The Red Eye

Ocular infections

• Spectrum from preseptal cellulitis, postseptal cellulitis, subperiosteal abscess, orbital abscess and cavernous sinus thrombosis (most severe)
• CT scan differentiates pre- from post-septal
• Endophthalmitis (infection of globe) is entirely separate
• Panophthalmitis is endopthalmitis + periorbital structures beyond sclera

Chandler’s classification

• 1. Preseptal
• 2. Orbital
• 3. Subperiosteal abscess
• 4. Orbital abscess
• 5. Cavernous sinus thrombosis

Pre-septal vs. orbital cellulitis

• Signs of orbital cellulitis include:
  • Ophthalmoplegia with diplopia
  • Pain with eye movement
  • Visual impairment
  • Proptosis
  • Chemosis (rare in preseptal)
  • Toxic/irritable/photophobia
  • Abnormal colour vision
  • RAPD

• CT is confirmatory

Pre-septal cellulitis

• Usually associated with eyelid skin problems and rarely sinusitis
• Mostly children <10yo
• S. aureus, S. epidermidis, Streptococcus
• Presents with URTI sx, low-grade fever, redness and swelling of eyelid and epiphora (excessive tearing)
• VA and pupil unchanged and full painless ocular motility is observed
• CT mandatory if reduced ocular movements or in young child with difficult examination or systemically unwell. MRI an alternative
• BC only if toxic/suspected orbital cellulitis
• If non-toxic: Oral augmentin, hot packs and r/v in 24 hours
• If young child or unwell: Ceftriaxone 50mg/kg BD + Vanc 30mg/kg stat then 15mg/kg BD + Ophthalmology review

Orbital cellulitis

• Most commonly from paranasal sinusitis
• Inflammation does not spread to upper eyebrow or eyelid as limited by orbital septum
• Ethmoid sinus most often implicated
• Trauma, intraorbital FB, periorbital skin infection, seeding from bacteraemia and ocular surgery are all risk factors
• Often polymicrobial (S. aureus, S.pneumoniae and anaerobes)
• Consider Hib in unimmunised children, mucormycosis in diabetics and immunocompromised
• Insidious onset, rhinitis, facial pressure, fever, pain with eye movement, reduced VA, chemosis, proptosis, abnormal pupillary response
• CN III, IV, VI involvement suggests cavernous sinus thrombosis
• Admit, IV Cefotaxime 2g IV q8h OR Ceftriaxone 2g daily + flucloxacillin
• Consider emergent lateral canthotomy if raised IOP or optic neuropathy evident
• Need CT or MRI
• Complications include cavernous sinus thrombosis, frontal bone osteomyelitis, meningitis, subdural empyema, epidural abscess and brain abscess 

Eyelid disorders

• Stye (external hordeolum)
  • Acute staph infection of follicle of eyelash and adjacent sebaceous gland (of Zeis) or sweat gland (Moll)
  • Located at lash line
  • Warm compress +- topical chlorsig
• Internal hordeolum
  • Acute staph infection of Meibomian gland
  • Pustule on inner surface of tarsal plate
  • Warm compresses and erythromycin ophthalmic ointment twice daily for 7-10 days
  • Can remove offending eyelash
  • Systemic antibiotics if surrounding preseptal cellulitis
  • If I&D required, refer ophthalmology
• Chalazion
  • Acute or chronic inflammation of eyelid due to blockage of meibominan or Zeis oil glands
  • Tends to be subacute, chronic, painless
  • Treat the same as hordeolum
  • Can be injected with steroids or excised via ophthal
• Blepharitis
  • Inflammation of eyelash follicles causing chronic red eye
  • Often overgrowth of S. epidermidis with inflammation due to deltalike toxin
  • Associated with seborrhoic dermatitis, atopic dermatitis and occasionally lice or S. aureus infection
  • Presents with conjunctival injection, crusting, swollen pruritic eyelids and sometimes eye pain
  • Treatment – Careful cleaning of eyelids/eyelashes + antibiotic drops or ointment at night for severe cases

Conjunctivitis

• Usually viral and self-resolving
• Must identify serious bacterial cases or corneal herpetic involvement that warrant aggressive treatment
• Bacterial more common than viral in children
• DDx
  • Viral (preauricular lymphadenopathy)
  • Bacterial (incl. gonococcal and chlamydial)
  • Parasitic
  • Fungal
  • Allergic
  • Toxic
  • Chemical

• Keratoconjunctivits = corneal involvement (usually punctate ulcerations)

