Introduction to Ophthalmology • Ophthalmic symptomatology • Secretions and appearance
Abnormal Ocular Secretions and Appearance: Watery, Purulent Discharge and Redness
Watery eyes, sticky or purulent discharge, swelling and redness are common reasons for seeking care. They may reflect a benign surface disorder, but the same appearance can occur in corneal ulcer, uveitis, acute glaucoma, orbital cellulitis, chemical injury or neonatal infection. The clinician must describe the secretion and vascular pattern, measure vision and search for pain, photophobia and systemic danger signs.
Urgent warning: Redness with reduced vision, severe pain, photophobia, corneal opacity, hypopyon, high-risk trauma/chemical exposure, contact-lens use, proptosis, fever, painful eye movements or a fixed/irregular pupil needs same-day ophthalmic assessment. Neonatal profuse purulent discharge is an emergency.
Learning objectives
- Distinguish watery, mucoid, mucopurulent and purulent ocular secretions.
- Describe conjunctival, ciliary, episcleral and diffuse redness accurately.
- Differentiate common conjunctivitis from keratitis, uveitis, acute glaucoma, trauma and orbital infection.
- Take a focused history, perform an initial eye examination and identify referral red flags.
- Provide safe hygiene, infection-control, irrigation and referral advice.
1. Describe what is visible
| Finding | Useful description | Possible meaning |
|---|---|---|
| Watery/serous tears | Clear, thin, continuous or intermittent; one or both eyes. | Viral infection, allergy, irritation, corneal abrasion, obstruction or reflex tearing from dry eye. |
| Mucoid/stringy | White/clear mucus, ropy strands, often with itching. | Allergy, dry eye or chronic surface disease. |
| Mucopurulent | Sticky yellow/green discharge that reforms after cleaning. | Bacterial conjunctivitis or other infection; severity and vision determine urgency. |
| Profuse purulent | Copious thick pus, eyelids stuck, rapid reaccumulation. | Hyperacute bacterial infection such as gonococcal conjunctivitis; emergency due to corneal melt/perforation. |
| Crusting | Dried discharge on lashes or lid margins. | Blepharitis or conjunctivitis; assess chronicity and recurrent lesions. |
| Diffuse conjunctival injection | Generalised superficial redness that blanches with pressure. | Conjunctivitis, irritation, allergy or dry eye. |
| Ciliary flush | Deep violaceous ring around the limbus. | Keratitis, anterior uveitis or acute glaucoma until assessed. |
| Subconjunctival haemorrhage | Well-demarcated bright-red patch beneath conjunctiva. | Often benign, but trauma, bleeding risk or recurrence require assessment. |
| Chemosis | Oedematous, ballooned conjunctiva. | Allergy, infection, trauma, inflammation or orbital venous congestion. |
| Corneal opacity/white spot | Loss of transparency, infiltrate, scar or oedema. | Corneal ulcer, keratitis, oedema or injury; vision-threatening if central/infectious. |
2. Focused history
- Onset/course: sudden, gradual, recurrent, progressive, after waking or following exposure.
- Laterality/spread: one eye then the other, bilateral from onset, household/school outbreak.
- Discharge: clear, mucous, yellow/green, bloody, amount, frequency and whether it reforms quickly.
- Vision: blur, reduced acuity, glare, halos, flashes, floaters or field loss.
- Pain/photophobia: surface irritation versus severe/deep pain and light intolerance.
- Trauma/exposure: chemical, dust, high-velocity object, welding, swimming, cosmetics or foreign body.
- Contact lenses: overnight wear, hygiene, water exposure, replacement and current use.
- Systemic context: fever, respiratory illness, rash, sexually transmitted infection risk, immunosuppression, autoimmune disease.
- Neonatal/pregnancy history: age at onset, delivery complications, maternal infection and prophylaxis.
- Past eye disease: glaucoma, uveitis, herpetic eye disease, surgery, injections or one-eyed status.
3. Initial examination
| Examination | What to document | Reason |
|---|---|---|
| Visual acuity | Each eye, correction/pinhole, CF/HM/PL if very poor. | Reduced VA is a red flag in a red eye. |
| Pupils | Size, shape, reactivity, RAPD. | Optic-nerve/retinal disease or acute glaucoma. |
| Lids/lashes | Swelling, crusting, vesicles, entropion, trichiasis and closure. | Blepharitis, herpes, exposure and cellulitis clues. |
| Conjunctiva | Pattern, blanching, chemosis, haemorrhage, follicles/papillae where trained. | Helps separate superficial from deep inflammation. |
| Cornea/anterior chamber | Clarity, epithelial defect, infiltrate, hypopyon, depth and cells/flare. | Keratitis, ulcer, uveitis and glaucoma can threaten sight. |
| Motility/orbit | Proptosis, movement restriction/pain and diplopia. | Orbital cellulitis or compartment pathology. |
| Fluorescein/IOP | Only if safe and equipment/training are available. | Detects epithelial damage; pressure helps selected cases but is unsafe with open globe. |
4. Watery eyes (epiphora)
| Mechanism | Examples | Clues |
|---|---|---|
| Reflex overproduction | Corneal abrasion, foreign body, keratitis, dry eye, allergy, smoke/wind. | Tearing accompanies irritation, pain, itching or blinking. |
| Drainage obstruction | Punctal stenosis, canalicular disease, nasolacrimal duct obstruction, infection. | Overflowing tears, often unilateral; discharge/medial canthal swelling may occur. |
| Lid malposition | Entropion, ectropion, laxity, facial-nerve palsy. | Abnormal punctal position or exposed ocular surface. |
| Inflammation/infection | Viral conjunctivitis, uveitis, keratitis. | Redness, photophobia or visual reduction changes urgency. |
Dry eye can paradoxically cause tearing: an unstable tear film stimulates corneal nerves and produces reflex aqueous tears that rapidly overflow because the underlying surface remains abnormal.
