Intravitreal dexamethasone implant migration into the anterior chamber: A Multicenter Study from the Pan-American Collaborative Retina Study Group

Purpose:To establish the prevalence and risk factors for intravitreal dexamethasone implant migration into the anterior chamber in eyes with macular edema.Methods:This was a multicenter, retrospective, observational chart review of data that included patients with macular edema who had been treated with at least one intravitreal dexamethasone injection. Patients with incomplete chart information during the follow-up period were excluded.Results:The prevalence of implant migration in 468 patients, considering the number of injections, was 1.6%, with significant associations between implant migration and cataract surgery (P = 0.043) and intraocular lens status (P = 0.005) and a trend toward statistical significance (P = 0.057) with vitrectomy. A higher rate of implant migration into the anterior chamber was observed in vitrectomized eyes (4.8%) when compared with patients who did not undergo a vitrectomy (1.6%). The implants that migrated were removed with forceps with/without viscoelastic expression or with 20-gauge cannulas connected to the vitreous cutter machine.Conclusion:The risk of implant migration into the anterior chamber was 1.6%. Risk factors were a history of cataract surgery or vitrectomy and aphakia. When anterior migration occurs, rapid removal is advised, especially if corneal edema is present.