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Chen/Peter Qiu, Paul J Donaldson, Ehsan Vaghefi; Monitoring the optical changes of the lens in real time under physiological perturbations. Invest. Ophthalmol. Vis. Sci. 201657(12):.
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© 2017 Association for Research in Vision and Ophthalmology.
Develop a laser ray tracing (LRT) system to monitor in real time how changes to the cellular physiology of organ cultured bovine lenses alters the gradient of refractive index (GRIN) and lens geometry, and how changes to these key parameters impact the overall optical properties of the lens and bovine eye.
Bovine lenses were organ cultured in three separate chambers that contained Artificial Aqueous Humor (AAH), AAH+high K+, and AAH+Ouabain (1.0 mM). LRT was performed on all three lenses using a fully custom built and coded system. Images of the passage of the laser light through the lens was recorded using two cameras orthogonal to each other, and the resultant data was analysed using an established tomography based method that used deflection angles and exterior ray paths to calculate the GRIN1. Changes in lens shape in the meridional plane were also extracted using an original image processing routine. These key optical parameters were implemented in a ZEMAX model of the bovine eye to quantify what effect each physiological perturbation had on lens power, spherical aberration, focal length and overall vision quality.
Preliminary results showed that ray deflection angles and radius of curvature both increased when the lenses were incubated in AAH+Ouabain and AAH+High-K+. Both conditions decreased the refractive index in the outer cortex (1.38 to 1.36), while at the core AAH+Ouabain increased (1.44 to 1.46) and AAH+High K+ decreased (1.44 to 1.43) the refractive index, respectively. These changes to the optical parameters of the lens produced an increase in overall refractive power of the lens, with changes in geometry contributing primarily to the shift in the optical power, while changes in the GRIN were primarily responsible for a shift towards positive spherical aberration.
An automated LRT system has been developed that allows up to three lenses to be sequentially monitored in real time, enabling the effects of perturbations to their cellular physiology to be linked to changes in their optical properties. LRT is a powerful alternative to previous approaches that measure the optical properties of the lens due to lower cost, improved ex vivo control and better temporal and spatial resolution.1. Vazquez. D et al, the Optical Society of America, 2551-2565, 2006Acknowledgements; this work was supported by the Marsden Fund of New Zealand
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.
Real time ray-tracing system rig
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