Subconjunctival Hemorrhage: A Detailed Guide to Differential Diagnosis and Management

Red eye is a frequent presentation in both primary care and emergency settings. Among the various causes, subconjunctival hemorrhage (SCH) stands out as a common, often benign condition, yet one that can sometimes signal a more serious underlying health issue. This article provides an in-depth exploration of subconjunctival hemorrhage, with a particular focus on differential diagnosis to aid clinicians in effectively evaluating and managing patients presenting with this condition.

Understanding Subconjunctival Hemorrhage: Etiology and Risk Factors

Subconjunctival hemorrhage occurs when small blood vessels beneath the conjunctiva, the clear membrane covering the white part of the eye (sclera), rupture and bleed. This results in a visible collection of blood, often alarming to patients due to its dramatic appearance. SCH is broadly classified into two categories: traumatic and spontaneous.

Traumatic Subconjunctival Hemorrhage

Traumatic SCH is often associated with direct injury to the eye. Common causes include:

Contact Lens Wear: Increased contact lens use is linked to higher rates of conjunctivochalasis, pinguecula, and superficial punctate keratitis. These conditions can heighten inflammation and friction, potentially leading to vessel rupture. Lens defects or deposits can further exacerbate this risk.⁴, ⁵
Ocular Surgery: Procedures like cataract surgery, refractive surgery, and sub-Tenon injections, especially in patients on anticoagulants, elevate SCH risk.
Minor Eye Trauma: Even seemingly insignificant actions like eye rubbing or a foreign body can cause vessel damage. Patients may not always recall such minor incidents.
Significant Trauma: In cases of severe trauma, SCH can be a component of more serious injuries, such as open globe injuries or orbital fractures. SCH extending from the fornix without direct globe trauma might indicate a basilar skull fracture.⁶
Non-Accidental Trauma: Bilateral SCH in infants, particularly when accompanied by facial petechiae, should raise suspicion for non-accidental trauma or child abuse. Traumatic asphyxia syndrome, resulting from chest and upper abdomen compression, can also cause SCH in children.⁷
Newborn Hemorrhage: SCH in newborns after vaginal delivery is relatively common (1-2%) due to pressure from uterine contractions during birth.⁸

Spontaneous Subconjunctival Hemorrhage

Spontaneous SCH arises without any identifiable trauma. Key risk factors include:

Hypertension and Vascular Disorders: Hypertension, diabetes, and hyperlipidemia are major predisposing factors. These conditions can weaken blood vessels, making them prone to spontaneous rupture. Hypertension is a significant risk factor even when managed with medication. Spontaneous SCH can also be an indicator of undiagnosed hypertension.⁹, ¹⁰
Anticoagulation and Medications: Anticoagulants like warfarin and heparin, as well as NSAIDs (aspirin) and P2Y12 inhibitors (clopidogrel), increase bleeding risk, even with therapeutic INR levels.¹¹
Elevated Venous Pressure: Activities that increase venous pressure, such as coughing, vomiting, strenuous exercise, heavy lifting, and Valsalva maneuvers, can trigger SCH.
Acute Hemorrhagic Conjunctivitis: Enterovirus 70 is a known cause, although its prevalence is decreasing.
Menstruation: In some cases, menstruation may be associated with SCH, possibly due to underlying blood dyscrasias or venous pressure changes.
Systemic Diseases: Less commonly, SCH can be an initial sign of conditions like Steven-Johnson syndrome, hemochromatosis, and dermatologic vascular diseases (Kaposi’s sarcoma, pyogenic granuloma, telangiectasias, hemangiomas).
Idiopathic Causes: Almost half of spontaneous SCH cases remain without a clear identifiable cause.

