Comparison of glistenings formation and their effect on forward light scatter between the Acrysof SN60WF and Eternity Natural Uni NW-60 intraocular lenses

Abstract

Aims

To compare the characteristics of glistenings and forward light scatter between the Alcon Acrysof SN60WF and Santen Eternity Natural Uni NW-60 intraocular lenses (IOLs).

Methods

Five Acrysof SN60WF and five Eternity Natural Uni NW-60 IOLs were studied. All IOLs were single piece blue blockers with the same dioptric power (20D) and optic diameter (6.0 mm). Glistenings were induced by a thermal accelerated ageing process. Glistenings were objectively quantified using bespoke image processing software. The angular distribution of forward light scatter was measured using an optical bench system and the straylight parameter calculated from the light scatter function.

Results

The median increase in the number of glistenings was 15 and 525 for the Eternity and Acrysof IOLs, respectively, which was statistically significantly different (p=0.012). Median glistenings diameter was 23.8 μm (Acrysof) and 32.8 μm (Eternity). Four (80%) of the Acrysof lenses had straylight values higher than a 20-year-old CIE standard glare observer and in two cases the straylight exceeded that of the 70-year-old CIE standard glare observer. None of the Eternity lenses had straylight values that exceeded the value for the 20-year-old CIE standard glare observer.

Conclusions

The Eternity Natural Uni NW-60 IOLs resisted the induction of glistenings more than the Acrysof SN60WF IOLs. Although the Acrysof IOLs developed smaller glistenings than the Eternity IOLs, there were sufficient numbers to produce a higher straylight parameter.