Ophthalmology Β· SCA case

Red Eye

NICE CKS MGD/Conjunctivitis SCA-ready
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Red Eye · GP Clinical Reasoning Framework v2
GP & SCA · NICE CKS Red Eye · RCOphth Guidelines
24hMax wait for keratitis (same-day ophth)
IOP >21Raised intraocular pressure — glaucoma
20/60Visual acuity urgent referral threshold
15 minChemical injury irrigation duration
48hAciclovir window for HSV keratitis
1 weekMax conjunctivitis review if no improvement
6 metresStandard Snellen chart distance
2WWOcular melanoma / malignancy pathway
📋 Clinical Stem — Acute Red Eye Presentation
28-year-old contact lens wearer with 2-day history of right eye redness
Aisha presents with a 2-day history of red, sore right eye with watery discharge and a feeling that something is stuck in her eye. She has been wearing monthly contact lenses for 5 years and usually wears them 14–16 hours a day, sometimes overnight. She noticed her vision has been slightly blurry since yesterday. She has tried over-the-counter antihistamine drops with no improvement.
This stem adapts across diagnostic variants by changing the examination findings (discharge type, fluorescein staining, visual acuity) while keeping the presenting complaint (red eye, contact lens history) constant. The contact lens history is the critical contextual factor that shifts the differential dramatically β€” it dramatically increases keratitis risk and changes the management of any red eye in this setting.
Scenario A — Bacterial ConjunctivitisMucopurulent discharge, lids stuck in morning, VA 6/6 bilaterally, no corneal staining, mild diffuse conjunctival injection, no pain on movement, improving slightly with time
Scenario B — Viral ConjunctivitisWatery discharge, recent URTI, follicles on everted lid, bilateral (started contralateral 24h ago), preauricular lymphadenopathy, VA 6/6, no corneal staining, very contagious
Scenario C — Allergic ConjunctivitisIntense itching (bilateral), seasonal (spring/summer), pale boggy conjunctiva, cobblestone papillae on everted lid, associated rhinitis, VA 6/6, no staining, family history of atopy
Scenario D — Keratitis (Contact Lens-Associated)Severe pain, photophobia, reduced VA (6/12 or worse), corneal staining on fluorescein, white infiltrate visible, mucopurulent discharge, contact lens worn overnight, should not wear lenses
Scenario E — Anterior Uveitis / IritisDeep aching pain, photophobia, circumcorneal (ciliary) flush, irregular pupil or hypopyon, VA reduced, no discharge, onset 48h, prior episodes, associated IBD / AS / HLA-B27 positivity
Key differentiatorPain + photophobia + reduced VA = urgent / emergency. Discharge type: purulent = bacterial, watery = viral, no discharge + itch = allergic. Contact lens + pain + corneal staining = keratitis until proved otherwise.
Steps:
1
Step 1
History Taking — Open Question First · Targeted Questions · ICE · Contact Lens Screen
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Red eye is a diagnosis of exclusion. The history must rapidly discriminate between benign self-limiting causes (conjunctivitis) and sight-threatening emergencies (keratitis, AACG, uveitis). The most important historical discriminators are: pain severity, photophobia, visual change, and contact lens use. Any combination of pain + photophobia + reduced VA = treat as emergency until proved otherwise.
🎓 Consultation opener — use existing information first
"I can see you’ve come in with a sore, red eye that’s been troubling you for a couple of days. I’d love to hear what’s been going on in your own words first — can you describe what it’s been like?"
Contact lens history is in the notes — do not ask “do you wear contact lenses?” as your opening question. This wastes data-gathering time and loses Global Skills marks.
1A — Open question first, then targeted questions in order of clinical priority
Question to askWhy it matters clinicallyChanges what?
🟩 OPEN QUESTION — always start here"Can you describe the eye problem in your own words? What’s it been like?" Allows patient to describe the dominant symptom (pain vs itch vs discharge vs blur). Surfaces the hidden agenda (fear of blindness, career concern, cosmetic distress). Gives you diagnostic cues before directed questioning.SCA: scores Global Skills and begins Relating to Others domain DDxPsychosocial
Pain quality and severity"Would you describe it as a gritty feeling, or is it a deep aching pain inside the eye itself?" Gritty / foreign body sensation = conjunctivitis or corneal abrasion. Deep aching pain = uveitis, keratitis, AACG. Severe constant pain that is not improved by blinking = corneal involvement until proved otherwise.AACG: pain often described as severe, associated with nausea and vomiting, halos around lights DDx emergency vs benign999 if AACG
Visual change"Has your vision changed at all? Try covering the other eye — can you read the time on the clock across the room?" Any reduction in visual acuity (VA <6/6 in the affected eye) = urgent ophthalmology referral. VA 6/12 or worse = same-day referral. Normal VA in both eyes = conjunctivitis much more likely.Always test VA before instilling any drops — drops change the examination Urgent referral if VA reducedKeratitis / uveitis
Photophobia"Does the light bother your eye? Even a normal room — or is it the bright light that’s worse?" Photophobia = ciliary spasm = inflammation involving the uveal tract (uveitis) or cornea (keratitis). Conjunctivitis does NOT cause true photophobia. Any photophobia = treat as potentially sight-threatening.Distinguish: “I prefer the lights down” (mild, conjunctivitis) vs. “I cannot open my eye in any light” (uveitis / keratitis) Emergency referralUveitis / keratitis
Contact lens detail"Tell me more about how you wear your lenses — do you ever sleep in them or wear them longer than recommended?" Contact lens wear is the primary risk factor for Acanthamoeba and bacterial keratitis. Overnight wear increases keratitis risk 10-fold. Poor cleaning regimen (tap water rinse = Acanthamoeba) = high-risk. Any red eye in a CL wearer with pain = keratitis until proven otherwise.Contact lens wearers must be advised to stop lens wear immediately in any red eye Keratitis DDxStop lenses; urgent ophth
Discharge character"Has there been any discharge — what does it look like? Is it thick and yellow, or clear and watery?" Mucopurulent (yellow-green, sticky) = bacterial conjunctivitis. Watery / serous = viral conjunctivitis. No discharge + itching = allergic. No discharge + pain + photophobia = keratitis / uveitis (no discharge is typical of deeper pathology).Lids ‘stuck together’ in the morning = bacterial. Watery discharge after URTI = viral / adenoviral Bacterial vs viral vs allergicAntibiotic vs antihistamine
Itching"Is itching the main symptom? Is it in both eyes?" Bilateral itching = allergic conjunctivitis until proved otherwise (IgE-mediated mast cell degranulation). Itching without pain and without discharge = allergic. Itching that is unilateral and associated with discharge = consider combined bacterial + atopic.Also ask: seasonal pattern (spring/summer = SAC); perennial (house dust mite = PAC) Allergic DDxSodium cromoglicate / olopatadine
Laterality and onset"Is it one eye or both? Which eye came first? How quickly did it come on?" Unilateral = keratitis, AACG, uveitis, subconjunctival haemorrhage. Both eyes at same time = allergic. Contralateral spread after 24–48h = viral conjunctivitis (adenoviral). Sudden unilateral painless red “bloodshot” eye = subconjunctival haemorrhage.AACG: unilateral, sudden onset, very painful, associated nausea/vomiting, halos DDx laterality patternAACG unilateral acute
Halos around lights"Have you noticed haloes or rainbows around lights, especially at night?" Halos = corneal oedema = elevated intraocular pressure = AACG until proven otherwise. This is the classic symptom of acute angle closure — must not be missed. Associated with severe unilateral pain, vomiting, fixed dilated pupil, hard globe.Any patient describing halos + pain = check IOP immediately or admit as emergency 999 / Emergency ophthAACG DDx
Previous episodes"Have you had anything like this before? Has anyone in the family had similar eye problems?" Recurrent anterior uveitis = HLA-B27 association (ankylosing spondylitis, Reiter’s, IBD-related). Recurrent herpes simplex keratitis = typical (dendritic ulcer); aciclovir long-term prophylaxis after 2+ episodes. Previous AACG in fellow eye = urgent bilateral referral.FH of glaucoma = IOP check mandatory Uveitis / HSV keratitisAciclovir / systemic screen
Associated systemic symptoms"Any joint pain or stiffness? Bowel problems? Skin rashes? Recent cold or viral illness?" IBD + iritis = Crohn’s / UC. AS + iritis = HLA-B27. Recent URTI + bilateral watery conjunctivitis = adenoviral. Sarcoidosis = granulomatous uveitis. Reactive arthritis (Reiter’s) = urethritis + arthritis + conjunctivitis triad.Systemic link elevates urgency and guides referral pathway Rheumatology / GastroenterologyHLA-B27 / ESR / CRP
Chemical or foreign body exposure"Has anything got into your eye recently — a chemical splash, dust, or a small object?" Chemical injury (acid/alkali) = immediate copious irrigation × 15 min, then 999. Any retained foreign body on slit lamp = ophthalmology referral. Alkali burns penetrate deeper than acid — soak through to anterior chamber.Alkali burns (bleach, cement) are worse than acid burns — penetrate deeper Immediate irrigation + 999Ophth foreign body removal
Drug and topical treatment history"Have you used any drops or tried any treatment already? Are you on any regular eye drops?" Topical steroid use = risk of steroid-induced glaucoma, HSV reactivation, fungal infection. Antihistamine drops already tried = reduces allergic DDx. Previous antibiotic courses = risk of antibiotic resistance in bacterial conjunctivitis.Never prescribe topical steroids for a red eye without ophthalmology involvement — can cause catastrophic HSV dendritic ulcer expansion Adjust managementExclude steroid complication
Occupation and lifestyle impact"Does your job involve a lot of screen work or driving? How is this affecting your day-to-day?" Dry eye exacerbated by screen use (reduced blink rate). Healthcare worker + viral conjunctivitis = FOMITES risk: exclusion from patient contact until discharge resolves. Driver with reduced VA = DVLA duty if VA below standard.Contact lens wearer must stop lens use during treatment — this may significantly impact daily life and compliance Practical impactDry eye / screen hygiene
1B — Red flags: must not miss · must ask · must act
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Red Flags — Any one of these requires immediate action before continuing history

