Abstract
Purpose:
To measure the optical performance of new and artificially aged AcrySof Natural intraocular lenses (IOLs) and determine the potential effect of forward light scatter on foveal contrast vision.
Methods:
Forward light scatter for new and artificially aged AcrySof Natural (yellow tinted) IOLs were measured using the Complete Angle Scattering Instrument (CASI). Modulation Transfer Function (MTF) and Badal images of these IOLs were obtained using two separate testing systems. Accelerated aging with a heated bath was performed to produce lenses with equivalent ages of 1 to 15 years. The surface scattering values of IOLs were obtained using a Nidek EAS 1000 Scheimpflug system. The MTF and image acquisition test systems incorporate a custom eye model with a wet cell for mounting the IOL. Pupil sizes of 3 and 6 mm were evaluated.
Results:
Surface scattering values of AcrySof Natural lenses obtained using the Nidek EAS 1000 Scheimpflug system were 3.8, 26.2, 48.2, 76.0 and 103.5 CCT (Computer Compatible Tape) units for new, 1, 5, 10, and 15 years aged lenses respectively. The MTF values both at the 3 and 6 mm pupils do not degrade for these laboratory aged IOLs compared to a new IOL. Images obtained from the Badal bench do not show a noticeable difference for aged AcrySof Natural IOLs.
Conclusions:
To the best of the authors’ knowledge this is the first study to analyze the optical quality and performance with forward light scatter for new and artificially aged AcrySof Natural IOLs. Study results do not show a trend between the measured MTF and CCT values for the AcrySof Natural IOLs. The higher CCT values represent an increase in back scatter that may be visible by slit lamp examination. However, this effect does not equate with forward scatter. The increase in forward scatter with aging is small enough for visual impact. Therefore these studies do not show a noticeable difference in the optical quality and performance of the AcrySof Natural IOLs for both smaller and larger pupils.
Keywords: 445 cataract •
567 intraocular lens •
630 optical properties