12-phase flow (12)

1. 1FRAME
   Frame the acute red eye as a TRIAGE problem: the dominant task is separating the ~80-95% benign self-limited red eye (conjunctivitis, subconjunctival hemorrhage, episcleritis, blepharitis, dry eye, pterygium) from the sight-threatening can't-miss set (microbial keratitis, anterior uveitis, scleritis, acute angle-closure glaucoma, endophthalmitis, orbital cellulitis, chemical burn, globe rupture, hyphema). This engine OWNS the triage + routing; definitive management of each dangerous cause is routed OUT by engine_id, not re-authored here (AAO PPP Conjunctivitis 2024; Wills Eye Manual red-eye triage).
   advance: triage scope confirmed; definitive-management concerns flagged for route-out by engine_id
2. 2ENTRY
   Capture the undifferentiated red eye and immediately elicit the DANGER TRIAD up front: TRUE ocular pain (vs gritty/itch), visual-acuity change, photophobia. Any one positive moves the prior decisively toward the sight-threatening set and out of the uncomplicated-conjunctivitis lane (Beaver Compr Ther 2001 PMID 11569323; Perumal NZ Med J 2011 PMID 21952383).
   inputs: pain_character, visual_acuity_change
   actions: workup.acute_red_eye
   advance: red-eye entry recognised; danger triad (pain/acuity/photophobia) screened
3. 3CONTEXT
   Build the triage prior: photophobia + ciliary flush; discharge character (watery=viral, mucopurulent=bacterial, ropy+itch=allergic); contact-lens wear & hygiene; laterality + sick contacts; zoster (V1/Hutchinson) features; immunocompromise. This phase assigns the pre-test probability across the full benign-vs-dangerous differential (Johnson JAMA 2022 PMID 35699701; Stapleton Ophthalmology 2008 PMID 18538404).
   inputs: photophobia_and_ciliary_flush, discharge_character, contact_lens_use_and_hygiene, unilateral_vs_bilateral_and_contact_history, herpes_zoster_features, immunocompromise
   actions: workup.acute_red_eye, workup.lymphadenopathy
   advance: pre-test differential prior assigned across benign + sight-threatening causes
4. 4RED_FLAGS
   Hard sight-threat / globe-emergency screen, each recognised then routed OUT by engine_id: (1) chemical/alkali splash → STOP and irrigate copiously FIRST (before vision/exam) then route; (2) globe rupture / penetrating trauma → shield, no pressure, route; (3) fixed mid-dilated pupil + steamy cornea + IOP↑ + halos → acute angle-closure (protocol.angle_closure) → ophtho.acute-angle-closure-glaucoma.core.v1; (4) contact-lens painful red eye + corneal infiltrate → microbial keratitis → ophtho.microbial-keratitis.core.v1; (5) proptosis/painful motility/lid signs → orbital cellulitis → ophtho.orbital-cellulitis.core.v1; (6) post-op/post-injection red painful eye + hypopyon → endophthalmitis → ophtho.acute-vision-loss.core.v1; (7) sudden painless visual loss with quiet/red eye → consider CRAO (protocol.crao). These are recognised here, NOT managed here.
   inputs: trauma_or_chemical_exposure, pupil_and_corneal_clarity, intraocular_pressure, proptosis_motility_lid_signs, recent_intraocular_surgery_or_injection
   actions: protocol.angle_closure, protocol.crao, calc.qsofa
   advance: all globe-emergency red flags screened and routed by engine_id if positive
5. 5INITIAL_WORKUP
   Structured bedside triage exam: visual acuity (each eye, pinhole), penlight/slit-lamp injection pattern (diffuse conjunctival vs perilimbal ciliary flush), pupil, FLUORESCEIN under cobalt blue (dendrite=HSV → no steroid; ulcer/infiltrate=microbial keratitis; punctate=dry/exposure), IOP, lid eversion for foreign body. Bloods only when systemic/orbital/sepsis context (CBC/inflammation/CMP) — most benign red eye needs NO labs (AAO PPP Bacterial Keratitis 2024; HEDS Ophthalmology 1994 PMID 7997323).
   inputs: fluorescein_uptake_pattern
   actions: panel.cbc, panel.inflammation, panel.cmp
   advance: acuity + injection pattern + pupil + fluorescein + IOP documented; corneal/AC pathology screened
6. 6BRANCHING_WORKUP
   Triage decision tree off the exam: corneal infiltrate/ulcer ± hypopyon → microbial keratitis arm (scrape/route); anterior-chamber cells/flare, small irregular pupil, ciliary flush → anterior uveitis arm; deep boring pain, violaceous non-blanching scleral vessels → scleritis arm; fixed pupil + IOP↑ → AACG arm; sectoral blanching injection, mild → episcleritis (benign); diffuse + discharge + normal acuity → conjunctivitis arm (benign); blood under conjunctiva, painless, normal vision → subconjunctival hemorrhage (benign); slit-lamp / orbital CT when occult rupture, foreign body, or orbital cellulitis suspected (Wills Eye Manual; AAO PPP Anterior Uveitis 2023).
