The contribution of choroidal vasculature to the pathogenesis of age-related macular degeneration (AMD) has been long debated. The present narrative review aims to discuss the primary molecular and choroidal structural changes occurring with aging and AMD with a brief overview of the principal multimodal imaging modalities and techniques that enable the optimal in vivo visualization of choroidal modifications. The molecular aspects that target the choroid in AMD mainly involve human leukocyte antigen (HLA) expression, complement dysregulation, leukocyte interaction at Bruch’s membrane, and mast cell infiltration of the choroid. A mechanistic link between high-risk genetic loci for AMD and mast cell recruitment has also been recently demonstrated. Recent advances in multimodal imaging allow more detailed visualization of choroidal structure, identifying alterations that may expand our comprehension of aging and AMD development.

Diabetes mellitus (DM) significantly impacts ocular health, particularly the retina and choroid, leading to diabetic retinopathy (DR) and diabetic macular edema (DME). This study aimed to evaluate the effects of intravitreal dexamethasone (IVD) on the choroidal vascularity index (CVI) in order to evaluate its potential as a biomarker. This was a retrospective observational study in which 37 eyes with DME treated with IVD were included. Baseline and follow-up (2 and 4 months post-injection) comprehensive ophthalmological examinations and spectral domain optical coherence tomography (SD-OCT) were performed. The CVI, luminal area (LA), stromal area (SA), and total area (TA) were assessed. No statistically significant changes in CVI, LA, SA, and TA were observed in the overall patient sample from baseline to 2 and 4 months post-IVD injection. However, a significant CVI reduction was noted in responder patients at 4 months. Positive correlations were found between the CVI and central macular thickness (CMT) at 2 months, suggesting that higher CMT values are associated with higher CVI values. This study indicated that IVD influences choroidal circulation, as evidenced by CVI reduction in responder patients. The CVI could potentially serve as an objective biomarker for treatment response in DME. Larger, prospective studies are warranted to clarify these findings further.

Background/Objectives: The aim of the current investigation was to assess the short-term changes in retinal-choroidal vasculature and the morphological complexity of non-exudative macular neovascularization (NE-MNV) using optical coherence tomography angiography (OCTA) and spectral-domain optical coherence tomography (SD-OCT). Methods: Sixteen eyes of 12 patients with NE-MNV underwent baseline and six-month follow-up examinations, including comprehensive ophthalmological assessment and imaging. Central macular thickness, foveal avascular zone, vessel density, flow area, and choroidal vascularity index were analyzed. NE-MNV morphology was quantitatively assessed for area, vessel characteristics, and fractal dimensions. Results: Significant changes in NE-MNV morphology were noted over six months, especially in fractal dimensions, vessel junctions, and vessel length (p-values: 0.01, 0.037, and 0.036, respectively). While there was an increase in the NE-MNV area, it did not reach statistical significance. No significant changes were shown regarding the standard SD-OCT and OCTA output parameters or choroidal measurements. Conclusions: The increase in NE-MNV fractal dimensions suggests rising complexity in the neovascular network and may indicate possible implications for clinical management. The correlation between baseline and follow-up measures underscores a trend toward complexity, pointing to the necessity for closer monitoring of patients with higher NE-MNV fractal dimensions.