Red flagWhy dangerousAction
Severe unilateral pain + halos + vomiting + fixed dilated pupilAcute Angle Closure Glaucoma (AACG) — IOP can reach 60–80 mmHg; optic nerve damage occurs within hours. Irreversible blindness without emergency treatment.999 immediately
Chemical splash to eye (especially alkali: bleach, cement, ammonia)Alkali liquefies proteins and penetrates to anterior chamber within minutes. Permanent corneal scarring and blindness if not irrigated immediately for 15 min minimum.Irrigate 15 min now + 999
Contact lens wearer + pain + photophobia + reduced VAMicrobial keratitis (Pseudomonas, Acanthamoeba) — can cause corneal perforation within 24 hours without aggressive antibiotic treatment. Same-day ophthalmology essential.Same-day ophthalmology
Hypopyon visible (white fluid layer in anterior chamber)Endophthalmitis or severe uveitis — ophthalmic emergency. Vision loss can occur within 24–48 hours without intravitreal antibiotics.Emergency ophthalmology
Corneal opacity or white infiltrate visible to naked eyeBacterial or Acanthamoeba keratitis with established corneal infiltrate. Corneal scarring and perforation risk. Requires intensive topical antibiotics under ophthalmological supervision.Same-day ophthalmology
Post-operative red eye (within 6 weeks of intraocular surgery)Endophthalmitis — devastating infection of the vitreous cavity. Commonest after cataract surgery. Presents with severe pain, reduced VA, hypopyon. Emergency intravitreal antibiotics needed.Emergency ophthalmology
VA <6/12 in affected eye on Snellen testingAny unexplained visual loss = urgent referral threshold. Keratitis, uveitis, AACG all reduce VA. Visual loss not explained by simple conjunctivitis must be investigated immediately.Same-day ophthalmology
Penetrating eye injury or traumaOpen globe injury — do NOT apply pressure. Risk of vitreous prolapse, endophthalmitis, permanent blindness. Shield the eye and transfer immediately.999 — do not press
🛡️

Safeguarding Considerations — Red Eye in Context

Red eye can be a marker of harm. Periorbital or ocular injury in the context of domestic violence, non-accidental injury in children, or self-harm must be considered when the mechanism of injury does not fit the presentation. A contact lens wearer who presents with bilateral chemical injury or blunt trauma to both orbits warrants careful enquiry.
🏠 Domestic Violence — Periorbital Injury
  • Periorbital bruising, subconjunctival haemorrhage, or blunt ocular trauma with inconsistent or vague mechanism → safeguarding concern
  • Use DASH tool: "Does anyone make you feel frightened or unsafe at home?"
  • Document injuries photographically if possible. Follow MARAC pathway if DASH ≥14
  • Never promise confidentiality before the patient discloses
👴 Non-Accidental Injury in Children
  • Bilateral retinal haemorrhages in an infant = non-accidental injury (shaken baby syndrome) until proven otherwise
  • Ophthalmoscopy mandatory if NAI suspected — dilated fundoscopy by ophthalmologist
  • Any red eye in a child with unexplained bruising or delayed presentation → paediatric safeguarding referral
  • Do not discharge the child without a safeguarding plan if NAI suspected
👴 Self-Harm — Chemical or Foreign Body
  • Chemical injury to the eye can be a form of self-harm, particularly in patients with known mental illness or in crisis
  • Screen sensitively: mental health history, current stressors, PHQ-2
  • If self-harm suspected: refer to psychiatry / crisis team after ophthalmological treatment
  • Do not discharge without a safety plan and documented risk assessment
💊 Occupational Exposure & Work Safety
  • Chemical eye injury in the workplace may indicate inadequate PPE provision — this is a Health and Safety (RIDDOR) reportable incident
  • Advise patient of their employer’s duty to provide appropriate eye protection
  • Fit note may be required if reduced VA impairs ability to work safely
  • For healthcare workers with viral conjunctivitis: exclude from direct patient contact until discharge has resolved
If a safeguarding concern is identified: Record contemporaneously and specifically. Duty of confidentiality may be overridden where there is risk of serious harm. For children: refer immediately to paediatric safeguarding team. For adults: consult GP safeguarding lead; consider MARAC referral. Never promise confidentiality before you know what is about to be disclosed.
1C — PMH · Drug history · Social history: clinical impact
🧬 PMH / FH — changes management
FactorWhy it mattersManagement impact
Previous HSV keratitisRecurrent herpes simplex can cause progressive corneal scarring. 2+ episodes = prophylactic aciclovir consideration.Aciclovir 3% ointment 5× daily; topical steroid ONLY under ophthalmology guidance
Ankylosing spondylitis / IBD / Reactive arthritisHLA-B27 associated uveitis in up to 30% of AS patients. Can be recurrent and severe. Inflammatory bowel disease = granulomatous uveitis risk.Same-day ophthalmology; rheumatology or gastroenterology co-management; systemic immunosuppression may be needed
Atopy (asthma, eczema, hay fever)Vernal keratoconjunctivitis (VKC) in children; giant papillary conjunctivitis (GPC) in contact lens wearers; seasonal allergic conjunctivitis in adultsTopical antihistamine (olopatadine) + sodium cromoglicate; avoid rubbing
Glaucoma (self or FH)Raised IOP risk; topical steroids can precipitate steroid-induced glaucoma in susceptible individuals — never prescribe without ophthalmology involvementCheck IOP; ophthalmology review; never start topical steroids without specialist input
SarcoidosisGranulomatous uveitis is a recognised extra-pulmonary manifestation. Keratic precipitates on slit lamp — needs ophthalmology & respiratory medicineSystemic immunosuppression; ophthalmology for slit-lamp confirmation
RosaceaOcular rosacea causes chronic blepharitis, meibomian gland dysfunction, recurrent chalazion, and secondary keratitis. Commonest missed cause of chronic red eye.Long-term doxycycline; lid hygiene; artificial tears; dermatology co-management
Recent intraocular surgeryEndophthalmitis risk in post-operative period (peak: 1–5 days). Any pain or visual loss after cataract / vitreoretinal surgery = emergencyEmergency ophthalmology; intravitreal antibiotics without delay
Immunosuppression (HIV, transplant, chemotherapy)Opportunistic infections: CMV retinitis, Toxoplasmosis, fungal keratitis. Presentations can be atypical and severe.Lower threshold to refer; ophthalmology urgently; consider CMV / toxo serology
💊 Drug history · Social history
FactorWhy it mattersManagement impact
Topical steroids (current use)Steroid-induced IOP rise (steroid-response glaucoma) in ~30% after 4 weeks. Steroid use + HSV = catastrophic dendritic ulcer expansion. Never prescribe without slit-lamp diagnosis.Stop steroids; check IOP; ophthalmology review; NEVER prescribe topical steroids in primary care for undifferentiated red eye
Amiodarone / HydroxychloroquineCorneal microdeposits (amiodarone) visible on slit lamp; hydroxychloroquine causes maculopathy. Both require regular ophthalmological monitoring.Ophthalmology monitoring programme; dose adjustment with cardiology / rheumatology
Isotretinoin (Roaccutane)Causes dry eye and meibomian gland dysfunction — can trigger or worsen blepharitis and dry eye syndromeArtificial tears; lid hygiene; dermatology coordination; consider dose reduction
Anticoagulants (warfarin, DOACs)Subconjunctival haemorrhage is more likely and dramatic in appearance. The haemorrhage itself is benign but the patient may be alarmed by the blood-red eye appearance.Reassure: fully resolves in 2–3 weeks; check INR if on warfarin; no treatment needed
Swimming / water sportsTap water + contact lens = Acanthamoeba keratitis risk. Swimming pool exposure = adenoviral or Acanthamoeba risk. Contact lens wearers must never swim in lenses.Corneal scrapes for Acanthamoeba; same-day ophthalmology; intensive PHMB + propamidine treatment
Screen use / dry work environmentReduced blink rate with prolonged screen use causes aqueous tear deficiency and dry eye symptoms mimicking conjunctivitis — bilateral, gritty, worse eveningHypromellose 0.3% QDS; 20-20-20 rule; humidifier; optician review
Occupation: healthcare worker, nursery teacher, office workerHealthcare worker / nursery teacher with viral conjunctivitis = FOMITE risk — must be excluded from patient or child contact until discharge has resolvedSick note if viral conjunctivitis; strict hand hygiene; dedicated towels; advise when safe to return
DVLA — drivingVA <6/12 in better eye = cannot drive Group 1 vehicle. Severe red eye with reduced VA requires DVLA notification if the condition is expected to be prolonged or recurrent.Advise not to drive if VA impaired; DVLA notification for persistent visual impairment
1D — ICE: Ideas · Concerns · Expectations
💡 Ideas
"What do you think might be causing your eye to be like this? Have you had any thoughts about it?"
Patients often self-diagnose “conjunctivitis” and may resist further investigation. Those with contact lenses may know about the keratitis risk. Eliciting ideas avoids dismissing a genuinely informed patient and surfaces blind spots in their understanding.
😟 Concerns
"What worries you most about this? Are you concerned about your eyesight at all?"
Fear of blindness is very common with any eye symptom. Patients may also be concerned about: career impact (driving, screen use), cosmetic appearance, infection spreading to partner/children, or long-term contact lens ability. These concerns drive concordance with treatment.
🎯 Expectations
"What were you hoping we’d be able to do today? Were you hoping for antibiotic drops, or something else?"
Many patients with red eye expect antibiotic drops as a matter of course — even in viral or allergic conjunctivitis where antibiotics are not indicated. Managing the expectation before the plan prevents conflict and enables shared decision making.
🎓 SCA Checkpoint — Step 1TasksRelating to OthersGlobal Skills
Key phrases that score
"Because you wear contact lenses, I need to ask a few specific questions — the lenses change what might be going on with your eye."
"Has the light been bothering you at all — even normal room lighting?"
"Try covering your other eye for me — can you see clearly, or is it blurry?"
"I want to ask about your concerns — is there anything about this that worries you?"
Deductions (examiner flags)
  • Not asking about VA early in the history — VA is the single most important discriminator
  • Missing the contact lens detail — the key risk factor for keratitis
  • Not asking about photophobia — distinguishes conjunctivitis from keratitis / uveitis
  • Asking about information already in the stem (e.g. “do you wear contact lenses?”)
  • Not eliciting all three ICE components
🔴 Red — failing
No VA assessed · Photophobia not asked · Contact lens risk not explored · No ICE
🟠 Amber — borderline
Most questions asked but photophobia or VA missed · ICE partially explored
🟢 Green — passing
VA + photophobia + CL risk + red flags + ICE all covered · Data gathering by 7 min
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Step 2
Triage Engine — Emergency · Urgent · Routine
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Any pain + photophobia + reduced VA = urgent or emergency until proven otherwise. In a contact lens wearer with these symptoms, assume keratitis until ophthalmology review. Never prescribe topical steroids in primary care for undifferentiated red eye.
🔴 Emergency

999 / Same-Day Emergency Ophthalmology

Act within minutes
  • Acute Angle Closure Glaucoma: severe pain + halos + vomiting + fixed dilated pupilIOP 60–80 mmHg → irreversible optic nerve damage within hours → 999 immediately; pilocarpine 2% if available, IV acetazolamide at hospital
  • Chemical splash (especially alkali)Irrigate copiously with normal saline or water for 15 min minimum without delay; then 999 or blue-light transfer to ophthalmology / A&E
  • Penetrating eye injury / open globeDo NOT press or pad the eye — risk of vitreous prolapse; shield only; 999; nil by mouth in case of surgery
  • Hypopyon (white level in anterior chamber visible)Endophthalmitis / severe uveitis → intravitreal antibiotics without delay → emergency ophthalmology
  • Post-operative red eye within 6 weeks of intraocular surgeryEndophthalmitis → same-day emergency ophthalmology; intravitreal vancomycin + ceftazidime
🟠 Urgent

