Corneal Topography as a Screening Method for Keratoconus Suspects

Abstract

Abstract: : Purpose: To evaluate the effectiveness of corneal topography indexes to detect keratoconus. Methods: Ninety four eyes obtained from our topographer data base were included. Corneal topography was performed with a Placido's ring-based system (Zeiss, Humphrey) and diagnosis indexes were obtained from the Pathfinder Corneal Analysis software. Specificity and sensitivity were calculated using clinical examination as gold standard. Subjects were considered as keratoconus suspects if they presented scissors reflex at retinoscopy, irregular keratometric readings, and oblique astigmatism of 3 diopters or higher. They were considered as keratoconus if any of the clinical signs of keratoconus were present at clinical examination. Results:Twenty eight eyes were considered as normal and 66 as keratoconus and keratoconus suspects. The topography indexes showed a sensitivity of .87 and a specificity of .92. Table shows the association between the clinical evaluation and the topography diagnosis. Conclusion: Topography indexes appear to be a reliable method for the screening of keratoconus. Diagnosis of Keratoconus  

Keywords: 369 cornea: clinical science • 450 keratoconus • 599 topography