see also: [[Red eye]]
#infectious_diseases
> skip to [[#Periorbital and orbital cellulitis]] section
# infections of the lid and border
## Blepharitis
![[Pasted image 20240328133704.png]]
- inflammation of eyelid
- rims are red, eylashes may stick
- "dandruff of the eyelid"
- RF: seborrheic dermatitis, chronic strep/staph infection
- Tx: gentle lid scrubs with baby shampoo
- topical abx
## Hordeolum
- acute *painful* nodule from blocked glands (abscess of lid margin)
- external ("stye") or internal
- "horders live in a pig stye" ; HORDelum = style
- usually staph aureus
- Tx: warm compress → abx ointment → I&D if severe (send to opthal)
![[Pasted image 20240328133854.png]]
![[Pasted image 20240328133905.png]]
## Chalazion
- *chronic* stye
- painless
- chronic internal granulomatous rxn of meibomian gland
- Tx: warm compress → refer to opthal for excision
## Dacrocystitis
![[Pasted image 20240328140022.png]]
![[Pasted image 20240328140036.png]]
- infection of lacrimal system
- usually staph aureus
- tears that don't drain, purulent discharge
- adjacent cellulitis from obstruction
- Tx: warm compresses, abx
# Red eye
See also: [[Red eye]]
## Conjunctivitis
- bacterial or viral ("pink eye")
- also allergic, chemical
- Can be presenting symptom of [[SJS and TENs|SJS]]!
| | General | clinical features | treatment |
| --------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------- | ---------------------------------------------- |
| Viral | - usually adenovirus<br>- highly contageous<br>- epidemic keratoconjunctivitis -- severe form | - unilateral or bilateral red eye<br>- thin, watery discharge<br>- pre-auricular adenopathy<br>- a/w URTI | - eye washes<br>- cold compress<br>- no school |
| Bacterial | - strep or staph<br>- pseudomonas in contact lens<br>- usually self limited<br>- rare: chlamydia/gonorrhoea (copious discharge from gonococcal conjunctivitis) | - copious purulent discharge<br>- eyes glued shut in morning | topical abx (systemic if STI) |
## Iritis / uveitis / choroiditis
==anterior uveitis = iritis== (see [Eye and Ear anterior uveitis guideline](x-devonthink-item://FE49069D-E78A-4F23-B2C0-EE2697EA5DA9))
> Not usually an infection; can be autoimmune eg HLA-B27 or sarcoidosis or trauma, see below
Inflammation of iris, ciliary body, or choroid — all continuous with one another and collectively called the *uvea*.
> [!pearl]- Uvea anatomy brief
> ![[65229B07-97F2-4E62-90A7-59436590C7BE.png]]
> Uvea is between outer sclera and cornea and inner retina.
>
> **Iris** - controls amt of light hitting retina. Sympathetic dilates, parasympathetic constricts
>
> **Ciliary body** - secretes aqueous fluid into posterior chamber and controls shape of lens. Contains sphincter muscles that relax zonular fibers.
>
> **Choroid** - a bed of blood vessels under the retina. Supplies nutrition to outer 1/3 of retina (rods and cones receptors). Retinal detachments can separate from this source of nutrition, causing photoreceptors to die!
