Use of AcrySof Toric intraocular lenses for correction of residual astigmatism in cataract patients

Objective To evaluate the safety,efficacy,and stability of AcrySof Toric intraocular lens (IOL) implanting in correcting residual astigmatism in patients who have cataract surgery.Methods This was a prospective case control study.Sixty-nine eyes of 59 consecutive cataract patients during a 12-month period who had more than 0.75 diopters (D) of pre-existing astigmatism of the cornea were included.After phacoemulsification,33 patients (37 eyes) were implanted with AcrySof Toric IOL (test group) and 26 patients (32 eyes) with AcrySof SN60AT IOL (control group).One day,1 week,1 month,and 3 months after IOL implantation,uncorrected visual acuity (UCVA),best corrected visual acuity (BCVA),residual refractive sphere and cylinder,corneal keratometry,and the AcrySof Toric IOL axis were measured.Visual acuity and residual refractive cylinder distribution were analyzed by Fisher's exact probability and refractions were analyzed by independent samples t tests.Results UCVA:three months after implantation,1 eye (3％) in the test group and 10 eyes (31％) in the control group presented with 0.1-0.3; 22 eyes (60％) in the test group and 15 eyes (47％) in the control group presented with 0.4-0.6; 5 eyes (14％) in the test group and 6 eyes (19％)in the control group presented with 0.7-0.9; and 9 eyes (24％) in the test group and 1 eye (3％) in the control group presented with 1.0 or better.There were statistically significant differences between the two groups (Fisher's exact=0.000,P＜0.05).Residual refractive cylinder:68％ of the test group eyes and 12％ of the control group eyes had 0-0.75 D; 32％ of test group eyes and 59％ of the control group eyes had 1-1.75 D; and 0％ of the test group eyes and 28％ of the control group eyes had more than 2 D.There were statistically significant differences between the two groups (Fisher's exact=0.000,P＜0.05).Rotational stability:3 months after implantation,all AcrySof Toric IOL had rotated less than 20 degrees:IOL in 21 eyes (57％) had rotated less than 5 degrees,IOL in 7 eyes (19％) had rotated 6°-10°,and IOL in 9 eyes (24％) had rotated 11°-15°.The mean AcrySof Toric IOL axis rotation was 5.8°±5.0° (0°-15°).Surgically induced astigmatism (SIA):the mean SIA was (0.66±0.17)D in the test group and (0.62±0.24)D in the control group.There was no statistically significant differences between the two groups.Conclusion The results show that phacoemuisification and AcrySof Toric IOL implantation are safe and effective to correct residual astigmatism 3 months after cataract surgery. Key words: Lenses,intraocular,astigmatism;  Astigmatism;  Phacoemulsification