Artikel
Influence of axial length, corneal curvature, and surgically-induced changes on the compensation of spherical aberration of the eye with an aspherical intraocular lens
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Autoren
Veröffentlicht: | 22. September 2004 |
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Gliederung
Text
Objective
Comparative clinical studies have demonstrated that the spherical aberration of the eye after cataract surgery can be eliminated by modifying the anterior surface of the IOL. Investigating the Tecnis Z9000 (Pfizer) in intraindividual studies, the reduction of spherical aberration lead to a significant improvement of contrast vision. These results based on mean values with some interindividual differences.
Methods
Data of two studies with the Tecnis-IOL were analysed with regard to the influence of further factors on spherical aberration and contrast vision. Because of the impact of the pupil diameter only eyes with of 3.5-4.0 mm pupil diameter were investigated.
Results
The postoperative spherical aberration was correlated to the axial length and corneal curvature: shorter eyes with a steeper corneal curvature gained particular improvement of spherical aberration. In some eyes the effect of the aspherical IOL was canceled out by surgically induced changes of the corneal spherical aberration. Contrast vision did not correlate to the amount of the total postoperative spherical aberration in all eyes.
Conclusions
Mean values had shown a reduced spherical aberration and improved contrast sensitivity in eyes with an aspherical IOL. Analysis of the individual data showed marked interindividual differences. The efficacy of the Tecnis-IOL was greater in shorter eyes with steeper corneas and was counteracted in some cases by surgically induced changes of the corneal spherical aberration. The lack of correlation between spherical aberration and contrast sensitivity in serveral eyes needs further evaluation.