Fig. 6

The relative importance of features within the dataset for predicting the severity class labels based on the Gini method (n = 40). Asph_QB, asphericity coefficient (Q value) of the corneal back surface (posterior), asphericity Q value refers to the variation in the curvature of the cornea from its center to the periphery; Asph_QF, asphericity coefficient (Q value) of the corneal front surface (anterior); Astig_B (D), central corneal astigmatism (posterior corneal values measured in diopters); Astig_F (D), central corneal astigmatism (anterior corneal values measured in diopters); Axis_B (flat), corneal meridian of the least astigmatic power (posterior); Axis_F (flat), corneal meridian of the least astigmatic power (anterior); CKI, central keratoconus index; D0mm_Patchy – D10mm_Pachy, average pachymetry on concentric rings with radii (0–10 mm) around corneal thinnest point, respectively; IHA, index of height asymmetry; IHD, index of height decentration; ISV, index of surface variance; IVA, index of vertical asymmetry; KI, keratoconus index; KMax_Seg_Front (D), keratometry of the steepest point (anterior); Num_Ecc_B and Num_Ecc_F, Fourier-based posterior and anterior eccentricity in central 30 degrees, respectively; Pachy_Apex, corneal thickness in apex; Patchy_Min, thinnest pachymetry (µm); Pachy_Min_Pos_X and Pachy_Min_Pos_Y, x- and y-coordinates of the thinnest location, respectively; Pupil_Pos_X and Pupil_Pos_Y, x- and y-coordinates of the pupil position relative to the corneal apex, respectively; Pachy_Pupil, corneal thickness at the pupil center; Rh_F (mm), central radius in horizontal direction (anterior); Rm_B (mm), curvature radius of the back surface of the cornea (posterior); Rm_F (mm), curvature radius of the front surface of the cornea (anterior); Rs_F (mm), steepest radius (anterior); R_Per_F (mm), average anterior radius of curvature between 6 mm and 9 mm zone; R_Per_B (mm), average posterior radius of curvature between the 6 mm and 9 mm zone; Rv_B (mm), central radius in vertical direction (posterior); Rv_F (mm), central radius in vertical direction (anterior)