Anatomical and visual outcomes of Retreatment with Intravitreal Dexamethasone Implant versus shifting to intravitreal Aflibercept for refractory Diabetic macular edema after an initial Intravitreal Dexamethasone Implant.

Abstract

Purpose: to evaluate the anatomical and visual outcomes of retreatment with repeated intravitreal dexamethasone implants versus repeated aflibercept injections for refractory diabetic macular edema after an initial intravitreal dexamethasone implant. Subjects and Methods:A retrospective cohort study was done on eyes diagnosed with refractory non-tractional diffuse diabetic macular edema after an initial intravitreal Dexamethasone implant, that had been retreated between 2016 and 2022, and were followed up for 12 months . They were divided into 2 groups. Group A included eyes that had been retreated with Intravitreal Dexamethasone Implants. Group B included eyes that had been retreated with intravitreal Aflibercept injections.Outcome measures included: changes in central macular thickness, changes in best corrected visual acuity (BCVA), and number of injections of both Dexamethasone implants and Aflibercept during 12 months. Results:We enrolled a total of 58 eyes. Group A (38 eyes) achieved a CMT reduction 191 ± 100 u, and 4.1 ± 1.1 lines of improvement of BCVA, with 1.7 ±0.8 dexamethasone implant injections. Group B (20 eyes) achieved a CMT reduction 161 ± 84, and 2.0 ± 0.9 lines of improvement of BCVA, with 3.7 ± 1.2 aflibercept injections. Elevated intra ocular pressure happened in 11% of eyes in group A, and in 5% of eyes in group B. Conclusion:Retreatment with intravitreal dexamethasone implant maybe safe and effective for management of refractory diabetic macular edema after an initial intravitreal dexamethasone implant. It may be more effective than shifting to Aflibercept injections, with much less number of retreatments.