   inputs: slit_lamp_or_orbital_ct
   actions: workup.acute_vision_loss, workup.acute_headache
   advance: single best diagnostic arm selected; dangerous arm routed by engine_id
7. 7DIFFERENTIAL
   Terminal red-eye differential with explicit pivot findings — BENIGN: viral conjunctivitis (bilateral watery + preauricular node + sick contact + normal vision pivot), bacterial conjunctivitis (mucopurulent + lids stuck pivot), allergic conjunctivitis (bilateral itch + ropy + atopy pivot), subconjunctival hemorrhage (painless flat blood + normal vision pivot), episcleritis (sectoral, blanches with phenylephrine, no photophobia pivot), blepharitis/dry eye (chronic gritty + lid-margin pivot), pterygium. SIGHT-THREATENING: microbial keratitis (contact-lens + corneal infiltrate + pain pivot), anterior uveitis (ciliary flush + AC cells + photophobia + miosis pivot), scleritis (severe boring pain + violaceous deep vessels not blanching pivot), acute angle-closure glaucoma (fixed mid-dilated pupil + IOP↑ + halos + headache/vomiting pivot), endophthalmitis (post-op/injection + hypopyon + rapid vision loss pivot), orbital cellulitis (proptosis + painful motility + fever pivot), chemical burn / globe rupture / hyphema (history + exam pivot). Co-existence flagged (e.g., keratitis with secondary uveitis).
   advance: best diagnosis selected; benign vs sight-threatening lane assigned; co-existence flagged
8. 8RISK_STRATIFICATION
   Convert exam into urgency tier driving disposition: TIER 1 same-hour ophthalmology emergency (AACG, chemical burn, globe rupture, endophthalmitis, microbial keratitis with central/large infiltrate, orbital cellulitis); TIER 2 same-day ophthalmology (anterior uveitis, scleritis, HSV/HZO keratitis, hyphema, contact-lens keratitis small peripheral); TIER 3 routine/self-care (viral/allergic conjunctivitis, subconjunctival hemorrhage, episcleritis, blepharitis, dry eye). qSOFA/NEWS2 only when systemic/orbital sepsis context (orbital cellulitis, septic endophthalmitis source) (Wills Eye Manual triage; Papier Am Fam Physician 2007 PMID 18217520).
   inputs: visual_acuity_change, intraocular_pressure
   actions: calc.qsofa, calc.news2
   advance: urgency tier assigned; route-out targets identified by engine_id
9. 9TREATMENT
   TRIAGE engine — definitive treatment of each dangerous cause is ROUTED OUT, not authored here. What IS done here: (1) chemical burn → immediate copious irrigation to neutral pH (non-pharm, the only thing that must precede everything); (2) topical anaesthetic (proparacaine) for EXAM ONLY — never dispensed; (3) shield (no pressure) for suspected rupture; (4) stop contact-lens wear and never patch a contact-lens-associated red eye; (5) WITHHOLD topical steroids until HSV/microbial keratitis excluded; (6) symptomatic care for confirmed-benign causes (artificial tears, cool compress, antihistamine for allergic, lid hygiene for blepharitis); (7) systemic analgesia bridge for severe pain pending route-out. Antibiotic stewardship: most acute conjunctivitis is viral/self-limited — do NOT reflexively prescribe topical antibiotics (Johnson JAMA 2022 PMID 35699701; AAO PPP Conjunctivitis 2024).
   inputs: pregnancy, fluorescein_uptake_pattern
   advance: immediate-harm-prevention steps done (irrigation/shield/no-patch/withhold-steroid); definitive Rx routed by engine_id; benign-cause symptomatic plan started
10. 10DISPOSITION
    Tier 1 → emergency same-hour ophthalmology + route by engine_id (AACG → ophtho.acute-angle-closure-glaucoma.core.v1; microbial keratitis → ophtho.microbial-keratitis.core.v1; endophthalmitis → ophtho.acute-vision-loss.core.v1; orbital cellulitis → ophtho.orbital-cellulitis.core.v1; chemical burn after irrigation → ophtho.microbial-keratitis.core.v1/ophthalmology). Tier 2 → same-day ophthalmology (uveitis → ophtho.uveitis.core.v1; scleritis; HSV keratitis). Tier 3 benign → primary-care self-care + explicit return precautions (any new pain, vision drop, photophobia → re-present). Document the eye-specific safety-net (Beaver Compr Ther 2001 PMID 11569323; Konstantakopoulou BMJ Open 2016 PMID 27515757).
    inputs: visual_acuity_change
    advance: disposition + route-out engine_id documented; benign cases given vision-specific return precautions
11. 11MONITORING
    For benign causes retained here: re-evaluate at 48-72 h if not improving — any emergent pain, falling acuity, photophobia, or corneal change converts a presumed-benign red eye into a sight-threat and re-triggers RED_FLAGS routing. Counsel that viral conjunctivitis can worsen over the first 3-5 days before improving (prevents premature antibiotic escalation). Confirm route-out engines received carryover state for the dangerous cases (Johnson JAMA 2022 PMID 35699701; AAO PPP Conjunctivitis 2024).
    inputs: visual_acuity_change, pain_character
    actions: workup.acute_red_eye
    advance: benign cause improving by 48-72 h OR re-triage triggered; route-out carryover confirmed
12. 12FOLLOWUP
    Benign causes: education + return precautions are the core deliverable — explicit "RED-FLAG return": new true pain, any vision drop, severe photophobia, halos, contact-lens-associated symptoms → immediate re-present. Contact-lens hygiene counselling (no overnight wear, no tap-water/showering in lenses, replace case) — the dominant preventable microbial-keratitis driver (Stapleton Ophthalmology 2008 PMID 18538404). Allergic: allergen avoidance + mast-cell stabiliser bridge. Recurrent HSV: suppression decision routed to keratitis engine (HEDS Arch Ophthalmol 2000 PMID 10922194). For routed dangerous cases, ownership transfers to the receiving engine.
    inputs: contact_lens_use_and_hygiene
    advance: return-precaution + prevention counselling documented; recurrent/HSV/contact-lens prevention routed if applicable