Prospective interventional study, open, non-comparative and non-randomized. The research concerns physiological parameters of the coronary and ocular blood circulation.

At the coronary level, the curves of pressure and Doppler flow will be extracted from ComboMap® (Philips). The coronary microvascular resistances, basal and hyperemic, will be determined by the average ratio of the distal pressure and flow.

At the ocular level, a fundus oculi and an OCTA (angiography by tomography in optical coherence) examination will be performed. The measures of the FFR and the coronary microvascular resistance will be determined by a guidewire allowing measures of pressure and by a guidewire allowing measures of Doppler flow (ComboWire®, Volcano), in 123 patients with intermediate stenosis of the left anterior descending artery (LDA). Topological parameters characterizing the retinal area and choriocapillaries will be determined by statistical approaches and mathematical morphology.

To establish a predictor of the coronary microvascular resistance from the eye vascular parameters, we shall use a non-linear regression by supervised machine learning. The main cardiovascular risk factors (hypertension, diabetes, dyslipidemia, age, sex) will be part of predetermined input features for the machine learning.

Inclusion Criteria:

1. Male and female patient's ≥18 years of age with coronary arterial indication as usual and with proximal and / or mean IVA stenosis ≥ 50%.
2. Signed informed consent
3. Affiliation to the social security system

Exclusion Criteria:

1. Unstable Coronary Artery Disease
2. Atrial fibrillation
3. History of myocardial infarction <6 months in the territory of the proximal and / or mean IVA.
4. Asthma
5. Aortocoronary bypass surgery.
6. Collateral development at the level of the proximal and / or mean IVA.
7. Allergy to iodine, severe renal insufficiency.
8. Ametropia> = 6 diopters.
9. History of retinal ocular pathologies other than uncomplicated diabetic retinopathy and hypertensive retinopathy.
10. History of ophthalmic treatments such as macular or panretinal laser photocoagulation, intravitreal injection of anti-VEGF or cortisone.
11. Chronic glaucoma
12. Patients under guardianship or curators.
13. Pregnant or lactating women.
14. Patient's not affiliated to the French social security.
15. Persons placed under the protection of justice,
16. Subject participating in another research including an exclusion period still in progress at pre-inclusion