Intravitreal Dexamethasone Implant for Persistent Macular Thickening and Edema After Vitrectomy for Epiretinal Membrane

This study seeks to evaluate the effect of the intravitreal 0.7mg dexamethasone implant on central macular thickness and visual acuity in those patients with persistent macular edema after pars plana vitrectomy for epiretinal membrane.

Macular edema is a relatively common occurrence after pars plana vitrectomy. Kim et al described that 47% of eyes undergoing vitrectomy for epiretinal membrane, macular hole, or vitreous hemorrhage had evidence of macular thickening on optical coherence tomography scan.1 Post-vitrectomy macular edema can limit potential visual acuity gain from removal of a symptomatic epiretinal membrane. Typical treatment of post-operative macular edema consists of topical non-steroidal anti-inflammatory drugs (NSAIDs) and topical corticosteroids; however, there are still resistant cases with refractory macular thickening.

The dexamethasone intravitreal implant (Ozurdex; Allergan, Irvine, CA) is currently FDA-approved for the treatment of posterior uveitis as well as macular edema secondary to retinal vein occlusion and diabetic retinopathy. Furino et al reported a retrospective series describing how a single injection of the 0.7mg dexamethasone intravitreal implant resulted in a substantial increase in best-corrected visual acuity (BCVA) and a decrease in central macular thickness (CMT) on spectral-domain optical coherence tomography (SD-OCT) in 8 patients with persistent macular thickening after pars plana vitrectomy for epiretinal membrane. There has been no prospective study evaluating the efficacy of this pharmacologic agent in this setting.

As such, the purpose of this study is to prospectively evaluate the effect of the intravitreal 0.7mg dexamethasone implant on CMT and BCVA in those patients with persistent macular edema after pars plana vitrectomy for epiretinal membrane.

The results of this study will help delineate whether the intravitreal dexamethasone implant has efficacy in improving CMT and/or visual acuity in those patients with refractory macular thickening after pars plana vitrectomy for epiretinal membrane.

Eligibility Criteria:
Inclusion Criteria:

1. Patient of the Wills Eye Institute Retina service, including all Mid-Atlantic Retina offices
2. Volunteer patients age 18 years and older
3. Healthy enough to participate in the study
4. Willing and able to consent to participation in the study
5. History of pars plan vitrectomy for symptomatic epiretinal membrane at least 3 months prior to study enrollment date
6. BCVA of 20/40 or worse
7. CMT of at least 400 micrometers with or without cystoid macular edema on SD-OCT
8. Prior treatment with topical NSAIDs without resolution of macular thickening or visual acuity improvement

Exclusion Criteria:

1. Advanced glaucoma (cup-disc ratio of 0.8 or greater)
2. History of glaucoma filtering or tube shunt implant surgery
3. Steroid responsive intraocular hypertension
4. Diabetic retinopathy
5. History of uveitis
6. Use of systemic or intraocular corticosteroids
7. Active or suspected ocular or periocular infections
8. Other confounding intraocular pathology