Ray Visualization and Through-Focus Optical Quality of Diffractive Enhanced Monofocal and Extended-Depth-of-Focus Intraocular Lenses.

PURPOSE

We compared two hybrid refractive-diffractive IOLs with enhanced depth of focus in an in vitro study with regard to optical quality in monochromatic and polychromatic light as well as their ray-propagation behavior.

METHODS

The Mono-EDoF ME4 IOL (Santen Pharmaceutical, Osaka, Japan) and the Tecnis Symfony IOL (Johnson & Johnson Vision, USA) were assessed using the OptiSpheric IOL PRO 2 (Trioptics GmbH, Germany) to measure the through focus (TF) modulation transfer function (MTF) using monochromatic green (546 nm) and polychromatic light at different spatial frequencies. Ray propagation imaging was performed using monochromatic green light (520 nm) projected through each IOL, while submerged in a bath of fluorescein solution. The visual pathways were captured by a camera mounted on a microscope. Ray visualization was additionally performed for a monofocal control IOL (W60-R IOL, Santen Pharmaceutical).

RESULTS

The Mono-EDoF IOL showed superior TF-MTF performance for defocus of up to -1.3D compared to the Symfony IOL in monochromatic and polychromatic light. For higher defocus values, however, the Symfony showed superior performance than the Mono-EDoF. Image quality in polychromatic light decreased for both IOLs compared to monochromatic light. Ray propagation imaging revealed one distinct focus for the monofocal IOL. The Mono-EDoF demonstrated an elongated focus area. The Symfony showed two focal points.

CONCLUSION

We found comparable deterioration of image quality in polychromatic light for both IOLs with improved intermediate range. The Mono-EDoF demonstrated an elongated focus and superior TF-MTF performance at lower defocus values, but it did not match the standard EDoF model at higher defocus.