In vitro Strehl ratios with spherical, aberration free, average and customized spheri

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In vitro Strehl ratios with spherical, aberration free, average and customized spherical aberration correcting intraocular lenses. Invest Ophthalmol Vis Sci. 2008 Oct 31; Authors: Pieh S, Fiala W, Malz A, Stork W Purpose: To determine in vitro image qualities of artificial eyes achieved with spherical, aberration free, average spherical aberration correcting and customized spherical aberration correcting IOLs in centered, decentered and tilted positions. Method: The in vitro performance of these IOL models was determined by optical bench measurements. The experimental setup included a laser light source controlled by aperture stops which corresponded to a 3 and 5 mm pupil aperture, an artificial eye with three alternative corneal models exhibiting low, intermediate and high spherical aberration (SA), IOLs mounted to an immersed IOL holder which could be moved laterally and tilted, a CCD camera and software to determine three-dimensional point spread functions (PSF), modulation transfer functions (MTF) and Strehl ratios. Results: The differences between the various lens models turned out to be low for a 3 mm pupil. For a pupil aperture of 5 mm the customized IOLs showed the best results in case of perfect lens positioning. With ongoing decentration and tilt, the customized IOLs rapidly lost their advantages, particularly in the case of corneas with high SA and IOLs of high diopters. Spherical IOLs were always inferior to aberration free IOLs. Conclusions: Reasonably well centered aberration correcting IOLs may provide considerably better image quality than conventional spherical IOLs. In the presence of significant postoperative decentration and tilt of the IOL, aberration free IOLs are the safest option among the various intraocular lens designs. PMID: 18978351 [PubMed - as supplied by publisher]

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