Monofocal Lenses With Extended Depth Of Field Versus Spherical And Aberration-Neutral Iols

EDoF (Extended Depth of Focus) IOLs elongate the focal point into the myopic range, thereby improving intermediate vision. Aberration-neutral IOLs in combination with a cornea that has a positive spherical aberration also produce a focal point that is elongated to a certain extent into the myopic range. The question arises whether the aberration-neutral IOL is an alternative to EDoF IOLs in selected cases when the spherical aberration of the cornea is particularly high, especially when the high decentration insensitivity of aberration-neutral implants is taken into account. In addition, a classic spherical lens is to be evaluated in this comparison.

Medical University of Vienna, Department of Ophthalmology and Optometry

The Primus HD (OphthalmoPro) with an aberration correction of -0.2 µm, an aberration-neutral 409 MP (Zeiss), Hoya 150 (Hoya) and an Eyhance (J&J) are examined on an optical bench. Using 3 different corneas with a spherical aberration of 0.13 µm, 0.2 µm and 0.27 µm and a pupil width of 3.0 and 4.5 mm, the through focus response and the through focus MTF (modulation transfer function) were determined for 25, 50 and 100 lp/mm. With the cornea, which has a spherical aberration of 0.2 µm, the image quality is determined for a decentration of these IOLs of up to 0.5 mm in 0.1 mm steps.

The EDOF IOL shows the strongest elongation of the focal point with all corneas examined, particularly with the 3 mm pupil. The spherical lens as well as the aberration-neutral lens only show a corresponding elongation of the focal point into the myopic range at a 4.5 mm pupil opening. The aberration-neutral lens exhibits by far the best decentration behavior. 

EDOF lenses elongate the focal point at a pupil opening of 3 mm significantly more than an aberration-neutral lens and a spherical lens, even if the spherical or aberration-neutral lens is combined with a cornea with high spherical aberration.