J Korean Ophthalmol Soc.  2007 Dec;48(12):1599-1606.

Corneal Topographic Study Using Orbscan II between Keratoconus and Keratoconus Suspect

• Lee SU
• Lee CH
• Lee JE
• Lee JS

Abstract

PURPOSE: To compare corneal topographic changes using Orbscn II between keratoconus and keratoconus- suspected eyes.
METHODS
Thirty-seven keratoconus eyes, 17 keratoconus-suspected eyes and 37 normal eyes were evaluated by using Orbscan II corneal topography. We compared central phachymetry, anterior elevation from best-fit sphere (BFS), posterior elevation from BFS, most protruded corneal thickness, central corneal thickness, anterior chamber depth, corneal diameter, and pupil size.
RESULTS
Central pachymetry, anterior and posterior elevation from BFS, central corneal thickness, and anterior chamber depth were statistically significantly different between keratoconus and control eyes. Anterior elevation from BFS showed a significant difference between keratoconus-suspected and control eyes. There were statistically significant differences in central pachymetry, posterior elevation from BFS, central corneal thickness and most protruded corneal thickness between keratoconus and keratoconus-suspected eyes. Corneal diameter and pupil size showed no differences among the 3 groups.
CONCLUSIONS
Suspected keratoconus eyes have a higher value of anterior elevation from BFS on Orbscan II topography as compared with control eyes. Central pachymetry, posterior elevation from BFS, central corneal thickness and most protruded corneal thickness may be helpful in distinguishing between keratoconus and keratoconus-suspected eyes.

Keyword

Anterior chamber depth; Best fit sphere (BFS); Keratoconus; Keratoconus suspect; Orbscan II corneal topography

MeSH Terms

Anterior Chamber
Corneal Topography
Keratoconus*
Pupil

Figure

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  Figure 1. The map of Orbscan II topography in keratoconus. The parameters including central corneal power, anterior and posterior elevation from BFS and central corneal thickness are significantly different from normal eyes.

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  Figure 2. The map of Orbscan II topography in keratoconus suspect. Anterior elevation from BFS is the only significantly different parameter comparing with normal eyes, and central corneal power, posterior elevation from BFS, central corneal thickness and most protruded corneal thickness are the parameters significantly different from keratoconic eyes.

Reference

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