Ausgleich des kornealen Astigmatismus mit torischer Intraokularlinse: Ergebnisse der Multicenterstudie

Abstract

This clinical trial was conducted to evaluate visual acuity, refraction and rotation after implantation of the foldable toric intraocular lens (IOL) MicroSil Toric. 68 eyes of 48 patients from four different surgical departments were examined over a follow-up of three months after cataract surgery. An individually produced IOL with cylindrical correction between 2.0 and 12.0 D was implanted in all eyes. Postoperatively, 68 % of the eyes achieved an uncorrected visual acuity (VA) of 0.5 or better, 12 % achieved 1.0 or better. A corrected VA of 0.5 or better was achieved by 85 %, 31 % achieved a corrected VA of 1.0 or better. Corrected VA improved by 3 (+/- 2) lines. The uncorrected VA improved by 6.0 lines in the mean. The increases in uncorrected and corrected VA were statistically significant (p < 0.001). The efficacy index amounted to 1.1 in the median and 1.3 (+/- 1.5) in the mean. Residual refraction (spherical equivalent) was 0.89 D (+/- 0.7 D) in the mean and was reduced by 5.14 D (+/- 4.78 D) in the mean. The total astigmatic error was reduced both in a statistically as well as in a clinically significant manner from 4.6 D (+/- 2.3 D) to 1.12 D (+/- 0.9 D) in the mean. 75 % of eyes needed a postoperative cylindrical correction of less than 1.5 D, 95 % less than 2.25 D. Corneal astigmatism was not changed significantly (p = 0,435). The surgically induced astigmatism (Naeser) amounted to 0.7 D in the median. In 85 % of the cases IOL rotation was less than 5 degrees. 15 % of the IOLs rotated more than 5 degrees, one IOL more than 10 degrees (max. 28 degrees). Patients ranked their surgical outcome on a scale from 1 (very good) to 6 (poor) which resulted in a mean score of 1.9 (+/- 1.0; min. 1.0; max. 5.0). No clinically relevant correlations of clinical parameters and satisfaction were detected. Implantation of the foldable, toric IOL with Z-haptics decreased the refractive error and improved postoperative visual outcome. This IOL was suitable for low as well as for high astigmatism. IOL rotation was low during the follow-up of three months resulting in sufficient correction of the pre-existing astigmatism.