Incidence of postoperative hypotony in 25-gauge vitrectomy: oblique versus straight sclerotomies.

To compare the incidence of hypotony after oblique and straight sclerotomies in 25-gauge transconjunctival sutureless vitrectomy (TSV).Retrospective, comparative, interventional case series.Two hundred seventy-five eyes of 250 patients.We reviewed 275 consecutive cases of 25-gauge TSV. Oblique incisions were performed on 141 eyes and straight incisions on 134 eyes.On postoperative day 1, there was no significant difference in the incidence of hypotony (9.9% vs. 9.2%; p = 0.85) between oblique and straight incisions. The type of incision showed no statistical effect on hypotony in eyes filled with fluid (p = 0.91) or air-gas (p = 0.81). Hypotony was significantly reduced using air-gas endotamponade (4.8%) as compared to fluid-filled eyes (20.0%; p = 0.0001).Oblique incisions do not reduce the incidence of postoperative hypotony in fluid-filled eyes or with air-gas tamponade. Air-gas tamponade use results in a 4-fold reduction in the incidence of hypotony.