Light scattering, straylight, and optical quality in hydrophobic acrylic intraocular lenses with subsurface
Liliana Werner1, John C Stover1, Jim Schwiegerling1
1From the John A Moran Eye Center (Werner), University of Utah, Salt Lake City, Utah; The Scatter Works, Inc. (Stover), Tucson, Arizona; College of Optical Sciences (Schwiegerling), University of Arizona, Tucson, Arizona; Alcon Laboratories, Inc. (Das), Fort Worth, Texas, USA.
Purpose:
To evaluate forward light scattering and straylight in single-piece hydrophobic acrylic intraocular lenses (IOLs) (Acrysof) removed from cadaver eyes and design- and power-matched controls, as well as the effect of subsurface nanoglistenings on other optical quality and performance indicators.
Setting:
John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA.
Design:
Experimental study.
Methods:
Seventeen single-piece IOLs (11 blue light-filtering; 6 without blue-light filter) with subsurface nanoglistenings were removed from cadaver eyes. The Complete Angle Scatter Instrument scatterometer was used to measure the forward-scattered light; straylight values at various angles were calculated. The modulation transfer function (MTF) and Badal images were also obtained. Backscatter was measured with a Scheimpflug camera (EAS-1000) and light transmittance with a spectrophotometer (Lambda 35 UV-VIS) to confirm findings in previous studies.
Results:
The mean straylight values at a scattered angle of 10 degrees were 1.06 ± 0.23 log(s) for blue light-filtering IOLs, 0.97 ± 0.28 log(s) for IOLs without a blue-light filter, and 0.22 ± 0.22 log(s) for controls. The MTF and Badal image contrast of IOLs removed from cadaver eyes were similar to control values (no subsurface nanoglistenings). Backscatter was significantly higher in IOLs from cadaver eyes, although light transmittance was similar to that of controls.
Conclusion:
Straylight in hydrophobic IOLs resulting from subsurface nanoglistenings was well below the value of straylight hindrance and would not cause noticeable visual impairments.
Financial Disclosure:
Dr. Das is an employee of Alcon Laboratories, Inc. The Complete Angle Instrument scatterometer was developed by Dr. Stover at the Scatterworks, Inc. Neither of the other authors has a financial or proprietary interest in any method or material mentioned.
