Subconjunctival haemorrhage
Overview
•Bright red patch on the conjunctiva - sharply defined edges, flat
•Asymptomatic in most cases - mild irritation or sensation of fullness possible
•Visual acuity normal - preserved VA distinguishes from sight-threatening red eye
•Pupil reactions normal - normal direct and consensual reflexes
•No discharge - distinguishes from conjunctivitis
•Colour change over time - red → green → yellow, resolves over 1-2 weeks
•Bilateral haemorrhage - raises suspicion of underlying bleeding disorder or systemic cause
Investigations
Clinical diagnosis - no investigations needed for a first episode with obvious precipitant. Investigate if recurrent, bilateral, or no clear cause found.
•Blood pressure measurement - essential in all presentations; hypertension is common and treatable
•Medication review - warfarin, DOACs, aspirin, NSAIDs
•Full blood count - exclude thrombocytopenia in recurrent or bilateral cases
•Clotting screen (PT, APTT) - if coagulopathy suspected
Differential diagnosis
Management
🥇 First-line
•reassurance - resolves spontaneously within 1-2 weeks, no eye drops required
•Symptomatic relief: artificial tears (lubricating eye drops) for mild irritation
•Address modifiable risk factors - manage newly identified hypertension; review anticoagulation if supratherapeutic
•Urgent ophthalmology referral - no visible posterior margin after trauma, significant eye injury, or visual acuity affected