Intravitreal bevacizumab as an adjunctive therapy before diabetic vitrectomy

Abstract

Purpose: To evaluate the effect of intravitreal injection of Avastin, bevacizumab (IVA) on diabetic vitrectomy and on the postoperative course.

Methods: Thirty patients undergoing diabetic vitrectomy were distributed to standard vitrectomy (group 1) or vitrectomy with preoperative IVA (group 2). Bevacizumab was injected 5 to 7 days before surgery. Patients of both groups were matched as much as possible according to surgical indication and preoperative visual acuity. Main outcome measures were the feasibility of surgery and the postoperative complications. Feasibility of surgery was evaluated through recording surgical time, intraoperative bleeding, use of endodiathermy, relaxing retinotomies, use of perfluorocarbon liquid (PFCL) and silicone oil tamponade.

Results: Follow up ranged between 7 and 18 months. There was significant reduction of mean surgical time, bleeding frequency, and diathermy use in group 2 compared to group 1. The rate of PFCL use and relaxing retinotomies were less in group 2 in comparison to group 1. Gas or air was used in 80% of patients in group 2 while silicone oil represented 60% of group 1. Postoperative visual acuity improvement was highly significant in both groups but the difference in both groups was not statistically significant. Vision improved in 87% in group 2 and 80% in group 1. Primary anatomical attachment was achieved in 90.3% in group 2 and 86.6% in group 1. Rate of subsequent surgeries and persistent cataract were higher in group 1. Postoperative bleeding was reported in 26.6% of cases in group 1 and none in group 2. In group 2, no complications related to avastin injection or progression of traction were reported during the preoperative period.

Conclusion: Preoperative IVA was helpful in achieving the surgical and anatomical goals by reducing the time of surgery, the intraoperative and postoperative bleeding, and the use of silicone oil with subsequent reduction of second surgery.

Keywords: diabetic vitrectomy; diabetic vitreous hemorrhage; intravitreal bevacizumab; proliferative diabetic retinopathy; vascular endothelial growth factor.

Figure 1

Fundus photographs of a case in group 2. A before injection of bevacizumab showing vitreous and subhyaloid hemorrhage and tractional retinal detachment. B 1 week after injection of bevacizumab showing evident regression of retinal neovascularization and C 12 months after vitrectomy with retina attached with near confluent laser marks.