Intravitreal Dexamethasone Implant for Persistent Macular Thickening and Edema After 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.

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