cornea and external eye diseases Flashcards
4 RFs of subconjunctival haemorrhage
- trauma
- blood thinners
- HTN
- valsava manoeuvre
presentation of subconjunctival haemorrhage
- sudden onset red eye
- painless
- no BOV
mx of subconjunctival haemorrhage
conservative - reassure
if no RFs and recurrent, work up for haematological abnormalities
3 types of keratitis (corneal infection)
viral
bacterial
fungal
which types of keratitis should be referred
herpetic (dendritic ulcer)
bacterial keratitis
fungal keratitis
viral keratitis main features
vision affected (but not too bad), some pain
features of bacterial keratitis
contact lens, trauma
ulcer, abscess
pain ++, poor vision
features of fungal keratitis
immnocompromised
trauma
herpetic keratitis main causes
herpes simplex virus 1 more common than 2
symptoms of herpetic keratitis
red eye
pain
tearing
photophobia
clinical signs of herpetic keratitis
conjunctival injection
reduced corneal sensation
dendritic or geographic ulcers (stain with fluorescein) - epithelial keratitis
stromal infiltratino and corneal edema - stromal keratitis
3 RFs for herpetic keratitis
- reduced host immunity (eg HIV)
OR long term immunosuppression - recent ocular surgery
mx of herpetic keratitis
topical acyclovir (epithelial keratitis)
+/- topical steroids (stromal/endothelial keratitis)
immunocompromised or children: oral acyclovir
recurrent HK: oral acyclovir for prophylaxis
avoid topical steroids in epithelial keratitis
cx of herpetic keratitis
- recurrence
- neurotrophic keratopathy with persistent epithelial defect or ulcer
- stromal scarring –> high astig
herpes zoster ophthalmicus (HZO)
Caused by reactivation of varicella zoster virus
Manifests as a painful vesicular rash along the CN V1 nerve
clinical features of HZO
- painful vesicles or pustules (crust and heal within 2-6 weeks) along the V1 dermatome
- +/- corneal sensation, VA
- raised IOP
- conjunctival injection on slit lamp
- hutchinson’s sign
hutchinson’s sign
tip of nose rash: increased risk of corneal involvement (nasociliary branch affected)
3 RFs for HZO
- adv age
- psychological stress
- immunocompromised
mx for HZO
- isolate pt
- oral acyclovir
- acyclovir ointment if there is corneal involvement
- topical abx cream to skin lesions
- steroid eye drops if there is ocular inflammation
LT cx from HZO
- Neurotrophic keratopathy due to impaired corneal innervation
- Post-herpetic neuralgia (10–17%)
neurotrophic keratopathy
degenerative disease of the cornea caused by damage of the trigeminal nerve, which results in impairment of corneal sensitivity, spontaneous corneal epithelium breakdown, poor corneal healing and development of corneal ulceration, melting and perforation.
in herpetic keratitis and HZO
bacterial keratitis common organisms (4)
- Staph aureus
- Strep pyogenes
- Strep pneumoniae
- Psuedonomas aeruginosa
4 RFs for bacterial keratitis
- contact lens wear
- contaminated water contact with eye
- trauma
- prolonged use of topical steroids
hypopyon without corneal ulcers with clear cornea
anterior uveitis or endopthalmitis
hypopyon with hazy cornea
keratitis
hypopyon
accumulation of white blood cells that form a whitish layer of fluid in the lower portion of the eye’s anterior chamber –> severe inflammation or infection
clinical signs of bacterial keratitis
HCCCCEA
1. hypopyon
2. conjunctival injection
3. corneal infiltrate
4. corneal ulcer
5. corneal edema
6. epithelial defect
7. anterior chamber reaction
symptoms of bacterial keratitis
- pain
- watering and discharge
- decreased vision
- photophobia
inx of bacterial keratitis
- corneal scraping to send for gram stain, fungal smear and culture, aerobic and anerobic culture
- send contact lens solution for culture
abx and other meds for bacterial keratitis
- topical cefazolin and gentamicin
- topical cycloplegia
- systemic abx if sclera involved
what to avoid in bacterial keratitis?
