Optical performance of two new trifocal intraocular lenses: through-focus modulation transfer function and influence...

To compare the in vitro optical quality of two new trifocal intraocular lenses at different focal points as a function of pupil size.

Two intraocular lenses having different design approaches were evaluated: the AT LISA tri 839MP with a trifocal diffractive design, and the FineVision, which combines two distinct apodized bifocal diffractive profiles resulting in three foci. A PMTF optical bench was used to assess the intraocular lenses' performance, and as optical quality metrics, the through-focus modulation transfer function was selected; that is, it was measured at 10 focal points and for four different apertures (2.0, 3.0, 3.75 and 4.5 mm).

For both lenses, the through-focus curve showed three peaks, corresponding to far, intermediate and near focal point. At the 0.0 D focal point, the FineVision yielded better results for larger pupils. At the -1.5 D focal point, both lenses performed worse for larger pupils. At the -3.0 D, the FineVision provided better results for all apertures. However, at the -3.5 D focal point, it was the AT LISA tri 839MP that outperformed the FineVision for larger pupils.

The two trifocal intraocular lenses under analysis have modulation transfer function peaks that correspond to the far, intermediate and near focal points. For larger pupil sizes, the FineVision seems to provide better results at far focal points, while the AT LISA tri 839MP not only provides better results at the intermediate and near focal points, but is also less pupil size-dependent.