Table 2

Patient demographics of the study population

Mean±SD (range)Keratoconus groupControl groupp Value
Age (years)37.6±12.3 (14 to 64)37.9±10.2 (25 to 71)0.79
Gender (% female)29400.15
Anterior elevation difference (μm)19.6±12.5 (0 to 63)1.7±2.6 (−9 to 6)<0.001
Anterior elevation (μm)12.3±10.9 (−2 to 59)1.3±1.4 (−3 to 4)<0.001
Posterior elevation difference (μm)49.5±32.7 (6 to 152)5.0±5.4 (−3 to 26)<0.001
Posterior elevation (μm)32.0±30.9 (−9 to 162)1.6±3.2 (−6 to 12)<0.001
Minimum pachymetry (μm)453.6±66.7 (197 to 583)542.6±32.6 (477 to 614)<0.001
Central pachymetry (μm)472.1±62.8 (254 to 657)546.2±33.2 (479 to 616)<0.001
Mean keratometry (D)49.5±5.7 (42.2 to 71.3)43.0±1.7 (40.4 to 46.8)<0.001
Cylinder (D)4.0±3.1 (0.1 to 14.3)1.4±0.7 (0.2 to 3.1)<0.001
CTSP 2 mm (μm)480.1±57.0 (289 to 598)540.2±36.4 (461 to 625)<0.001
CTSP 4 mm (μm)548.4±38.3 (428 to 641)572.9±33.9 (502 to 658)<0.001
CTSP 6 mm (μm)625.4±37.8 (529 to 743)629.0±34.5 (541 to 713)0.60
CTSP 8 mm (μm)705.2±52.0 (561 to 887)705.0±41.1 (600 to 805)0.43
CTSP 10 mm (μm)800.2±50.6 (639 to 998)796.6±55.8 (682 to 935)0.62
PTI 2 mm (%)7.3±6.9 (1 to 49)1.9±0.9 (1 to 4)<0.001
PTI 4 mm (%)24.3±20.8 (5 to 152)8.2±2.9 (4 to 15)<0.001
PTI 6 mm (%)43.0±32.4 (12 to 241)18.9±5.6 (11 to 34)<0.001
PTI 8 mm (%)61.7±41.4 (19 to 323)33.5±8.3 (22 to 59)<0.001
PTI 10 mm (%)82.2±41.6 (38 to 272)50.7±11.8 (30 to 90)<0.001
Progression index3.2±2.8 (0.8 to 18.9)1.2±0.4 (0.7 to 2.1)<0.001
D value11.5±7.7 (0.8 to 46.1)1.6±1.5 (0.1 to 4.4)<0.001
  • CTSP, corneal thickness spatial profile; D, dioptres; PTI, percentage thickness increase.