Table 3.

Tomographic parameters of eyes by group

Parameters	TNC	FFKC	MKC	Statistics	P
KmF (D)	43.9 ± 1.4	43.7 ± 1.5	44.3 (41.5–48.5)	3.916	0.141
Kmax (D)	45.1 ± 1.7	45.2 ± 1.9	49.0 (43.8–57.3)#&	45.110	< 0.001
Astig F (D)	1.1 (0.1–4.6)	1.1 (0.1–2.2)	1.5 (0.1–5.2)	2.806	0.246
ISV	18.68 ± 5.83	19.72 ± 5.66	41.00 (17.00–82.00)#&	92.504	< 0.001
IVA	0.11 (0.05–0.35)	0.16 (0.06–0.33)	0.40 (0.16–1.02)#&	90.624	< 0.001
KI	1.03 (0.95–1.07)	1.04 (1.00–1.10)	1.10 (1.00–1.23)#&	76.787	< 0.001
CKI	1.01 (1.00–1.02)	1.01 (1.00–1.04)	1.02 (0.97–1.13)#&	28.187	< 0.001

TNC thin normal cornea; FFKC forme fruste keratoconus; MKC mild keratoconus; KmF mean keratometry from the anterior corneal surface; Kmax maximum keratometry from the anterior corneal surface; Astig F central astigmatism from the anterior corneal surface; ISV index of surface variance; IVA index of vertical asymmetry; KI keratoconus index, CKI central keratoconus index

P is the value among the three groups. *, ^# and ^&represent statistically significant difference with TNC and FFKC, TNC and MKC, FFKC and MKC, respectively