Bacterial conjunctivits

• Painless, uni- or bilateral mucopurulent discharge
• Often adherence of eyelids on waking
• Conjunctiva injected and cornea clear without fluorescein staining
• Chemosis (oedema of conjunctiva) is common
• Pre-auricular lymphadenopathy absent (except gonococcal)
• Typically staph or strep
• Perform fluorescein staining to rule out corneal abrasions/ulcers/herpetic dendrites
• Consider MCS/PCR in severe cases or contact lens
• Topical chlorsig ointment BD for 5-7 days
• If wears soft contact lenses, ofloxacin or tobramycin preferred for Pseudomonas cover

Conjunctival injection

Chemosis

Viral conjunctivitis

• Adenovirus most common
• Measles, influenza and mumps can also cause this
• Herpes simplex and herpes zoster also potential agents
• Lead to corneal scarring if untreated
• Epidemic keratoconjunctivitis
  • More severe form of adenovirus infection, highly contagious and occurs in epidemics
  • Preceded by cough, fever, malaise and myalgias followed by marked eye redness, photophobia, FB sensation and epiphora
  • Examines as severe viral conjunctivitis
• Usually preceded by viral URTI. No pain unless corneal involvement. Usually one eye, then the other within days
• Examination
  • Conjunctival injection, occasional chemosis, small subconjunctival haemorrhages + preauricular lymphadenopathy
  • Slit lamp shows follicles on inferior palpebral conjunctiva
  • Punctate fluorescein uptake represents keratitis (look for dendrites)
• Treatment
  • Cool compresses, Ocular decongestants 1 drop TDS (Naphcon-A), artificial tears
  • Takes 1-3 weeks to resolve and highly contagious
  • Can prescribe chlorsig ointment if unsure if bacterial and f/u with ophthalmologist

Allergic conjunctivitis

• Erythematous swollen lids, injected and oedematous conjunctiva with papillae on inferior conjunctival fornix
• Try to identify and eliminate allergen
• Cool compresses, artificial tears
• Moderate cases – Topical antihistamine, mast cell stabiliser or NSAID
• Severe symptoms – Topical steroids (ophthal)

Subconjunctival haemorrhage

• Reassure and should resolve within 2 weeks
• If multiple recurrent episodes, look for cause of cough or precipitant and coagulation studies + ophthal referral

Herpes simplex keratoconjunctivitis

• Herpes simplex can affect eyelids, conjunctiva and cornea
• Eyelid may show typical vesicles
• Infection tends to be unilateral with preauricular node
• Conjunctiva may be injected, but often presents with only corneal involvement
• Dendrite seen on fluorescein staining with linear branching pattern or geographic ulcer (amoeba-shaped defect with dendrites at edge)
• Can be difficult to diagnose as may present with:
  • Neurotrophic ulceration (smooth-edged ulcer over underlying corneal stromal disease)
  • White infiltrates with intact corneal epithelium and associated mild iritis with keratitic precipitates
  • An isolated uveitis, without epithelial or stromal involvement and with elevated IOP

• Always check corneal sensation before anaesthetic instillation
• PCR should be sent to confirm
• Can progress to corneal scarring
• Treatment (urgent) 
  • Eyelids – PO acyclovir 5x daily
  • Conjunctival – Topical aciclovir 3% 5x daily + chlorsig ointment to prevent secondary bacterial infection
  • Oral acyclovir does NOT prevent progression to stromal involvement/scarring

Herpes zoster ophthalmicus

• Shingles involving V1 with ocular involvement
• Only involves upper eyelid (rarely V2/V3)
• Involvement of nasociliary nerve with cutaneous lesion on tip of nose (Hutchinson sign) is highly predictive of ocular involvement
• Pain/paraesthesia in V1 distribution, fever, headache, malaise, red eye, blurred vision and photophobia
• Eye involvement may be:
  • Epithelial keratitis
  • Stromal keratitis
  • Uveitis
  • Retinitis
  • Choroiditis
  • May suffer optic neuritis and raised IOP
• Examination
  • Cornea may show pseudodendrite (poorly staining mucous plaque with no epithelial erosion)
  • Anterior chamber may show cells and flare of iritis
• Treatment
  • Skin involvement – Cool compresses
  • If rash <7 days – Oral acyclovir 800mg 5 times daily for 7-10 days
  • Cutaneous lesions – Bacitracin or erythromycin ointment to prevent secondary bacterial infection
  • Conjunctivitis – Chlorsig ointment BD
  • Iritis – Topical steroids
  • Analgesia – Topical cycloplegics [dilates] (cyclopentolate 1% one drop TDS)
  • If orbit, optic nerve, cranial nerve involvement or immunocompromised/unwell – IV acyclovir