5. Purulent and mucopurulent discharge
Common bacterial conjunctivitis
- Redness, gritty discomfort, mucopurulent discharge and eyelids stuck on waking; vision should remain near baseline after discharge is cleared.
- Usually superficial, but contact-lens wear, pain, photophobia, corneal opacity or reduced VA suggests keratitis and requires urgent review.
- Hand hygiene, individual towels and avoidance of sharing cosmetics reduce spread. Antibiotic treatment depends on clinical assessment and local protocol.
Hyperacute purulent conjunctivitis
Copious rapidly recurring pus, severe chemosis, pain or corneal involvement should be treated as an emergency. Gonococcal infection can invade intact epithelium and cause corneal ulceration/perforation. Obtain urgent ophthalmic and sexual-health/infectious-disease assessment; collect appropriate specimens before treatment when this does not delay care, and arrange partner/public-health management.
Neonatal purulent discharge
Profuse discharge in a newborn may be caused by gonococcal or chlamydial infection and can rapidly damage the cornea. Urgent paediatric/ophthalmic evaluation and systemic treatment are required; do not rely on routine topical drops alone.
6. Red eye: pattern matters
| Pattern | Likely categories | Features that demand escalation |
|---|---|---|
| Diffuse superficial injection | Viral/allergic/bacterial conjunctivitis, irritation, dry eye. | Reduced VA, severe pain, photophobia, corneal opacity, contact lens, neonatal age. |
| Marked itching and chemosis | Allergic conjunctivitis. | Airway/facial swelling, severe unilateral disease or visual change. |
| Perilimbal/ciliary flush | Keratitis, uveitis, acute glaucoma. | Any pain, photophobia, reduced VA, irregular/fixed pupil or hypopyon. |
| Sectoral deep redness | Episcleritis or scleritis. | Deep severe pain, tenderness, autoimmune symptoms or visual loss. |
| Subconjunctival haemorrhage | Spontaneous, trauma, cough/strain, hypertension or anticoagulation. | Penetrating trauma, recurrent bleeding, pain or reduced vision. |
| Red swollen lids with fever | Preseptal/orbital cellulitis. | Proptosis, restricted painful movements, RAPD, reduced VA or systemic toxicity. |
7. Differential diagnosis of red eye
| Condition | Pain | Photophobia | Vision | Pupil/cornea | Urgency |
|---|---|---|---|---|---|
| Viral conjunctivitis | Mild gritty. | Mild. | Usually preserved. | Clear cornea; watery discharge. | Routine unless atypical/severe. |
| Allergic conjunctivitis | Itch/burning. | Usually mild. | Preserved. | Chemosis/stringy mucus. | Urgent if severe swelling/airway symptoms. |
| Bacterial conjunctivitis | Mild-moderate. | Usually mild. | Preserved after cleaning. | Mucopurulent; cornea usually clear. | Urgent if hyperacute or corneal involvement. |
| Keratitis/ulcer | Moderate-severe. | Marked. | Reduced. | Defect/infiltrate/opacity. | Emergency. |
| Anterior uveitis | Deep ache. | Marked. | Reduced/blurred. | Ciliary flush, small/irregular pupil, cells/flare. | Urgent. |
| Acute angle closure | Severe. | Variable. | Reduced/halos. | Hazy cornea, mid-dilated pupil, high IOP. | Emergency. |
| Scleritis | Severe boring. | Possible. | May reduce. | Deep violaceous redness/tenderness. | Urgent. |
| Orbital cellulitis | Deep/movement pain. | Possible. | May reduce. | Proptosis/restricted movements. | Emergency. |
8. First aid and infection control
- Wash hands before and after examination; do not share towels, pillows, cosmetics, eye drops or contact-lens equipment.
- Use clean single-use gauze for discharge and wipe from the inner to outer canthus; discard safely.
- For chemical exposure, irrigate immediately and copiously; remove accessible contact lenses and continue according to protocol.
- For suspected foreign body or open globe, do not rub, press, patch tightly or attempt home extraction; shield and refer.
- Do not instil topical steroid or anaesthetic for an undiagnosed red eye. Steroids can worsen infection; repeated anaesthetic can damage the cornea.
