The first large study published reported the efficacy and safety of Ozurdez in the treatment of macular edema (causes of macular included diabetic retinopathy, retinal vein occlusions, uveitis, or Irvine-Gass syndrome with persistent macular edema). This was a 6 month, multi-center trial with 315 patients enrolled. Of the patients randomized to the 0.7 mg dexamethasone implant, 35 % demonstrated a 10 or more letter improvement (via ETDRS testing) at 90 days from injection compared to 13 % of the control group (sham injection). Improvement in BCVA (best corrected visual acuity) of 15 letters or more was achieved in 18 % of patients versus 6 % in controls. Additionally, the concern regarding intraocular pressure (IOP) elevation was lower than expected with 11 % of patients developing a 10 mm hg or higher rise in IOP compared to 2 % of controls.

During the study, OCTs were used to monitor response with a dramatic improvement/resolution of macular edema in those treated with Ozurdex [7]. However, in the entire study, there were only 5 patients with uveitis enrolled.

To further expand the possible benefit of the implant specifically in patients with uveitis, a large scale randomized clinical trial was completed to evaluate the efficacy of the dexamethasone implant in patients with non-infectious posterior uveitis (Huron Study). Patients were randomized to sham injection or one of two dexamethasone dosages (0.35, 0.7 mg).

In this study, 229 patients from 18 countries were enrolled. 81 % had the diagnosis of intermediate uveitis with the remainder having various forms of posterior uveitis. Those patients receiving the 0.7 mg injection had a dramatic improvement in vitreous haze (Fig. 46.5) with nearly half of the patients achieving a haze score of “0”. 90 % had a one step improvement in haze and a significant portion had a two step improvement (Figs. 46.6 and 46.7) with the effect continuing for 6 months.

Fortunately, the complications of the sustained release dexamethasone implant were lower than those reported for Retisert. The rate of cataract formation in the implant group was 11.8 % compared to 5.3 % in those receiving sham injection. Additionally, IOP elevation of 10 mm hg over baseline was only seen in 15–20 % of patients, with the majority of patient not requiring IOP lowering medications. With those that required therapy, most only needed one topical drop (Fig. 46.8) compared to 40 % or greater in patients receiving the Retisert^® implant.