Causes of Intraocular Hemorrhage (Bleeding in the Globe of the Eye)
Most Common Etiologies
The most common causes of bleeding within the eye globe are proliferative diabetic retinopathy (accounting for approximately 35% of cases), trauma (18%), retinal vein occlusions (7-11%), and retinal tears with or without detachment (12% combined). 1, 2
Primary Vascular Causes
Retinal Vein Occlusions are the second most common retinal vascular disorder after diabetic retinopathy and represent a major cause of intraocular hemorrhage. 3
Central retinal vein occlusion (CRVO) occurs when the retinal vein is obstructed at or posterior to the optic nerve head, resulting in intraretinal hemorrhages throughout the retina due to increased intravenous pressure and vascular leakage. 3
Branch retinal vein occlusion (BRVO) is 6-7 times more common than CRVO and typically occurs at arteriovenous crossing points where vessels share a common adventitial sheath, most frequently in the superior temporal quadrant. 3
Risk factors include older age (peak incidence 6th-7th decade), systemic arterial hypertension, diabetes, hyperlipidemia, arteriosclerosis, coronary artery disease, glaucoma, carotid occlusive disease, and sleep apnea. 3
Complications include vitreous hemorrhage from retinal neovascularization (especially with significant capillary nonperfusion), macular edema, and in CRVO cases, iris neovascularization leading to neovascular glaucoma in approximately 25% of patients. 3
Proliferative Diabetic Retinopathy is the single most common cause of spontaneous vitreous hemorrhage, accounting for 32-35% of cases. 1, 2
Retinal Arterial Macroaneurysm can rupture and cause subretinal or intraretinal hemorrhage, particularly in patients with hypertension. 4
Retinal Structural Causes
Retinal tears and posterior vitreous detachment collectively account for approximately 38% of spontaneous vitreous hemorrhages. 2
- Retinal tears without detachment cause 7% of cases, while tears with detachment cause 5%. 1
- Posterior vitreous detachment without retinal tear accounts for 6-8% of cases. 1, 2
Age-Related and Degenerative Causes
Age-related macular degeneration with choroidal neovascularization causes subretinal hemorrhage in 2% of cases, arising from abnormal new vessels beneath the retina. 1, 4
- This risk is dramatically increased in patients on anticoagulation therapy, where massive intraocular hemorrhage can occur from rupture of extrachoroidal neovascular vessels through the retinal pigment epithelium. 5
Hemoglobinopathy-Related Causes
Proliferative sickle cell retinopathy accounts for 6% of vitreous hemorrhages, particularly in Black patients where it represents over 15% of spontaneous cases. 1
Trauma
Ocular trauma causes 18% of vitreous hemorrhages and can result in bleeding from disruption of normal retinal vessels or extension of hemorrhage from other ocular structures. 1, 2
Medication-Related Causes
Antithrombotic therapy significantly increases intraocular hemorrhage risk. 6
- Aspirin, clopidogrel, warfarin, apixaban, and rivaroxaban all demonstrate increased reporting of intraocular hemorrhage under monotherapy. 6
- Combination therapy (dual antiplatelet therapy, antiplatelet plus anticoagulant, or triple therapy) further elevates risk. 6
- Highest risk occurs in younger patients on aspirin and elderly patients on warfarin, with most hemorrhages occurring within the first 90 days of treatment initiation. 6
- Patients with pre-existing age-related macular degeneration on anticoagulation require close ophthalmologic monitoring due to risk of massive intraocular hemorrhage. 5
Less Common Causes
Other etiologies collectively account for approximately 9% of cases and include: 1, 4
- Hypertensive retinopathy (2%)
- Presumed ocular histoplasmosis syndrome
- High myopia with choroidal neovascularization
- Retinal phlebitis
Critical Clinical Considerations
Systemic hypertension is strongly associated with hemorrhages from retinal vein occlusion and should be aggressively managed. 1
Patients with retinal vein occlusions have increased cardiovascular mortality compared to age-matched controls due to higher prevalence of cardiovascular disease and diabetes, warranting coordination with primary care for systemic risk factor management. 3
In patients under age 50 with CRVO, 58% have nontraditional risk factors including hypercoagulable states (factor V Leiden, elevated homocysteine, antiphospholipid antibodies), requiring hematologic evaluation. 3