- Contact-lens wearers with pain, photophobia or reduced vision need urgent assessment rather than routine conjunctivitis treatment.
9. Hospital evaluation and management
| Problem | Evaluation | Management principle |
|---|---|---|
| Likely uncomplicated conjunctivitis | History, VA, pupils, external exam and corneal check where indicated. | Supportive care/appropriate topical therapy, hygiene, sick-contact advice and review if worse. |
| Corneal ulcer/keratitis | Slit lamp, fluorescein, corneal sensation where appropriate, cultures/scrapings by specialist. | Urgent intensive antimicrobial treatment and close review; avoid steroid until specialist direction. |
| Anterior uveitis | Slit lamp cells/flare, pupil, IOP and systemic review. | Specialist-directed anti-inflammatory/cycloplegic therapy and cause evaluation. |
| Acute glaucoma | VA, pupil, cornea, IOP and angle assessment. | Immediate pressure-lowering and definitive ophthalmic treatment; monitor systemic effects. |
| Orbital cellulitis | VA, pupils, motility, proptosis, systemic status and orbital imaging when indicated. | Admission, intravenous antimicrobial therapy and surgical review if abscess/complication. |
| Hyperacute purulent disease | Urgent microscopy/culture/NAAT as appropriate and sexual-health assessment. | Systemic and topical treatment under specialist/public-health guidance; partner management. |
10. When to refer urgently
- Any decrease in visual acuity, abnormal pupil/RAPD or visual-field defect.
- Severe pain, photophobia, ciliary flush, corneal opacity, ulcer, hypopyon or hazy cornea.
- Contact-lens wearer with pain/redness/photophobia or a high-velocity foreign body.
- Copious purulent discharge, rapidly worsening swelling or neonatal eye discharge.
- Proptosis, fever, painful/restricted eye movements, diplopia or systemic toxicity.
- Penetrating/chemical trauma, hyphema, irregular pupil or recent intraocular surgery/injection.
11. Applied cases
Case 1: Watery red eye in a student
A student has bilateral watery eyes, mild gritty discomfort and a colleague with similar symptoms. Vision is normal, pain is mild and there is no corneal opacity. Viral conjunctivitis is likely, but give hygiene advice and clear return precautions for pain, photophobia or visual reduction.
Case 2: Copious pus
A patient has profuse purulent discharge that reappears minutes after cleaning, marked chemosis and early blur. Treat as hyperacute bacterial infection: urgent ophthalmology, microbiology/sexual-health coordination and systemic treatment; routine conjunctivitis drops alone are unsafe.
Case 3: Red eye with a small pupil
A patient has deep ache, photophobia, ciliary flush and a small irregular pupil. Anterior uveitis is possible. Measure VA and seek urgent ophthalmic assessment; avoid assuming bacterial conjunctivitis.
Case 4: Swollen eyelid and fever
A child has fever, proptosis and painful restricted eye movements. Orbital cellulitis threatens the optic nerve and brain. Arrange emergency admission, imaging and intravenous treatment through the appropriate team.
12. Self-test
- How do watery and purulent discharge differ clinically?
- What is ciliary flush and why is it concerning?
- Name three red-eye findings that make routine conjunctivitis unlikely.
- Why is hyperacute purulent conjunctivitis an emergency?
- What should be done first after a chemical splash?
- Which newborn eye symptom requires urgent assessment?
- What distinguishes orbital from preseptal cellulitis?
- Why should steroid drops not be started for an undiagnosed red eye?
- When is a subconjunctival haemorrhage not simply benign?
- What must be documented in a red-eye referral?
Answers
- Watery is clear/serous and often viral, allergic or reflex; purulent is thick yellow/green discharge suggesting bacterial infection, especially if copious/recurrent.
- A ring of deeper perilimbal redness from ciliary vessels; it can indicate keratitis, uveitis or acute glaucoma.
- Reduced VA, severe pain, photophobia, corneal opacity/ulcer, hypopyon, abnormal pupil, contact-lens use, proptosis or painful movements.
- Gonococcal infection can rapidly invade and melt the cornea, causing perforation and blindness.
- Immediate copious irrigation; do not delay for detailed assessment.
- Profuse purulent discharge, especially in the first weeks of life.
- Orbital disease has proptosis, painful/restricted movements, reduced vision, RAPD or systemic toxicity; preseptal disease is anterior with normal vision/movement.
- Steroids can worsen herpetic, fungal or bacterial infection and delay healing.
- After trauma, with pain/visual loss, recurrent bleeding, anticoagulation or other abnormal findings.
- Onset/laterality, discharge type, VA each eye, pupils/RAPD, pain/photophobia, cornea, IOP if safe, motility/orbit, trauma/contact lenses, treatment and urgency.
Key takeaways
- Describe secretion and redness precisely; do not diagnose from colour alone.
- Vision, pain, photophobia, cornea, pupil and motility determine urgency.
- Copious pus, corneal involvement, contact-lens symptoms, neonatal discharge and orbital signs are emergencies.
- Use hygiene and safe irrigation, but avoid pressure, unsupervised steroid/anaesthetic drops and delayed referral.
