Comparison of pseudoaccommodation and visual quality between a diffractive and refractive multifocal intraocular lens

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Optics

Background:

• Intraocular lenses (IOLs) are crucial for vision restoration after cataract surgery.
• Multifocal IOLs aim to provide pseudophakic accommodation, improving uncorrected vision at various distances.
• Diffractive and refractive IOL designs offer different optical principles for achieving multifocality.

Purpose of the Study:

• To compare the depth of focus and overall visual quality between a diffractive IOL and a refractive IOL.
• To evaluate the visual performance of two distinct multifocal intraocular lens designs.

Main Methods:

• A comparative study involving 10 eyes (9 patients) with a diffractive IOL (3M 825x + 4) and 13 eyes (9 patients) with a refractive IOL (AMO Array SSM 26NB).
• Depth of focus was assessed across a range of -6.0 to +3.0 diopters.
• Snellen visual acuity was measured at distance and near visual tasks.

Main Results:

• Both IOLs achieved good distance visual acuity (1.0 +/- 0.2 for 3M, 0.91 +/- 0.13 for AMO).
• Near visual acuity peaks were higher for the diffractive IOL (0.82 +/- 0.15) compared to the refractive IOL (0.55 +/- 0.14).
• A visual acuity of 0.5 or better was maintained within a defocus range of +1.0 to -4.0 D (3M) and +1.0 to -3.5 D (AMO).

Conclusions:

• Both diffractive and refractive multifocal IOLs can provide pseudoaccommodation and good distance vision.
• Visual acuity for intermediate distances may be limited, depending on the activity.
• The diffractive IOL demonstrated statistically significant superior visual acuity at near distances.