Subconjunctival haemorrhage results from bleeding of the conjunctival or the episcleral blood vessels into the subconjunctival space. The cause is usually unknown but may be the result of trauma or related to systemic illness.
- It occurs frequently.
- The mean annual incidence of non-traumatic subconjunctival haemorrhage is about 0.6%.
- It can occur at all ages but is more common with increasing age, probably as a result of increasing frequency of risk factors.
- It is more common in women than it is in men.
- It is common in the newborn.
The cause is usually idiopathic.
- Valsalva manoeuvre (eg, coughing, sneezing, vomiting or straining; weight lifting; it has also been reported as a complication of bronchoscopy and endoscopy).
- Trauma - surgical or accidental (isolated or associated with retrobulbar haemorrhage or ruptured globe).
- Contact lenses.
- Bleeding disorders.
- Diabetes mellitus.
- Coronary heart disease.
- Various drugs - eg, warfarin, aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs), steroids.
- Normal sequelae of ocular surgery even if there is no conjunctival incision.
- Febrile systemic infections.
- Red eye, usually unilateral.
- It is usually asymptomatic.
- The patient may not be aware of its presence but it has been reported to them by family or friends, who can find its appearance quite alarming.
- The patient may have mild irritation.
- The most common appearance is a flat, bright red patch anywhere in the conjunctiva with sharply defined edges and relatively normal conjunctiva surrounding it.
- Overall they are most commonly found in the inferior conjunctiva but traumatic subconjunctival haemorrhages are more common in the temporal area.
- The haemorrhage may spread and become green or yellow, like a bruise. Usually this disappears within two weeks.
- Examination of the eye, including pupil responses and visual acuity, is otherwise normal.
It is worth noting that a haemorrhage without a posterior margin (ie extends posteriorly so that the whole extent of the haemorrhage cannot be seen) may be associated with an intracranial bleed or an orbital roof fracture (associated with a black eye) - the history should guide you as to whether to consider this or not.
Other causes of acute red eye, including:
If it is a persistent haemorrhage (as opposed to the conjunctival injection seen in a red eye), consider rarer causes such as:
- Kaposi's sarcoma
- Other conjunctival neoplasms
- Check blood pressure.
- No laboratory studies are indicated if it is an isolated problem.
- If there is history of trauma, the patient may need referral to rule out more extensive eye injury.
- In recurrent cases, investigation for an underlying bleeding disorder may be indicated.
- Medical care is not required, unless there is an underlying disorder.
- Artificial tears can be used four times per day for mild irritation.
- Discourage elective use of aspirin products or NSAIDs.
- Simultaneous bilateral haemorrhages, and persistent or unexplained recurrence, warrant a referral to the ophthalmologist.
- Subconjunctival haemorrhage is a benign, self-limiting condition when not associated with systemic illness.
- Prognosis is excellent.
- There may be a small increased risk of stroke in the three years following a subconjunctival haemorrhage.
Further reading and references
Tarlan B, Kiratli H; Subconjunctival hemorrhage: risk factors and potential indicators. Clin Ophthalmol. 20137:1163-70. doi: 10.2147/OPTH.S35062. Epub 2013 Jun 12.
Hu DN, Mou CH, Chao SC, et al; Incidence of Non-Traumatic Subconjunctival Hemorrhage in a Nationwide Study in Taiwan from 2000 to 2011. PLoS One. 2015 Jul 1610(7):e0132762. doi: 10.1371/journal.pone.0132762. eCollection 2015.
Mimura T, Usui T, Yamagami S, et al; Recent causes of subconjunctival hemorrhage. Ophthalmologica. 2010224(3):133-7. doi: 10.1159/000236038. Epub 2009 Sep 9.
Lim HY, Puah SH, Ang LJ, et al; Subconjunctival haemorrhage from bronchoscopy: A case report. Respir Med Case Rep. 2015 Sep 316:97-100. doi: 10.1016/j.rmcr.2015.08.008. eCollection 2015.
Mimura T, Yamagami S, Mori M, et al; Contact lens-induced subconjunctival hemorrhage. Am J Ophthalmol. 2010 Nov150(5):656-665.e1. doi: 10.1016/j.ajo.2010.05.028. Epub 2010 Aug 14.
Mimura T, Yamagami S, Usui T, et al; Location and extent of subconjunctival hemorrhage. Ophthalmologica. 2010224(2):90-5. doi: 10.1159/000235798. Epub 2009 Aug 28.
Cronau H, Kankanala RR, Mauger T; Diagnosis and management of red eye in primary care. Am Fam Physician. 2010 Jan 1581(2):137-44.
Wang TJ, Keller JJ, Sheu JJ, et al; A 3-year follow-up study on the risk of stroke among patients with conjunctival haemorrhage. Acta Ophthalmol. 2013 May91(3):226-30. doi: 10.1111/j.1755-3768.2011.02359.x. Epub 2012 Mar 9.