Same-Day Ophthalmology Referral

Within 24 hours
  • Contact lens wearer + pain + photophobia + reduced VAMicrobial keratitis → same-day ophthalmology; stop contact lenses immediately; no antibiotic drops until corneal scrapes taken
  • Anterior uveitis / iritis: circumcorneal flush, photophobia, irregular pupilSame-day ophthalmology; topical cyclopentolate + steroids under specialist guidance only
  • Corneal opacity or white infiltrate visible to naked eyeCorneal ulcer / keratitis with infiltrate → same-day ophthalmology; corneal scrapes before initiating antibiotics
  • VA <6/12 in affected eye not explained by refractive errorUrgent ophthalmology referral — any unexplained visual loss requires slit-lamp assessment
  • Herpes simplex keratitis (dendritic ulcer on fluorescein)Aciclovir 3% ointment 5× daily; urgent ophthalmology; NEVER topical steroids alone
🟢 Routine

Primary Care Management

GP / pharmacist
  • Bacterial conjunctivitis (mucopurulent discharge, VA normal, no pain, no photophobia)Chloramphenicol 0.5% drops QDS (or fusidic acid 1% gel BD); self-limiting in 7–14 days; hygiene measures; review if no improvement at 1 week
  • Viral conjunctivitis (watery discharge, recent URTI, bilateral, follicles)Self-limiting; cool compresses; hand hygiene; no antibiotics unless secondary infection; 2–3 weeks resolution; healthcare workers: exclude from work while symptomatic
  • Allergic conjunctivitis (itch, bilateral, seasonal, atopy, VA normal)Olopatadine 0.1% BD or sodium cromoglicate 2% QDS; oral antihistamine if rhinitis; allergen avoidance; cool compresses
  • Dry eye syndrome (bilateral, gritty, worse evening, screen use, VA normal)Hypromellose 0.3% QDS; 20-20-20 rule; optician review; preservative-free drops if frequent use
  • Subconjunctival haemorrhage (painless, unilateral, sharp red patch, VA normal)Reassure: fully resolves in 2–3 weeks; no treatment; check BP; check INR if anticoagulated
  • Blepharitis (lid margin inflammation, flaky debris, both eyes, chronic)Lid hygiene (warm compress + cotton bud cleaning) twice daily; long-term management; fusidic acid if infected; doxycycline if rosacea-associated
🎓 SCA Checkpoint — Step 2TasksGlobal Skills
Key phrases that score
"Because you wear contact lenses and you’ve noticed your vision is slightly blurry, I want to be cautious — I’m going to refer you to the eye hospital today to make sure there’s no problem with the surface of your eye."
"Please stop wearing your lenses right away — this is very important while we find out what’s going on."
Deductions (examiner flags)
  • Prescribing chloramphenicol drops to a CL wearer with pain + reduced VA without ophthalmology referral
  • Not advising cessation of contact lens wear immediately
  • Prescribing topical steroids for an undifferentiated red eye in primary care
  • Discharging without safety-netting the signs of worsening / AACG
🔴 Red
Topical steroids prescribed · CL wearer with pain discharged without referral · VA not checked
🟠 Amber
Correct triage but CL cessation not mentioned · Referral not explained in patient language
🟢 Green
Correct triage · CL cessation advised · Ophthalmology referral explained · Patient concern addressed
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Step 3
Do I Need This Examination?
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Examination of the red eye in primary care is targeted but systematic. Always test VA before any drops are instilled. The sequence is: VA → external inspection → lid eversion → fluorescein staining (if available) → IOP (if AACG suspected). Narrate findings as you examine.
ExaminationWhy it mattersWhat finding changes managementChanges management?
Visual acuity (Snellen chart) — each eye separatelyThe most important single examination. VA reduced → urgent referral regardless of cause. VA 6/6 bilaterally → conjunctivitis far more likely than sight-threatening pathology.Test before any drops; use pinhole to distinguish refractive from structuralVA <6/12 → same-day ophthalmology; VA 6/6 bilateral = conjunctivitis more likelyYES — urgent referral
Pupillary reactions (direct + consensual)Fixed dilated pupil = AACG. Irregular pupil = uveitis (posterior synechiae). Relative afferent pupillary defect (RAPD) = optic nerve involvement (retinal pathology, optic neuritis).RAPD: shine light in one eye, then other — the defective eye dilates when light shone in itFixed dilated + painful → 999 AACG; irregular → uveitis same-dayYES — emergency
Pattern of conjunctival injectionCircumcorneal (ciliary) flush = uveitis or keratitis. Diffuse conjunctival redness = conjunctivitis. Sector redness with scleral nodule = episcleritis / scleritis.Ciliary flush: ring of redness around corneal limbus, does NOT move with conjunctivaCiliary flush → urgent ophthalmology; diffuse → conjunctivitis pathwayYES
Corneal inspection (naked eye + pen torch)White infiltrate = microbial keratitis. Corneal haze = corneal oedema (AACG, severe keratitis). Branching dendritic pattern on fluorescein = HSV keratitis.Any corneal opacity in a CL wearer = same-day ophthalmology without exceptionAny corneal infiltrate or haze → same-day ophthalmologyYES — urgent
Lid eversion (tarsal plate examination)Follicles (lymphoid aggregates) = viral conjunctivitis. Papillae (vascular cores) = bacterial or allergic. Giant papillae = GPC (contact lens-related). Subtarsal foreign body → remove under magnification.Always evert both lids; subtarsal FB is easily missed and causes persistent abrasionFollicles → viral pathway; giant papillae → GPC / allergyYES
Fluorescein staining (if available)Staining pattern is diagnostic: dendritic ulcer = HSV; punctate epithelial erosions = dry eye / CL-related; single staining area = corneal abrasion; ring lesion = Acanthamoeba.Use blue cobalt light with Wood’s lamp or slit lamp; stain then examine within 60sPositive staining → ophthalmology referral; dendritic = HSV → aciclovir + urgent ophthYES
IOP assessment (if AACG suspected)IOP >21 mmHg = raised (normal 10–21). In AACG, IOP can reach 60–80 mmHg. Non-contact tonometry (air puff) available in some GP practices; otherwise ophthalmology required.Globe firmness on gentle palpation through closed lid (hard globe = high IOP) is a crude but useful signHigh IOP → emergency ophthalmology; pilocarpine 2% topically if available pending transferYES — emergency
Preauricular lymphadenopathyPalpable preauricular lymph node = hallmark of viral conjunctivitis (adenoviral). Also seen in HSV primary infection. Not seen in bacterial conjunctivitis or allergic disease.Can be small and tender; palpate below and in front of the tragus of the earPositive → viral pathway; no antibiotics needed; healthcare worker exclusionContext dependent
Blood pressure (if subconjunctival haemorrhage)Spontaneous subconjunctival haemorrhage in the absence of trauma may be the first presentation of hypertension, especially if recurrent. Also consider anticoagulant use.Always check BP in recurrent subconjunctival haemorrhage without clear causeHigh BP → hypertension management; recurrent SCH + normal BP → check clotting / INRContext dependent
🎓 SCA Checkpoint — Step 3TasksGlobal Skills
Key phrases that score
"I’m going to check your vision first in each eye separately — I always do this before anything else with an eye problem."
"I’m checking the pattern of the redness around your cornea — that’s the clear part at the front of your eye…"
Deductions (examiner flags)
  • Instilling drops before testing VA — drops alter the examination
  • Not examining both eyes (bilaterality is a key diagnostic sign)
  • Skipping pupillary reactions when AACG or uveitis is possible
🔴 Red
VA not tested · Findings not communicated · Drops instilled before VA
🟠 Amber
VA tested but not both eyes · Pupils not checked · Examination not narrated
🟢 Green
VA first (both eyes) · Pupils · Injection pattern · Lid eversion · Findings narrated
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Step 4
Do I Need This Investigation?
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Most red eye diagnoses in primary care are clinical. Investigations are reserved for: suspected systemic cause (uveitis with HLA-B27), microbiological confirmation (corneal scrapes in keratitis), or identifying underlying risk factors. Never take corneal scrapes in primary care — this is performed by ophthalmologists with slit-lamp guidance.
InvestigationClinical question it answersWhat result changes management?
Visual acuity (Snellen) — primary careSingle most important clinical measurement. Discriminates sight-threatening from benign. Documents baseline for medico-legal purposes.Always document both eyes separately including with glasses if wornVA <6/12 → same-day ophthalmology regardless of cause
Fluorescein staining — Wood’s lamp (primary care if available)Staining reveals epithelial defects not visible to naked eye. Dendritic pattern = HSV; punctate = dry eye / CL-related; single ulcer = bacterial keratitis.Most GP practices can perform this with a simple Wood’s lamp and fluorescein stripsPositive staining → ophthalmology referral; dendritic = HSV → aciclovir + urgent
Conjunctival swab for MC&SRarely needed for standard bacterial conjunctivitis — empirical antibiotic treatment is appropriate. Indicated in: neonatal conjunctivitis, gonorrhoea / chlamydia suspected (NAAT swab), treatment failure after 7 days.GC conjunctivitis: copious purulent discharge, very rapid onset, very painful → requires IM ceftriaxoneGC confirmed → IM ceftriaxone; Chlamydia → oral doxycycline 100mg BD × 3 weeks; treat partner
Corneal scrapes for MC&S, microscopy, culture (ophthalmology only)Performed by ophthalmologist under slit lamp. Identifies the organism in microbial keratitis: Pseudomonas aeruginosa (most common in CL wearers), Acanthamoeba, Fusarium, MRSA.Do NOT start antibiotics before scrapes in potential keratitis — masks the organismAcanthamoeba → PHMB + propamidine (intensive); Fungal → natamycin or voriconazole
HLA-B27 (serology)Positive in 90% of ankylosing spondylitis patients. Recurrent anterior uveitis in a young male = HLA-B27 positivity → screen for AS (sacroiliac X-ray / MRI, ESR, CRP).HLA-B27 positive + recurrent uveitis + back pain = refer rheumatology + gastroenterology (to exclude IBD)Positive → screen for AS / IBD / Reiter’s; rheumatology co-management; longer-term systemic immunosuppression if recurrent
ESR / CRP + FBCElevated inflammatory markers in: scleritis (associated with RA, Wegener’s, SLE), severe uveitis, orbital cellulitis. FBC: eosinophilia in atopic / parasitic eye disease.Orbital cellulitis: unilateral proptosis + restricted eye movement + fever → CT orbit + IV antibiotics urgentlyRaised CRP + proptosis + restricted movement → CT orbit + same-day referral; orbital cellulitis vs cavernous sinus thrombosis
Blood pressure measurementHypertensive retinopathy can present with visual symptoms. Spontaneous subconjunctival haemorrhage may indicate uncontrolled hypertension or anticoagulant over-dosage.Always check BP in recurrent SCH without clear causeElevated BP → start antihypertensive; recheck INR if anticoagulated
STI screen (chlamydia / gonorrhoea NAAT)Chlamydial conjunctivitis: chronic follicular conjunctivitis, mucopurulent discharge, age 18–35, no response to standard antibiotics. Gonorrhoeal conjunctivitis: copious hyper-purulent discharge, rapid onset, very contagious.Both require treatment of sexual partners — refer GUM clinic; notifiablePositive chlamydia → doxycycline 100mg BD × 3 weeks; contact tracing; GUM referral
Thyroid function testsThyroid eye disease (Graves’ ophthalmopathy): proptosis, lid lag, periorbital oedema, diplopia, restricted eye movements. Can cause severe exposure keratopathy if lids don’t close fully.Check if bilateral proptosis, lid retraction, or diplopia without other explanationHyperthyroidism confirmed → endocrinology + ophthalmology co-management; selenium supplementation in active TED
🎓 SCA Checkpoint — Step 4TasksGlobal Skills
Key phrases that score
"I want to check your vision in each eye separately first — that’s the most important test I can do for your eyes today."
"Because of your contact lenses and the blurring you’ve noticed, I think you need to be seen at the eye clinic today so they can look at the surface of your eye under a microscope."
Deductions (examiner flags)
  • Not testing VA before instilling any treatment drops
  • Taking corneal scrapes in primary care — this is an ophthalmological procedure
  • Starting antibiotics in a CL wearer before ophthalmology review (masks organism on scrapes)
🔴 Red
VA not assessed · Prescribing antibiotics to CL wearer with pain without referral
🟠 Amber
VA assessed but not both eyes · Investigations not explained to patient
🟢 Green
VA first (both eyes) · Fluorescein explained · Ophthalmology scrapes explained · Rationale shared
5
Step 5
Reaching a Diagnosis & DDx — Explained in Plain Language
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🗣️ Explaining the diagnosis in plain language (Scenario D — Keratitis)

