Table 2.

Corneal parameters and ocular higher-order aberrations for keratoconus group, keratoconus subjects with visual acuity of 0.00 LogMar and for control group.

	Keratoconus group	Control group	Keratoconus with VA 0.00 LogMar	PMann–Whitney Keratoconus versus controls	PMann–Whitney Keratoconus with 0.00 LogMar versus controls
Scheimpflug/Placido Disc measurement
K1 (mm)	7.50 ± 0.43	7.89 ± 0.30	7.57 ± 0.43	u = 1055.0 p < 0.001**	u = 538.0 p < 0.001**
K2 (mm)	7.26 ± 0.47	7.75 ± 0.30	7.36 ± 0.47	u = 1114.0 p < 0.001**	u = 568.0 p < 0.001**
Kave (mm)	7.38 ± 0.44	7.82 ± 0.30	7.47 ± 0.75	u = 1100.0 p < 0.001**	u = 560.0 p < 0.001**
TCT (µm)	477.25† ± 35.26	532.47 ± 25.61	484.02 ± 32.35	u = 1167.0 p < 0.001**	u = 614.0 p < 0.001**
CCT (µm)	493.73† ± 31.40	536.52 ± 24.11	496.69 ± 28.78	u = 1112.0 p < 0.001**	u = 595.0 p < 0.001**
Hartmann-shack ocular high-order aberrations
Total RMS HOA (µm)	1.14 ± 1.00	0.20 ± 0.13	0.97 ± 1.04	u = 93.0 p < 0.001**	u = 59.0 p < 0.001**
Trefoil (µm)	0.40 ± 0.32	0.09 ± 0.07	0.38 ± 0.36	u = 146.0 p < 0.001**	u = 97.0 p = 0.001**
Total Coma (µm)	0.95 ± 0.94	0.13 ± 0.11	0.80 ± 0.93	u = 169.0 p < 0.001**	u = 97.0 p = 0.001**
Tetrafoil (µm)	0.12 ± 0.07	0.03 ± 0.02	0.11 ± 0.08	u = 95.0 p < 0.001**	u = 75.0 p < 0.001**
High-order astigmatism (µm)	0.27 ± 0.28	0.04 ± 0.04	0.22 ± 0.29	u = 142.0 p < 0.001**	u = 110.0 p < 0.001**
HOA Spherical aberration (µm)	0.18 ± 0.18	0.05 ± 0.06	0.17 ± 0.23	u = 214.0 p < 0.001**	u = 147.0 p < 0.001**

*Significant level of < 0.05, **significant level of < 0.005. ^†One subjects did not have good Scheimpflug pictures for 1 keratoconus suspect eye, therefore central corneal thickness and thinnest corneal thickness are average results for 37 eyes (not 38).

VA, visual acuity; K, keratometry; CCT, central corneal thickness; TCT, thinnest corneal thickness; RMS, root mean square; HOA, higher-order aberrations; µm, micrometer.