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10 March 1987 Quasi-Elastic Light Scattering And Other Objective Measures Of Cataractous Change In Vivo
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Proceedings Volume 0712, Lasers in Medicine; (1987)
Event: Cambridge Symposium-Fiber/LASE '86, 1986, Cambridge, MA, United States
Quasielastic light scattering technology provides a means of obtaining a linear measure of the total light scattered by the lens or cornea. This technology has been applied to a population of normal volunteers and a group of patients with different types of cataracts. The replicate errors have been measured for 5 and 50 microsecond sample times in both the cortex and the nucleus of the human crystalline lens in vivo, and they vary from 10-13%. The regional error associated with a change in the location of the pickup, a variation over an area of 225 square microns, is 18-20%. The change from a clear to a cataractous cortex is associated with wide fluctuations in total light scattered; in our population, the mean decreased slightly. In the nucleus, the total light scattered by opaque nuclei was 400% greater than that scattered from non-cataractous, age-matched control nuclei. It appears as if the signal-to-noise ratio for this instrument applied to humans is likely to be 10-20/1. This should enable one to detect small changes in the light scattering properties of the lens in vivo and should make clinical trials of anticataract drugs tolerably short in duration and affordable. Other film-based technologies for in vivo objective measurement of cataractous change along with their strengths and weaknesses are also discussed. Specifically the Topcon SL-45, the Topcon SL-5D/6E, the Neitz CTR and the Zeiss-Kawara cameras are discussed.
© (1987) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Leo T. Chylack,Jr. and David Magnante "Quasi-Elastic Light Scattering And Other Objective Measures Of Cataractous Change In Vivo", Proc. SPIE 0712, Lasers in Medicine, (10 March 1987);

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