Abstract
Purpose: :
To study characteristics and outcomes of patients with proliferative diabetic retinopathy (PDR) receiving intravitreal bevacizumab prior to pars plana vitrectomy (PPV).
Methods: :
A retrospective chart review identified patients with PDR who received intravitreal bevacizumab (1.25 mg) prior to 23-g PPV from 1/06 to 10/07. Patients receiving silicone oil or who had < 2 months follow-up were excluded. Analysis included demographics, surgical indication, time from injection to surgery, phakic status, pre- and postoperative VA, surgical time, intra- and postoperative complications, pre- and postoperative IOP, time to best visual acuity, and incidence of postoperative vitreous hemorrhage.
Results: :
39 eyes of 37 patients had at least two months postoperative follow-up by review. Patients were 43.6% male and 56.4% female with mean age of 53.7 years. Patients had a mean of 4.9 months post-operative follow-up. Bevacizumab was injected a mean 11.7 days preoperatively. Indications were non-clearing vitreous hemorrhage (NCVH, 27 eyes) and tractional retinal detachment (TRD, 8 eyes). An additional 4 eyes had proliferative epiretinal membrane without TRD. Mean overall preoperative VA was logMAR 1.51 and logMAR 1.70 and 1.11 in the NCVA and TRD groups respectively. Mean surgery time was 46.7 and 81.0 minutes in the NCVA and TRD groups respectively. Mean overall best postoperative VA (BVA) was logMAR 0.63, achieved at a mean 2.4 months after surgery. Mean postoperative BVA for NCVH and TRD patients was logMAR 0.51 and 0.97 respectively. Change from preoperative to BVA was logMAR -1.18 (p<0.001) and -0.13 (p=0.58) in the NCVA and TRD groups respectively. There was no correlation between number of days before surgery that bevacizumab was given and BVA. No patients had intra- or immediate postoperative complications, but postoperative vitreous hemorrhage occurred in 33.3% and 37.5% of eyes in the NCVH and TRD groups respectively at a mean 80.8 days postoperatively.
Conclusions: :
Preoperative intravitreal bevacizumab has been noted to reduce vascular engorgement and intraoperative bleeding. Risk of progression to severe TRD following intravitreal bevacizumab requires surgery to be performed soon after injection. In this study, injection was at a mean of 11.7 days preoperatively and there was no incidence of iatrogenic TRD. There was a higher incidence of postoperative vitreous hemorrhage than that previously reported in diabetic vitrectomy without bevacizumab. Further study correlating the timing of injection with incidence of iatrogenic TRD and postoperative vitreous hemorrhage may help determine the optimal window for injection of bevacizumab.
Keywords: diabetic retinopathy • vitreoretinal surgery • injection