Table 4.

Correlations between the corneal thickness differences, pupillary center position and TA, J ₀, J ₄₅, HOA in keratoconic patients after FBDALK (n=47)

Variable	TA3 mm		J 0		J 45		HOA3 mm		HOA6 mm
	r	Sig.	r	Sig.	r	Sig.	r	Sig.	r	Sig.
Corneal thickness difference
S-I2 mm	0.27	0.07	0.31	0.03*	0.42	0.00*	0.37	0.01*	0.48	0.00*
S-I4 mm	0.25	0.09	0.21	0.15	0.28	0.06	0.30	0.04*	0.46	0.00*
S-I6 mm	0.25	0.09	0.27	0.07	0.14	0.35	0.28	0.06	0.54	0.00*
S-I8 mm	0.05	0.74	0.19	0.20	−0.07	0.65	0.40	0.01*	0.35	0.01*
N-T2 mm	−0.12	0.43	−0.23	0.13	−0.16	0.30	0.08	0.60	0.03	0.86
N-T4 mm	−0.09	0.56	−0.08	0.61	−0.02	0.88	0.04	0.78	0.12	0.43
N-T6 mm	−0.09	0.54	−0.05	0.72	0.13	0.38	0.18	0.23	0.19	0.20
N-T8 mm	−0.06	0.66	−0.11	0.47	−0.05	0.73	0.15	0.33	−0.05	0.76
Distance from pupillary center to corneal apex
Lineal distance	−0.01	0.94	0.17	0.26	0.03	0.84	0.07	0.63	0.24	0.10
X-axis distance	0.06	0.70	−0.05	0.73	0.29*	0.05	−0.01	0.95	0.21	0.15
Y-axis distance	−0.05	0.76	−0.01	0.92	−0.03	0.86	−0.21	0.15	−0.11	0.45

^*Pearson correlation, significant (Sig.) at the 0.05 level. S-I_{2 mm}, S-I_{4 mm}, S-I_{6 mm}, S-I_{8 mm}: superior-inferior corneal thickness differences at 2, 4, 6, and 8 mm diameter concentric circles from the corneal apex, respectively; N-T_{2 mm}, N-T_{4 mm}, N-T_{6 mm}, N-T_{8 mm}: nasal-temporal corneal thickness differences at 2, 4, 6, and 8 mm diameter concentric circles from the corneal apex, respectively; TA_{3 mm}: total corneal astigmatism at 3 mm from the corneal apex; J ₀: cylindrical power at 90° or 180° meridian; J ₄₅: cylindrical power at 45° or 135 ° meridian; HOA_{3 mm}: corneal total higher-order aberration at 3 mm pupil diameter; HOA_{6 mm}: corneal total higher-order aberration at 6 mm pupil diameter