Acrylic IOLs offer best optical quality, bench testing shows

Acrylic IOLs, especially those with an asymmetrically biconvex profile, have the best optical quality as determined by spatial frequency analysis, according to a group of Italian researchers.

Lenses with a higher spatial frequency response should provide better quality of vision, the researchers suggested

Daniele Tognetto and colleagues at the University of Trieste evaluated the optical quality of 24 models of foldable IOL using optical bench testing. The researchers analyzed the optical Fourier transform of a test image through each type of lens and converted this to a modulation transfer function for each lens. This allowed the researchers to determine the quality of the lens in terms of spatial frequency response.

According to the researchers, a passband value was calculated by computer analysis of the modulation transfer function for each lens. The passband value was considered an objective index of the lens quality. Among the 24 IOL types tested, a large range of passband values was found.

The lowest passband value was measured in the Lenstec LH3000 and the highest in Alcon’s Acrysof SA30AL, according to the researchers.

A lens with a higher frequency response “should determine a better quality of vision once implanted and the frequency response should therefore be considered when choosing the IOL model,” the researchers concluded in the August issue of Investigative Ophthalmology & Visual Science.