The use of computerized corneal topography in the assessment of astigmatism

Victor L Perez Quinones, I. Krashin-Bichler, M. Dunn, B. A. Schwartz, C. Lee, D. K. Shu, P. A. Asbell

Research output: Contribution to journalArticle

Abstract

Purpose. The keratometer has been the predominate device used to evaluate astigmatism. The introduction of computerized corneal topography offers an alternate means for measuring astigmatism. Our purpose was to evaluate 2 computerized corneal topography systems, EyeSys and PAR, in the assessment of astigmatism. Methods. Readings obtained from 12 astigmatic patients with otherwise normal eyes (21 eyes) using EyeSys and PAR were compared to data from the Topcon™ Auto-Keratometer, which was chosen as a reference. Eye Sys uses placido disc imaging, whereas PAR utilizes rasterstereography to determine corneal contour. We evaluated these 2 new methods and compared results with standard keratometry. Results. The cylindrical range is Topcon™: 0.12D to -5.37D; EyeSys 0.00D to -4.96D; PAR 0.35D to -4.61D. The standard error for all three instruments is ±0.25D. Both EyeSys and PAR differ from Topcon™ by +2° in the measurements of the principal meridians. Mean deviations from Topcon™ in refractive power at the flattest/steepest axis are 0.02D/0.46D for EyeSys and 0.71D/0.68D for PAR. T-tests confirm that data obtained from the 3 instruments are not statistically different from one another (p>0.05). Conclusions. In assessing astigmatic patients with normal eyes, both the EyeSys and PAR computerized corneal topography systems are consistent with measurements by autokeratometry.

Original languageEnglish (US)
JournalInvestigative Ophthalmology and Visual Science
Volume37
Issue number3
StatePublished - Feb 15 1996
Externally publishedYes

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Corneal Topography
Astigmatism
Meridians
Reading
Equipment and Supplies

ASJC Scopus subject areas

  • Ophthalmology

Cite this

Perez Quinones, V. L., Krashin-Bichler, I., Dunn, M., Schwartz, B. A., Lee, C., Shu, D. K., & Asbell, P. A. (1996). The use of computerized corneal topography in the assessment of astigmatism. Investigative Ophthalmology and Visual Science, 37(3).

The use of computerized corneal topography in the assessment of astigmatism. / Perez Quinones, Victor L; Krashin-Bichler, I.; Dunn, M.; Schwartz, B. A.; Lee, C.; Shu, D. K.; Asbell, P. A.

In: Investigative Ophthalmology and Visual Science, Vol. 37, No. 3, 15.02.1996.

Research output: Contribution to journalArticle

Perez Quinones, VL, Krashin-Bichler, I, Dunn, M, Schwartz, BA, Lee, C, Shu, DK & Asbell, PA 1996, 'The use of computerized corneal topography in the assessment of astigmatism', Investigative Ophthalmology and Visual Science, vol. 37, no. 3.
Perez Quinones VL, Krashin-Bichler I, Dunn M, Schwartz BA, Lee C, Shu DK et al. The use of computerized corneal topography in the assessment of astigmatism. Investigative Ophthalmology and Visual Science. 1996 Feb 15;37(3).
Perez Quinones, Victor L ; Krashin-Bichler, I. ; Dunn, M. ; Schwartz, B. A. ; Lee, C. ; Shu, D. K. ; Asbell, P. A. / The use of computerized corneal topography in the assessment of astigmatism. In: Investigative Ophthalmology and Visual Science. 1996 ; Vol. 37, No. 3.
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