CLINICAL FEATURES OF INTRAVITREAL DEXAMETHASONE IMPLANTATION IN VITRECTOMIZED EYES OF PATIENTS WITH DIABETIC MACULAR EDEMA

Purpose:To identify the clinical outcomes of intravitreal dexamethasone implantation (IVD) in previously vitrectomized eyes of patients with diabetic macular edema.Method:We performed a retrospective observational study. We recorded central subfield thickness, best-corrected visual acuity, and intraocular pressure up to 12 months after IVD implant placement. We compared the duration of IVD action, intraocular pressure trends, and the prevalence of ocular hypertension after the first IVD treatment of nonvitrectomized and vitrectomized eyes. We also compared the central subfield thickness, best-corrected visual acuity, number of IVD treatments, and prevalence of ocular hypertension between the 2 groups after 12 months.Results:We found no significant between-group differences in the central subfield thickness, best-corrected visual acuity, or the prevalence of ocular hypertension during treatment. However, the duration of action of the first IVD treatment was significantly shorter in vitrectomized eyes, and these eyes required more IVD treatments during the 12-month follow-up period. The maximal average intraocular pressure was observed at 2 months after the first IVD treatment in the nonvitrectomized group, but 1 month after the first IVD treatment in the vitrectomized group.Conclusion:These findings suggest that the IVD pharmacokinetics and pharmacodynamics differ between vitrectomized and nonvitrectomized eyes. Nevertheless, given the relatively long-lasting effectiveness of the treatment and the good clinical results, consecutive IVD treatments may be beneficial for patients with diabetic macular edema with previously vitrectomized eyes.