Our eyes need a steady supply of blood to work well. Blood brings oxygen and nutrients to the eye, just like it does for the heart and brain. When the blood flow to the eye becomes very low, a serious condition called Ocular Ischemic Syndrome (OIS) can develop.
OIS happens when:
- The carotid artery becomes very narrowed or blocked
- This artery runs along each side of the neck and supplies blood to the eye and brain
- Narrowing is caused by atherosclerosis (buildup of fatty deposits, also called “hardening of the arteries”)
- Severe blockage limits blood flow to the eye
Common Symptoms
- Slow loss of vision in one eye
- Temporary vision loss lasting seconds or minutes
- Dull ache or pressure around the eye
- Redness in the eye
- Delayed vision recovery after exposure to bright light
What an Eye Doctor May See
- Dilated retinal veins that are not very twisted
- Retinal hemorrhages (small spots of bleeding)
- Neovascularization (growth of abnormal new blood vessels)
- Possible development of neovascular glaucoma, which can be painful
How It Is Diagnosed
- Evaluation of blood flow in the neck
- Carotid ultrasound
- CT angiography
- MR angiography
Treatment Options
- Laser therapy for abnormal blood vessels
- Anti-VEGF injections to prevent further damage
- Carotid endarterectomy (surgical removal of plaque)
- Stenting to improve blood flow in the carotid artery
Why OIS Matters
- Not very common, but important to recognize
- Often a warning sign of serious vascular disease
- Associated with higher risk of stroke and heart disease
Ongoing Care
- Care may involve multiple providers:
- Eye doctor
- Primary care doctor
- Vascular specialist
- Early diagnosis and treatment can help protect vision and overall health