Optometry

Physics

Lens (geology)

Optical transfer function

Visual acuity

Mathematics

Aperture (computer memory)

Ophthalmology

Optics

Acoustics

Focus (optics)

Materials science

Geometry

Multifocal intraocular lens

Phacoemulsification

Tilt (camera)

Near vision

Optical axis

Medicine

Journal of Cataract & Refractive Surgery

Purpose To assess the effects of decentration and tilt at different orientations on the optical quality of a rotationally asymmetric multifocal intraocular lens (IOL). Setting Shandong Eye Institute, Qingdao, China. Design Experimental study. Methods A rotationally asymmetric multifocal IOL (SBL-3) was tested using standardized optical bench testing. The optical quality was quantified using the modulation transfer function (MTF), through-focus MTF, and images of the United States Air Force Target test at apertures of 3.0 mm and 4.5 mm. The multifocal IOL was measured while it was centered, decentered by 0.3 mm and 0.5 mm, and then tilted by 3 degrees and 5 degrees at near–horizontal (near vision zone), distance–horizontal (distance vision zone), and vertical orientations of the long axis of the multifocal IOL. Results The optical performance was better at the aperture of 4.5 mm than at 3.0 mm for the centered multifocal IOL. The optical quality was improved at near focus and decreased at distance focus for the near–horizontal decentration, contrary to the status for the distance–horizontal decentration, with a more obvious tendency at the 3.0 mm aperture than at 4.5 mm. For the near–horizontal tilting, the optical quality at near focus was more significantly deteriorated than distance focus, opposite to that for the distance–horizontal tilting, with a more distinct tendency at a 4.5 mm aperture than at 3.0 mm. Conclusions The optical quality of the asymmetric multifocal IOL was sensitive to and varied significantly after decentration and tilt at specific directions. The decentration induced increased or decreased optical quality, whereas tilt just yielded decreased optical quality.

Effects of decentration and tilt at different orientations on the optical performance of a rotationally asymmetric multifocal intraocular lens