Evaluation of microaneurysms as predictors of therapeutic response to anti-VEGF therapy in patients with DME

Real-World Outcomes of a Loading Phase with Intravitreal Faricimab in Neovascular Age-Related Macular Degeneration (n-AMD) and Diabetic Macular Edema (DME)

INTRODUCTION

The aims of this work were to evaluate the real-world efficacy and safety of a loading dose of intravitreal faricimab in eyes with active neovascular age-related macular degeneration (n-AMD) or diabetic macular edema (DME) and to analyze the treatment outcome in relation to specific biomarkers.

METHODS

Patients with active n-AMD or DME, treated with four monthly intravitreal injections of faricimab, were enrolled in this retrospective, uncontrolled study. Best-corrected visual acuity (BCVA), central subfield thickness (CST), presence of retinal fluid (RF) on optical coherence tomography (OCT), and adverse events were assessed at baseline and at weeks 4, 8, 12, and 16. Predefined biomarkers were evaluated at baseline (BL) and at last visit.

RESULTS

Sixteen eyes of 15 patients with n-AMD (n-AMD group) and 15 eyes of 12 patients with DME (DME group) were included. Mean (± standard deviation) logarithm of minimum angle of resolution (logMAR) BL BCVA changed from 0.68 (± 0.43) to 0.53 (± 0.36; P = 0.13) and from 0.51 (± 0.34) to 0.32 (± 0.24; P: 0.048) at week 16 in n-AMD and DME group, respectively. A statistically significant mean CST reduction was reported in both groups at last visit (n-AMD: - 166.5 μm; P = 0.0009/DME: - 110.8 μm; P = 0.0086). Seventy-five and 33% of eyes with n-AMD and DME respectively achieved complete RF resolution at last visit. Subfoveal inner and outer retinal damage correlated with a lower final BCVA in n-AMD group. The presence of large (> 100 μm) juxtafoveal microaneurysms (MAs) was significantly correlated with a higher chance of residual fluid in eyes with DME.

CONCLUSIONS

Both n-AMD and DME groups achieved satisfactory anatomical results after a loading-dose of intravitreal faricimab. BCVA improvement might be hampered by pre-existing retinal damage in eyes with n-AMD. Large, juxtafoveal MAs might represent a hallmark of a slower anatomical response to the treatment in eyes with DME.

Optical coherence tomography angiography in diabetic retinopathy: A major review

Diabetic retinopathy (DR) is characterized by retinal vasculopathy and is a leading cause of visual impairment. Optical coherence tomography angiography (OCTA) is an innovative imaging technology that can detect various pathologies and quantifiable changes in retinal microvasculature. We briefly describe its functional principles and advantages over fluorescein angiography and perform a comprehensive review on its clinical applications in the screening or management of people with prediabetes, diabetes without clinical retinopathy (NDR), nonproliferative DR (NPDR), proliferative DR (PDR), and diabetic macular edema (DME). OCTA reveals early microvascular alterations in prediabetic and NDR eyes, which may coexist with sub-clinical neuroretinal dysfunction. Its applications in NPDR include measuring ischemia, detecting retinal neovascularization, and timing of early treatment through predicting the risk of retinopathy worsening or development of DME. In PDR, OCTA helps characterize the flow within neovascular complexes and evaluate their progression or regression in response to treatment. In eyes with DME, OCTA perfusion parameters may be of predictive value regarding the visual and anatomical gains associated with treatment. We further discussed the limitations of OCTA and the benefits of its incorporation into an updated DR severity scale.

Correlation between Topographic Vessel Density and Retinal Thickness Changes in Patients with Diabetic Macular Edema Treated with Anti-VEGF Therapy: Is It a Suitable OCTA Biomarker?

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.