Epidemiology of Subconjunctival Hemorrhage

Generally, SCH affects both genders equally. However, traumatic SCH is more frequent in young males, likely due to occupational and recreational activities. Non-traumatic SCH incidence may be slightly higher in women (male-to-female ratio of 0.8 in one study). Spontaneous SCH prevalence increases significantly with age, particularly after 50, due to the higher likelihood of comorbidities like hypertension, hyperlipidemia, and diabetes. Some studies suggest a seasonal variation, with increased incidence in summer, possibly linked to more frequent presentation of children during summer holidays.³, ¹², ¹³

Pathophysiology: Why Does Subconjunctival Hemorrhage Occur?

SCH results from the rupture of small conjunctival or episcleral blood vessels, leading to blood accumulation in the subconjunctival space. Age and underlying vascular conditions contribute to vessel fragility. In older individuals, the elastic and connective tissues of blood vessels weaken, facilitating bleeding. Traumatic SCH tends to be localized, while spontaneous SCH may be more diffuse. The temporal aspect of the eye is more commonly affected, possibly due to the larger bulbar conjunctiva, higher incidence of conjunctivochalasis, and less protection compared to the nasal side. Blood often gravitates inferiorly, making the inferior aspect more prone to SCH.¹⁴, ², ⁴

Histopathology of Subconjunctival Hemorrhage

Histologically, the bleeding occurs between the conjunctiva and episclera, specifically within the substantia propria. As the hemorrhage resolves, the blood undergoes breakdown, similar to a bruise, causing color changes from red to blue and yellow as hemoglobin degrades.

History and Physical Examination: Key to Differential Diagnosis

A thorough history and physical examination are crucial to differentiate benign SCH from those indicating more serious conditions.

History Taking

Trauma History: Inquire about any ocular trauma, even minor incidents. SCH after blunt trauma requires careful evaluation for ruptured globe or retrobulbar hematoma.
Medical History: Obtain detailed medical history, particularly regarding hypertension, hyperlipidemia, diabetes, coagulopathies, and blood dyscrasias.
Medication Review: Document any anticoagulant or antiplatelet therapy, including NSAIDs. Assess medication compliance.
Contact Lens Use & Ocular Surgery History: Note contact lens wear and any prior eye surgeries.
Provoking Factors: Ask about viral-like illnesses, coughing, vomiting, or constipation, which could raise venous pressure.
Associated Symptoms: Inquire about visual loss, discharge, photophobia, foreign body sensation, or headache. These symptoms suggest alternative diagnoses.

Physical Examination

Visual Inspection: SCH presents as a painless, abrupt, sharply defined area of blood beneath the conjunctiva. It is typically unilateral. Visual acuity remains normal. Traumatic SCH may be more localized, while spontaneous SCH, especially in the elderly, can be more diffuse. The inferotemporal conjunctiva is the most frequent location.
Exclusion of Serious Signs: A simple SCH should not exhibit chemosis (conjunctival swelling), proptosis (eye bulging), purulent discharge, or ophthalmoplegia (eye muscle weakness).
Scleral Rupture Assessment: In suspected scleral rupture, look for elevated, bullous-appearing hemorrhage due to intraocular blood leaking into the subconjunctival space.²
Conjunctival vs. Ciliary Injection: Distinguish between conjunctival and ciliary injection. Conjunctival injection is diffuse redness over the sclera due to superficial vessel dilation. Ciliary injection (circumcorneal flush), a halo of redness around the cornea, suggests deeper intraocular inflammation (iritis, keratitis, ciliary body inflammation). Ciliary injection is associated with more serious conditions like iritis, acute glaucoma, episcleritis, and scleritis.¹⁵
Differentiation from Conjunctivitis: SCH needs to be differentiated from conjunctivitis. Conjunctivitis often presents with pain, more diffuse redness (not sharply demarcated), and discharge. Viral conjunctivitis is usually bilateral, while SCH is typically unilateral.¹⁵

Image: Subconjunctival hemorrhage appearance in a patient taking warfarin, highlighting the diffuse redness and blood collection.

