Perfluoropropane 12% versus 20%. Effect on intraocular pressure and gas tamponade after pars plana vitrectomy.

A randomized prospective study was performed on 30 nonglaucomatous eyes undergoing pars plana vitrectomy and intraoperative fluid-gas exchange, comparing the effect of two perfluoropropane gas concentrations (12% and 20%) on postoperative intraocular pressure, early postoperative bubble size, and intravitreal longevity. No significant differences in mean intraocular bubble size at 36 to 48 hours and mean peak and final follow-up intraocular pressure were found between the 12% group (n = 15) and the 20% group (n = 15, unpaired T-test). Intravitreal longevity was significantly greater for the 20% concentration (mean +/- standard deviation = 8.4 +/- 1.8 weeks) compared with the 12% concentration (mean +/- standard deviation = 6.7 +/- 1.6 weeks). In nonglaucomatous eyes under careful observation and appropriate antiglaucoma therapy, the choice between a 12% or 20% concentration of perfluoropropane gas determined primarily longevity of gas tamponade rather than postoperative pressure or early bubble size.