MAY 02, 2017
This phase IIIb, prospective control trial assessed whether an adjunctive slow-release dexamethasone implant (Ozurdex, Allergan) could improve outcomes following surgery for proliferative vitreoretinopathy (PVR).
Subjects included 140 patients requiring pars plana vitrectomy with silicone oil tamponade for rhegmatogenous retinal detachment with established (grade C) PVR. At the end of surgery, patients randomized to the adjunct group received a 0.7-mg dexamethasone implant and a second implant during tamponade removal 4 months postoperatively. Control patients received no implants. Data from this study was gathered during a 6-month follow-up; however, subsequent reports will describe 12-month results.
Key take-home points:
- At 6 months, the percentage of patients in the implant and control groups who achieved the primary outcome measure of stable retinal reattachment after silicone oil removal was not statistically different, at 49% and 46%, respectively (P=0.733). Subgroup analysis by stratifying for baseline PVR severity also failed to reveal a significant difference in reattachment rate.
- Change in mean VA from baseline and rates of tractional detachment and PVR recurrence were also similar between the groups.
- Rates of cystoid macular edema were significantly lower in implant eyes than control (42.7% vs. 67.2%; P=0.004), and a higher proportion of implant eyes showed central foveal thickness >300 microns in the A1 subfield (P=0.023).
- The study was powered to detect a 50% reduction in failure rate. A larger, multicenter trial may be able to detect smaller differences in both anatomic and visual outcomes.
- Though the anatomical success rate was low (under 50%), the mean postoperative VA compares favorably to other studies. This result suggests that future studies should be powered to detect differences in visual rather than anatomical outcomes, a direction that is also supported by patient groups.
- The dexamethasone implant did not improve anatomic outcomes when used in conjunction with vitrectomy and silicone oil placement for retinal detachments complicated by PVR.
- This is the first clinical trial investigating the use of a slow-release corticosteroid for PVR.