Red eye
Not covered: trauma, chemical injury, acute glaucoma and uveitis, which these sources do not address.
Don't miss
- INESSS Institut national d'excellence en santé et services sociaux
| Decision | Guideline |
|---|---|
| Alarm signs | These signs suggest eye involvement:Reduced visual acuity
Photophobia
With zoster: red eye (conjunctival or ciliary) or painful eye
With zoster: diplopia or abnormal eye movements from a 3rd, 4th or 6th nerve palsy
With HSV: ciliary flush, a small pupil (miosis) or a painful eye INESSS ocular zoster guide, p. 2 opens in a new tabINESSS ocular HSV guide, p. 2 opens in a new tab |
| Alarm sign present | Slit-lamp exam as fast as possible within 24 h.Done by a qualified professional, mainly an optometrist or an ophthalmologist. INESSS ocular zoster guide, p. 3 opens in a new tabINESSS ocular HSV guide, p. 3 opens in a new tab |
| Zoster, unwell or spreading | Emergency department now for marked general illness or a rash spread to other dermatomes. |
| Child with suspected zoster | Emergency department now, with an ophthalmology discussion within 24 h.While waiting for ophthalmology, strongly consider an IV antiviral, started right after discussion with infectious diseases. INESSS ocular zoster guide, p. 3 opens in a new tabINESSS ocular zoster guide, p. 5 opens in a new tab |
| HSV, age 3 months and under | Emergency department now for care by a pediatrician.Discuss with ophthalmology within 24 h.
Under 8 weeks, HSV can disseminate to several organs. INESSS ocular HSV guide, p. 2 opens in a new tabINESSS ocular HSV guide, p. 3 opens in a new tab |
| Child with suspected HSV keratitis | Urgent assessment by an ophthalmologist |
| Fluorescein | No uptake does not rule out corneal involvement, especially without a slit lamp.In doubt, with an alarm sign, a slit-lamp exam is required. INESSS ocular zoster guide, p. 3 opens in a new tabINESSS ocular HSV guide, p. 3 opens in a new tab |
| Blepharitis alarm signs | Consider a slit-lamp exam for:New or worse photophobia Vision loss Severe eye or lid pain Marked redness with diffuse conjunctival hyperemia Keratitis with fluorescein uptake |
Diagnose
- INESSS Institut national d'excellence en santé et services sociaux
- MSSS Ministère de la Santé et des Services sociaux
| Decision | Guideline |
|---|---|
| Viral | Often with a respiratory infection.Clear tearing.
Often a preauricular node.
Bilateral conjunctivitis is most often viral, with a clear, much scantier discharge. INESSS blepharitis guide, p. 2 opens in a new tabMSSS conjunctivitis chapter, p. 1 opens in a new tab |
| Bacterial | Purulent discharge.More often one eye.
Lasts 7–10 days. INESSS blepharitis guide, p. 2 opens in a new tabMSSS conjunctivitis chapter, p. 1 opens in a new tabMSSS conjunctivitis chapter, p. 2 opens in a new tab |
| Allergic | Itch is the main symptom.Tearing and conjunctival redness (palpebral and bulbar). Often other allergy symptoms, such as rhinorrhea. |
| STI risk factors | Consider N. gonorrhoeae and C. trachomatis as possible causes.See Sexually transmitted infections. |
| Ocular zoster | Pain and vesicles on one side of the V1 dermatome, usually not past the midline.Pain can come days before the rash.
Vesicles on the side of the nose (Hutchinson sign) go with eye involvement. INESSS ocular zoster guide, p. 1 opens in a new tabINESSS ocular zoster guide, p. 2 opens in a new tab |
| Ocular HSV | Usually recurrent and one-sided.Grouped vesicles that do not follow a dermatome and can cross the midline, usually preceded by tingling. Conjunctival redness and tearing. Pain is not always marked or present. |
| Blepharitis | History and exam of the eyes and surrounding skin.Chronic blepharitis is usually bilateral, even when symptoms sound one-sided.
Risk factors: rosacea, seborrheic dermatitis, atopic dermatitis. INESSS blepharitis guide, p. 1 opens in a new tabINESSS blepharitis guide, p. 2 opens in a new tab |
| One red lid | Consider sebaceous carcinoma.Redness of one lid only, often with lash loss and distorted lid anatomy. |
Investigate
- INESSS Institut national d'excellence en santé et services sociaux
- MSSS Ministère de la Santé et des Services sociaux
| Decision | Guideline |
|---|---|
| Office exam | Visual acuity, lids, conjunctiva, eye movements and corneal integrity.Check the cornea with fluorescein (slit lamp if available). INESSS ocular zoster guide, p. 3 opens in a new tabINESSS ocular HSV guide, p. 3 opens in a new tab |
| Conjunctivitis | Clinical picture. |
| Ocular zoster | |
| Adult, no alarm sign | Slit-lamp exam within 1–3 days to assess involvement and severity.With an alarm sign, as fast as possible, within 24 h. |
| Immunosuppressed | Discuss with ophthalmology within 24 h as soon as signs appear. |
| Ocular HSV | |
| Lid only, no red eye | Slit lamp only if the clinician judges it needed |
| Blepharoconjunctivitis | Slit-lamp exam within 1–3 days to assess the cornea and severity.With an alarm sign, as fast as possible, within 24 h. |
| Immunosuppressed, no alarm sign | Discuss with ophthalmology within 24–48 h |
| Child over 3 months, no alarm sign | Discuss with ophthalmology within 24 h, directly or through the emergency department. |
Treat
- INESSS Institut national d'excellence en santé et services sociaux
- MSSS Ministère de la Santé et des Services sociaux
| Decision | Guideline |
|---|---|
| Conjunctivitis | |
| Viral | Usually no treatment |
| Bacterial | Antibiotic eye ointment or drops if symptoms last beyond 48–72 hThey can speed healing.
