What are the common causes of an acute hemorrhage to the eye in a patient without any known foreign body, injury, or vision changes?

Common Causes of Acute Eye Hemorrhage Without Trauma or Vision Changes

Subconjunctival hemorrhage in the absence of trauma or vision changes is most commonly caused by spontaneous rupture of small conjunctival vessels, with systemic vascular disease (hypertension, diabetes, arteriosclerosis) being the primary underlying risk factors in older adults, while younger patients more often have idiopathic causes or Valsalva-related events. 1

Primary Etiologies by Age Group

In Older Adults (Most Common)

• Systemic vascular diseases are the predominant risk factors, including:
  • Hypertension 1
  • Diabetes mellitus 1
  • Arteriosclerosis 1
• These conditions weaken vessel walls, predisposing to spontaneous rupture even without identifiable precipitating events 1

In Younger Patients

• Idiopathic causes (no identifiable trigger) are more common 1
• Valsalva maneuver from coughing, sneezing, straining, or vomiting can cause acute subconjunctival hemorrhage 2
• Contact lens usage is a risk factor in this age group 1

Serious Systemic Causes Requiring Investigation

Hematologic Disorders

• Thrombocytopenia can present initially as isolated subconjunctival hemorrhage before other manifestations appear 3
• Essential thrombocythemia may cause severe spontaneous bleeding around the eye 4
• Bleeding diathesis should be considered, particularly in recurrent cases 1, 2

When to Pursue Further Workup

If subconjunctival hemorrhage is recurrent or persistent, comprehensive evaluation is warranted including: 1

• Complete blood count with platelet count to exclude thrombocytopenia 3
• Blood pressure measurement to identify undiagnosed hypertension 1
• Coagulation studies if bleeding disorder suspected 1
• Evaluation for systemic or ocular malignancies in appropriate clinical context 1

Critical Distinction: Subconjunctival vs. Intraocular Hemorrhage

Subconjunctival Hemorrhage (Benign)

• Bright red blood visible on the white of the eye, beneath the conjunctiva 1
• No vision changes - this is the key distinguishing feature 1
• Generally benign and self-limited 1

Intraocular Hemorrhage (Requires Urgent Evaluation)

• Vitreous hemorrhage can occur with posterior vitreous detachment, with two-thirds of patients presenting with spontaneous vitreous hemorrhage having at least one retinal break 5
• Retinal hemorrhages may indicate retinal vein occlusion, which presents with sudden visual symptoms including decreased central vision 5
• These conditions typically cause vision changes, distinguishing them from simple subconjunctival hemorrhage 5

Common Pitfall to Avoid

Do not dismiss spontaneous subconjunctival hemorrhage as purely benign without considering the clinical context. 3 While most cases are indeed benign, the appearance of spontaneous subconjunctival hemorrhage can be the initial sign of serious systemic disorders, particularly hematologic conditions like idiopathic thrombocytopenic purpura 3. A thorough history regarding recurrence, medication use (especially anticoagulants), and systemic symptoms is essential 1.

Practical Management Algorithm

1. Confirm true subconjunctival hemorrhage (no vision changes, blood beneath conjunctiva only) 1
2. Assess for trauma history including minor trauma, Valsalva events 1, 2
3. Check blood pressure at the visit 1
4. Review medications for anticoagulants or antiplatelet agents 1
5. If first episode in older adult with vascular risk factors: reassurance and observation 1
6. If recurrent, persistent, or in younger patient without clear cause: obtain CBC with platelets, consider coagulation studies 3, 1