OCT-Angiography Changes in Patients with Diabetic Macular Edema Treated with Intravitreal Dexamethasone Implant

Abstract

Purpose: To evaluate, using optical coherence tomography angiography (OCTA), the impact of intravitreal dexamethasone (DEX) implant on quantitative vascular measurements in patients with diabetic macular edema (DME).

Methods: Prospective, randomized, and open-label study. Primary endpoints were mean changes in vessel density (VD) and vascular perfusion (VP) in superficial capillary plexus (SCP) and VP in deep capillary plexus (DCP) and peripapillary capillary plexus (PCP).

Results: Thirty-four eyes from 19 patients were included. Mean age was 67.4±7.3 years and 24 (76.5%) were men. VD in SCP in the 6 mm × 6 mm perifoveal ring was significantly decreased from 15.2±2.7 mm/mm² at baseline to 13.5±3.1 at month-2, p, 0.0029. VP in SCP in the 6 mm × 6 mm perifoveal ring decreased significantly from baseline to month-2 (mean change -3.8%; 95% confidence-interval: -7.7% to -1.7%, p, 0.0028). Compared to baseline, the VP in DCP was significantly reduced at month 2 in the perifoveal ring of the 6 mm × 6 mm scan (p, 0.0063), and in the parafoveal ring of the 6 mm × 6 mm scan (p, 0.0048). Foveal avascular zone (FAZ) area did not change throughout the study. Central macular thickness significantly decreased from baseline in 210.3 µm (149.9-270.8 µm) and 201.8 µm (140.4-263.3 µm), p < 0.0001 each at month-2 and month-3, respectively.

Conclusions: Besides functional and anatomical improvements, DEX implant significantly reduced VD and VP in DME patients.

Keywords: OCTA; diabetes; diabetic macular edema; diabetic retinopathy; vascular perfusion; vessels density.