***Causes:***
- traumatic iritis
- hit in eye
- pupil usually constricted
- hurts b/c of spasm from ciliary body
- dilate pupil can help pain
- infective
- [[Syphilis]]
- [[Tuberculosis]]
- HSV / CMV / VZV
- Toxoplasmosis
- Post-infectious
- systemic (eg rheumatologicla cause)
- HLA-B27
- Psoriatic arthritis
- Reactive arthritis
- Sarcoidosis (consider if also restrictive lung issues, skin findings in a female)
- Behcet syndrome (young adult with recurrent, painful oral apthous ulcers, genital ulcers, eye lesions (eg uveitis), skin lesions, thrombosis)
- 50% of cases are idiopathic
***Findings:***
- decreased visual acuity, pain, *consensual photophobia* (pain in symptomatic eye when unaffected eye is exposed to light), no discharge
- slit lamp: cell and flare (WBCs in anterior chamber)
![[Pasted image 20240328135407.png|ciliary flush: limbus around iris of inflammation. means inflammation is past conjunctivae, helpful to differentiate from conjunctivitis]]
![[Pasted image 20240328153351.png| more dramatic ciliary flush]]
**Treatment**
- dilate pupil
- +/- steroids (consult with opthal before giving steroids)
# less scary conditions
## Episcleritis
- benign, self-limiting inflammatory disease affecting the episclera (thin layer of tissue between conjunctiva and sclera (white of eye)
- abrupt onset painless [[Red eye]]
- distinct from [[#Iritis / uveitis / choroiditis|uveitis]] because uveitis is in the *anterior chamber* whereas episcleritis is superficial
- redness in eye due ot engorgement of the large episcleral blood vessels, which run in a radial direction from the limbus (pigmented zone between cornea, conjunctiva, and sclera
- most cases resolve in 7-10 days
- smoking tobacco delays response
- *nodular type* more aggressive and takes longer to resolve
- some cases can rarely progress to scleritis
***causes:***
- idiopathic (most common)
- vasculitis (polyarteritis nodosa, behcet disease, granulomatosis with polyangiitis)
- [[Systemic rheumatic diseases]] (rheumatoid arthritis, SLE, psoriatic arthritis, ankylosing spondylitis, [[Inflammatory Bowel Disease]]
- rare: lyme disease, TB, syphilis, herpes zoster
***DDx:***
- [[#Iritis / uveitis / choroiditis]] → patients often have similar risk factors and uveitis is more significant because it affects the anterior chamber
- [[#pinguecula]]
- [[#pterygium]]
- exclude evidence of [[#hypopyon]]
***Treatment:***
- lubricating eye drops
- d/w opthal if considering steroids
![[Pasted image 20250516120610.png]]
> [!caption] Eye with episcleritis
![[Pasted image 20250516120448.png]]
![[Pasted image 20250516120530.png]]
The corneal limbus manifests as a dark ring around the iris
## subconjunctival haemorrhage
- painless
- no vision loss
- sharp demarcation at limbus
- from trauma, valsalva, etc
- Tx: cold compresses, reassurance, resolves in weeks
## pinguecula
a chronic exposure to dry windy conditions. buildup of protein, fat, calcium. like a callus of the skin on the eye. can get inflamed. but no need for treatment.
![[Pasted image 20240328185859.png]]
## pterygium
similar to pinguecula but is a vascular triangular mass that grows from the nasal side towards the centre of eye, sometimes creeps in on cornea and into visual axis
![[Pasted image 20240328190018.png]]
# Cornea infection
## corneal abrasion
Doesn’t usually cause infection; often discharge with chlorsig eye drops and protection
See [[eye trauma#corneal foreign body]]
![[Pasted image 20250516120448.png]]
## keratitis
- diffuse, superficial, punctate keratitis
- pain, photophobia, redness, foreign body sensation
- causes:
- UV keratitis
- topical eye drug toxicity
- dry eye
- mild chemical injury
- Tx: artificial tears, topical abx to preventinfection , +/- cycloplegics for analgesia
![[Pasted image 20240328175854.png]]
> Do not keratitis confuse with *cataracts* which are painless. can happen after electrical injury. painless
## Corneal ulcers
- focal, white opacity
- +/- corneal epithelial defect
- pain, red, photophobia, vision defect
- ==pseudomonas in contact lens wearers can blind an eye in 1 day== → needs local abx therapy
- causes:
- bacterial
- fungal
- viral (HSV)
- refer to opthal (eg often treated with steroids)
- if branching/dendritic pattern, may be *herpetic*
![[Pasted image 20240328175931.png]]
# anterior chamber infections
## hypopyon
- purulence in the *anterior chamber* of eye
- can see white cells in anterior chamber
- need opthal referral
- ==not to be confused with== **[[eye trauma#hyphema]]** -- blood in the anterior chamber
![[Pasted image 20240328171949.png]]
## endophthalmitis
see guideline [here](x-devonthink-item://BD6E1E69-3E55-4455-8D0E-C46002590C65)
![[Pasted image 20240328172509.png]]
- extreme version of hypopyon
- infection of the **deep eye structures**
- pain and vision loss
- infected chambers hazy and opaque
- often caused by *ocular surgery* ; other causes include globe rupture, penetrating eye injury, foreign body
- Tx: ophthal referral, intraocular abx and systemic abx
# Periorbital and orbital cellulitis
> anatomical difference: is the infection past the orbital septum or not?