MSSS names no drug. MSSS conjunctivitis chapter, p. 2 opens in a new tabMSSS conjunctivitis chapter, p. 3 opens in a new tab |
| Ocular zoster or HSV | |
| Start now | Oral antiviral as soon as possible, even when a specialty consult is already requested.The treating clinician starts it. INESSS ocular zoster guide, p. 4 opens in a new tabINESSS ocular HSV guide, p. 4 opens in a new tab |
| Zoster: do not | No oral steroid.It does not reduce postherpetic neuralgia. Topical steroid only after a slit-lamp exam and discussion with the ophthalmologist who will follow. |
| HSV: do not | Topical steroids are contraindicated in epithelial HSV keratitis.No contact lenses. |
| Blepharitis, hordeolum, chalazion | |
| First line, adult and child | Warm compress or heated mask, about 40–45 °C, for at least 5–10 min.Acute: 2–4 times a day. Chronic: once a day, every day. Chronic: prefer dry heat, except in children. |
| Hordeolum or chalazion | Non-drug care only, unless periorbital cellulitis is suspected.No result after 3 months: consider ophthalmology for excision. |
| Antiviral | Acyclovir is first line in pregnancy.Acyclovir and valacyclovir are compatible with breastfeeding. INESSS ocular zoster guide, p. 5 opens in a new tabINESSS ocular HSV guide, p. 5 opens in a new tab |
Children: weight-band doses and IV acyclovir are in the INESSS ocular zoster guide opens in a new tab and the INESSS ocular HSV guide opens in a new tab.
| Drug | Ocular zoster | HSV epithelial keratitis |
|---|---|---|
| Valacyclovir | 1000 mg PO TID | 500–1000 mg PO BID |
| Famciclovir | 500 mg PO TID | 250 mg PO BID |
| Acyclovir | 800 mg PO 5×/jour | 400 mg PO 5×/jour |
| Drug | Dose |
|---|---|
| First-line | |
| Erythromycin 0.5% ointment | A strip on the affected eye or lid margin, DIE at bedtime |
| Allergy or intolerance | |
| Fusidic acid 1% drops | 1 drop or a strip on the affected eye or lid margin, DIE at bedtime |
| Polymyxin B-gramicidin drops | 1 drop or a strip on the affected eye or lid margin, DIE at bedtime |
The blepharitis dose differs from the product monographs; it reflects the INESSS experts' advice for this indication.
Follow-up
- INESSS Institut national d'excellence en santé et services sociaux
| Decision | Guideline |
|---|---|
| Zoster, no eye involvement | See again in 7–10 days, sooner if worse.Eye involvement can appear within a week. |
| Zoster with eye involvement | Ophthalmology follows, according to severity.Child or immunosuppressed: follow-up as ophthalmology or infectious diseases advise. |
| Zoster pain | Manage pain, including post-zoster neuralgia (over 30 days). |
| Zoster, late complications | Watch for:Raised eye pressure Cataract Corneal inflammation or scarring Uveitis Reduced vision |
| HSV | Refer to ophthalmology if not improving as expected within 4 days of starting treatment.Dendrites or corneal lesions still there after 2 weeks: suspect another cause. |
| HSV recurrence | Each recurrence needs a visit, even without alarm signs. |
| Blepharitis: refer | Refer to ophthalmology for:Alarm signs Keratitis No response after several weeks of optimal non-drug care plus 1 month of topical antibiotic Atypical signs that suggest another disease Hordeolum or chalazion that persists and needs excision |
| After a topical steroid | Reassess within a few weeks for raised eye pressure and cataract. |
Children
- INESSS Institut national d'excellence en santé et services sociaux
- MSSS Ministère de la Santé et des Services sociaux
| Decision | Guideline |
|---|---|
| Suspected ocular HSV | Send to ophthalmology or the emergency department, directly if possible.Start an oral antiviral now while waiting. Weight-band doses: INESSS ocular HSV guide opens in a new tab. |
| Blepharitis | Non-drug care.Warmth like bath water.
No dry heat (heated mask), to avoid burns.
Chronic blepharitis not controlled: ophthalmology. INESSS blepharitis guide, p. 3 opens in a new tabINESSS blepharitis guide, p. 6 opens in a new tab |
| Daycare and school | Conjunctivitis alone does not justify exclusion.Exclude only on the general MSSS criteria. |
| When the daycare sends the child | Physician or nurse practitioner assessment for fever or marked eye involvement:Edema
Marked redness
Heavy discharge
Severe pain
Photophobia
Reduced vision Readmission
|
| With acute otitis media | Amoxicillin-clavulanate (7:1) for otitis media with purulent conjunctivitis, in the INESSS guide for children 3 months and older. INESSS otitis guide, p. 3 opens in a new tabMSSS conjunctivitis chapter, p. 1 opens in a new tab |
Reviewed 17 October 2026 against the official sources below.
Sources
Blue square: Québec. The code names the body; each section's key gives its full name.