Optical quality measurements of hydrophobic acrylic intraocular lenses.

Purpose: To compare the optical quality of several models of hydrophobic acrylic intraocular lenses (IOLs).

Methods: Modulation transfer function (MTF) measurements were performed using a model eye system on four models of hydrophobic acrylic IOLs. Models tested were the AcrySof SA60AT, MA60AC, and MA60BM (Alcon, Ft Worth, Tex), as well as the model VA-60BB (Hoya, Tokyo, Japan). For benchmarking, the Alcon model MZ60BD polymethylmethacrylate (PMMA) lens was also measured. Three lenses of each model were tested at frequencies of 50 and 100 line pairs (lp)/mm (corresponding to 20/40 and 20/20, respectively).

Results: With a 3-mm aperture, the Alcon AcrySof models had mean MTF values ranging from 58.5% to 60.3% at 100 lp/mm and 78.0% to 79.7% at 50 lp/mm. The Hoya model VA-60BB provided statistically significantly lower (P<.05) MTF values than the Alcon AcrySof models at both frequencies (47.3 +/- 1.2% at 100 lp/mm and 71.8 +/- 1.9% at 50 lp/mm). With a 5-mm aperture, the Alcon AcrySof models had MTF values ranging from 32.9% to 34.3% at 100 lp/mm and 45.2% to 46.7% at 50 lp/mm. Under these larger aperture conditions, the Hoya model VA-60BB also had statistically significantly lower MTF values (20.9 +/- 0.8% at 100 lp/mm and 27.2 +/- 1.1% at 50 lp/mm). Under both apertures and frequencies, the Alcon PMMA lens had statistically significantly higher MTF values than the Hoya lens and statistically significant lower MTF values than all AcrySof models.

Conclusions: Using both 3- and 5-mm aperture settings as well as frequencies corresponding to 20/20 and 20/40 vision, statistically significantly higher MTF values were obtained for AcrySof lenses, which were greater than the PMMA lens, which were greater than the Hoya model VA-60BB. The differences in MTF values between lens models are more exaggerated with a 5-mm aperture and may highlight differences in lens manufacturing processes.