Two or more dexamethasone intravitreal implants as monotherapy or in combination therapy for macular edema in retinal vein occlusion: subgroup analysis of a retrospective chart review study

Michael A Singer, Antonio Capone Jr, Pravin U Dugel, Richard F Dreyer, David G Dodwell, Daniel B Roth, Rui Shi, John G Walt, Lanita C Scott, David A Hollander, for the SHASTA Study Group

Dexamethasone intravitreal implant (DEX implant) is a sustained-release biodegradable implant approved for treatment of macular edema associated with retinal vein occlusion (RVO). The safety and efficacy of treatment of RVO-associated macular edema with sequential DEX implants in clinical practice was evaluated in patients who received DEX implant as monotherapy compared with patients who received DEX implant in combination with other RVO treatments. A multicenter, retrospective, open-label chart review study (one study eye/patient) evaluated use of DEX implant and outcomes in 289 patients with branch or central RVO who received at least 2 DEX implant treatments in the study eye. Data were collected from the time of the first implant (baseline) to 3-6 months after the last implant. Subgroup analysis evaluated outcomes in patients receiving only DEX implant during the study versus patients receiving DEX implant plus adjunctive RVO treatments. Endpoints included best-corrected visual acuity (BCVA) and central retinal thickness (CRT) change from baseline. DEX implant was used as monotherapy in 84 (29.1%) patients and in combination with other therapy in 205 (70.9%) patients. Mean number of DEX implant treatments received was 3.1 in the monotherapy group and 3.3 in the combination therapy group (P = 0.344). Mean time between implants was longer in the combination therapy group (177 vs. 151 days, P < 0.001). Mean change from baseline BCVA after the first through sixth DEX implants ranged from +0.6 to +3.4 lines in the monotherapy group and +1.3 to +2.8 lines in the combination therapy group. Mean decrease from baseline CRT ranged from 165 to 230 μm in the monotherapy group and 136 to 175 μm in the combination therapy group. Increased intraocular pressure was more common in the combination therapy group. Treatment of RVO-associated macular edema with at least 2 sequential DEX implants was safe and effective both when used alone and when combined with other RVO treatments. Improvements in BCVA and CRT were generally similar in the monotherapy and combined therapy groups. ClinicalTrials.gov NCT01411696 .