By J. Fernando Arevalo, MD, FACS
This retrospective study found that the 0.7-mg dexamethasone intravitreal implant is a promising adjunctive treatment for patients with severe posterior noninfectious uveitis recalcitrant to various immunosuppressive agents.
The dexamethasone drug delivery system is a biodegradable intravitreal implant with potent anti-inflammatory properties and a favorable side-effect profile. Recent studies have demonstrated that this implant is able to improve visual acuity and macular thickness in different ocular conditions, such as macular edema associated with retinal vein occlusion and uveitis.
The authors describe their experience treating 12 patients with recalcitrant and severe cases of noninfectious posterior uveitis with the 0.7-mg dexamethasone intravitreal implant (Ozurdex; Allergan Inc., Irvine, Calif.) as an adjunctive anti-inflammatory treatment. Before treatment with the implant, they had inadequate control of uveitis despite use of different immunosuppressants and periocular corticosteroid therapy.
At a mean follow up of nine months from implantation, uveitis activity decreased and visual acuity improved in all patients. BCVA improved from 20/80 to 20/40 at the end of follow-up, and mean retinal thickness improved from 496 to 226 µm.
Adverse events included: IOP elevation in three eyes, vitreous hemorrhage in one eye in a patient on systemic anticoagulation for chronic atrial fibrillation, and subconjunctival hemorrhage in one eye.
Three patients reduced their daily systemic corticosteroid dosage after treatment. All patients continued systemic immunosuppressive therapy.
One of the interesting features of this article is that before the intravitreal injection, these patients were treated with different systemic corticosteroids and/or immunosuppressants and periocular steroid injections. Despite these different treatment strategies, the patients had experienced recurrences of intraocular inflammation in the form of macular edema, vitritis or retinal vasculitis, but with intravitreal dexamethasone treatment, all improved in BCVA and uveitis activity. In addition, the authors observed a decrease from baseline central macular thickness on OCT in patients with macular edema; the reduction of macular thickness was extremely rapid and noticeable around the second week after injection.
Twenty-five percent of the patients developed a moderate IOP increase after dexamethasone intravitreal implant treatment and required combined antiglaucoma therapy. This is in concordance with what has been described in the literature.
No patients developed cataract but the series was very small with a short follow up and a limited number of injections.
The authors note that careful selection of patients is warranted to avoid complications; patients with infectious forms of uveitis and masquerade syndromes, or with prior IOP elevation or known history of glaucoma, should be excluded.
They conclude that future studies will need to determine the relative efficacy and safety profiles among the different types of uveitis and to assess the long-term effects of repeated use of the dexamethasone implant for recurrent uveitis.