Evaluation and Diagnostic Approach

The diagnosis of SCH is primarily clinical, based on its characteristic appearance. However, further evaluation is important to rule out underlying conditions and guide management.

Slit-Lamp Examination: A slit-lamp examination with fluorescein staining is essential to assess for ocular trauma, corneal abrasions, foreign bodies, or other local ocular conditions that might have triggered the SCH.
Blood Pressure Measurement: Routine blood pressure check is recommended for all patients presenting with SCH to identify potential hypertension.
INR Testing: For patients on warfarin, check INR levels.
Hemostatic Workup: In cases of persistent or recurrent SCH, or if there are other bleeding symptoms, consider a workup for bleeding disorders or hypocoagulable states. However, extensive hemostatic testing is generally not warranted in isolated SCH without other bleeding manifestations.², ⁹, ¹⁶
Fundoscopy: Generally not indicated for simple SCH.

Subconjunctival Hemorrhage Differential Diagnosis

Differentiating SCH from other red eye conditions is crucial for appropriate management. The differential diagnosis of subconjunctival hemorrhage includes:

Traumatic Etiologies (When Trauma is Suspected)

Globe Rupture: A sight-threatening emergency requiring immediate ophthalmologic consultation. Signs include proptosis, chemosis, decreased visual acuity, and a tear-drop pupil.
Retrobulbar Hematoma: Another sight-threatening condition requiring urgent ophthalmology referral. May present with proptosis, resistance to retropulsion of the globe, and elevated intraocular pressure.
Corneal Abrasion: Painful condition with foreign body sensation, tearing, and photophobia. Fluorescein staining reveals corneal epithelial defect.
Conjunctival Laceration: A tear in the conjunctiva, often associated with trauma. Requires careful examination to rule out deeper injuries.
Ocular Foreign Body: Sensation of something in the eye, tearing, and potential corneal abrasion. Requires careful examination and removal of the foreign body.
Traumatic Iritis (Anterior Uveitis): Inflammation of the iris and anterior chamber following trauma. Presents with pain, photophobia, and ciliary flush.
Traumatic Hyphema: Blood in the anterior chamber, usually visible as a fluid level. Requires ophthalmologic evaluation to manage potential glaucoma and corneal staining.

Non-Traumatic Etiologies

Conjunctivitis (Viral, Bacterial, Allergic): Inflammation of the conjunctiva. Viral conjunctivitis often bilateral, with watery discharge and preauricular lymphadenopathy. Bacterial conjunctivitis may have purulent discharge. Allergic conjunctivitis typically presents with itching and bilateral involvement. Unlike SCH, conjunctivitis usually involves diffuse redness and discharge.
Episcleritis: Inflammation of the episclera, the tissue layer between the conjunctiva and sclera. Characterized by sectoral redness, mild pain or discomfort, and no discharge. Less dramatic in appearance than SCH.
Inflamed Pterygium or Pinguecula: Pterygium is a wing-shaped growth of conjunctival tissue onto the cornea. Pinguecula is a yellowish nodule on the conjunctiva. Inflammation of these can cause localized redness.
Corneal Erosions or Ulcers: Disruptions of the corneal epithelium. Present with pain, photophobia, foreign body sensation, and often ciliary flush. Fluorescein staining helps visualize corneal defects.
Keratitis: Inflammation of the cornea. Can be infectious (bacterial, viral, fungal, Acanthamoeba) or non-infectious. Symptoms include pain, photophobia, blurred vision, and ciliary flush.
Anterior Uveitis (Iritis): Inflammation of the iris and anterior chamber. Presents with pain, photophobia, blurred vision, and ciliary flush. May have constricted pupil and cells and flare in the anterior chamber.
Acute Angle-Closure Glaucoma: Ophthalmologic emergency characterized by sudden onset of severe eye pain, blurred vision, halos around lights, nausea, and vomiting. Presents with ciliary flush, corneal edema, and elevated intraocular pressure.
Corneal Ulcer: Open sore on the cornea, often infectious. Severe pain, photophobia, blurred vision, and ciliary flush are common.
Endophthalmitis: Severe intraocular infection, often after surgery or trauma. Significant pain, decreased vision, and often chemosis and proptosis.
Scleritis: Inflammation of the sclera. Deep, boring eye pain, often radiating to the face, and can be associated with systemic autoimmune diseases. Redness may be diffuse or nodular, and may have a bluish hue.

