ABSTRACT
We performed the intravitreal injection of air and pure perfluoropropane (C3F8) gas in the pigmented rabbits and observed the changes of gas levels by the ultrasonography. We also observed the changes of the intra-ocular gas levels by the ultrasonography and measured the intraocular pressures (lOPs) in 9 patients who had undergone vitrectomy and fluid-gas exchange with 20% sulfur hexafluoride (SF6) and 14% perfluoropropane (C3F8) gases. In the pigmented rabbits, the air was not expanded and completely absorbed within 2 days, and the C3F8 gas was expanded maximally at 3 to 7 days and completely absorbed after 3 weeks. Among nine human eyes treated with vitrectomy and fluid-gas exchange, the intraocular pressures were elevated above 25mmHg at 1 day after operation in 2 eyes, which were controlled with medical therapy. The lOPs were significantly correlated with the amount of the intraocular gases (r=0.3476, p<0.05). The assessment of intraocular gas level by ultrasonography seems to be easier and more objective method than others previously reported.