Intravitreal ranibizumab shows little benefit after hemorrhage

By Joanna Lyford, Senior medwireNews Reporter

Ranibizumab given intravitreally offers no clear benefit in the treatment of vitreous hemorrhage due to proliferative diabetic retinopathy (PDR), a randomized clinical trial indicates.

Ranibizumab, a vascular endothelial growth factor inhibitor, failed to impact vitrectomy rates at 16 weeks, although treatment was associated with improvements in some short-term secondary outcomes.

Noting that the 16-week vitrectomy rates were lower than expected in both active and control arms, the researchers write: "This study suggests little likelihood of a clinically important difference between ranibizumab and saline on the rate of vitrectomy by 16 weeks in eyes with vitreous hemorrhage from PDR."

The trial was conducted by the Diabetic Retinopathy Clinical Research Network under the direction of Karisse Torres (Jaeb Center for Health Research, Tampa, Florida, USA). They enrolled 261 adult patients with Type 1 or Type 2 diabetes mellitus and vitreous hemorrhage due to PDR. In all cases, the hemorrhage was causing vision impairment and precluding the completion of panretinal photocoagulation.

Patients were randomly assigned to have their eyes treated bilaterally with intravitreal ranibizumab 0.5 mg or intravitreal saline at baseline, 4, and 8 weeks.

At 16 weeks, vitrectomy rates were 12% in the ranibizumab group and 17% in the saline group, a nonsignificant difference. Rates of complete panretinal photocoagulation were also similar between ranibizumab and saline groups, at 44% and 31%, respectively.

Other outcome measures suggested advantages of ranibizumab over saline, however. Visual acuity improved between baseline and 12 weeks by an average of 22 letters in the ranibizumab group versus 16 letters in the saline group.

Also, rates of recurrent vitreous hemorrhage at 16 weeks were 6% with ranibizumab versus 17% with saline, a highly significant difference.

With regard to adverse events, one eye (0.74%) in the saline group developed endophthalmitis; rates of traction retinal detachment, rhegmatogenous retinal detachment, elevated intraocular pressure, ghost cell glaucoma were similar in the two groups.

The researchers say that their results fail to support a clinically important advantage of using ranibizumab rather than saline to treat eyes with vitreous hemorrhage from PDR.

However, they note that vitrectomy rates - the study's primary outcome - were lower than expected with observation alone in both groups. "It is unknown whether observation alone would have resulted in a higher rate of vitrectomy or a slower rate of vitreous hemorrhage clearance than what was observed in this study," they admit.

Torres et al conclude: "Secondary outcomes… suggest biologic activity and perhaps faster hemorrhage clearing with intravitreal ranibizumab. This study reports short-term findings; long-term benefits of either of these intravitreal regimens remain unknown."

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