Safe outcomes seen at 1 year with first or second corticosteroid implant injection

Ophthalmology. 2011;118(12):2453-2460.

Single and repeated treatment of macular edema related to central or branch retinal vein occlusion using an intravitreal dexamethasone implant may be safe over a 1-year period, a study found.

The analysis included two identical multicenter, prospective trials. Each one had a 6-month randomized, double-masked, sham-controlled phase and a 6-month open-label extension. At baseline, 1,256 patients with vision loss attributable to macular edema received 0.7 mg Ozurdex (dexamethasone intravitreal implant, Allergan), 0.35 mg dexamethasone or sham therapy in one eye.

At day 180, patients with best corrected visual acuity less than 84 letters or retinal thickness greater than 250 µm received 0.7 mg dexamethasone. This second injection occurred in 997 patients.

Incidence of ocular adverse events did not change with second treatment, aside from cataract progression, which was present in 90 of 302 phakic eyes (29.8%) treated with repeat injection compared with five of 88 phakic eyes (5.7%) treated with sham.

"The difference in cataract incidence could be due to the cumulative effects of two treatments with [dexamethasone] implant or to a slow development of cataracts after the first injection," the study authors wrote.

They added that, while duration of IOP-lowering medication varied and may have confounded analysis of IOP elevation, outcomes suggested no progressive increase in number of patients with increased pressure following repeat treatment.

Of note, an improvement in best corrected visual acuity of at least 15 letters was achieved by 30% and 32% of patients 60 days after first and second injection, respectively.

Study limitations included the unaddressed question of optimum re-treatment interval and the small number of patients receiving a single implant over 12 months.