Outcome of silicone oil tamponade combined dexamethasone implantation in patients with proliferative diabetic retinopathy and retinal detachment undergoing vitrectomy: a prospective randomized controlled clinical trial.

Purpose: To report the outcome of adjunctive intravitreal dexamethasone (Ozurdex) implantation in patients with proliferative diabetic retinopathy (PDR) and retinal detachment (RD) undergoing vitrectomy and silicone oil (SO) tamponade.

Design: A one-year, single-center, prospective, randomized controlled clinical trial.

Methods: A total of 30 people (34 eyes) with PDR and RD who need vitrectomy and silicone oil tamponade were randomly assigned as 1:1 to study group and control group. Eyes in study group were injected with Ozurdex after vitrectomy and just before silicone oil tamponade. Primary outcome was the changes of epiretinal proliferative membranes area from 1 month to 12 months after the first operation. Anatomical and functional outcomes were also assessed during follow-up.

Results: There was no significant difference in baseline characteristics between the two groups. The incidence of preretinal proliferation progression from 1-month to 12-months follow-up in the study group was significantly lower than that in the control group (23.5% vs. 88.2%, p=0.000). The area of preretinal proliferation in the study group was significantly smaller than that in the control group at 1-month, 3-months, 6-months, and 12-months follow-up and this difference increased with the prolongation of follow-up time. During the follow-up period, the incidence of macular epiretinal membrane in the study group (11.8%) was significantly lower than that in the control group (41.2%) (p=0.024). The mean best corrected visual acuity (BCVA) between the two groups only showed a significant difference at 12-months follow-up, with better BCVA in study group (0.61±0.70 logMAR) than in the control group (1.02±1.00 logMAR) (p=0.024). The mean central retinal thickness (CRT) of the study group at 1 and 6 months were 225.9 ± 106.9 µm and 223.0±118.9 µm respectively which was significantly lower than that of the control group (450.8 ± 301.4 µm and 275.5±131.9 µm, p=0.008 and 0.024, respectively).

Conclusion: In patients with proliferative diabetes retinopathy complicated with retinal detachment, the combination of vitrectomy with silicone oil tamponade and dexamethasone implantation can reduce the incidence of preretinal proliferative membrane and macular epiretinal membrane and improve the visual outcome during 1 year follow-up.