Difference in the efficacy of intravitreal dexamethasone implant before and after silicone oil removal: A case report

RATIONALE: An intravitreal dexamethasone (IV-DEX) implant is safe and effective for the treatment of macular edemas; however, the efficacy of IV-DEX implants in silicone oil (SO)-filled eyes remains controversial. There is no previous study comparing an IV-DEX implant in the same eye with and without intravitreal SO. PATIENT CONCERNS: A 72-year-old man with proliferative diabetic retinopathy, macular edema, and rhegmatogenous retinal detachment, treated with pars plana vitrectomy with SO tamponade had refractory macular edema. DIAGNOSIS: Refractory macular edema. INTERVENTION: Subtenon triamcinolone injection, intravitreal anti-vascular endothelial growth factor injection, and IV-DEX implantation were performed; this was followed by intravitreal SO removal combined with IV-DEX implantation. OUTCOMES: The macular edema did not decrease significantly with posterior subtenon triamcinolone injection, intravitreal anti-vascular endothelial growth factor injection, and IV-DEX implantation; however, the edema was relieved after SO removal and a new IV-DEX implantation. LESSONS: IV-DEX implant may be less efficacious in the treatment of macular edema in an SO-filled eye than that in a normal vitreous cavity.