Vitreous Hemorrhage Causes: Understanding Why the Eye Bleeds
- sakai208
- Dec 18, 2025
- 2 min read
I. Introduction: What is Vitreous Hemorrhage Causes
In a healthy state, the blood vessels within the eye are robust and contained. However, certain diseases and injuries can cause these vessels to rupture, leading to a vitreous hemorrhage. Understanding vitreous hemorrhage causes is vital because the treatment for a bleed caused by diabetes differs significantly from a bleed caused by a physical injury or a retinal tear.
Generally, the causes of vitreous hemorrhage fall into three categories: abnormal vessel growth, mechanical trauma, and vascular damage.
II. Abnormal Vessel Growth (Neovascularization)
The most common cause of spontaneous vitreous hemorrhage is the growth of fragile, abnormal new blood vessels, a process called neovascularization.
1. Proliferative Diabetic Retinopathy (PDR):
This is the leading cause of vitreous hemorrhage in adults. Chronic high blood sugar starves the retina of oxygen, triggering the body to grow new vessels. These vessels are extremely weak and lack the structural integrity of normal ones, causing them to leak or burst under the slightest pressure.
2. Retinal Vein Occlusion (RVO):
When a vein in the retina is blocked, it causes "back-pressure," leading to swelling and eventually the growth of abnormal vessels that can bleed into the vitreous.
3. Wet Age-Related Macular Degeneration (nAMD):
While primarily affecting the area under the retina, severe cases of wet AMD can involve blood breaking through into the vitreous cavity.
III. Mechanical Trauma and Retinal Tears
Even healthy blood vessels can rupture if they are subjected to physical force.
1. Retinal Tears and Detachment:
As we age, the vitreous gel shrinks and pulls away from the retina (Posterior Vitreous Detachment). If the gel is stuck too firmly, it can tear the retina. If a blood vessel crosses that tear, it will rupture, leading to a sudden hemorrhage.
2. Blunt or Penetrating Trauma:
A direct blow to the eye (from a ball, an accident, or an assault) can cause the eye to deform momentarily, snapping internal blood vessels. Penetrating injuries from sharp objects can also cause immediate and severe bleeding.
IV. Other Vascular and Systemic Causes
1. Terson Syndrome:
This is a unique condition where a hemorrhage inside the brain (subarachnoid hemorrhage) causes a sudden spike in pressure that manifests as a vitreous hemorrhage in the eye.
2. Eales Disease:
An inflammatory condition of the retinal vessels (vasculitis) that primarily affects young men and can lead to recurrent vitreous bleeds.
3. Blood Disorders:
Conditions that affect clotting, such as leukemia or severe thrombocytopenia, can make an individual more prone to spontaneous ocular bleeding.
V. Summary of Key Risks
Cause Category | Primary Conditions | Mechanism |
Neovascular | Diabetes (PDR), Vein Occlusion | Fragile new vessels burst easily. |
Mechanical | Retinal Tears, PVD, Trauma | Physical force snaps healthy vessels. |
Systemic/Other | Terson Syndrome, Blood Disorders | Pressure spikes or clotting issues. |
VI. Conclusion: Finding the Source
Identifying the specific vitreous hemorrhage causes is the first priority for any retina specialist. A hemorrhage is rarely an isolated event; it is a "red flag" signaling that something is wrong with the retinal anatomy or systemic health. Whether it is a diabetic complication or a mechanical tear, treating the source is the only way to prevent the bleeding from recurring.
This article was reviewed by
Dr. Daiki Sakai, MD
