Short-term outcomes of intravitreal dexamethasone in relation to biomarkers in diabetic macular edema.

Abstract

The purpose of this study was to determine the effects of dexamethasone implant (0.7 mg) on biomarkers such as hyper-reflective dots, external limiting membrane integrity and disorganization of retinal inner layers in treatment-naïve patients, patients who received less than three anti-vascular endothelial growth factor injections and non-responder cases with diabetic macular edema and its effects on edema and visual acuity. This is a prospective study of treatment-naïve patients, patients who received less than three anti-vascular endothelial growth factor injections and non-responder patients with diabetic macular edema, treated with single dexamethasone implant. Pre- and post-injection-based best-corrected visual acuity, central macular thickness, hyper-reflective dots, external limiting membrane integrity and disorganization of retinal inner layers were assessed. A total of 27 diabetic macular edema eyes, including 9 non-responder eyes, 9 eyes which received less than three anti-vascular endothelial growth factor injections and 9 treatment-naïve eyes, were included in this study. Baseline hyper-reflective dots were 22.22 ± 11.76, 30 ± 7.91 and 19.44 ± 8.82 which reduced to 3.33 ± 1.32, 9 ± 8.35 and 8.78 ± 2.53 four months after implant in treatment-naïve patients, patients who received less than three anti-vascular endothelial growth factor injections and non-responder cases, respectively. Baseline central macular thickness was 589.44 ± 175.37, 537 ± 181.81 and 673.11 ± 138.24 and the central macular thickness after dexamethasone implant was 272.11 ± 39.00, 336.44 ± 132.88 and 524.00 ± 200.39 in treatment-naïve patients, patients who received less than three anti-vascular endothelial growth factor injections and non-responder cases, respectively. External limiting membrane integrity was restored in two patients in each group, whereas two patients with disorganization of retinal inner layers in treatment-naïve group showed reorganization of retinal structures after treatment with dexamethasone implant. Better response to dexamethasone implant in cases with more hyper-reflective dots shows that these hyper-reflective dots can be used as a predictive biomarker. Dexamethasone implant might help in restoring external limiting membrane integrity and resolution of disorganization of retinal inner layers.