Purchase this article with an account.
G. C. Wong, J. Chang, M. D. Mifflin; Pentacam Topography as a Primary Screening Tool for Refractive Surgery Candidates. Invest. Ophthalmol. Vis. Sci. 2009;50(13):580.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Detection of keratoconus and subclinical keratoconus is extremely important among refractive surgery candidates, as these are major causes of post-refractive surgery corneal ectasia. When screening for at-risk patients, surgeons have traditionally used the Rabinowitz criteria, which is based on Placido disk-based videokeratography. The Pentacam, on the other hand, is an elevation-based corneal topographic technology. In this study, we attempt to establish normative Pentacam data for our population of patients who come for refractive screening. Of these patients, we will look at the outcome of those eyes that have been operated on. We hope to find that the Pentacam alone can be an effective screening tool for refractive surgery candidates.
This is a retrospective study in which 220 eyes of a population of consecutive refractive screening patients from the Moran Eye Center from June 2007 to February 2008 were selected. Data from their screening Pentacam scans were taken, including steepest corneal curvature, central corneal thickness (CCT), thinnest corneal thickness and its displacement, and various elevation data (e.g. anterior and posterior highest vs. lowest elevation). Normal distribution curves were constructed. Eyes that underwent surgery that had values greater than 2 standard deviations from the mean were analyzed for post-surgical outcomes.
Steepest corneal curvature: average=45.12, standard deviation (SD)=2.20. CCT: avg=536.5, SD=41.9. Thinnest CT: avg=533.2, SD=40.6. Displacement: avg=0.7, SD=0.36. Anterior Lowest Superior/Inferior (S/I) Difference: avg=5.1, SD=5.3. Posterior Lowest S/I Diff: avg=11.5, SD=12.3. Anterior Highest/Lowest (H/L) Diff: avg=35.2, SD=21.8. Posterior H/L Diff: avg=83.5, SD=38.4. A total of 29 eyes were beyond 2 standard deviations from the mean values in at least 1 of the above criteria. Final surgical results of these eyes will be presented.
Based on our analysis, the Pentacam alone can be an effective screening tool for refractive surgery candidates.
This PDF is available to Subscribers Only