Intravitreal long-acting gas in the prevention of early postoperative vitreous hemorrhage in diabetic vitrectomy

Objective: To evaluate the hemostatic effects of intravitreal infusion of 10% C3F8 in patients undergoing diabetic vitrectomy on the occurrence of early postoperative recurrent vitreous hemorrhage. Design: Prospective, randomized, observational case series. Participants: Sixty-one eyes (59 patients) that underwent primary pars plana vitrectomy for complications of proliferative diabetic retinopathy from September 2004 to April 2005, with postoperative retinal reattachment 3 months and follow-up > 6 months were enrolled. Methods: Sixty-one cases were randomly divided into either group 1 (intravitreal 10% C3F8 infusion at the end of surgery) or group 2 (no intravitreal gas). Ultrasound biomicroscopy (UBM) examination of the 3 sclerotomy sites was performed at : 2 months postoperatively. Demographic data, history, intraoperative findings, and management of recurrent vitreous hemorrhage were recorded. Main Outcome Measures: Initial time to vitreous clearing (ITVC), percentage of prolonged ITVC (> 5 weeks), and early (<= 4 weeks) versus late (> 4 weeks) manifest postoperative recurrent vitreous hemorrhage in groups 1 and 2 were compared to determine the effects of 10% C3F8 on prevention of early recurrent vitreous hemorrhage. Multiple logistic regression analyses were performed to examine risk factors related to early recurrent vitreous hemorrhage. Results: Group 1 ITVC was 13.2 +/- 9.6 days, and group 2 ITVC was 11.3 +/- 11.1 days (P = 0.26). Prolonged ITVC (> 5 weeks) in each group was 1/31 (3.2%) and 2/30 (6.7%; P = 0.53). Early manifest recurrent vitreous hemorrhage rates in groups 1 and 2 were 0/31 (0%) and 5/30 (16.7%), respectively (P = 0.02). Early manifest recurrent hemorrhage plus prolonged ITVC in the 2 groups were 1/31 (3.2%) and 7/30 (23.3%), respectively (P = 0.02). The incidences of elevated intraocular pressure, iris neovascularization, and significant cataract formation among the 2 groups were too low to detect statistical significance. No evidence of fibrovascular ingrowth was found by UBM examination in either group. Multiple logistic regression analyses in non-gas-infused cases showed that an increased extent of membrane peeling raised the possibility of significant early vitreous rebleeding. Conclusions: Intraocular tamponade with 10% C3F8 may be a useful adjunct to vitrectomy for proliferative diabetic retinopathy in the reduction of early postoperative recurrent vitreous hemorrhage.