Keratoconus: The ABCD Grading System

Belin, Michael W.; Duncan, Joshua K.

doi:10.1055/s-0042-100626

Cited by 256 publications

(244 citation statements)

References 27 publications

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“…Some demographic and tomographic data are shown in Table 1. Table 2 shows their ABCD classification, 23 their oculomotor and sensory status, and the spherical equivalent of both eyes of the KG.…”

Section: Kg and Cg: Demographic Tomographic And Bcva Datamentioning

confidence: 99%

Oculomotor Status, Binocular Vision, and Stereoacuity in a Series of Keratoconus Subjects

Antunes-Foschini

Coutinho

Rocha

et al. 2018

Invest. Ophthalmol. Vis. Sci.

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In our study, the KG presented a higher frequency of strabismus and impaired binocular vision. Frontal astigmatism was different between groups with gross and fine stereopsis, in both the CG and KG. Future studies are needed to elucidate or reinforce the factors associated with the loss of binocularity in keratoconus. Testing for stereopsis may be helpful to consider in the treatment guidelines for keratoconus.

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Section: Kg and Cg: Demographic Tomographic And Bcva Datamentioning

confidence: 99%

Oculomotor Status, Binocular Vision, and Stereoacuity in a Series of Keratoconus Subjects

Antunes-Foschini

Coutinho

Rocha

et al. 2018

Invest. Ophthalmol. Vis. Sci.

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“…52,53 As opposed to excluding the 3.0 to 4.0 mm zone to normalize the reference surface, we employed the exclusion zone centered on the thinnest point as this area more globally represents the ectatic region than a single point parameter, such as Kmax or maximal elevation. The newly described ABCD kerato conus grading system uses the anterior and posterior radius of curvature taken from the 3.0 mm zone centered on the thinnest point ("A" for anterior, "B" for back surface) and the corneal thickness at the thinnest point ("C" for corneal thickness) as well as best-corrected distance visual acuity ("D" for distance visual acuity).…”

Section: Tomographic-based Assessment Of Ectatic Progressionmentioning

confidence: 99%

Assessing Progression of Keratoconus and Cross-linking Efficacy: The Belin ABCD Progression Display

Belin¹,

Meyer²,

Duncan³

et al. 2017

International Journal of Keratoconus and Ectatic Corneal Diseases

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Several methods have been described to both evaluate and document progression in keratoconus and to show efficacy of cross-linking, however, there are no consistent generally accepted parameters. Modern corneal tomography, including both anterior and posterior elevation and pachymetric data can be used to screen for ectatic progression, be employed to detect earlier change and additionally to show efficacy of new treatment modalities, such as crosslinking.To describe specific quantitative values that can be used as progression and efficacy determinants, the normal noise measurements of the three parameters used in the ABCD keratoconus classification (corneal thickness at the thinnest point, anterior and posterior radius of curvature taken from the 3.0 mm optical zone centered on the thinnest point), were determined. Values were obtained from both a normal population and a known keratoconic population. The 80 and 95% one-sided confidence intervals for all three parameters were surprisingly small, suggesting that they may perform well as progression and efficacy determinants.

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“…Recently, a newer grading system (ABCD Belin grading) has been introduced . This was incorporated into the Scheimpflug tomography device (Pentacam HR; OCULUS Optikgeräte GmbH, Wetzlar, Germany).…”

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confidence: 99%

Impact of classifying keratoconus location based on keratometry or pachymetry on progression parameters

Bardan

Kubrak-Kisza

Kisza

et al. 2020

Clinical and Experimental Optometry

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Background This study sought to assess the impact of classifying keratoconus location based on thinnest pachymetry or maximum keratometry (Kmax) on progression parameters after corneal crosslinking (CXL). Methods In this observational study, patients were followed up at one, three, six and 12 months after CXL. All patients underwent visual acuity, Scheimpflug tomography and slitlamp assessment at all follow‐ups. Keratoconus was classified as central, paracentral and peripheral based on X and Y co‐ordinates of either thinnest pachymetry (Group 1) or Kmax (Group 2). Progression parameters Kmax, ABCD grading, anterior, posterior and total wavefront (WF) aberrations were compared between the groups. Results Fifty‐two eyes (43 patients) were classified into Groups 1 and 2: there were 82.8 per cent, 13.4 per cent, 3.8 per cent and 42.3 per cent, 38.4 per cent, 19.2 per cent central, paracentral and peripheral cones respectively. Central cones: Group 1: ‘C’ decreased after three months, Kmax, ‘A’, anterior and total WF decreased after six months. Group 2: Kmax, anterior and total WF decreased after three months, ‘A’ decreased at 12 months, whereas ‘C’ increased from three months. Paracentral cones: Group 1: no significant changes. Group 2: Kmax and ‘A’ decreased after six months, ‘C’ increased after three months. Peripheral cones: Group 1: no significant changes. Group 2: ‘C’ increased only at one month. Conclusion Thinnest pachymetry and Kmax should not be used interchangeably when categorising keratoconus. Although keratoconus may have thin cornea centrally, the Kmax may not be central. For the majority of parameters considered for monitoring progression, changes were noticed earlier when the keratoconus was classified based on Kmax.

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Keratoconus: The ABCD Grading System

Cited by 256 publications

References 27 publications

Oculomotor Status, Binocular Vision, and Stereoacuity in a Series of Keratoconus Subjects

Oculomotor Status, Binocular Vision, and Stereoacuity in a Series of Keratoconus Subjects

Assessing Progression of Keratoconus and Cross-linking Efficacy: The Belin ABCD Progression Display

Impact of classifying keratoconus location based on keratometry or pachymetry on progression parameters

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