Keratoconus staging by decades: a baseline ABCD classification of 1000 patients in the Homburg Keratoconus Center

Abstract

BackgroundThis retrospective cross-sectional study aims to analyse the keratoconus (KC) stage distribution at different ages within the Homburg Keratoconus Center (HKC).Methods1917 corneae (1000 patients) were allocated to decades of age, classified according to Belin’s ABCD KC grading system and the stage distribution was analysed.Results73 per cent (n=728) of the patients were males, 27% (n=272) were females. The highest KC prevalence occurred between 21 and 30 years (n=585 corneae, 294 patients). Regarding anterior (A) and posterior (B) curvature, the frequency of A was significantly higher than B in all age groups for stage 0, 1 and 2 (A0>B0; A1>B1; A2>B2; p<0.03, Wilcoxon matched-pairs test). There was no significant difference between the number of A3 and B3, but significantly more corneae were classified as B4 than A4 in all age groups (p<0.02). The most frequent A|B combinations were A4|B4 (n=451), A0|B0 (n=311), A2|B4 (n=242), A2|B2 (n=189) and A1|B2 (n=154). Concerning thinnest pachymetry (C), most corneae in all age groups were classified as C0>C1>C2>C3>C4 (p<0.04, Wilcoxon matched-pairs test). For the best distance visual acuity (D), a significantly higher number of corneae were classified as D1 compared to D0 (p<0.008; D1>D0>D2>D3>D4).ConclusionThe stage distributions in all age groups were similar. Early KC rather becomes manifest in the posterior than the anterior corneal curvature whereas advanced stages of posterior corneal curvature coincide with early and advanced stages of anterior corneal curvature. Thus, this study emphasises the necessity of posterior corneal surface assessment in KC as enabled by the ABCD grading system.

Stadiengerechte Therapie des Keratokonus

“…Ein 25-jähriger Patient stellte sich bei uns im Homburger Keratokonus Center (HKC) [21], in das wir seit dem Jahr 2010 mehr als 2000 Patienten eingeschlossen haben, mit beidseitiger Kontaktlinsen(KL)-Intoleranz vor. Der cum-correctione(cc-)Brillenvisus betrug am rechten Auge (RA) 0,1 (Refraktion: -21,50/-2,75/A176°)/am linken Auge (LA) 0,2 (Refraktion: -6,00/-5,50/10° "Muraine-Nähte" bei akutem Keratokonus und die Hornhauttransplantation -unterteilt in tief lamellär (DALK), perforierend (PKP) oder die zentrale Korneoskleralplastik [26,27].…”

Reliability analysis of successive Corneal Visualization Scheimpflug Technology measurements in different keratoconus stages

“…To compensate for this limitation, all corneae included in this study were re‐classified according to the recent ABCD KC classification, which includes posterior corneal curvature analysis (Belin et al. 2015; Belin & Duncan 2016; Flockerzi et al 2020b. ; Fig.…”

“…2013) or Scheimpflug tomographic imaging (Belin & Ambrósio 2013; Belin 2020; Flockerzi et al. 2020a,b) and biomechanical analysis of the cornea (Elham et al. 2017; Langenbucher et al.…”

Keratoconus: An updated review

“…Epidemiological studies indicate substantial global variation as the prevalence and incidence rates of keratoconus have been estimated to be between 0.2 and 4,790 per 100,000 persons and 1.5 and 25 per 100,000 persons/year, respectively (Table 1; Figs. 1 and 2), with the highest prevalence and incidence rates typically occurring in 20 to 30 year olds [27][28][29]. Differences between studies have been attributed to differences in geographic location and ethnicity, the definition of keratoconus and diagnostic criteria, study design, and the age and cohort of subjects assessed (Table 1; Figs.…”