ABSTRACT
AIMS: To determine the presence of sectoral changes in vessel density (VD) patterns induced by vascular endothelial growth factor inhibitors (anti-VEGF) in patients with diabetic macular edema (DME) using optical coherence tomography angiography (OCTA). METHODS: Prospective, interventional study. A total of 43 patients (63 eyes) were initially enrolled in the study. We performed swept source (SS) OCT and sectorial OCTA measurement to determine parafoveal VD at baseline and after six months of anti-VEGF treatment. In the locations with statistically significant differences in VD between baseline and month 6, we performed univariate and multivariate analyses to determine which, if any, of the baseline variables were associated with the observed changes. RESULTS: A total of 34 patients (48 eyes) were included in the final analysis. Mean VD decreased from baseline to month 6 (from 45.2 (± 3.5) to 44.6 (± 3.2) % in the SCP and from 50 (± 3.3) to 49 (± 3.9) % in the DCP). The only significant changes in VD were observed in the nasal sector of the deep capillary plexus, with a decrease of 2.9% (p = 0.001). On univariate and multivariate analyses, the only variable significantly associated with changes in VD in the nasal sector after 6 months of treatment was baseline VD in the same sector. CONCLUSIONS: Anti-VEGF therapy has a small impact on VD values over time. These variations observed after treatment seems to be related to changes over areas of vascular anomalies and displaced vessels adjacent to cystic areas, with no significant changes over ischemic areas. No correlation was observed between this trend and other clinical baseline features.
ABSTRACT
The objective of this study was to determine the correlation between topographic vessel density (VD) and retinal thickness (RT) reductions induced by vascular endothelial growth factor inhibitors (anti-VEGF) in patients with diabetic macular edema (DME) using optical coherence tomography angiography (OCTA). This was a prospective, interventional case series. VD and RT measurements were separately taken in four parafoveal subfields at baseline and after six months of treatment. This correlation was statistically assessed using Spearman's rho correlation coefficient after adjustment for multiple comparisons. The study included a total of 48 eyes in the final analysis. Mean VD decreased from baseline to month 6 (from 45.2 (±3.5) to 44.6% (±3.2) in the superficial capillary plexus and from 50 (±3.3) to 49% (±3.9) in the deep capillary plexus). Statistically significant reductions in RT were observed in all ETDRS sectors (p < 0.0001). No significant association was found between RT and VD, even when analyzing responders and non-responders separately. After six months of anti-VEGF treatment, no significant correlation was observed between the topographic VD and RT values. These findings suggest that reductions in VD values may not solely result from a reduction in microaneurysms, also being affected by the repositioning of displaced vessels due to edema and a reduction in their caliber. Therefore, VD changes may not be a suitable indirect OCTA biomarker of microaneurysm turnover and treatment response.
ABSTRACT
PURPOSE: To assess the functional and anatomical outcomes of intravitreal dexamethasone implant Ozurdex® in eyes with diabetic macular edema that did not adequately respond to vascular endothelial growth factor inhibitors. METHODS: Multicenter, retrospective, and real-life case series study conducted on consecutive diabetic macular edema patients who underwent treatment with one or more dexamethasone implant injections and were followed up for a minimum of 12 months. Subjects were divided into three groups: I-naïve patients, II-previously treated eyes that received three intravitreal antivascular endothelial growth factor inhibitors injections before the study (early switch), and III-previously treated eyes that received >3 intravitreal antivascular endothelial growth factor inhibitors injections before the study (late switch). Primary endpoints were best-corrected visual acuity and central retinal thickness at month 12. RESULTS: A total of 129 eyes (21 naïve and 108 previously treated, Group II: 32 and Group III: 76) were included. At month 12, best-corrected visual acuity significantly improved from 0.27 ± 0.23 and 0.31 ± 0.22 at baseline to 0.36 ± 0.25 and 0.37 ± 0.23 at month 12 in naïve and previously treated eyes, respectively, and p = 0.0063 and 0.0060, respectively. Central retinal thickness, in naïve and previously treated eyes, was significantly reduced from 483.0 ± 143.4 and 431.3 ± 115.5 µm, at baseline, to 278.8 ± 72.1 and 269.3 ± 66.2 µm, at month 12, respectively, and p < 0.0001 each, respectively. Best-corrected visual acuity improvement was significantly greater in both absolute and percentage values, p = 0.0393 and 0.0118, respectively, in Group II than in Group III. CONCLUSION: In eyes with insufficient response to antivascular endothelial growth factor inhibitors, switching to dexamethasone at the time to 3-monthly antivascular endothelial growth factor inhibitors injections provided better functional outcomes than those that received >3 antivascular endothelial growth factor inhibitors injections.
