We evaluated the surgical results of vitrectomy for macular hole, according to the type of gas. Retrospective analysis was performed on the clinical data of 45 patients who underwent macular hole surgery without any complication influencing visual acuity who were included in this study. They were divided into two groups according to the type of gas: Group 1 - SF6, Group 2 - C3F8. We compared the anatomical results of these groups. This study shows that the type of gas does not significantly influence surgical results. However, large sized macular holes lead to poor post-operative visual acuity.

Sulfur hexafluoride has an extremely high global warming potential (GWP) because of strong absorption of infraredradiation and long atmospheric lifetime which cause the global warming effect. This study is to identify the effects ofdestruction and removal efficiency of SF6 by the addition of conditioning agent (oxygen, water vapor and hydrogen) whenusing the high ionization energy. The irradiation intensity of ionization energy was 2mA, 5mA, 10mA and 15mA. TheSF6 was completely removed with H2O and H2 gas injection at 2mA. Main by-products were HF and F2 gases. HF andF2 gas formation was increased with irradiation intensity increasing. Most of the by-products of particle were sulfur andmetal sulfate.

SF6 (sulfur hexafluoride) gas has an extremely high global warming potential (GWP) because of strong absorption of infrared radiation and long atmospheric lifetime which cause the global warming effect. The objective of this study is to identify the effects of destruction and removal efficiency (DRE) of SF6 by the addition of oxygen, water vapor and hydrogen. The applied dose of ionization energy was 1,028 kGy(5 mA). The initial concentrations of SF6, O2, H2O and H2 gases were 1,000 ppm, 1,000 ppm, 3,000 ppm, 3,000 ppm, respectively. The DRE was increased about 2 times with O2 gas injection. The SF6 was completely removed with H2O and H2 gas injection. By-products formed by SF6 destruction were mainly HF and F2 gases. In addition, SF2, NF3, N2O, SO2, SO2F2, and NOx gases were produced.

Destruction and removal efficiency (DRE) of SF6 was tested with low degrees of ionization. The applied dose of ionization energy varied from 63.70 to 212.34 kGy. The initial concentration and flow rate of SF6 gas were 1,000 ppm and 50L/min, respectively. In order to increase the DRE, injection of conditioning agent (H2) were conducted. The DRE of SF6 increased about 2 times with injection of H2 gas.