzer. Device-generated SimK’s and device-specific CLMI and Kmax indices as well as map data, were exported from each device. Index values for multiple exams were averaged. The map data were processed using The Ohio State University Corneal Topography Tool (OSUCTT) to calculate CLMI parameters, Kmax and SimK values using consistent algorithms on all three devices. Maps were averaged before calculation for multiple examinations. Repeated measures analysis of variance and posthoc analysis were used to identify differences between devices. Results: The anterior axial CLMI calculated from the Keratron data was significantly higher than CLMI for the Galilei (p = 0.0443) or Pentacam (p < 0.0004) with keratoconus, 12.23 compared with 11.20 and 11.00 diopters, respectively. Kmax was also significantly higher in the Keratron than the Galilei (p = 0.0063) or the Pentacam (p < 0.0002). Galilei and Pentacam were not significantly different from each other in either CLMI (p = 0.6287) or Kmax (p = 0.2115). The anterior CLMI values for the postrefractive surgery ectasia eyes were not significantly different between devices. Posterior CLMI values were calculated from the Galilei and Pentacam data and were –2.60 and –2.46 diopters (p = 0.1173) for keratoconus and –2.66 and –3.04 diopters (p = 0.2242) for postrefractive surgery ectasia. Conclusion: The small cone Placido measured dioptric values that were greater than the pure Scheimpflug system, but the difference was only about 1 diopter, which is not relevant clinically in evaluating and managing ectasia. The combined dual Scheimpflug-Placido system produced measured dioptric values between the other two technologies. The anterior CLMI calculations accurately predicted keratoconus with all three devices. The posterior CLMI in ectasia may be a potentially valuable calculation in demonstrating asymmetric steepening.

international journal of keratoconus and ectatic corneal diseases

Comparison of Placido, Scheimpflug and Combined Dual Scheimpflug-Placido Technologies in Evaluating Anterior and Posterior CLMI, SimK's as well as Kmax, in Keratoconic and Postrefractive Surgery Ectasia