The vitreous itself lacks blood vessels and does not bleed. Vitreous hemorrhage usually results from ocular vascular diseases and trauma but can also occur due to systemic diseases. The blood in the vitreous comes entirely from surrounding affected tissues, with potential causes either related to systemic diseases manifesting in the eye, such as diabetic retinopathy, hypertensive retinopathy, or leukemia, or due to ocular conditions, such as ocular trauma, eye surgeries, retinal vascular occlusion, or age-related macular degeneration (AMD).
Etiology
The causes include:
- Retinal tears and retinal detachment.
- Posterior vitreous detachment (PVD).
- Ocular trauma.
- Retinal vascular diseases with ischemic changes:
- Proliferative diabetic retinopathy (PDR).
- Central retinal vein occlusion (CRVO) or branch retinal vein occlusion (BRVO).
- Retinal periphlebitis (Eales disease).
- Sickle cell disease.
- Retinopathy of prematurity (ROP).
- Retinal angiomatosis.
- Inflammatory diseases possibly accompanied by ischemic changes:
- Retinal vasculitis.
- Uveitis.
- Subretinal hemorrhage in the macular region: Most commonly associated with AMD complicated by choroidal neovascular membranes, leading to macular subretinal hemorrhage. Large volumes of blood may pass from the subretinal space into the vitreous cavity, which is especially common in polypoidal choroidal vasculopathy (PCV).
- Other retinal neovascularization disorders:
- Familial exudative vitreoretinopathy (FEVR).
- Retinoschisis.
- Retinal telangiectasia.
- Terson syndrome (subarachnoid hemorrhage-related vitreous hemorrhage).
Clinical Manifestations
Symptoms
Small amounts of bleeding may present as red, smoky floaters in front of the eye.
Large amounts of bleeding can cause acute and severe vision loss, sometimes reducing vision to only light perception.
Ocular Findings
Fundus examination may reveal floating blood-like material in the vitreous cavity. When the amount of bleeding is significant, the entire fundus may become obscured.
Persistent large hemorrhages may be difficult to resorb, leading to cholesterol crystal deposits and hemoglobin pigment deposition within the vitreous, partial vitreous liquefaction, and vitreous contraction. Posterior vitreous detachment (PVD) may also occur.
Recurrent vitreous hemorrhage can trigger proliferative responses in the vitreous, forming fibrovascular proliferation membranes with neovascularization. These can cause further hemorrhage, retinal tears, or even retinal detachment.
Without timely treatment, longstanding vitreous hemorrhage can become organized and appear white. In later stages, complications such as secondary cataracts, neovascular glaucoma, and phthisis bulbi may develop.
Diagnosis
Diagnosis is based on symptoms and fundus examination. Bilateral fundus examinations should be performed to identify potential causes. When the fundus is obscured, ultrasound imaging may be conducted to exclude conditions like retinal detachment or intraocular tumors. After two days of bed rest with the head elevated, additional fundus evaluations may provide clearer insights.
Treatment
Small amounts of bleeding generally require no specific treatment, allowing natural resorption to resolve the condition.
When retinal tears are suspected, patients may be advised to rest in a supine position to allow the blood to settle. Laser photocoagulation or cryotherapy can then be applied to seal the retinal tears.
Persistent or unresolved large hemorrhages without retinal detachment or fibrovascular membranes may warrant observation for 4–6 weeks. If the hemorrhage does not resolve, vitrectomy may be considered. For cases involving retinal detachment, vitrectomy should be performed promptly.
Anti-vascular endothelial growth factor (anti-VEGF) therapy may be administered to address retinal or choroidal neovascularization.