人工硝子体の屈折率,波長分散の術後視機能におよぼす影響

Abstract

In order to make ideal artificial vitreous, it is important to have knowledge of the opical properties of actual vitreous and vitreous replacement substance. The measurement of the refractive index, chromatic dispersion and its thermal alteration of the pig vitreous, silicone oil, and perfluorodecalin were made by using Abbe refrectometer. The mean refractive index of pig vitreous was 1.3351, silicone oil 1.4053, and perfluorodecalin 1.3152 at 20℃ using wavelength of 589nm. The longer the measured wavelength the smaller the refractive index. The refractive index tends to be small as the temperature of measurement rises. The difference of the refractive index between 42℃ to 20℃ was very small (The pig vitreous 0.003, silicone oil 0.009, perfluorodecalin 0.009) so that variation of refractive index according to the thermal alteration of measurement was demonstrated to be very small. Postoperative refraction was calculated by ray tracing method based on Gullstrand's schematic eye. When the vitreous cavity of a phakic eye is filled with silicone oil, 8D hyperopic shift was predicted and with perfluorodecalin 2.5D myopic shift was predicted. Chromatic dispersion of pig eye was 0.8D, with silicone oil, 0.88D, with perfluorodecalin 0.53D so that the chromatic aberration may unaffected by these mate- rials, and variation of chromatic aberration according to the thermal alteration was demonstrated to be very small.