Purpose
To evaluate the impact of light scatter from glistenings in pseudophakic eye models
Methods
A pseudophakic eye model is constructed in ZEMAX using established eye models. The lens is optimized for a polychromatic MTF for field angles 0, 1.4 and 2 Degrees corresponding with Foveal vision. The modeling and evaluation of scatter and image resolution (MTF) are performed for various materials (hydrophobic acrylic, PMMA) for various size and grades (density) of glistenings, all under scotopic and photopic conditions.
Results
Results from the evaluation demonstrate that light scatter increases and MTF decreases with increase in glistening density for both materials. The difference in index of refraction between the cavitations filled with water and the IOL material causes the scatter. As predicted by Mie theory as the relative difference between the scatterer and media increases the amount of scatter will increase. Size of glistenings/cavitations also plays a crucial role in the extent of light scatter and loss of MTF. 2 micron sized glistenings were found to more significant than 200 micron sized glistenings in influencing resolution of image.
Conclusions
Incorporation of scatter metrics into a model eye allows us to learn more about the impact of various phenomena on quality of vision. Mathematical modeling demonstrated that glistening can have a significant effect on scatter and resolution of image. Smaller cavitations and larger density have a more pronounced effect on the MTF than larger cavitations and smaller density. The effect is more pronounce in higher index materials with glistenings. Further evaluation will focus on the effect of surface haze, and more importantly the role of neuroadaptation that may depress the predicted outcomes in-vivo.
Keywords: 567 intraocular lens