By Jennifer I. Lim, MD
A surgical adjunct that can safely shorten surgical duration by decreasing bleeding episodes, promoting regression of active neovascularization and reducing the need for multiple instruments would be welcomed by retinal specialists. Intravitreal Avastin may be such a tool.
This noteworthy, small, interventional, randomized, case-control study examined the surgical results of 11 proliferative diabetic retinopathy (PDR) patients who were given intravitreal Avastin prior to pars plana vitrectomy (PPV) and 11 PDR patients who underwent PPV but did not receive Avastin. All of the subjects were required to have tractional retinal detachment, tractional-rhegmatogenous retinal detachment or tractional detachment complicated by vitreous hemorrhage.
Patients in the Avastin group received one 1.25 mg intravitreal injection five to seven days before undergoing surgery, with no complications reported. Mean surgical time was 57 minutes in the Avastin group versus 83 minutes in the control group, despite similar levels of surgical complexity and use of the same surgical technique. The study's researchers attributed these results to the regression and subsequent fibrosis of retinal neovascularization seen in the patients given Avastin.
Similarly, there was a mean of 27 tool exchanges in the Avastin group compared with 53 in the control group. The mean number of intraoperative bleeding incidents during fibrovascular proliferation removal was five in the Avastin group versus 16 in the control group, and endodiathermy was applied two versus nine times, respectively. Mean best-corrected visual acuity six months after surgery was significantly better in the Avastin group compared with the control group, although there had been no difference preoperatively.
One concern surrounding the use of Avastin preoperatively is whether the occurrence of adverse events outweighs the treatment's benefits. It appears that if surgery is performed within five to seven days of intravitreal Avastin administration, there are no ocular adverse events.
This study's major limitations are the small number of eyes included and its short follow-up time. It is important to find out whether preoperative Avastin use causes any systemic adverse events; studying many more patients is necessary in order to answer this question. Also it would be interesting to know whether there are any long-term ocular consequences of anti-VEGF usage in ischemic eyes. Nonetheless, it appears that the pharmacotherapeutic era for diabetic surgical ocular disease has begun.
Financial Disclosures
Dr. Lim is a consultant to Quark Biotech, Inc., Genentech, Inc., Novartis, Allergan, Inc., and Bausch & Lomb Surgical. Dr. Lim receives lecture fees from Genentech and Optovue Corp., and grant support from Genentech, Pfizer Ophthalmics, QLT PhotoTherapeutics, Inc., and Icon Bioscience.