"The redness and pain in your eye, combined with the slightly blurry vision, is concerning me because you wear contact lenses. There’s a specific type of infection called keratitis — that’s an infection of the clear surface at the front of your eye, the cornea. Contact lenses, especially when worn overnight, create the perfect conditions for this type of infection. I can’t fully assess this without the specialist equipment they have at the eye hospital, so I’m going to refer you to be seen there today. I know that sounds worrying — most people who are seen promptly do very well — but it is important we don’t delay. Please stop wearing your contact lenses right now and don’t put them back in until the specialist says it’s safe."

💬 Addressing the patient’s own explanation

"I thought it was just conjunctivitis — can’t I just have some antibiotic drops?"
"It might well turn out to be something mild — but the combination of the blurriness and the pain, especially given you wear contact lenses, means I can’t be sure without a specialist look. The problem with just giving drops without knowing what’s happening at the surface of your eye is that we could make things worse if it turns out to be a particular type of infection. I’d rather be cautious today and know you’re safe."

"Am I going to lose my sight?"
"I completely understand why that’s your first thought — the eye is precious and of course you’re worried. The good news is that most cases of contact lens keratitis, when they’re picked up early and treated promptly, do resolve well. By coming in today and acting quickly, you’re doing exactly the right thing. The specialist today will be able to tell you much more once they’ve examined your eye properly."

Differential diagnosis grouping — A (GP-manageable) · B (Refer) · C (Emergency)
A — GP-Manageable Conditions
Primary care diagnoses

Bacterial Conjunctivitis

Mucopurulent discharge · lid crusting in morning · VA 6/6 · no photophobia · self-limiting 7–14 days

Viral Conjunctivitis

Watery discharge · recent URTI · follicles on everted lid · preauricular node · bilateral spread · no antibiotics

Allergic Conjunctivitis

Bilateral itch · seasonal · atopy · pale boggy conjunctiva · VA 6/6 · antihistamine drops

Subconjunctival Haemorrhage

Painless · unilateral · sharp red sector · alarming but benign · VA 6/6 · resolves 2–3 weeks

Dry Eye Syndrome

Bilateral gritty · worse evening · screen use · VA 6/6 · artificial tears

Blepharitis

Lid margin inflammation · flaky debris · chronic · lid hygiene · rosacea-associated

B — Refer to Ophthalmology
Specialist assessment needed

Anterior Uveitis / Iritis

Circumcorneal flush · photophobia · irregular pupil · deep pain · reduced VA · HLA-B27 / IBD association

Keratitis (CL-associated)

Pain + photophobia + reduced VA + CL history · white infiltrate · same-day ophthalmology · corneal scrapes

HSV Keratitis

Dendritic ulcer on fluorescein · previous cold sores · reduced VA · aciclovir 3% ointment + urgent ophth

Scleritis

Severe deep boring pain · tender to touch · scleral nodule · associated RA / Wegener’s · urgent ophthalmology

C — Emergency / 999
Act immediately

Acute Angle Closure Glaucoma

Severe pain · halos · vomiting · fixed dilated pupil · hard globe · IOP >50 → 999

Endophthalmitis

Severe pain · hypopyon · reduced VA · post-op or post-injection → intravitreal antibiotics within hours

Chemical Injury

Alkali splash → irrigate 15 min immediately → 999 · do not delay for any reason

Orbital Cellulitis

Proptosis · restricted eye movement · fever · periorbital oedema → CT orbit + IV antibiotics → 999

📊 Diagnostic Classification — Red Eye Causes by Key Features
DiagnosisPain?Photophobia?VA reduced?Discharge?Management
Bacterial conjunctivitis🟠 Gritty🟢 No🟢 6/6🔴 MucopurulentChloramphenicol
Viral conjunctivitis🟢 Mild🟢 No🟢 6/6🟠 WaterySupportive only
Allergic conjunctivitis🟢 Itch only🟢 No🟢 6/6🟢 MinimalAntihistamine drops
Dry eye🟠 Gritty🟢 No🟢 6/6🟢 None / wateryArtificial tears
Keratitis (CL-related)🔴 Severe🔴 Yes🔴 Reduced🟠 MucopurulentSame-day ophth
Anterior uveitis🔴 Deep ache🔴 Yes🟠 Often reduced🟢 NoneSame-day ophth
AACG🔴 Severe🔴 Yes🔴 Yes + halos🟢 None999 now
Subconjunctival haemorrhage🟢 Painless🟢 No🟢 6/6🟢 NoneReassure; resolves
🎓 SCA Checkpoint — Step 5TasksRelating to Others
Key phrases that score
"The combination of the blurriness, pain and your contact lenses makes me think the surface of your eye may be affected — this is called keratitis."
"I know that sounds worrying — if we act on it today, most people do very well with treatment."
"Does that make sense? What questions do you have for me right now?"
Deductions (examiner flags)
  • Diagnosing “conjunctivitis” without considering keratitis in a CL wearer with pain and reduced VA
  • Not addressing the blindness concern explicitly
  • Providing a diagnosis without inviting questions or chunk-and-check
🔴 Red
Wrong diagnosis · Concern not addressed · No plain-language explanation
🟠 Amber
Correct diagnosis but in jargon · Fear of blindness not addressed
🟢 Green
Correct plain-language diagnosis · Blindness concern named and addressed · Questions invited
6
Step 6
If Referral Is Needed — What the GP Does Before & During
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Most conjunctivitis does not require referral. Any suspicion of keratitis, uveitis, scleritis, or angle closure = ophthalmology referral. The GP’s role is accurate triage and rapid, safe transfer with the right information. Never start treatment that could mask the diagnosis before the specialist has assessed.
Condition / ReferralUrgencyWhat GP does before referralWhat GP must NOT do
AACG — Emergency ophthalmology / 999EmergencyCheck IOP if available. Pilocarpine 2% topically if diagnosed. IV acetazolamide 500mg if available and able to give. Do not delay transfer for any further examination.Do not apply pressure to globe. Do not give IV fluids unnecessarily. Do not prescribe topical steroids.
Chemical injury — Immediate irrigationImmediate / 999Irrigate immediately with normal saline (or water) for minimum 15 minutes. Remove contact lenses first. Check pH after irrigation (target 7.0–7.4). Then 999 or emergency transfer.NEVER delay irrigation to find out the exact chemical. NEVER patch or pad the eye before irrigation.
Microbial keratitis (CL wearer + pain + reduced VA)Same-dayStop contact lens wear immediately. Document VA. Do not instil antibiotic drops before specialist assessment (masks scrape result). Refer with full history including CL wearing pattern.Do NOT start antibiotics before corneal scrapes are taken — this significantly reduces diagnostic yield. Do not reassure and discharge a CL wearer with pain and reduced VA.
Anterior uveitis / iritis (same-day ophthalmology)Same-dayDocument VA. Assess for systemic associations (HLA-B27 conditions: AS, IBD, Reiter’s). Do not start topical steroids without slit-lamp confirmation of diagnosis.Do not prescribe topical steroids without slit-lamp-confirmed diagnosis. Steroids in HSV uveitis without antiviral cover = catastrophic.
HSV keratitis (dendritic ulcer on fluorescein)Same-day / urgentAciclovir 3% ointment 5 times daily can be started immediately — within 48h window. Document VA. Refer urgently for slit-lamp confirmation. NEVER add topical steroids alone.Never prescribe topical steroids without antiviral cover in HSV keratitis — causes dendritic ulcer to expand dramatically. This is a well-recognised cause of iatrogenic blindness in primary care.
Neonatal conjunctivitis (ophthalmia neonatorum)Urgent / same-dayAny conjunctivitis in a neonate <28 days = urgent referral. Swab for GC, Chlamydia (NAAT). Gonococcal: IM/IV ceftriaxone urgently. Notify Public Health England.Never delay referral in neonatal conjunctivitis. GC can penetrate the intact cornea of neonates within hours. Chlamydial infection requires systemic erythromycin (prevents pneumonitis).
Recurrent uveitis / systemic workupRoutine + ophthalmologyCheck HLA-B27, ESR/CRP, ANA. Review for systemic disease (AS: sacroiliac pain; IBD: bowel symptoms; Reiter’s: urethritis + arthritis). Refer rheumatology + gastroenterology as appropriate.Do not treat recurrent uveitis as isolated without systemic screen. Missing AS or IBD represents a significant missed diagnosis opportunity.
Contact lens advice — optometrist follow-upRoutineAfter ophthalmology discharge: review CL hygiene regimen. Consider daily disposables instead of monthly. Advise: never sleep in lenses; never rinse in tap water; replace case monthly.Do not clear patient to return to contact lens use without ophthalmology sign-off. Do not underestimate the risk of recurrent keratitis with poor CL hygiene.
🎓 SCA Checkpoint — Step 6TasksRelating to Others
Key phrases that score
"I’m going to refer you to the eye hospital to be seen today — not because I think it’s definitely serious, but because with contact lenses and blurred vision, I want the specialists to check with their equipment."
"Please don’t put your contact lenses back in today or until the specialist tells you it’s safe."
Deductions (examiner flags)
  • Prescribing topical steroids for suspected HSV or undifferentiated keratitis
  • Starting antibiotic drops in a CL wearer before ophthalmology scrapes
  • Not advising cessation of CL wear as part of the referral safety advice
🔴 Red
Topical steroids prescribed · Antibiotics before scrapes · CL cessation not mentioned
🟠 Amber
Referral correct but not explained · CL cessation mentioned but not emphasised
🟢 Green
Referral explained in plain language · CL cessation emphasised · Safety-netting given · Concern addressed
7
Step 7
Management — Expectation · Goals · Eye Hygiene · Drug Selector · Drug Cards · Psychosocial · Follow-Up · Safety-Netting
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7A — Address the patient’s expectation first
🤝
Manage the expectation of antibiotic drops — the commonest request in red eye consultations
1
Validate — name the expectation

Most patients with a red eye expect antibiotic drops as a matter of course. This expectation is so embedded it is rarely even verbalised — which is why you must name it before the plan.

