Classification of Normal Corneal Topography Based on Computer-Assisted Videokeratography

Stephen J. Bogan, George O. Waring, Osama Ibrahim, Carolyn Drews, Linda Curtis

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220 Citations (Scopus)


We evaluated the topography of 399 normal corneas in 212 subjects with computer-assisted videokeratography. The mean subject age was 37 years (range, 8 to 79 years). Mean spherical equivalent refraction was −1.00 diopters (range, +5.50 to −8.37 diopters). A qualitative classification system for corneal topography was derived based on patterns seen on color-coded topographic maps. Corneas were classified into groups by three independent masked ophthalmologists based on this system. Patterns included round (22.6%), oval (20.8%), symmetric bow tie (17.5%), asymmetric bow tie (32.1%), and irregular (7.1%). All corneas were steeper centrally and flatter peripherally. There was a statistically significant difference among patterns for keratometric astigmatism, but not for spherical equivalent refraction, mean keratometric power, or age of subject. Classification of normal corneal topography is an important step in the process of characterizing the shape of normal and pathologic corneas.

Original languageEnglish
Pages (from-to)945-949
Number of pages5
JournalArchives of Ophthalmology
Issue number7
Publication statusPublished - 1990 Jul
Externally publishedYes

ASJC Scopus subject areas

  • Ophthalmology


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