Corneal ulcer

• Involves multiple layers of cornea with break in epithelial barrier leading to invasion of corneal stroma
• Initial disruption to epithelial layer may be due to desquamation, trauma or direct microbial invasion
• Exposure keratitis from Bell’s palsy can cause sloughing, bacterial access and ulcer formation
• S. pneumoniae and S. aureus are common causes of corneal ulceration
• Pseudomonas a risk in contact lens use
• Risk increases dramatically with extended-wear lenses or if slept with them in
• Fungal and viral ulcers seen with use of both topical and systemic immunosuppressant use
• Always ask about herpes infections
• VA reduced if ulcer in central visual axis or if uveitis exists
• Associated iritis may cause miotic pupil and consensual photophobia due to ciliary spasm
• Slit-lamp shows ulcer with white/hazy base extending into underlying stroma due to WCC infiltration. May see flare/cells from iritis and hypopyon
• DDx
  • Bacteria
    • Pseudomonas, S. pneumoniae, S. aureus, Moraxella
  • Viruses
    • Herpes simplex
    • Varicella zoster
  • Fungi
    • Candida, Aspergillus, Penicillium, Cephalosporium
• Treatment
  • Take MCS/viral PCR swabs
  • Urgent ophthal review for scraping/swab
  • Ciprofloxacin or ofloxacin topical drops, one drop every hour to affected eye
  • If high suspicion for viral or fungal involvement, topical antiviral + antifungal indicated
  • Cyclopentolate 1% to treat iritis (dilates)
  • Steroid eye drops if not viral initiated by ophthal
• Complications
  • Refer for follow-up within 24 hours
  • Corneal scarring, corneal perforation, anterior/posterior synechiae, glaucoma and cataract

Ultraviolet keratitis

• Can cause death of epithelial cells
• ‘Snow blindness’ or welder’s flash
• Multiple short exposures accumulate = one long exposure
• Corneal cells die slowly so symptoms arise 6-12 hours later with FB sensation, mild photophobia, progressive severe pain
• May wake with severe pain
• Examination
  • Blepharospasm, conjunctival injection, prominent tearing (epiphora)
  • Slit lamp shows diffuse punctate corneal oedema + diffuse punctate corneal abrasions
• Treatment
  • Cycloplegics, chlorsig and oral analgesics with healing over 24-36 hours

Uveitis

• Inflammation of uvea (middle layer)
  • Anterior uveitis = Iris and ciliary body
  • Posterior uveitis = Choroid
• Anterior uveitis = Iritis
  • Cells and flare in anterior chamber
  • If ciliary body involved = iridocyclitis
• Posterior uveitis = Leukocytes in vitreous humor and chorioretinal inflammation
  • Presents with floaters/visual loss and usually painless

Anterior uveitis/iritis

• Inflammation of the anterior segment of the uveal tract
• Pain is due to irritation of ciliary nerves and ciliary muscle spasm and therefore worse with eye movement and accommodation
• Direct and consensual photophobia (specific for anterior uveitis)
• Ciliary spasm irritates the trigeminal nerve and can cause photophobia
• Miotic usually
• Keratitic precipitates are inflammatory cells seen on endothelial aspect of cornea
• Proteinaceous transudate seen as flare in anterior chamber
• WCC can be seen as cells (snowflakes)
• May have conjunctival infection, photophobia and reduced VA
• Usually no discharge
• DDx – Systemic disease (RA, SLE, UC, CD), malignancy, infection (viral), trauma 
• Systemic arthritis, urethritis and GI symptoms are not uncommon
• PMHx- TB, genital herpes or previous symptoms
• Ask about recent trauma/UV exposure/welding
• Examination
  • Perilimbal flush or diffuse conjunctival injection without purulent discharge (vs. perilimbic sparing in conjunctivitis)
  • Consensual photophobia (shining light on unaffected eye causes pain in affected eye) is highly suggestive of iritis (due to ciliary spasm/pain)
  • Pupil usually miotic and poorly responsive
  • Flare and cells +- hypopyon
  • Fluorescein staining may show abrasions, ulcerations, dendrites or nothing

• Treatment
  • Long-acting cycloplegic (tropicamide (24 hours) or homatropine (2-4 days) with ophthal review in 24-48 hours
• DDx
  • Systemic
    • Juvenile RA, Ankylosing spondylitis (HLA-B27), ulcerative colitis, Reiter’s, Behcet’s, Sarcoidosis
  • Infectious
    • Herpes simplex, herpes zoster, Toxoplasmosis (surprisingly common in normal host), Syphilis, Adenovirus, TB, CMV (immunosuppressed), cat scratch disease
  • Malignant
    • Leukaemia, lymphoma, malignant melanoma
  • Trauma
    • Corneal FB, post-traumatic (blunt trauma), UV keratitis
  • Idiopathic (30%)

Herpes keratouveitis

• Usually unilateral 
• Clues include periocular vesicles, dendrites/pseudodendrites, reduced corneal sensation, elevated IOP and iris atrophy

Complications of uveitis

• Band keratopathy (calcium deposits on corneal epithelium)
• Posterior synechiae
• Cataract
• Glaucoma
• Cystoid macular oedema