"You’ve probably come in expecting antibiotic eye drops, which I completely understand — most people do with a red eye."
2
Explain — share your clinical reasoning

Explain why antibiotics are or are not the right answer in this specific case. Patients respond to the reasoning, not the refusal.

"In your case, because of the blurriness and your contact lenses, I actually need the specialists to look at your eye first — starting drops now could make it harder for them to identify what’s causing this."
3
Negotiate — offer something today

Even if antibiotic drops are not appropriate, there is always something you can offer: a clear plan, a referral, advice on hygiene and comfort measures.

"What I can do today is get you seen at the eye clinic this afternoon. I’ll also give you some advice on what you can do in the meantime to keep comfortable."
7B — Treatment goals tailored to this patient
Treatment Goals
✓ Eliminate causative organism (keratitis) ✓ Preserve corneal clarity and visual acuity ✓ Reduce inflammation (uveitis) ✓ Control IOP if raised (AACG) ✓ Alleviate symptoms (discharge, itch, discomfort) ✓ Prevent contralateral spread (viral/bacterial) ✓ Return to contact lens wear safely (if appropriate) ✓ Identify and treat underlying systemic cause (uveitis)
Motivational language — tailored to a contact lens wearer
"Getting this sorted properly now means you’re much more likely to be able to wear your lenses again in the future — cutting corners now risks the cornea scarring."
"I know stopping lenses is inconvenient — but it’s the most important thing you can do for your eye right now, and it’s temporary."
7C — Non-medication management: eye hygiene and safety behaviours
🗂️
Contact Lens Cessation
Stop immediately · do not resume without ophth clearance
Mechanism

Contact lenses create a hypoxic microenvironment, reduce corneal epithelial integrity, and act as a vector for bacterial adherence (Pseudomonas has high affinity for CL material). Overnight wear further reduces oxygen delivery to an already compromised cornea.

Practical

Stop lenses today. Discard current lenses and case. Do not resume wearing until ophthalmology explicitly clears you. Switch to daily disposables after recovery. Never sleep in lenses. Never rinse case with tap water (Acanthamoeba risk).

Most important single intervention in CL-associated keratitis
🥥
Hand Hygiene (Viral / Bacterial)
Wash hands before and after touching eye
Mechanism

Adenoviral conjunctivitis is highly contagious (fomite transmission on shared towels, pillow cases, hands). Can survive on surfaces for up to 49 days. Secondary spread to household contacts and through healthcare settings is common.

Practical

Dedicated personal towel. Do not share eye makeup. Avoid rubbing the eye. Healthcare workers and nursery staff must be excluded from work while symptomatic with viral conjunctivitis.

Prevents spread to partner, children and colleagues
❄️
Cool Compresses
Cool damp cloth for 10 min, QDS
Mechanism

Vasoconstriction reduces hyperaemia and reduces mast cell degranulation in allergic conjunctivitis. Reduces lid oedema and provides symptomatic relief in viral conjunctivitis. Lubrication helps remove discharge in bacterial conjunctivitis.

Practical

Use a clean, cool, damp flannel held gently over closed eyelids for 10 minutes, 4 times a day. For allergic: refrigerated artificial tears applied QDS also reduce itch. Do not use hot compresses unless blepharitis (opposite effect in conjunctivitis).

Safe for all types; reduces itch and hyperaemia
👁
Avoid Rubbing
No eye rubbing — especially in keratoconus / allergy
Mechanism

Eye rubbing in allergic conjunctivitis causes mechanical mast cell degranulation, amplifying the allergic response. In keratoconus or post-LASIK corneas, rubbing causes progressive corneal ectasia. In keratitis, rubbing spreads the organism and worsens epithelial damage.

Practical

Teach patient to use cool compress instead of rubbing. Antihistamine drops reduce itch (trigger for rubbing). In children: consider nighttime cotton mittens. Alert any allergy patient about keratoconus risk from chronic rubbing.

Prevents worsening; reduces allergy amplification
💖
Lid Hygiene (Blepharitis)
Warm compress + cotton bud cleaning twice daily
Mechanism

Blepharitis is caused by Staphylococcal colonisation of the lid margin and meibomian gland dysfunction. Warm compresses liquefy the inspissated meibomian secretions. Lid scrubs remove the colonising organisms and keratin debris.

Practical

Warm compress (warm flannel) over closed eyelids for 2 minutes. Then gently scrub the lid margin with cotton bud dipped in diluted baby shampoo (1:10 in boiled cooled water) or proprietary lid wipes (Blephasol). Twice daily long-term.

Cornerstone of blepharitis management; reduces recurrence
💻
Screen Hygiene (Dry Eye)
20-20-20 rule · blink consciously
Mechanism

Prolonged screen use reduces blink rate from ~15/min to ~5/min, reducing tear film replenishment. This causes aqueous tear deficiency and evaporative dry eye, both of which cause red, gritty, uncomfortable eyes that mimic conjunctivitis.

Practical

20-20-20 rule: every 20 minutes, look at something 20 feet away for 20 seconds. Position screen below eye level (reduces palpebral fissure width = less evaporation). Use preservative-free artificial tears QDS if symptoms frequent.

Addresses root cause of screen-related dry eye
7D — Prescribing principles: what to start and what never to prescribe
Bacterial conjunctivitis: topical antibiotic
  • First-line: Chloramphenicol 0.5% drops — QDS for 5–7 days; or 1% ointment at night
  • Alternative: Fusidic acid 1% gel BD (better tolerance; used especially in pregnancy)
  • Self-limiting in 7–14 days — antibiotics shorten course by 1–2 days only (NNT high)
  • Do NOT prescribe for viral or allergic conjunctivitis — antibiotic stewardship
Avoid in neonates (chloramphenicol is licensed from 0 days but use with caution). Consider allergy.
Allergic conjunctivitis: mast cell stabilisers + antihistamines
  • Olopatadine 0.1% drops — BD; dual action: antihistamine + mast cell stabiliser; faster onset
  • Sodium cromoglicate 2% drops — QDS; mast cell stabiliser; takes 2–4 weeks for full effect; better for long-term prevention
  • Add oral antihistamine (cetirizine or loratadine) if rhinitis coexists
  • Avoid allergen; cool compresses; no rubbing; refrigerate drops for extra relief
Cromoglicate: start 2 weeks before expected pollen season for prevention.
⚠ Never prescribe without ophthalmology input
  • Topical steroids (dexamethasone, prednisolone) in primary care — risk of: steroid glaucoma, herpes simplex dendritic ulcer expansion, fungal keratitis, cataract. Never prescribe for undifferentiated red eye.
  • Combined antibiotic + steroid drops (e.g. Maxitrol) — equally dangerous without a confirmed bacterial + inflammatory diagnosis
  • Oral steroids for ocular disease — only under specialist guidance
Prescribing topical steroids in primary care for undifferentiated red eye is a recognised cause of iatrogenic blindness in the UK.
HSV keratitis: antiviral treatment
  • Aciclovir 3% ophthalmic ointment — 5 times daily for 7–10 days (licensed indication); within 48h window
  • Urgent ophthalmology referral required alongside — slit-lamp confirmation of dendritic pattern
  • After 2+ episodes: prophylactic oral aciclovir 400mg BD may be considered (ophthalmology decision)
  • NEVER add topical steroids without concurrent antiviral and ophthalmology cover
Dry eye & lubricants
  • Hypromellose 0.3% (HPMC) — artificial tear; QDS or more frequently; suitable for frequent use
  • Preservative-free formulations preferred if using >4 times/day (e.g. Minims or unit-dose preservative-free)
  • Carbomer 0.2% gel (Viscotears) — longer-lasting; useful at night
  • For blepharitis + dry eye: lid hygiene + lubricant; consider omega-3 supplements (modest evidence)
7E — Medication selection tool — select confirmed diagnosis

Select confirmed diagnosis — drug card highlighted below ↓

Prescribing guidance
Select confirmed diagnosis above to highlight the relevant drug card and see prescribing guidance
7F — Drug reference cards
Chloramphenicol
0.5% eye drops · 1% eye ointment · topical antibiotic
✓ Recommended
1st Line Bacterial0.5% drops QDS
✓ Prefer when
Bacterial conjunctivitis: mucopurulent discharge, lid crusting, VA 6/6, no photophobia
Confirmed bacterial aetiology — do not prescribe for viral or allergic conjunctivitis
Available OTC — most pharmacists can supply under PGDS (Patient Group Direction)
⚠ Administration tips
Drops: 1 drop QDS for 5–7 days; apply to lower conjunctival sac
Ointment: 1% at bedtime (can blur vision temporarily — warn patient)
Store drops in fridge after opening; discard after 28 days
Wash hands before and after application; do not share drops
✗ Avoid
Contact lens keratitis with reduced VA — start only after ophthalmology corneal scrapes
Chloramphenicol allergy (rare) — use fusidic acid instead
Aplastic anaemia risk is very rare with topical use but documented — advise to report unusual bruising or bleeding
💬 Counselling

"These drops will help clear up the infection. Put one drop in your lower eyelid four times a day for 5 to 7 days, wash your hands before and after, and don’t share them with anyone. Your eye should start to improve within 2–3 days — if it doesn’t, come back."

SCA: Warn about viral conjunctivitis resistance — antibiotics are not needed and will not help if the cause is viral. If prescribing, explain the rationale. Healthcare workers with bacterial conjunctivitis must still follow exclusion guidance.

