Intravitreal Dexamethasone Implant in the Treatment of Diabetic Macular Edema Focusing on the Role of OCT Biomarkers.

Objective: The aim of this study was to evaluate the outcomes of Ozurdex® (DEX) implant in patients with diabetic macular edema (DME) in real-world clinical practice, and to determine the correlation between known OCT biomarkers and the effect of treatment.

Material And Methods: This retrospective study included 42 eyes of 33 patients (16 women, 17 men) treated with DEX at the Department of Ophthalmology, Faculty of Medicine and Dentistry of Palacký University and University Hospital Olomouc for DME indication between 2020 and 2023. Follow-up examinations were conducted at 1, 3, and 6 months after the first DEX application. The main assessed parameters were: best-corrected visual acuity (BCVA), intraocular pressure (IOP), central retinal thickness (CRT), OCT biomarkers. The results were subsequently statistically evaluated.

Results: At the first follow-up after DEX application, there was an average decrease in CRT of 186 ±146µm and a gain of 3 ±7 letters. Positive morphological and functional responses were observed in 39 eyes (92.9%) and 23 eyes (54.8%) respectively. The disorganization of retinal inner layers (DRIL) biomarker was initially present in 41 eyes (97.6%), with reduction or disappearance observed in 13 eyes (31%) post-application. Eyes with ellipsoid zone disruption (EZ disruption) had an average initial BCVA of 49.6 letters, compared to 57.8 letters in the group without this biomarker. The mean gain in BCVA was +8.7 letters in treatment-naive eyes and +2.1 letters in previously treated eyes. Chronic DME was less frequent in treatment-naive (n = 1, 14.3%) compared to previously treated eyes (n = 28, 84.8%). All these results were statistically significant (p < 0.05). An increase in IOP post-DEX application occurred in 9 patients (21.4%).

Conclusion: Our results confirm DEX as a safe and effective treatment option for DME. Treatment-naive patients achieved better functional outcomes. We confirmed ellipsoid zone disruption (EZ disruption) as a negative biomarker. Additionally, we demonstrated the capacity of DEX to reduce disorganization of the retinal inner layers (DRIL).