Abstract
Purpose:
To investigate the effect of sub-surface nano glistening(SSNG)in hydrophobic acrylic intraocular lens (IOL) on irradiance, forward light scattering and imaging characteristics of retina by optical simulation.
Methods:
To simulate the effect of SSNG we used optical design software LightTools and CODE V (Synopsis) to evaluate the peak value of irradiance on retina, forward light scattering, and the modulation transfer function (MTF) with Liou-Brenann model eye (JOSA, 1997). The physicality and shape of IOL was set as acrylic IOL (SN60AT, Alcon). Ong et al (JCRS, 2012) found in explanted acrylic IOLs with severe SSNG, particles of diameter 150 nm located up to 60μm from the surface of the anterior and posterior side of the IOL at a volume ratio of SSNG particle, which corresponds to the density, of 0.05%. In the present optical simulation, particle diameter and volume ratios were set at 100 nm, 150 nm and 200 nm and 0%, 0.05%, 0.1%, 0.2%, 0.5%,1.0%, 2.0%, 5.0% and 10.0%.
Results:
Peak value irradiance reduced with increased volume ratio and particle size of SSNG. At volume ratio 0.05%, peak values of irradiance for SSNG particle diameters 100nm, 150nm and 200nm reduced by 0.7%, 1.8% and 2.9%, respectively, compared with those at volume ratio 0% (no SSNG). At volume ratio 0.1%, peak values of irradiance for SSNG particle diameters 100nm, 150nm and 200nm reduced by 1.5%, 3.6% and 5.7%, respectively. Forward light scattering increased with increased size of SSNG particle and volume ratio. MTF did not change with increased size of SSNG particle and volume ratio.
Conclusions:
Although SSNG in this condition setting slightly increased forward scattering and reduced irradiance, there was no effect on the characteristics of retinal imaging. These results suggest that the effect of SSNG on visual function is very slight in eyes without severe retinal diseases.
Keywords: 567 intraocular lens •
445 cataract