Related Subjects:
|Episcleritis
|Scleritis
|Assessing a Red eye
|Acute Angle Closure Glaucoma
|Allergic and Infective Conjunctivitis
|Anterior and Posterior Uveitis
|Herpes simplex keratitis (HSK)
|Acute Blepharitis
|Corneal Abrasion
💉 Intravitreal injections (for AMD, diabetic macular oedema, retinal vein occlusion) have revolutionised retinal care, preventing blindness in thousands.
⚠️ Rare but devastating complication: endophthalmitis.
👉 Any patient with pain, redness, or vision loss post-injection = same-day urgent ophthalmology review.
👁️ Acute Red Eye – Introduction
- “Red eye” is a symptom, not a diagnosis.
- Causes range from benign (conjunctivitis) → sight-threatening (acute glaucoma, keratitis, uveitis, endophthalmitis).
- ⚠️ Red, painful eye + ↓ vision = ophthalmic emergency until proven otherwise.
🔎 Causes of Acute Red Eye
- 👁️ Conjunctivitis – bacterial (purulent), viral (watery, contagious), allergic (itchy, chemosis).
- 🦠 Corneal disease: abrasion, ulcer, infective keratitis → pain + photophobia.
- 🪙 Foreign body: irritation, tearing, fluorescein uptake with abrasion.
- 🔥 Uveitis (iritis): deep pain, photophobia, ciliary flush, constricted pupil.
- 🚨 Acute angle-closure glaucoma: severe pain, haloes, headache, N/V, mid-dilated fixed pupil, corneal haze.
- 🌿 Blepharitis: lid margin inflammation, gritty sensation.
- 💧 Dry eye syndrome: chronic irritation, worse with screen use.
- ⚡ Endophthalmitis: post-op/injection, severe pain + ↓ vision. Sight-threatening.
- ☢️ Chemical injury: irrigate immediately before full history/exam.
🧾 Key Symptoms
- 👁️ Redness (sectoral vs diffuse).
- 😖 Pain (mild → severe boring pain).
- 💧 Discharge (watery vs mucopurulent vs stringy).
- 🌞 Photophobia (suggests corneal/uveal pathology).
- 📉 Blurred vision or vision loss → red flag.
- 🪙 Foreign body sensation.
🩺 Diagnostic Approach
- History: Onset, discharge, photophobia, vision changes, trauma, CL wear, autoimmune disease.
- Exam: Visual acuity first, pupils, corneal staining (fluorescein), slit-lamp, IOP if glaucoma suspected.
- Phenylephrine blanching: Episcleritis (blanches) vs scleritis (persists).
- Microbiology: Swab in purulent conjunctivitis or corneal ulcer.
🚨 Complications if Untreated
- 🦠 Corneal ulceration → scarring → blindness.
- 🔄 Uveitis sequelae: synechiae, glaucoma, cataract.
- ⚡ Endophthalmitis → rapid, irreversible sight loss.
💊 Treatment by Condition
- 👁️ Bacterial conjunctivitis: Chloramphenicol drops, hygiene, avoid CL use. Treat high-risk groups.
- 🦠 Viral conjunctivitis: Supportive (lubricants, cold compress). Highly contagious → hygiene + avoid school/work.
- 🌼 Allergic conjunctivitis: Topical antihistamines/mast-cell stabilisers, cold compress, oral antihistamines if systemic.
- 🪙 Corneal abrasion: Lubricants + prophylactic topical abx. No patch if CL-related (risk of Pseudomonas).
- 🪛 Foreign body: Remove at slit-lamp, topical abx, evert lid, follow up if rust ring/central cornea.
- 🔥 Uveitis: Topical steroids + cycloplegics (only under ophthalmology). Screen for systemic cause (HLA-B27, sarcoid, IBD).
- 🚨 Acute angle-closure glaucoma: IV acetazolamide + topical β-blocker/pilocarpine. Urgent iridotomy.
- ⚡ Endophthalmitis: Emergency vitreous tap + intravitreal abx. Any post-op/post-injection red eye = same-day referral.
- 🌿 Blepharitis: Lid hygiene, warm compress, lubricants. Chronic course, linked with rosacea/seb derm.
- 💧 Dry eye: Lubricants, punctal plugs if severe. Exacerbated by age, antihistamines, SSRIs, screens.
💡 Teaching Pearls
- 📉 Visual acuity must always be checked first — even before slit-lamp.
- ⏱️ Time-critical: Angle-closure and endophthalmitis are true emergencies.
- 🧪 Fluorescein staining is invaluable in corneal disease.
- 🧠 Think systemic: Uveitis often linked with autoimmune disease.
- 🙅 Never patch a contact-lens abrasion → risk of Pseudomonas keratitis.
