# Efficacy of Intravitreal Dexamethasone Implant (Ozurdex®) in Naïve and Refractory Patients with Different Morphological Subtypes of Diabetic Macular Edema

## TL;DR

This study examines how well a dexamethasone implant treats different types of diabetic macular edema, finding it effective in reducing swelling and improving vision, especially in certain subtypes and previously treated patients.

## Contribution

The study evaluates the effectiveness of dexamethasone implants in distinct DME subtypes and treatment histories, revealing subtype-specific and treatment-experienced outcomes.

## Key findings

- Dexamethasone implants significantly reduced central subfoveal thickness in diabetic macular edema patients.
- Serous retinal detachment showed greater anatomical improvement compared to other subtypes.
- Previously treated patients had better visual acuity and anatomical outcomes at 6 months.

## Abstract

Background and Objectives: To investigate anatomical and functional outcomes in different morphological subtypes of diabetic macular edema (DME) treated with an intravitreal dexamethasone implant (Ozurdex) over 6 months follow-up. Materials and Methods: A retrospective, comparative study on patients with DME who received an intravitreal dexamethasone implant. Best-corrected visual acuity (BCVA), central subfoveal thickness (CST) and maximum CST on optical coherence tomography (OCT) were measured. The recruits were divided into three groups based on the morphological patterns of DME: serous retinal detachment (SRD), cystic macular edema (CME) and diffuse retinal thickening (DRT). The presence or absence of previous treatment were considered as being previously treated with anti-VEGF (PT) vs. naïve eyes (TN). All subjects received a single injection of the dexamethasone implant. The primary outcomes included changes in BCVA, CST and CSTMax at 2-, 4- and 6-months of follow-up. Results: CST was significantly reduced following one dexamethasone injection in the whole cohort from a total mean value of 513.3 μm to 368.2 μm at 2 months, 447.2 μm at 4 months and 471.5 μm at 6 months. The change in CST was significantly greater in SRD as opposed to the DRT and CME group at all time points. Overall, BCVA improved from 0.82 at baseline to 0.75 and 0.76 LogMAR at 2 and 4 months, respectively, whilst showing an overall deterioration to 0.84 at 6 months. The CME group showed the best BCVA at 6 months. Concerning treatment status (TN vs. PT), there was no significant difference in CST at 2 and 4 months, while CST was reduced at 6 months for the PT group (p = 0.023). Similarly, BCVA was significantly better in the PT group at 6 months (p = 0.017). Conclusions: The dexamethasone implant was effective in reducing DME and providing short-term BCVA improvement. The presence of SRD was associated with more favorable anatomical results, while CME was associated with better visual acuity. Dexamethasone provided superior results in previously treated patients.