Repeated Dexamethasone Intravitreal Implant for the Treatment of Diabetic Macular Oedema Unresponsive to Anti-VEGF Therapy: Outcome and Predictive SD-OCT Features

Abstract

Purpose: To investigate dexamethasone intravitreal implant 0.7 mg (DEX implant) for the treatment of diabetic macular oedema (DME) refractory to anti-vascular endothelial growth factor (anti-VEGF) therapy and evaluate predictive factors. Methods: Two-centre retrospective interventional case series, including 40 eyes of 31 patients treated with DEX implant for at least 2 consecutive cycles. Results: Mean ± SD intervals from implantation to recurrence in the first (4.2 ± 1.0 months) and second cycles (4.0 ± 0.9 months) were not significantly different. Best corrected visual acuity improved significantly (p < 0.001) by 7.0 ± 8.4 letters from baseline to month 2, and by 5.1 ± 6.9 letters between the first and second cycles. Central retinal thickness reduction 2 months after implantation was greater after the first (–194 ± 172 µm) than the second cycle (–134 ± 150 µm). Ellipsoid zone-external limiting membrane (EZ-ELM) disruption score decreased from 1.39 ± 1.16 at baseline to 1.24 ± 1.16 (p = 0.0832) after cycle 1 and remained stable 2 months after cycle 2. Eyes with persisting severe EZ-ELM disruption (score >2, n = 10) 2 months after the first DEX implant showed significantly (p = 0.0153) smaller visual acuity (VA) gains than eyes with less severe (score ≤2) EZ-ELM disruption. Conclusion: Repeated intravitreal DEX injections with average intervals of 4 months are valuable in patients with DME refractory to anti-VEGF therapy. Disorganization of outer retinal layers (EZ-ELM) may predict smaller VA gains if evaluated after initial reduction of macular oedema.

Anterior migration of intravitreal fluocinolone acetonide (Iluvien®) implant in a pseudophakic eye with intact posterior capsule

“…Iluvien™ intravitreal implants were found to be effective in achieving substantial and prolonged improvement of vision in patients with DME, including cases recalcitrant to previous anti-vascular endothelium growth factor therapy. 1 , 2 …”

“…Iluvien® implant (Alimera Sciences Inc., Alpharetta, GA, USA) is a sustained release biodegradable implant which provides a therapeutic intravitreal concentration of fluocinolone acetonide for up to 36 months. 1 , 2 …”

<p>Clinical-Decision Criteria to Identify Recurrent Diabetic Macular Edema Patients Suitable for Fluocinolone Acetonide Implant Therapy (ILUVIEN^®) and Follow-Up Considerations/Recommendations</p>

“…13,42 Compared with FAc implants, dexamethasone implants have a short-term effect, resulting in a see-saw pattern of intermittent improvement and regression in macular thickness. [43][44][45] DME management with reactive regimens leads to periods of undertreatment. The decision to re-treat patients involves "watching and waiting" for retinal signs or symptoms, which means frequent clinic visits periodically, based on a set of prespecified criteria, as determined by the physician (eg, visual acuity (VA) and optical coherence tomography (OCT)/fluorescein angiography assessments).…”

“…13 , 42 Compared with FAc implants, dexamethasone implants have a short-term effect, resulting in a see-saw pattern of intermittent improvement and regression in macular thickness. 43 – 45 …”

<p>Dexamethasone implant in the management of diabetic macular edema from clinician’s perspective</p>

“…The presence of a higher number of HRS and subretinal fluid may indicate a prevalent inflammatory component in DME 69,74. In a patient subgroup with a higher number of HRS, better morphological and functional outcomes were observed if treated with DEX implant73–76 compared to anti-VEGF treatment 74. A reduction of HRS and better morphological and functional outcomes after treatment with DEX implant in patients with DME73–76 were found in the patients’ subgroup with a higher number of HRS in comparison to anti-VEGF treatment 74…”