Evaluation of Retinal Capillary Density using OCT Angiography according to Acute Ischemic Stroke Etiologies - A Matched Case -Control Study.

Purpose: To investigate retinal microvascular changes in ischemic stroke patients using optical coherence tomography angiography (OCT-A) and assess these alterations based on stroke etiology.

Methods: Case-control study conducted at Montpellier University Hospital from May 2021 to March 2022 (IRB: 202000607). Retinal vascular features were compared between strokes patients and age- and sex- matched controls. OCT-A was performed using RTVue-XR-Avanti with AngioVue (Optovue). Multivariate mixed-effects ANCOVA models adjusted for age, sex, intraocular pressure (IOP), and cardiovascular risk factors were used.

Results: 92 eyes were included: 21 with micro/macro-angiopathy stroke, 12 with etiologically ambiguous stroke, 13 with cardioembolic stroke and 46 eyes from control subjects. After adjusting for age, sex, and IOP, stroke patients had significantly lower parafoveal SCP-VD (p = 0.013) and SCP Flow Index (p = 0.023) compared to controls, especially in the macro/micro-angiopathy subgroup. When cardiovascular risk factors were included, only the SCP Flow Index difference remained significant (p = 0.023). OCT-A's diagnostic accuracy was validated with an AUROC of 0.83.

Conclusion: OCT-A effectively detects retinal microvascular alterations in stroke patients, with persistent alterations in macro/micro-angiopathy strokes after adjusting for cardiovascular risk factors. These findings support OCT-A's role in stroke subtype classification.