Preoperative intravitreal bevacizumab and silicone oil tamponade for vitrectomy in diabetic retinopathy

AIM: To evaluate the outcomes and complications of vitrectomy for diabetic retinopathy using preoperative bevacizumab and silicone oil(SO) tamponade. METHODS: Eighty-four eyes(64 patients) that underwent vitrectomy to treat severe proliferative diabetic retinopathy were enrolled in this retrospective, interventional, serial case study. All patients provided signed informed consent preoperatively and the off-label use of bevacizumab was discussed with the patients and confirmed in the signed consent forms. Bevacizumab injections and SO tamponades were used in all cases and intraoperative complications, postoperative complications and postoperative outcomes were analyzed. The primary outcome was the occurrence of intraop-erative and postoperative bleeding during and after vitrectomy and SO removal. The secondary outcomes were other complications that occurred during the two surgeries, the surgical time and the postoperative best-corrected visual acuity(BCVA) in log MAR scale compared with the preoperative BCVA in logM AR. The statistical analysis was performed with GraphP ad Prism 5(Graph Pad Software, La Jolla, CA) using a column analysis(column statistics and frequency distribution) for the noncomparative analysis and a paired t-test for the comparative study;P < 0.05 indicated statistical significance. RESULTS: Eighty-four eyes of 64 patients were included in the study. Of the 88 eyes initially recruited, 4 eyes(0.45%) developed phthisis bulbi and were excluded from the statistical analysis. Bevacizumab was injected between 1 and 10 d before surgery, with a mean of 3.7 ± 2.2 d. Forty-six eyes(54.8%) had no complications during the surgery;6 eyes(7.1%) had vitreous hemorrhage;21(25%) had a single retinal tear;7(8.3%) had two or more retinal tears, one of which was in the posterior pole, temporal to the fovea;2(2.4%) had retinal tears associated with hemorrhage;1(1.2%) had choroidal detachment;and 1 eye(1.2%) had dialysis in the temporal entrance of the trocar. After the surgery and SO removal, 60 eyes(71.4%) had no complications, 8(9.5%) had vitreous hemorrhage, 2(2.4%) had a macular hole, 2(2.4%) had an epiretinal membrane, 7(8.3%) had rhegmatogenous retinal detachment, 2(2.4%) had neovascular glaucoma, 2(2.4%) had a corneal trophic ulcer, and 1(1.2%) had central venous occlusion. The surgical time ranged from 40 to 120 min, with a mean of 77.8 ± 20.7 min. The final status of the lens was 34 phakic eyes(40.5%) and 24 pseudophakic eyes(28.5%);in 26 eyes(31%), the lens was extracted via phacoemulsification combined with vitrectomy or SO removal. The preoperative BCVA in logM AR ranged from 0.1 to 3.0, with a mean of 1.6 ± 0.9;the postoperative BCVA in logM AR ranged from 0.0 to 3.0, with a mean of 0.9 ± 0.7;the preoperative and postoperativeBCVA values were significantly different(P < 0.0001). CONCLUSION: Bevacizumab may diminish intraoperative and postoperative bleeding, thus possibly facilitating intraoperative maneuvers, diminishing the complications and playing a role in the final outcomes of these eyes.