Endophthalmitis

• Inflammation of aqueous or vitreous humor
• Usually post-surgical, penetrating intraocular injuries or rarely haematogenous spread
• Hx
  • Ocular surgery, hammering steel, working with grinders/whipper snippers, ocular trauma
  • Headache, eye pain, photophobia, vision loss and ocular discharge
• Examination
  • Lid swelling/erythema, conjunctival and scleral injection, chemosis, hypopyon, uveitis/iritis
  • Extension beyond sclera into periorbital tissues = panophthalmitis
• Treatment
  • Need immediate ophthal review, admission, IV antibiotics +- aspiration of vitreous/intravitreal antibiotics
  • IV cephalothin and IV gent

Vitreous detachment and haemorrhage

• Vitreous is avascular and firmly attached at ora serrata anteriorly, aroundoptic nerve head posteriorly and along major retinal vessels
• Traction can cause detachment +- haemorrhage
• Sudden onset floaters (esp. with head movement) 
• Sudden painless vision loss and sudden appearance of black spots, cobwebs or generalised unilateral hazy vision
• Vitreous haemorrhage most associated with proliferative diabetic retinopathy, posterior vitreous detachment in elderly, ocular trauma (shaken baby)
• Examination
  • Fundoscopy may be impossible due to haemorrhage
  • Contralateral retina may show evidence of diabetic retinopathy
• DDx: Sickle cell, diabetes, retinal detachment, central retinal vein occlusion, subarachnoid haemorrhage and lupus
• Check INR if on warfarin and withold antiplatelet therapy
• Ocular USS can help rule out retinal detachment

Acute angle closure glaucoma

• Pupillary dilatation leads to adherence of iris to lens and reduced aqueous humor flow from ciliary body to canal of Schlemm
• Increased pressure leads to viscious circle
• Risk factors
  • Increased age
  • Narrow angle
  • Neovascularisation (rubeosus iridis)
  • FHx
  • SE Asian
  • Females 3x males
• Precipitants
  • Dark room
  • Mydriatics e.g. cyclopentolate
  • Nebulised ipratropium
  • Beta-agonists
  • Emotional upset
• Presentation
  • Acute severe unilateral pain, nausea, vomiting, red eye, mid-sized fixed pupil, cloudy cornea, keratitic precipitates, abnormal pupil shape
  • Shallow anterior chamber
  • Pressure >30mmHg
• Management
  • Drug therapy successful in 50%\
  • Acetazolamide 500mg IV stat then 250mg PO TDS
  • OR Mannitol 1g/kg
  • Opioid analgesia
  • Antiemetics
  • 4 cycles of below, q15min for 1 hour
    • Pilocarpine 2%
    • Lopidine 2%
    • Timolol 0.5%
  • Ophthal review
  • Surgical urgent peripheral or laser iridotomy

Episcleritis

• Redness, irritation and watery eye without loss of vision
• Often self-resolves
• 70% in females (mostly young/middle aged)
• Simple episcleritis
  • Sectoral or diffuse
  • Rarely associated with seronegative spondyloarthropathies, IBD, ANCA vasculitis
• Nodular episcleritis
  • Raised in one area of eyeball
  • Mostly idiopathic but can be associated with rheumatic disorders (esp. rheumatoid arthritis)
• Usually not painful
• No oedema or thinning of sclera
• 50% of cases are bilateral
• Usually resolves within 3 weeks with or without treatment
• Vs. scleritis
  • Intense ocular pain, photophobia, deep-red/purplish scleral hue
• Phenylephrine does not constrict scleral vessels and allows examination of sclera
• Vs conjunctivitis
  • Morning crusting, daytime discharge (not seen with episcleritis)
• Treatment (4 step ladder)
  • Topical lubricants 4-6x daily (avoid preservatives)
  • Topical NSAID 2-4x daily
  • Topical steroid
  • Oral NSAID

Scleritis

• Up to 50% associated with underlying systemic illness e.g. RA, Wegener’s
• Most patients require high-dose oral steroids
• Anterior scleritis
  • Diffuse anterior scleritis – Most common and least severe
  • Nodular anterior scleritis
  • Necrotising anterior scleritis – Mostly older women

• Presents with subacute onet, severe, constant, boring pain worse at night and radiating to periorbital regions
• Ocular movements worsen pain as muscles insert into sclera
• Ocular redness and photophobia
• If necrotic, get paradoxical easing of symptoms due to nerve death
• Essential sign if scleral oedema with violaceous discolouration of the globe and tenderness
• May involve cornea (incl. corneal melt), anterior uveitis, lens cataract or posterior segment
• Treatment:
  • Systemic NSAID, steroids, immunosuppression

Last Updated on March 14, 2022 by Andrew Crofton