The eye has long been recognized as a window to pathological processes occurring in the brain. By imaging the vascular system of the retina scientific understanding and clinical practice have been improved for a wide range of pathologies from diabetes to stroke and dementia.

Adaptive optics (AO) reveals retinal details that remain invisible with other current imaging techniques. Indeed, vessels can be perfectly visualized, making it possible to detect wall irregularities, accurately measure their different structures and monitor their evolution under treatment if necessary.

In AO, studies on retinal vessels involve the calculation of wall thickness (WT), outer diameter (OD), inner diameter (ID), wall cross-sectional area (WCSA) and wall to lumen ratio (WLR). An increase in WLR > 0.31 is characteristic of hypertensive microangiopathy and predictive of cardiovascular and brain damage. This accurate assessment of microvascular structure may even be required in the near future in all patients with arterial hypertension. For vessels > 300 microns in diameter, the increase in vessel wall thickness occurs without changing the ID, a process known as external hypertrophic remodeling. For small arteries < 300 microns, remodeling occurs differently. The total volume of the vessel wall remains constant, but the OD and ID each decrease, a process known as inward eutrophic remodeling.

The objective of this study is to describe the parameters measured in AO in patients in the acute phase of a stroke and then at 3 months.

Inclusion Criteria:

• For the patients with stroke: Inpatients with confirmed stroke (clinical and imaging) for less than 10 days
• For the controls: Individuals presenting at the Rothschild Foundation Hospital with no history of stroke who are matched to cases already included in the matching criteria: Age ± 5 years, Gender, high blood pressure (no history, untreated, treated) Diabetes (Yes, No), Body Mass Index (BMI < 25, 25 ≥ BMI < 30, BMI ≥ 30)

Exclusion Criteria:

• Pregnant or breastfeeding woman
• Insufficient state of consciousness or physical condition to perform the adaptive optics examination
• For the patients with stroke: Hemorrhagic post-traumatic hematoma stroke type, or symptomatic stroke of a brain tumour or an arteriovenous malformation.

Inpatients with confirmed stroke for less than 10 days and controls (Individuals presenting at the Rothschild Foundation Hospital with no history of stroke)