Observational clues during physical examination can significantly narrow the differential diagnosis. Globe rupture or retrobulbar hematoma may exhibit proptosis, chemosis, reduced vision, or a tear-drop pupil. Afferent pupillary defect suggests optic neuropathy, while consensual photophobia points towards iritis. Slit-lamp examination with fluorescein staining is invaluable for detecting corneal erosions, ulcers, and dendritic lesions suggestive of herpetic keratitis. Symptoms like grittiness or foreign body sensation are less common in simple SCH and more indicative of corneal or conjunctival surface issues.

Treatment and Management of Subconjunctival Hemorrhage

In most cases, SCH is benign and self-limiting, requiring no specific treatment. The blood typically resorbs within 1-2 weeks, depending on the extent of the hemorrhage. Resolution may take up to 3 weeks in patients on anticoagulants.

Conservative Management: Reassurance is key. Explain the benign nature of the condition and the expected time for resolution.
Symptomatic Relief:
- Artificial Tears: Can alleviate grittiness or dryness.
- Cold Compresses: May reduce swelling and discomfort, especially in the initial phase.
Ophthalmology Consultation: Emergent ophthalmology consultation is necessary if:
- SCH is associated with trauma and suspected intraocular injury or retinal damage.
- Differential diagnosis suggests a more serious underlying condition (globe rupture, retrobulbar hematoma, acute glaucoma, etc.).
Topical Vasoconstrictors (with caution): Dilute brimonidine or oxymetazoline have been used to improve comfort and reduce SCH incidence after intravitreal injections, but routine use is not recommended for simple SCH and should be considered cautiously due to potential rebound hyperemia with prolonged use.¹⁷, ¹⁸

Prognosis and Potential Complications

The visual prognosis for SCH is excellent. Vision is typically unaffected, and the condition resolves spontaneously. Recurrence of spontaneous SCH is approximately 10% without identifiable risk factors, and higher in patients on anticoagulant or antiplatelet therapy.¹⁶

Complications directly related to SCH are rare. However, SCH can be a manifestation of a more serious underlying condition, such as coagulopathy, severe asthma exacerbation, non-accidental trauma, or severe orbital trauma.¹⁹

Deterrence and Patient Education

Educate patients that SCH usually resolves within two weeks. Advise them to seek medical attention if they experience:

Recurrence or persistence of SCH.
Bruising elsewhere on the body, especially while on anticoagulants or antiplatelet medications.
Vision loss.
Ophthalmoplegia (eye movement problems).
Increasing pain or swelling.

Artificial tears can be recommended for symptomatic relief of grittiness. Patients should consult their primary care physician or an ophthalmologist if concerning symptoms arise.

Enhancing Healthcare Team Outcomes

Subconjunctival hemorrhage is a common presentation across various medical settings. Effective management requires a collaborative interprofessional approach. Primary care providers, emergency physicians, ophthalmologists, nurses, and pharmacists all play vital roles in patient care. Collaboration is crucial for accurate diagnosis, appropriate management, and addressing underlying risk factors. For patients on anticoagulation, communication with cardiologists or vascular surgeons is important. In pediatric cases, especially with suspected non-accidental trauma, neonatologists, pediatricians, and pediatric emergency physicians may be involved. A coordinated team approach ensures optimal patient outcomes and helps identify and manage any underlying systemic conditions associated with SCH.

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References

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