Intravitreal dexamethasone insert in diabetic macular edema super-refractory to anti-vascular endothelial growth factor therapy

Abstract

Background: Some patients with diabetic macular edema (DME) fail to completely respond to anti-vascular endothelial growth factor (VEGF) therapy. These patients have a high treatment burden in the absence of significant improvement. We investigate the role of intravitreal dexamethasone insert (IDI) in eyes with super-refractory DME. Methods: A non-randomized interventional study was performed among eyes with super-refractory DME refractory to anti-VEGF therapy. Eyes were treated with IDI after failing clinical response to anti-VEGF, with a minimum of 15 prior. Failure to respond was defined as failure of vision to improve at least one line on Snellen Acuity chart, central subfield thickness (CST) greater than 320 μm, or failure of CST to improve by 10% or more. Eyes with glaucoma or prior uncontrolled steroid-responsive ocular hypertension were excluded. Patient outcomes were analyzed at weeks 6, 12, 24, and year 1. Results: Six eyes of four patients were identified. All patients had failed aflibercept. The mean number of prior anti-VEGF injections was 34.5. Eyes received an average of 2.92 dexamethasone injections per person-year (PY) and required breakthrough anti-VEGF injection at 1.95/PY. Mean pre-treatment visual acuity was 0.475 LogMAR, improving to 0.342 at week 6, and 0.375 at 1 year. Mean CST pre-injection was 386.5 mm, improving to 315 mm at 1 year. No glaucoma developed. Conclusions: Intravitreal dexamethasone insert appears effective in eyes with super-refractory DME. IDI resulted in excellent anatomic improvement on SD-OCT as well as modest visual improvement. Injection burden was reduced in those who may otherwise receive years of monthly treatments.

Clinical Application of Intravitreal Aflibercept Injection for Diabetic Macular Edema Comparing Two Loading Regimens

“…A recent Diabetic Retinopathy Clinical Research (DRCR) study reported no significant differences in 2-year visual outcome for DME between aflibercept monotherapy and bevacizumab replaced with aflibercept, suggesting a rescue effect of later applied IVA [ 25 ]. However, in cases that do not respond to IVA, alternative methods such as steroids, laser treatment, or even surgery may be needed to treat the DME [ 15 , 26 ]. Of the four refractory cases presented in our study, two were treated with focal laser photocoagulation, while the others received intravitreal corticosteroid injections.…”

Switching to an Intravitreal Dexamethasone Implant after Intravitreal Anti-VEGF Therapy for Diabetic Macular Edema: A Review

“…A recent non-randomized interventional study investigated the possible role of a DEX implant in a limited sample of eyes with DME refractory to serial intravitreal injections [ 61 ]. Six eyes that had not responded clinically to previous aflibercept injections had DEX implants.…”

“…The mean BCVA improved and the CST decreased after one year. The authors concluded that the DEX implant showed good anatomic improvement and moderate visual improvement in eyes with DME that were resistant to repeated intravitreal injections [ 61 ].…”

Safety and Efficacy of Dexamethasone Intravitreal Implant Given Either First-Line or Second-Line in Diabetic Macular Edema

“…Considering DME refractory to a large number of intravitreal injections, a recent non-randomized interventional study explored the potential role of DEX implant in a small sample of such eyes. 54 Six eyes with failed clinical response after a mean of 43.5 (range 15–58) prior anti-VEGF injections, and all with failed aflibercept, underwent DEX implant plus a breakthrough anti-VEGF injection when required. At 1 year, the mean BCVA improved from 0.475 to 0.375 logMAR and central subfield thickness (CST) reduced from 386.5 to 315 μm.…”