Sodium Cromoglicate
2% eye drops · mast cell stabiliser
✓ Recommended
Allergic Conjunctivitis1–2 drops QDS
✓ Prefer when
Seasonal or perennial allergic conjunctivitis: bilateral itch, seasonal pattern, normal VA
Prophylaxis: start 2 weeks before anticipated allergen exposure (hay fever season)
Can be used in children ≥5 years; safe in pregnancy (category B)
⚠ Counselling essentials
Takes 2–4 weeks for full preventive effect — must counsel patient about delayed onset
Needs to be used regularly QDS for maximum benefit; not PRN
May sting briefly on instillation — normal; warn patient
✗ Cautions
Less suitable for acute itch (use olopatadine for faster relief)
Remove soft contact lenses before instillation; wait 15 min before replacing
💬 Counselling

"These drops prevent the allergic reaction rather than just treating it. They do take a couple of weeks to build up to full effect, so it’s important to use them regularly even when your symptoms are mild. Take your lenses out before using them."

SCA: The delayed onset is a key counselling point — patients who stop because they don’t feel immediate relief will not benefit. This scores counselling and adherence marks.

Olopatadine
0.1% eye drops · dual-action antihistamine + mast cell stabiliser
✓ Recommended
Allergic Conjunctivitis1 drop BD
✓ Prefer when
Allergic conjunctivitis needing rapid symptom relief (faster onset than cromoglicate)
Dual mechanism: H1-antihistamine + mast cell stabiliser in a single agent
Particularly useful for seasonal allergic conjunctivitis (SAC) with acute itch
⚠ Administration tips
1 drop BD (morning and evening); can be used up to 6 weeks continuously
Remove contact lenses before instillation; wait 15 min before replacing
Refrigerated drops feel more soothing (cooling reduces histamine-mediated itch)
✗ Cautions
Not recommended in children under 3 years (0.1% formulation)
Not suitable for keratitis or any red eye with reduced VA or photophobia
💬 Counselling

"These drops work in two ways — they block the allergic reaction and prevent it from starting. Take your contact lenses out first, put one drop in each eye morning and evening, and wait 15 minutes before putting your lenses back in. Keeping them in the fridge can help with the itching."

SCA: Distinguishing cromoglicate (preventive, delayed onset) from olopatadine (faster acting, dual mechanism) demonstrates clinical depth and scores prescribing knowledge marks.

Aciclovir 3%
3% ophthalmic ointment · antiviral
✓ Recommended
HSV Keratitis5 times daily
✓ Prefer when
Herpes simplex keratitis confirmed or strongly suspected: dendritic ulcer on fluorescein staining
Within 48-hour treatment window for maximum efficacy
After ophthalmological confirmation (ideally start alongside referral)
⚠ Dosing schedule
1 cm ribbon of ointment to lower conjunctival sac, 5 times daily (every 4 hours while awake)
Continue for 3 days after healing of ulcer (usually 7–10 days total)
Prophylaxis after 2+ episodes: oral aciclovir 400mg BD — ophthalmology decision
✗ Critical cautions
NEVER combine with topical corticosteroids without specialist ophthalmology supervision — steroids alone cause catastrophic HSV reactivation
May cause mild stinging and temporary blurred vision on application — warn patient
💬 Counselling

"This ointment treats the virus causing the problem on the surface of your eye. You need to apply it 5 times a day — I know that’s quite frequent. It will blur your vision for a few minutes after each application, which is normal. Keep going for the full course even if your eye feels better."

SCA: The “never topical steroids without antivirals in HSV” rule is a high-yield safety knowledge point. If asked about steroids, the answer is unambiguous: not in primary care, not without ophthalmology, never without antiviral cover in HSV.

Hypromellose
0.3% eye drops · artificial tear lubricant
✓ Recommended
Dry Eye1–2 drops QDS
✓ Prefer when
Dry eye syndrome: bilateral gritty, worse evening, screen use, reduced blink rate
Symptomatic relief in viral conjunctivitis (supportive treatment)
Safe in pregnancy, breastfeeding, and for long-term use
⚠ Formulation tips
Single-dose unit (Minims) or preserved bottle; use preservative-free if >4 times/day or CL wearer
Carbomer gel (Viscotears): longer-lasting; better for nighttime use; may blur vision briefly
Warm compresses + lid hygiene if meibomian gland dysfunction contributing
✗ Cautions
Preserved formulations can worsen dry eye with very frequent use — switch to preservative-free if using >QDS
Not a treatment for bacterial or allergic conjunctivitis — address underlying cause
💬 Counselling

"These are artificial tear drops — they top up your natural tears and relieve the dryness and grittiness. There’s no limit on how often you can use them. Try the 20-20-20 rule for screen work: every 20 minutes, look 20 feet away for 20 seconds — that helps your eyes rest and blink more."

SCA: Linking dry eye to the patient’s screen use and explaining the mechanism (reduced blink rate) demonstrates clinical depth. Recommending preservative-free drops if using frequently shows prescribing safety awareness.

Fusidic Acid
1% eye gel · topical antibiotic
✓ Recommended
Bacterial / Blepharitis1 drop BD
✓ Prefer when
Bacterial conjunctivitis as alternative to chloramphenicol (BD dosing improves adherence)
Staphylococcal blepharitis with infected lid margins — applied to lid margin BD
Preferred in pregnancy (category B) and in children <2 years (chloramphenicol safety data less robust)
⚠ Administration tips
1 application BD (twice daily) — better adherence than QDS chloramphenicol
Gel formulation stays in contact with the eye longer — fewer applications needed
Can be applied to lid margin in blepharitis — gently massage in along lid edge
✗ Cautions
Fusidic acid has narrow spectrum (primarily Gram-positive); less effective against Gram-negative organisms
Not suitable for contact lens keratitis with reduced VA — ophthalmology assessment required first
💬 Counselling

"This antibiotic gel treats the bacterial infection in your eye. It’s only twice a day, which is easier to remember. Apply it to your lower eyelid morning and evening, wash your hands before and after, and finish the whole course."

SCA: Being able to offer fusidic acid as an alternative to chloramphenicol (and knowing when to prefer it, e.g. pregnancy, children, BD for adherence) demonstrates prescribing knowledge depth and scores Tasks domain marks.

7G — Psychosocial impact: work, driving, contact lens identity & daily life
🤚
Living with a Significant Red Eye — Impact on Work, Identity and Daily Function
A red eye that requires cessation of contact lenses, time off work, or ophthalmology review has a significant practical impact that is rarely discussed in clinical consultations. For a young professional, being told to stop wearing lenses for weeks can feel devastating. Address this proactively.
💼
Work & Occupation

Viral conjunctivitis is highly contagious via fomite transmission. Healthcare workers, nursery teachers, and food handlers must be excluded from direct patient, child or food contact until discharge has fully resolved.

For office / screen workers: reduced VA + photophobia impairs computer work. Phased return or temporary adjustments may be needed. Occupational health referral if significant impact on function.

"Does your work involve contact with patients or children? While you have this, I’d advise you not to go in — I can give you a sick note for today."
🚘
Driving & DVLA

VA <6/12 in the better eye — cannot legally drive a Group 1 vehicle in the UK. If the unaffected eye meets the standard, short-term driving may continue but advise caution with depth perception from monocular effects.

For commercial vehicle drivers (HGV, LGV): stricter VA requirements. Any significant or prolonged visual impairment may require DVLA notification if bilateral or persistent.

"If your vision feels blurry, please don’t drive today — it’s not safe and could be an offence if your vision doesn’t meet the driving standard."
🗂️
Contact Lens Identity & Loss

For many young people, contact lens use is integral to daily life and identity (sport, appearance, social confidence, freedom from glasses). Being told to stop wearing lenses — potentially long-term — can provoke genuine anxiety and distress.

Acknowledge this explicitly. Reassure that most people can resume lenses safely after full recovery. Recommend daily disposables and a better wearing schedule. Optometrist review on discharge.

"I know stopping your lenses is a big deal — it affects so much of your daily life. The goal is to get your eye right so you can wear them again safely in the future."
👨‍👩‍👦
Spread to Family Members

Viral conjunctivitis is highly contagious. Partners, children and household members are at risk. Patients who do not receive clear prevention advice frequently cause secondary cases within the family within 48 hours.

Advise: separate towels, pillow cases, washcloths. No sharing eye makeup. Avoid touching the eye then touching surfaces. The adenovirus can survive on surfaces for weeks.

"To protect your family, please use a dedicated towel just for your face and don’t share anything that touches your eyes. Wash your hands very carefully whenever you touch your eye."
📸
Cosmesis & Appearance

A severely red or bloodshot eye — especially a subconjunctival haemorrhage — can be cosmetically alarming and cause significant social anxiety, embarrassment and concern. Patients may present primarily because of how the eye looks rather than any symptom.

Subconjunctival haemorrhage: explicitly reassure it is benign and will fully resolve. Bacterial conjunctivitis: reassure that discharge resolves within days on treatment.

"I understand it looks quite alarming — people tend to stare! But I can reassure you it’s completely harmless and will clear up on its own over about 2 to 3 weeks."
👀
Fear of Blindness

Eye symptoms — even mild ones — generate disproportionate fear of blindness. This is rational (the eye is precious and irreplaceable) but often goes unvoiced. Patients with keratitis or uveitis may be terrified but not say so.

Name the fear directly. Provide proportionate reassurance that includes the caveat: the key is acting promptly. Late presentation carries more risk than early presentation.

"I can see this is very worrying — and it’s completely understandable to be scared about your eyesight. The most important thing is that you’ve come in today. Most people who act quickly do very well."
7H — Follow-up schedule
1
48 hours — Treatment response check (bacterial conjunctivitis)

Phone or F2F: is the discharge reducing? VA still 6/6? Any new photophobia or pain (would suggest keratitis / uveitis developing)? If no improvement in 48h or worsening: immediate ophthalmology referral.

Bacterial conjunctivitis on antibioticsWorsening → ophthalmology same-day
2
1 week — Review if not resolved (all conjunctivitis)

Bacterial conjunctivitis should resolve within 7–14 days. Viral takes up to 3 weeks. If not resolving by 1 week: review diagnosis; consider chronic aetiology (blepharitis, dry eye, chlamydial, trachoma). Re-examine, check VA, evert lids.

All types of conjunctivitisNon-resolution → reassess DDx
3
Ophthalmology follow-up — as directed by specialist

For keratitis: daily review initially (to check corneal healing); then weekly. For uveitis: follow-up within ophthalmology for slit-lamp IOP monitoring and steroid tapering. GP’s role: manage systemic comorbidities, medication monitoring.

Keratitis: daily initiallyUveitis: ophthalmology-led
4
Optometrist review — 4–6 weeks post-resolution (CL wearers)

Contact lens wearers should not resume lenses until ophthalmology-cleared and seen by optometrist. Review lens type (switch to daily disposables), wearing schedule (reduce to max 12h/day), lens care regimen, and corneal topography if keratitis caused significant scarring.

CL wearers post-keratitisDaily disposables recommended
5
Systemic follow-up — for uveitis with HLA-B27 associations

Refer to rheumatology if HLA-B27 positive (screen for AS, Reiter’s). Refer to gastroenterology if IBD symptoms. Annual ophthalmology review for patients with recurrent uveitis on systemic immunosuppression (methotrexate, azathioprine — LFT/FBC monitoring).