see: [RCH - periorbital and orbital cellulitis](https://www.rch.org.au/clinicalguide/guideline_index/Periorbital_and_orbital_cellulitis/)
![[Pasted image 20241108153511.png|orbital septum is tissue continuous w/ periosteum of the orbital rim and fuses with upper and lower eyelids]]
**periorbital (pre-septal) cellulitis** - minimal pain, lid oedema (give abx). no pain on EOMs
- kids > adults
- may be from another infection (eg *dental spread* or *sinusitis*
- ==strep, staph, H flu, gram negative, sinus organisms, MRSA, anaerobes==
- *cefalexin 33mg/kg* (max 1g) oral TDS or cefuroxime if mild periorbital cellulitis in kids
**orbital cellulitis** - looks sick, ==pain with eye movement==
- ptosis, oedema, proptosis, exopthalmosis +/- purulent discharge
- no conjunctivitis
- may have chemosis (oedema of conjunctiva)
- decreased, painful eye movements
- mgmt:
- CT orbits + contrast, inpatient IV abx
- *ceftriaxone* 50mg/kg (2g IV) od + *fluclox* 50mg/kg (2g) IV QID or Vanc if suspected MRSA
- swab for mcs, culture, and viral PCR if any discharge
- consider [[Lateral canthotomy]] and cantholysis if evidence of orbital compartment syndrome
> consider *H influenzae* in non-immunised children. otherwise S pneumo, S aureus, gram negatives common
**complications**
- meningitis
- sepsis
- orbital/subperiosteal abscess
- [[Cerebral venous thrombosis#Cavernous sinus venous thrombosis|cavernous sinus venous thrombosis]]
- [[Cranial nerve palsies]] in CN III-VI
- vision loss from elevated IOP
- retinal detachment
| | Preseptal cellulitis | Orbital cellulitis |
| -------------------- | --------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| cause | - local trauma<br>- infected chalazion<br>- dacrocystitis<br>- URTI<br>- severe conjunctivitis<br>- recent surg | - acute sinusitis<br>- posterior extension of preseptal cellulitis<br>- orbital trauma, surg, foreing body<br>- dental or facial infection<br>- dacrocystitis |
| appearance | systemically well | may be unwell |
| fever | variable | often febrile |
| eyelids | - inflamed and swollen<br>- fluctance ?lid abscess | same as preseptal |
| conjunctiva | usually normal | chemosis (conjunctival oedema) |
| orbital signs | normal | - restricted/painful eye movements → **early** sign<br>- proptosis (late finding)<br>- [[Diplopia]] |
| optic nerve | normal | - [[Relative afferent pupillary defect\|RAPD]] (late / **red flag** finding)<br>- ↓ visual acuity (later finding)<br>- may have change in colour, visual fields |
| posterior<br>chamber | normal | - +/- optic disc swelling |
![[Pasted image 20240915191514.png]]
CT showing inflammation of right orbit involving pre- and post-septal regions, gas in right orbit, and right ethmoid sinusitis, supporting *orbital cellulitis*
![[Pasted image 20241108154021.png]]
![[Pasted image 20241108154552.png|Orbital anatomy on CT]]
RCH decision schema for periorbital and orbital cellulitis:
![[Pasted image 20241108152714.png]]
**Chandler classification of orbital infections**
![[Pasted image 20250108123633.png]]
- **stage I**: preseptal orbital cellulitis with inflammation and edema anterior to the orbital septum.
- **stage II**: orbital cellulitis with extension of the inflammation and edema beyond the orbital septum.
- **stage III**: [subperiosteal abscess](https://radiopaedia.org/articles/subperiosteal-abscess-of-the-orbit?lang=us)beneath the periosteum of lamina papyracea.
- **stage IV**: orbital abscess and purulent collection within orbit.
- **stage V**: [[Cerebral venous thrombosis|cavernous sinus thrombosis]] after posterior extension of the infection through the superior ophthalmic veins.