Multifocal intraocular lens providing optimized through-focus performance.

Area of Science:

• Ophthalmic optics
• Biomedical engineering
• Optical design

Background:

• Multifocal intraocular lenses (MIOLs) commonly use spherical aberration to enhance depth of focus.
• Current methods linking wavefront aberration to MIOL geometry are indirect.
• Designing effective MIOLs requires precise control over lens surface characteristics.

Purpose of the Study:

• To present a new strategy for designing MIOLs by directly optimizing surface geometries.
• To develop a method that overcomes the limitations of indirect geometry derivation.
• To create MIOLs with predictable and high optical performance.

Main Methods:

• Direct optimization of intraocular lens (IOL) surface geometries using aspheres with high-order coefficients.
• Utilized a multisurface pseudophakic eye model and a multiconfiguration approach.
• Employed a merit function that jointly evaluates optical quality at multiple object distances.

Main Results:

• A 22-diopter MIOL was designed, maintaining an ocular modulation transfer function (MTF) above 0.47 at 50 cycles/mm for all object locations.
• The designed MIOL demonstrated high optical quality for far and intermediate vision, with peak performance at near distances (MTF > 0.57).
• The design exhibited robust performance across a 3-5 mm pupil diameter range and maintained multifocal performance in approximately 40% of simulated patients with typical corneal aberrations.

Conclusions:

• The direct surface geometry optimization strategy provides a viable method for designing advanced MIOLs.
• The designed MIOL offers excellent visual performance across a range of distances and conditions.
• This approach holds promise for creating customized MIOLs with improved patient outcomes.