Treatment of Diabetic Macular Edema or Macular Edema Following Retinal Vein Occlusion Based on Repeated Injection of the Dexamethasone Intravitreal Implant: A Retrospective Real-World Analysis

Francis WB Sanders, Rhys Dumont Jones, David R Jones, Sean V Phillips, Gwyn S Williams Department of Ophthalmology, Singleton Hospital, Swansea, UKCorrespondence: Francis WB Sanders, Department of Ophthalmology, Singleton Hospital, Sketty Lane, Sketty, Swansea, SA2 8QA, United Kingdom, Tel +44 1792 205666, Email francis.sanders@wales.nhs.ukPurpose: To assess the “real world” utility of repeated injection with the dexamethasone intravitreal implant (DEX) in routine practice.Methods: This was a retrospective, single-center analysis of consecutive patients with diabetic macular edema, or macular edema following retinal vein occlusion, treated with DEX. None had received prior intravitreal steroid treatment. DEX was implanted as per the manufacturer’s instructions.Results: Seventy-eight individuals (95 eyes) were included (50.0% female; mean age: 68.1 ± 12.4 years; mean duration of macular edema: 13.2 ± 12.9 months). Thirty-three eyes (34.7%) had received previous treatment with an anti-vascular endothelial growth factor (anti-VEGF) and/or laser. Thirty eyes (31.6%) underwent one round of DEX implantation; the remainder received 2– 5 cycles (total: 225 cycles). Initial DEX treatment led to significant increases in visual acuity (VA) at 6 weeks (mean change: 4.6 letters; P=0.004). Greater VA improvements during the first treatment cycle were associated with inferior baseline VA (P=0.02), borderline associated with baseline central macular thickness (CMT; P=0.06), and independent of prior anti-VEGF treatment (P=0.39). In an analysis of all DEX injections, VA improvements were robust across cycles 1 and 2 but reduced in cycle 3 (P=0.03). CMT improvements did not differ based on injection number (P=0.20). Increases in intraocular pressure (IOP) were largest over the first 6 weeks (but rebounded towards baseline more rapidly) in cycle 1 versus cycles 2 and 3 (P< 0.001). IOP rises were typically manageable with topical medications.Conclusion: This analysis confirms the broad utility of DEX and may inform decision-making in routine practice.Keywords: corticosteroid, dexamethasone intravitreal implant, diabetic macular edema, intraocular pressure, retinal vein occlusion, visual acuity