Recurrent uveitisHLA-B27 workup
7I — Monitoring: the VISION mnemonic + targets

Memory rule — VISION monitoring framework

V — Visual acuity: document at each visit; target return to baseline
I — Infection response: is the discharge reducing? Is the cornea clearing on fluorescein?
S — Systemic disease: is uveitis linked to AS, IBD, Reiter’s? HLA-B27 result?
I — IOP (intraocular pressure): target <21 mmHg; recheck if on topical steroids (risk of steroid glaucoma)
O — Ophthalmology review: is follow-up secured? Date confirmed?
N — Non-pharmacological: CL cessation maintained? Lid hygiene? Fomite precautions in place?

Drug class / ConditionMonitoringTimingAction threshold
Bacterial conjunctivitis (chloramphenicol)Symptom review48h call; 1 week if neededNo improvement at 48h or worsening → same-day ophthalmology
HSV keratitis (aciclovir ointment)VA + fluorescein (ophthalmology)Daily initially; then weeklyCorneal ulcer not healing → intensify treatment; consider drug resistance
Uveitis (topical steroids — ophthalmology)VA + IOP + anterior chamber (ophthalmology)Weekly until controlledIOP rising >21 on steroids → add IOP-lowering agent; consider steroid-sparing
Systemic immunosuppression (uveitis)FBC + LFTs (methotrexate / azathioprine)Every 3 monthsLFT elevation / cytopenia → dose reduction; rheumatology / ophthalmology review
Allergic conjunctivitis (olopatadine/cromoglicate)Symptom score4–6 weeksOngoing severe symptoms → step up; add oral antihistamine; allergy referral
ScenarioTargetAction if not met
Bacterial conjunctivitis not clearing at 7 daysDischarge resolved; VA 6/6Reassess — swab if not done; consider chlamydial / STI screen; ophthalmology if cornea involved
VA not returned to baseline post-keratitisVA ≥6/6 (or pre-morbid baseline)Ophthalmology review for corneal scarring; consider corneal topography; contact lens resume deferred
IOP >21 on topical steroidsIOP <21 mmHgAdd topical beta-blocker (e.g. timolol) under ophthalmology; consider steroid formulation change
Recurrent uveitis despite treatmentUveitis-free intervals >6 monthsSystemic immunosuppression (methotrexate / mycophenolate) under ophthalmology / rheumatology
CL wearer with repeated keratitis episodesZero repeat episodesSwitch to daily disposables; strict no-overnight-wear education; consider extended break from lenses; corneal specialist review
7J — Safety-netting: exact phrases + medico-legal rationale

⚠ Three scenario-specific safety-netting phrases

🔴 Emergency — call 999 / go to A&E now
"If you develop severe pain in your eye, see halos or rainbows around lights, feel sick or start vomiting with the pain, or your pupil looks different (bigger or not reacting to light) — call 999 or go to A&E immediately. These could be signs of a serious pressure problem inside your eye that needs emergency treatment."
Covers AACG with the classic symptom triad (halos + severe pain + vomiting). Fixed dilated pupil and hard globe are examination findings but naming the symptoms empowers the patient to act. Medico-legally: documents that emergency symptoms were communicated.
🟠 Worsening — contact same-day / emergency ophthalmology
"If your vision gets blurrier, the pain gets significantly worse, or you become very sensitive to light at any point — please don’t wait for your appointment. Call us or go to the eye hospital directly that day. These are signs the infection may have spread to the cornea, and that needs urgent treatment."
Covers keratitis developing in a patient initially managed for conjunctivitis. Names specific symptoms (blurring, worsening pain, photophobia). Empowers patient to escalate without waiting. Medico-legally critical for contact lens wearers managed in primary care.
🟢 Non-response — return in 48h / 1 week
"I’d expect to see some improvement within 48 hours on these drops — less discharge, less redness. If things haven’t started to improve by then, please book in again rather than waiting the full week. And if it’s not completely better within a week, come back so I can check the diagnosis."
Sets explicit treatment response criteria and timeframes. Prevents patients continuing ineffective treatment indefinitely. Medico-legally: documents that follow-up was explicitly agreed and timeframe given.
48 HoursTreatment response check (bacterial conjunctivitis) · worsening → same-day ophth
1 WeekFull review if not improving · reassess diagnosis · consider STI screen
ImmediatelyHalos + severe pain + vomiting → 999 (AACG) · Blurring + photophobia worsening → ophthalmology same-day
🎓 SCA Checkpoint — Step 7 (Final)TasksRelating to OthersGlobal Skills
Closing the consultation
"I’m going to refer you to the eye hospital today — the blurriness and pain in the context of wearing lenses means I want the specialists to look at your cornea carefully."
"Please stop wearing your contact lenses right now and don’t put them back in until you’ve been seen and cleared. I know that’s inconvenient — but it’s the most important thing you can do for your eye."
"If you develop severe pain, see halos around lights, or feel sick with the eye pain — please call 999. That would be a different and more serious problem."
"How does that plan sound? Is there anything you’re worried about that we haven’t covered?"
"Is there anything else you wanted to cover today?"
Deductions — closing
  • Prescribing topical steroids for undifferentiated red eye — unacceptable in primary care
  • Starting antibiotic drops in a CL wearer with pain before ophthalmology scrapes
  • Not advising contact lens cessation — critical patient safety intervention
  • AACG symptoms not covered in safety-netting (halos + severe pain + vomiting)
  • Not acknowledging the blindness concern — must be named and addressed
  • No explicit follow-up timeframe offered
Tasks domain — full criteria
  • VA tested before any drops instilled
  • Red flags elicited and acted upon appropriately
  • Correct triage: CL wearer + pain + reduced VA = same-day ophthalmology
  • Contact lens cessation explicitly advised
  • Safety-netting: AACG symptoms + keratitis worsening named specifically
Relating to Others — full criteria
  • Blindness concern named and directly addressed
  • ICE explored and referenced in the management plan
  • CL cessation impact acknowledged empathetically
  • Antibiotic expectation addressed without dismissing
  • Plain English throughout; shared decision making
  • Closing question asked: “Is there anything else?”
🔴 Red — failing
Topical steroids prescribed · CL not stopped · AACG not safety-netted · Blindness concern ignored
🟠 Amber — borderline
Referral correct but not explained · CL cessation mentioned but not emphasised · Safety-netting generic
🟢 Green — passing
CL stopped · Ophthalmology referred with explanation · AACG safety-netted by name · Concern addressed · Follow-up explicit · Closing question
Red Eye — SCA Consultation Scorecard
Based on the official SCA Consultation Tool · RAG self-assessment · Use after every practice consultation
0/ 33 pts
🌏
Global Skills
Consultation structure, language and responsiveness
0/7
Tasks
Clinical reasoning, diagnosis, investigations and management
0/15
🤝
Relating to Others
Communication, rapport and shared decision making
0/11
RAG Self-Assessment Guide
🔴 Red — not achieved
Not demonstrated · Opposite done (steroids prescribed, CL not stopped) · Critical safety element missing
🟠 Amber — partially achieved
Present but incomplete or generic; not tailored to CL wearer or this specific patient’s context
🟢 Green — fully achieved
Clearly demonstrated, specific to this patient, integrated naturally — would satisfy a marking examiner
011172533
Fail
Borderline
Pass
Strong pass
📋
Complete the checklist above to see your score interpretation
"It’s been like this for 2 days and it’s getting worse. I’ve tried some antihistamine drops I had from last year but they haven’t helped at all. I’m quite worried about it…"
Who you are

Aisha, 28. Graphic designer working full-time from home. Wears monthly contact lenses for 5 years. Active social life; wears lenses 14–16 hours/day and admits to sleeping in them “occasionally” when she falls asleep on the sofa.

Hidden agenda

Terrified of going blind — her grandmother lost vision in one eye from glaucoma. She has been researching symptoms online and is scared it might be “something serious in my eye”. Will only disclose this fear if the GP asks directly about concerns.

Symptoms if asked directly
  • Right eye: moderately painful (5/10), worse when blinking and in bright light
  • Vision: slightly blurry right eye, clear left eye (she can tell the difference)
  • Discharge: slight watery/mucopurulent (if pressed: “a bit sticky in the morning”)
  • No halos, no vomiting, no nausea with the pain (AACG screen negative)
  • No previous episodes; no URTI; no joint problems
Trigger for resolution
  • Responds positively if the GP directly names the blindness concern and addresses it
  • Worried about the referral — asks: “Is it really necessary to go to hospital? I’ve got a busy afternoon.”
  • Accepts plan when GP explains the specific risk of contact lens-related corneal infection clearly
  • Asks about contact lenses: “Will I ever be able to wear them again?”
"I really just came in for some antibiotic eye drops. Can’t you just give me those? I really can’t face going to the hospital today."

Resolution: The patient accepts the plan and becomes cooperative if: (1) the GP directly names and addresses the blindness concern rather than ignoring it, (2) the specific risk of contact lens-associated keratitis is explained in plain language, and (3) the patient is explicitly told she can wear lenses again safely in the future if she follows the right advice. Dismissal or generic responses will result in the patient becoming resistant.