topical steroids
specific gram stain and culture of cornea scrapings
blood agar - most fungi and bacteria except neisseria
choc agar - neisseria and moraxella
sabourand agar - fungi
cx of bacterial keratitis
- corneal melt and perforation
- corneal scar
common causes of fungal keratitis
yeast: candida sp
filamentous: fusarium
RFs for fungal keratitis
- trauma especially organic matter
- immunocompromised
- prior topical steroid use
signs of fungal keratitis
- subacute
- feathery margins
- endothelial plaques
- satellite lesions
- immune ring
fungal keratitis: corneal scrapings to send for
- gram stain
- sabourad agar
mx of fungal keratitis
topical and systemic antifungal therapy
when should topical steroids be avoided
- epithelial keratitis in herpetic keratitis
- infective keratitis (bacterial, fungal)
indicated in
1. stromal or endothelial keratitis in herpetic keratitis - risk of scarring
2. HZO
3. psuedomembrane conjunc
conjunctivitis - safe (treat and watch)
- typical hx (contact, URTI, tearing)
- little pain, good vision (6/12), bilateral, watery discharge, conjunctival injection
conjunctivitis - not safe (refer early/immediately)
PPAC
1. atypical hx - contact lens users, trauma
2. pain, poor vision, purulent discharge (bacteria)
3. corneal involvement
4. prolonged course (>1 week)
allergic conjunctivitis
- acute allergic conjunct
- seasonal/perennial conjunct
- atopic keratoconjunct (AKC)
- vernal keratoconjunct (VKC)
- contact lens related
acute allergic conjunct sx
- lid edema/erythema
- conjunctival chemosis
- watery or mucoid discharge
- no papillae or corneal involvement (same for seasonal or perennial conjunc)
seasonal allergic conjunct triggers
pollen during spring
perennial allergic conjunct triggers
all year round, caused by animal dander, feathers or dust mites
VKC features
- giant papillae or cobblestone papillae
- limbitis / Horner trantas dots
- shield ulcer
sight threatening
AKC features
- papillary hypertrophy (seen on lid eversion) –> eyelid thickening and scarring
- periocular dermatitis
AKC a/w
- atopic dermatitis and asthma
- anterior and posterior subcapsular cataracts
AKC vs VKC epidemiology
AKC usually 5-20 yo males
VKC usually teenage to 50 year olds, chronic course with periodic acute exacerbations
4 common sx for all allergic conjunctivitis
- intense itch
- intermittent red eyes (conjunctival injection) - chronic
- lid swelling
- thick ropy mucoid discharge
cx from untreated VKC or AKC
KLCCCC
- keratoconus
- loss of eyelashes
- conjunc scarring
- corneal neovascularisation
- corneal ulcer
- corneal scarring
shield ulcers
due to accumulation of fibrin and mucus, at upper 2/3 of cornea
Changes in tarsal Conjunctiva rubbing against cornea - shield ulcers
not infective in nature, can use topical steroids for mx
RFs for allergic conjunc
- atopic hx of asthma, allergic rhinitis or eczema
- young male
mx of allergic conjunct (systemic)
- allergen avoidance
- skin prick test
- control of other allergies
mx of allergic conjunct (ocular)
- topical mast cell stabilisers, anti-histamines, immunomodulators
- topical lubricants
- topical steroids
- cold compress
most common cause of viral conjunc
adenovirus
sx of viral conjunc
- sequential red eyes
- sticky discharge
- tearing
- itch
- a/w recent URTI, lymphadenopathy, contact hx
6 clinical findings for viral conjunc
CCCPPH
1. conjunc injection
2. conjunc follicular reaction
3. haemorrhage
4. pseudomembranes
5. preauricular lymphadenopathy
6. corneal involvement - epithelial defects, keratitis etc
mx of viral conjunc
- topical lubricants
- self limiting 1-2 weeks
- good hand hygiene - viral conjunc is contagious
cx from viral conjunc
- corneal epithelial defect
- dry eyes
- numular keratitis (presence of anterior stromal infiltrates) - treat with topical steroids if risk of scarring
causes of psuedomembrane conjunc
herpes, strep, adenovirus
mx of psuedomembrane conjunc
- Peel off membranes
- Lubricants
- Topical steroids +/- abx cover
- Contact and hygiene precautions
common causes of bacterial conjunc
- Staph aureus
- Staph epidermis
- Strep pneumoniae
- Haemophilus influenzae
vs for bacterial keratitis
1. Staph aureus
2. Strep pyogenes
3. Strep pneumoniae
4. Psuedonomas aeruginosa
symptoms of bacterial conjunc
- subacute onset
- redness
- mucopurulent discharge
- burning/grittiness
- bilateral
signs of bacterial conjunc
- Crusty lids
- Conjunctival hyperaemia
- Mild papillary reaction
- Lids and conjunctiva may be edematous
mx for bacterial conjunc
topical abx eg chloramphenicol
chlamydial conjunctivitis
- follicular
- +/- keratitis
gonococcal conjunctivitis
- purulent
- keratitis and corneal perforation in severe cases
inx for chlamydial conjunc
conjunc scraping: direct IF stain or PCR
inx for gonococcal conjunc
G stain and culture on choc agar or thayer-martin
episcleritis vs scleritis
episcleritis: inflammation of superficial episcleral vessels of the eye, benign
scleritis: inflammation of deeper scleral vessels, sight threatening, systemic condition requiring systemic inx TRO autoimmune conditions
both have red eye
symptoms of episcleritis
- asymptomatic
- lid tearing/irritation
- tender to touch
- vessels blanch with phenylephrine
self limiting
symptoms of scleritis
**1. eye pain **
2. watering and photophobia
3. appearance violaceous (localised, diffuse, nodular)
4. signs of previous ocular surgery (eg pterygium excision or corneal wound - surgically induced necrotising scleritis)
inx for scleritis
- B scan ultrasonography - T sign
- systemic workup TRO infective and autoimmune conditions - FBC, ESR, RF, ANA, ANCA
mx for episcleritis
- topical NSAIDs
- topical steroids (rare)
- lubricants
mx for scleritis
- treat underlying condition (RA)
- NSAIDs
- corticosteroids
- immunosuppression
scleritis most commonly a/w
RA
cx of scleritis
- necrotising anterior scleritis - scleral thinning and perforation
- raised IOP
- serous retinal detachment
