Optic Nerve Head Evaluation Through Multimodal Blood Flow Analysis: a Prospective Observational, Multi-center Study

BACKGROUND AND RATIONALE The vascular component of the ONH, like that of the retina, is an essential part for the ONH homeostasis, but is considered difficult to be precisely analyzed, especially in optic nerve pathologies. Little is known about the vascular component and its role in both acute and chronic ONH diseases, particularly in conditions that cause swelling, where it is mandatory to differentiate edema from pseudo-edema.

Today, the gold standard for the vascular imaging of the retina is angiography, using either fluorescein or indocyanine green. However, conventional angiography has the disadvantage that the invasive administration of dye into the venous system is required, leading to low but potentially life-threatening side effects as allergic reactions; furthermore, data obtained are not standardizable or exploitable for a quantitative analysis. However, new technologies such as OCT-A can provide standardizable and quantifiable data on vascular structures that can be used in a statistical analysis. Additionally, eco-colordoppler ultrasound provides direct measurements of ONH blood-flow.

OBJECTIVES AND ENDPOINTS Objectives Endpoints: The aim of the study is to assess ONH vascular and structural components optic neuropathies with and without ONH edema or pseudo-edema through OCT-A (OCT-angiography) and ocular blood-flow through eco-colordoppler.

Primary Objective: to identify parameters correlated to the development and progression (prognostic biomarkers) of the diseases.

Primary Endpoint: Analysis of data collected in symptomatic and asymptomatic eyes, obtained through OCT-A in order to evaluate the relationship between functional and structural parameters in order to identify parameters correlated to the development and progression of the diseases.