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R. W. Frey, R. T. Olmstead, J. DeCastro, N. Zepkin, I. Thornton, R. H. Yeilding; Modification of Lens Mechanics of Human Cadaver and Porcine Lenses Using Photodisruption Laser to Change Lens Power and Increase Flexibility. Invest. Ophthalmol. Vis. Sci. 2007;48(13):3834.
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© ARVO (1962-2015); The Authors (2016-present)
To investigate the use of photodisruption techniques on the mechanics of the lens to allow for shape modification and increased flexibility in human cadaver lenses and in-vitro porcine lenses.
All lenses received treatment using a 1064nm wavelength ultrafast laser. The laser pulses were confined to a volume of less then 6mm in diameter and 3 mm in the lens A/P. Fifteen cultured porcine lenses were divided into three equal groups. In the first porcine group of lenses was subject to full laser treatment while in the second porcine group a 1.5 mm diameter in the center of the lens was spared, which we predicted with our FE model will increase the power in the lens. The third porcine group was used as a control. Also, seven human cadaver lenses, mean age 52.8 yrs received a treatment that spared the center. Before and after the lenses were laser treated, all the lenses were documented using a synchronous strobe illumination photographic spinning system for comparative analysis. The lenses were spun and photographed at various rates. The photography was then analyzed using image processing techniques to determine the lens curvature points in the imagery. The program would automatically detect the lens curvature of the lens surfaces and calculate an estimate of optical power of the lens.
In an analysis over the central 3mm of the lenses tested we found that the mean change in the human cadaver lens group was +5.8 Diopters with a standard deviation of 2.8 Diopters. The increase in power ranged from 2.22 to 8.57 Diopters. The net change in power due to spinning was greater in both lasered groups compared to the control group.
It has been shown that laser photodissruption is capable of producing dioptric and flexibility changes in porcine lenses. Laser photodissruption surgery on the crystalline lens may be able to treat myopia, hyperopia and presbyopia.
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