Fig. 3

Subgroup analysis of BCVA and minus cylinder power of refractive astigmatism according to type of IOL in each group. The minus cylinder power of refractive astigmatism was converted to absolute numerical value for easier understanding. Significant improvement in postoperative BCVA was observed in all types of toric IOLs and no difference was seen among all types of toric IOL, in both groups (a, c) (**p = < 0.001 in G1, *p < 0.05 in G2, paired t-test). There was preoperative difference in BCVA between front- and back-toric IOL in G1 (A) (*p < 0.05, unpaired t-test), while there was no difference among all types of IOL in G2 (C) (p > 0.05, unpaired t-test). Significant improvement in postoperative minus cylinder power of refractive astigmatism was observed in all types of toric IOLs in both groups (b, d) (**p = < 0.001 in G1, *p < 0.05 in G2, paired t-test). Bi-toric IOL showed significantly better postoperative minus cylinder power of refractive astigmatism compared to back-toric IOL in G1 (B) (Φp = 0.001, unpaired t-test), while there was no difference in G2 (D) (p > 0.05, unpaired t-test). G1 = normal corneal astigmatism group, G2 = post-penetrating keratoplasty astigmatism group, BCVA = best corrected visual acuity, IOL = intraocular lens