Table 1 Comparison of the non-Down syndrome (DS) keratoconus (KC) group and DS group with regards to age, refractive, aberrometric, pachymetric and morpho-volumetric data

Age (years)

27.1 ± 6.9

24.3 ± 11.3

0.145^a

Spherical equivalent (diopters)

− 1.99 ± 3.05

− 0.70 ± 4.52

0.098^b

HOA RMS (µm)

1.44 ± 0.79

1.22 ± 1.10

0.004 ^b

Central corneal thickness (µm)

500.6 ± 31.2

500.8 ± 29.5

0.453^a

D_apexant (mm)

0.003 ± 0.006

0.007 ± 0.010

< 0.0001 ^b

D_apexpost (mm)

0.161 ± 0.074

0.076 ± 0.048

< 0.0001 ^b

D_mctant(mm)

1.045 ± 0.322

1.453 ± 1.042

0.400^b

D_mctpost (mm)

0.975 ± 0.305

1.368 ± 1.015

0.425^b

A_ant (mm²)

43.19 ± 0.18

43.46 ± 0.25

< 0.0001 ^a

A_post (mm²)

44.39 ± 0.30

44.60 ± 0.42

0.018 ^b

A_tot (mm²)

103.22 ± 1.18

103.33 ± 1.51

0.641^a

A_apexant (mm²)

1.64 ± 1.98

3.98 ± 0.29

< 0.0001 ^a

A_apexpost (mm²)

3.99 ± 0.26

3.97 ± 0.27

0.625^a

A_mctpost (mm²)

3.98 ± 0.26

3.94 ± 0.28

0.400^a

C_x (mm)

0.016 ± 0.043

− 0.004 ± 0.048

0.012 ^a

C_y (mm)

0.026 ± 0.035

0.020 ± 0.041

0.408^b

C_z (mm)

0.763 ± 0.027

0.784 ± 0.029

0.001 ^b

V_total

23.95 ± 1.53

23.60 ± 1.82

0.239^a