Fig. 5
From: Comparative effects of various types of toric intraocular lenses on astigmatism correction
Mean numerical and absolute errors according to type of IOL in each group. Upper level graphs refer to mean numerical error and lower level graphs refer to mean absolute error. A and C are G1, while B and D are G2. Bi-toric IOL showed significantly more hyperopic shift of 0.291 ± 0.616 D compared to back-toric IOL (0.045 ± 0.053 D) in G1 (*p = < 0.05, ANOVA) (a), while there was no difference in G2 (b). No significant difference in mean absolute error in both groups was observed according to type of IOL (c, d). IOL = intraocular lens, D = diopters, G1 = normal corneal astigmatism group, G2 = post-penetrating keratoplasty astigmatism group, ANOVA = Analysis of variance test