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. 2020 Dec;68(12):2831-2834.
doi: 10.4103/ijo.IJO_2078_20.

ABCD: A new classification for keratoconus

Michael W Belin  1 , Gairik Kundu  2 , Naren Shetty  3 , Krati Gupta  2 , Ritika Mullick  2 , Prashansa Thakur  2
Affiliations

ABCD: A new classification for keratoconus

Michael W Belin et al. Indian J Ophthalmol. 2020 Dec.

Abstract

Recent advances in the diagnosis and treatment of ectatic corneal disease have mandated a more modern staging system. The new Belin ABCD keratoconus staging system incorporates anterior and posterior curvature centered on the thinnest point of the cornea, thinnest pachymetry values and distance visual acuity in grades from 0-4. By including posterior curvature and thickness measurements based on the thinnest point, as opposed to apical, the new staging system better reflects anatomical changes seen in keratoconus and other ectatic diseases.

Keywords: ABCD; classification; ectasia; keratoconus.

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Conflict of interest statement

None

Figures

Figure 1
Figure 1
The four ABCD parameters displayed graphically
Figure 2
Figure 2
Belin ABCD progression display- The normal based gates (shown in green) are suggested for young patients with early disease, while the keratoconic gates (shown in red) are meant for the more established cases
Figure 3
Figure 3
Belin ABCD Progression Display showing highly significant change (progression) on the posterior corneal surface (”B” parameter) in spite of a stable anterior surface (”A” parameter) and a stable Kmax (circled in blue)
See this image and copyright information in PMC

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