🏥
Clinic Quick Reference
Red Eye — Clinical Decision Framework
NICE CKS Red Eye · RCOphth Guidelines · First Presentation
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🚨 1 — Triage System
Red eye presentation → immediately assess: VA · pain · photophobia · contact lens use · VA reduction
🔴 Emergency — 999 / A&E
  • Severe pain + halos + vomiting + fixed dilated pupil (AACG)
  • Chemical splash (alkali or acid) → irrigate immediately first
  • Open globe / penetrating injury
  • Hypopyon visible (endophthalmitis)
  • Post-operative red eye within 6 weeks
999 / emergency ophthalmology now
🟠 Urgent — Same-day ophth
  • CL wearer + pain + photophobia + reduced VA (keratitis)
  • Anterior uveitis: circumcorneal flush, photophobia, irregular pupil
  • Dendritic ulcer on fluorescein (HSV keratitis)
  • VA <6/12 unexplained
  • Corneal opacity or white infiltrate visible
Same-day ophthalmology referral
🟢 Routine — Primary care
  • Bacterial conjunctivitis: mucopurulent discharge, VA 6/6, no pain, no photophobia
  • Viral conjunctivitis: watery, bilateral, URTI, follicles
  • Allergic: bilateral itch, seasonal, atopy
  • Dry eye, blepharitis, subconjunctival haemorrhage
Manage in primary care · safety-net
🔭 2 — Diagnostic Pathway
Key discriminators — examine in this order
VA (both eyes, Snellen) — FIRST, before drops
✓ Pupil reactions (direct + consensual + RAPD)
✓ Pattern of injection (diffuse vs circumcorneal / ciliary flush)
✓ Cornea: opacity? infiltrate? (naked eye + torch)
✓ Lid eversion: follicles (viral) vs papillae (bacterial/allergic)
✓ Fluorescein if available: dendritic = HSV; ring = Acanthamoeba
✓ Preauricular lymph node: positive = viral (adenoviral)
Diagnosis by clinical pattern
Mucopurulent discharge + VA 6/6 + no photophobia = bacterial conj
Watery discharge + URTI + bilateral + follicles = viral conj
Bilateral itch + seasonal + atopy + no discharge = allergic
Pain + photophobia + CL wear + reduced VA = keratitis
Deep pain + circumcorneal flush + irregular pupil = uveitis
Severe pain + halos + vomiting + fixed pupil = AACG
Painless + sector red + VA 6/6 = subconj haemorrhage
📊 3 — Key Numbers
VA <6/12
Urgent ophthalmology threshold
IOP >21
Raised IOP → glaucoma concern
15 min
Chemical irrigation minimum duration
48h
Aciclovir treatment window for HSV
24h
Maximum wait for keratitis (same-day preferred)
6 wks
Post-op red eye = endophthalmitis risk
7–14d
Bacterial conjunctivitis resolution
2–3 wks
Viral conjunctivitis resolution
2–3 wks
Subconj haemorrhage resolution
10×
Keratitis risk increase with overnight CL wear
BD
Fusidic acid dosing frequency (vs QDS chloramphenicol)
5× daily
Aciclovir 3% ointment frequency for HSV
💊 4 — Treatment by Diagnosis
Primary care treatments
Bacterial conj: Chloramphenicol 0.5% QDS × 5–7d (or fusidic acid 1% BD)
Viral conj: Supportive only — cool compresses; hand hygiene; no antibiotics
Allergic: Olopatadine 0.1% BD or sodium cromoglicate 2% QDS
Dry eye: Hypromellose 0.3% QDS; preservative-free if >4×/day
Blepharitis: Lid hygiene (warm compress + lid scrubs) BD; fusidic acid to lid margin if infected
Subconj haemorrhage: Reassure; no treatment; check BP; resolves 2–3 weeks
⚠ Never prescribe in primary care without ophthalmology
✗ Topical corticosteroids (dexamethasone, prednisolone)
Risk: steroid glaucoma, HSV dendritic ulcer expansion, fungal keratitis, cataract

✗ Combined antibiotic + steroid (Maxitrol, Tobradex)
Same risks; equally contraindicated in undifferentiated red eye

✗ Antibiotics before corneal scrapes in suspected keratitis
Masks organism; reduces diagnostic yield from >70% to <30%
⚠ 5 — Safety Netting & Follow-Up
🔴 AACG emergency — 999
"Severe pain + halos around lights + vomiting + pupil looks different → call 999 immediately."
🟠 Keratitis worsening — same-day
"Vision gets blurrier, light becomes unbearable, or pain significantly worsens → eye hospital same-day."
🟢 Non-response —48h / 1 week
"No improvement in discharge / redness at 48h (bacterial) or 1 week (any type) → come back."
Follow-up timeline
1
48h: Treatment response check (bacterial conjunctivitis on drops)
2
1 wk: Review if not improving · reassess DDx · consider swab
3
Ophth: As directed (keratitis: daily; uveitis: weekly)
4
4–6 wks: Optometrist for CL wearers post-resolution
5
Annual: Recurrent uveitis · systemic disease screen · HLA-B27 workup
⚠ Never clear CL wearer to resume lenses without ophthalmology sign-off
🔭 6 — Monitoring & Red Flags
Condition / DrugMonitorTimingAction threshold
Bacterial conj (chloramphenicol)Symptom response48h call; 1 week if neededNo improvement → same-day ophth; consider chlamydial screen
HSV keratitis (aciclovir ointment)VA + fluorescein (ophthalmology)Daily initiallyUlcer not healing at 7 days → consider resistance; ophthalmology intensifies
Uveitis (topical steroids — ophth)VA + IOP (ophthalmology)Weekly until controlledIOP >21 on steroids → add topical beta-blocker; switch steroid formulation
Allergic conj (olopatadine)Symptom severity score4–6 weeksOngoing severe symptoms → add oral antihistamine; allergy referral
Systemic immunosuppression (recurrent uveitis)FBC + LFTs (methotrexate)Every 3 monthsLFT elevation / cytopenia → dose reduction; haematology / rheumatology review
Contact lens-associated keratitisVA + corneal clarityDaily ophth initiallyVA not recovering at 2 weeks → consider corneal scarring; contact lens restriction long-term
🚨 Emergency return (999): Severe pain + halos + vomiting + fixed dilated pupil (AACG) · Chemical splash (irrigate then 999) · Penetrating injury
🛡️ Safeguarding: Periorbital trauma inconsistent with history (domestic abuse) · Bilateral retinal haemorrhages in infant (NAI) · Chemical injury in context of self-harm or workplace inadequate PPE
🎓
SCA Exam Quick Reference
SCA Consultation Blueprint
Tasks · Relating to Others · Global Skills · RAG guide
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🕐 12-Minute Consultation Flow — with Domain Scoring
0–2 min
Open + ICE
"Describe the eye problem in your own words — what’s it been like?"
Allow 45–60s; note dominant symptom (itch vs pain vs blur); probe all 3 ICE by 2 min
Relating to OthersGlobal Skills
✗ Opening with “do you wear contact lenses?” · Jumping to antibiotic reflex
2–6 min
Targeted Hx + Red Flags
"Does the light bother your eye? Has your vision changed at all?"
VA, photophobia, pain type, halos, CL wearing pattern, discharge character, laterality, previous episodes, systemic Hx
TasksGlobal Skills
✗ Missing VA · Not asking photophobia · Not exploring overnight CL wearing
6–8 min
Examination Plan
"I’m going to check your vision in each eye first, before anything else."
VA → pupils → injection pattern → lids → fluorescein if available. Never instil drops before VA.
Tasks
✗ Drops before VA · Not examining both eyes · Skipping pupil reactions
8–10 min
Diagnosis + Plan
"Because of the blurriness and your contact lenses, this could be an infection on the cornea — I’m referring you today."
Plain English diagnosis. Stop CL now. No antibiotics before scrapes. Address blindness fear. Validate antibiotic expectation.
TasksRelating to Others
✗ Prescribing topical steroids · Starting antibiotics before scrapes in CL keratitis · Ignoring blindness concern
10–12 min
Safety Net + Close
"If you get halos, severe pain or feel sick with the pain → call 999. Vision blurrier or light worse → eye hospital same-day."
Three specific scenarios named. Follow-up timeframe stated. Closing question asked.
TasksRelating to OthersGlobal Skills
✗ “Come back if worse” · AACG not named · CL cessation not reinforced · No closing question
🔴🟠🟢 RAG Scoring — All 3 Domains
Tasks Domain
🟢
VA tested first; red flags elicited; keratitis correctly triaged; CL stopped; no steroids; specific safety-netting (AACG + keratitis); follow-up named
🟠
Most elements present; VA tested but not both eyes; safety-netting vague; CL cessation mentioned but not emphasised
🔴
VA not tested; topical steroids prescribed; antibiotics before scrapes in CL keratitis; AACG symptoms not named in safety-netting
Relating to Others
🟢
Blindness fear named and addressed; antibiotic expectation managed; ICE in plan; CL impact acknowledged; shared decision making; closing question
🟠
Rapport present; blindness fear not named; ICE explored but not referenced in plan; limited SDM
🔴
No ICE; blindness concern ignored; plan imposed without involving patient; antibiotic expectation not addressed
Global Skills
🟢
Data gathering by 7 min; plain language; open question first; closing question; all elements within 12 min; systematic structure
🟠
Mostly structured; some jargon; data gathering slightly incomplete; closing question omitted
🔴
Disorganised; jargon heavy; VA not tested early; no open question; no closing
💬 Key Phrases — ICE, Diagnosis & Plan
Ideas
"What do you think might be going on with your eye? Have you had any thoughts about it?"
Concerns — name the fear
"Is there anything about this that worries you particularly? Are you concerned about your eyesight at all?"
Expectations
"What were you hoping I’d be able to do for you today — were you hoping for antibiotic drops?"
Validate & explain
"I understand why you expected drops — the reason I’m not starting those today is that I want the specialist to look at your cornea first, because drops now could mask what’s happening."
CL keratitis — plain language
"Contact lenses, especially worn overnight, can allow bacteria to infect the clear surface of your eye. I can’t rule that out without a microscope — so I’m sending you to the eye hospital today."
Close
"Please stop your lenses now and don’t put them back in until the specialist says it’s safe. Is there anything else I can help with today?"
🚫 9 Danger Zones — Instant Deductions
Prescribing topical steroids for undifferentiated red eye→ Never in primary care without slit-lamp diagnosis; risk of HSV expansion and glaucoma
Antibiotics before corneal scrapes in CL keratitis→ Masks organism; wait for ophthalmology corneal scrapes first
Not stopping contact lenses immediately→ Most important patient safety intervention; document explicitly
Not testing VA before instilling drops→ Always VA first; drops change the examination; document baseline
Ignoring the blindness fear→ Name it: “I know you’re worried about your vision — let me address that directly”
AACG not covered in safety-netting→ Always name: halos + severe pain + vomiting → 999. Must be specific.
Discharging CL wearer with pain + reduced VA→ CL + pain + blurred VA = same-day ophthalmology, no exceptions
Generic safety-netting: “come back if worse”→ Name 3 specific scenarios with specific actions and timeframes
Prescribing antibiotics for viral or allergic conjunctivitis→ Antibiotic stewardship; explain why antibiotics won’t help in viral or allergic cases
💊 Drug Quick-Pick by Diagnosis
Bacterial conjunctivitis (1st line)
Chloramphenicol 0.5% QDS × 5–7d
VA 6/6; no photophobia; no pain; not a CL wearer with reduced VA
Bacterial conj (alternative / pregnancy)
Fusidic acid 1% gel BD
Better adherence (BD); preferred in pregnancy; preferred in children <2
Allergic conjunctivitis (acute itch)
Olopatadine 0.1% BD
Faster onset than cromoglicate; dual antihistamine + mast cell stabiliser
Allergic conjunctivitis (prevention)
Sodium cromoglicate 2% QDS
Start 2 weeks before pollen season; regular QDS essential; delayed onset
HSV keratitis (within 48h window)
Aciclovir 3% ointment 5× daily
Always refer to ophthalmology alongside. NEVER add topical steroids alone.
Dry eye / viral conj (supportive)
Hypromellose 0.3% QDS
Preservative-free if >4×/day; safe in pregnancy, CL wearers (remove lenses first)
⚠ Never prescribe topical steroids without ophthalmology · Stop CL immediately in any red eye with pain + reduced VA · Antibiotics in viral conjunctivitis = no benefit and worsens antibiotic resistance · AACG = 999
Reviewed: July 2026 Β· citations verified against current NICE / UK guidance