Safety and efficacy of toric intraocular lens implantation for more than 5 years

Abstract

Objective: To evaluate the clinical safety and efficacy of toric intraocular lens (IOL) implantation for more than 5 years. Methods: This study was a prospective cohort study in which subjects were continuously observed over a two-year period (May 2014 to May 2016) in nine hospitals. The study randomly assigned subjects to two groups using a central dynamic randomization system: the study group, which received Proming® IQ toric IOL implants, and the control group, which received AcrySof® IQ toric IOL implants. The subjects completed a one-year follow-up, during which various measures were taken and evaluated, including visual acuity, IOL rotation, postoperative complications, intraocular pressure, and subjective evaluation (preoperatively and at 1 day, 6 months, 1 year, and 5 years post-surgery). The main statistical analysis methods include the Mann-Whitney U test, independent sample t-test, Wilcoxon signed rank test, paired sample t-test, chi-square test, and Fisher's exact test. Results: A total of 45 eyes (26 in the study group and 19 in the control group) completed the five-year continuous observation period. The mean age of the subjects was (72.07±10.67) years and the mean interval from surgery to the last visit was (5.39±0.47) years. After five years, there were no significant differences in uncorrected distance visual acuity (0.20±0.26 vs. 0.16±0.13, t=0.17,P=0.752), best corrected distance visual acuity[0.00(0.00, 0.20) vs. 0.05±0.10, U=188.00, P=0.880], uncorrected near visual acuity[0.50 (0.20, 0.60) vs. 0.42±0.20, t=0.35, P=0.857], and best corrected near visual acuity (0.13±0.16 vs. 0.17±0.23, U=161.00, P=0.884) between the two groups. However, all measures improved significantly from baseline levels in both groups (all P<0.05). Five years after surgery, no matter objective refraction [(-0.67±0.85) D vs. (-0.73±1.08)D] or subjective refraction[-0.50 (-1.00, 0.00)D vs. (0.69±0.87)D], the degree of cylindrical degree is significantly lower than preoperative corneal astigmatism [(1.27±0.49) D vs. (1.34±0.82) D, all P<0.001]. In addition, there were no significant differences in intraocular pressure, subjective evaluation of visual adverse symptoms, distance vision spectacle independence, or overall satisfaction evaluation between the two groups (all P>0.05). The IOL rotation was 3.0°(1.0°, 6.0°) in the study group and 4.0°(2.0°, 6.0°)in the control group (U=185.50,P=0.574), indicating no significant difference between the groups in terms of rotational stability. Five years after surgery, there were 7 cases of posterior capsular opacification in the study group and 4 cases in the control group. There were no cases of IOL glistening in the study group, but 5 cases (26.32%) were observed in the control group. Conclusions: The long-term effects of Proming® toric IOL implantation in correcting cataracts with regular corneal astigmatism are clear after five years, with few complications and stable results.