The conjunctiva is a relatively loose structure and any bleeding can easily spread and appear quite alarming. Patients are, however, often asymptomatic and may only become aware of having a red eye when looking in the mirror or having it pointed out to them.
The majority of subconjunctival haemorrhages occur spontaneously without an identifiable cause, the patient occasionally complaining of a sudden “popping” feeling in the eye. It is likely that many of these patients may have had mild trauma eg eye rubbing, which has contributed to the bleed.
Occasionally subconjunctival haemorrhage, especially if recurrent, can be an indication of more serious ocular or systemic disease:
- Subconjunctival haemorrhage secondary to significant direct blunt or sharp injury may be a sign of globe rupture. If there is any doubt urgent referral is necessary for specialist opinion and the patient may require a conjunctival peritomy and exploration of the injured area.
- Recurrent subconjunctival bleeds can be associated with a transient rise in venous pressure eg coughing, vomiting, Valsalva manoeuvre or may be due to uncontrolled hypertension.
- Recurrent subconjunctival bleeds can also be a feature of a systemic bleeding diathesis (ask about easy bruising and epistaxis) or a sign that an individual is over anticoagulated eg high international normalised ratio (INR) with warfarin.
- Acute haemorrhagic conjunctivitis eg adenoviral conjunctivitis, may often have a degree of subconjunctival haemorrhage but the patient would have other associated ocular symptoms +/- lymphadenopathy.
Unless associated with a serious cause no therapy is required and the patient should simply be reassured. The area of haemorrhage usually changes to a yellow-brown colour before resolving in 10 – 12 days.