Meta-analysis: aspheric IOLs provide better contrast vision

This meta-analysis of randomized controlled trials of cataract surgery with aspheric and spherical monofocal IOL implantation found that contrast sensitivity was better with aspheric IOLs, especially in dim light, but there was no relevant difference in BCVA.

The analysis included 43 studies comprising 2,076 eyes implanted with aspheric IOLs and 2,034 eyes implanted with spherical IOLs.

Only two of 38 studies found a statistically significant improvement in BCVA with aspheric IOLs. Of note, the subgroup analysis revealed no significant differences among the different types of aspheric IOLs, and the data did not reveal any evidence that newer aspheric IOLs would be superior over earlier implant designs. The authors write that the overall beneficial effect is small, and there is nothing to suggest aspheric IOLs outperform spherical IOLs based on BCVA.

Contrast sensitivity was better with aspheric IOLs at all spatial frequencies under mesopic light conditions. The effect sizes were moderate to large, with the strongest effect at 18 cycles per degree. Under photopic conditions, the effect sizes were only small.

The findings on the subjective perception of visual quality were heterogeneous with no clear result favoring either option.