Lecture 13 Corneal infiltrative events Flashcards
What are other terms for keratitis?
-corneal infiltrative event
-corneal inflammatory event
What are infiltrates?
White blood cells in corneal tissue as part of the body’s inflammatory response to presence of bacterial toxins
What is a corneal ulcer?
*Epithelial defect with underlying inflammation
*May be infective or non-infective
In what ways can you classify corneal infiltrative events?
Ulcerative vs. non-ulcerative
Suppurative vs. nonsuppurative
-Does it produce discharge (pus) or not
-not all microbial keratitis present with discharge
Central vs. peripheral keratitis
What corneal infiltrative events can you get?
clinically insignificant and asymptomatic:
-asymptomatic infiltrates
-asymptomatic infiltrative keratitis
clinically non-significant and symptomatic:
-infiltrative keratitis
-contact lens-induced red eye (CLARE)
-Contact lens-induced peripheral ulcer (CLPU)
serious and symptomatic:
-microbial keratitis
What can cause asymptomatic infiltrates?
What are the signs?
What is the management?
*Induced by environmental factors such as air pollution
*1 or more small (<0.2mm) discrete grey-white patches usually in periphery
*They are usually intraepithelial
*Formed from inflammatory cells
*No other signs of inflammation
*Patient lens care review
*Maybe review if concern over compliance and large number of infiltrates
What are the signs of asymptomatic infiltrative keratitis?
What is the management?
*Small focal infiltrates
*Up to 0.4mm
*Sub epithelial
*May be small punctate staining
*Mild limbal and/or bulbar redness
*Cease Lens Wear
*Review Patient
*Review fitting and advise against sleeping in lenses
What is infiltrative keratitis?
What are the signs?
What are the symptoms?
What is the management?
-An inflammatory reaction of the cornea
-characterised by anterior stromal infiltration
- with or without epithelial involvement, in the mid periphery to periphery of the cornea’
*Single (in some cases multiple) small round infiltrates in epithelium or anterior stroma
*May be unilateral or bilateral
*Sectorial bulbar and/or limbal hyperaemia
*Epithelium generally does not stain
*Minor infiltrates may be asymptomatic
*Discomfort, FB sensation, irritation
*Possible mild photophobia, lacrimation
*Symptoms reduce on lens removal
*Remove the cause e.g. use of particular solution or FB under lens etc
*Cease lens wear
*Use of lubricants for symptomatic relief
*Treat marginal disease
*Monitor progress
What causes CLARE?
what is the dd?
What are the signs?
What are the symptoms?
What is the management?
Inflammatory reaction of the cornea and conjunctiva immediately following a period of eye closure with CL wear due to endotoxins from gram negative bacteria
Differential diagnosis: microbial keratitis
*Acute, unilateral circumferential bulbar conjunctival hyperemia
*Small mid peripheral infiltrates.
*If severe, mild anterior chamber involvement
*Wake up in middle of the night with a painful red eye
*Lacrimation
*Photophobia
*FB sensation
*Self-limiting
*Remove lens
*Monitor-12-24 hrs to ensure correct diagnosis
*Ocular lubricants
*Address lens compliance and lid hygiene as appropriate
*Daily wear – Possible refit
*Prognosis good
What is a contact lens peripheral ulcer?
What is the differentiating factor to MK?
*Inflammatory reaction with focal excavation of the epithelium, infiltration, and necrosis of the anterior stroma
*Bowmans layer usually remains intact
*Differentiating factor: you get clear cornea between the ulcer and the limbus
What are the signs of CLPU?
What are the symptoms?
What is the management?
*Usually single, unilateral, small sterile infiltrate in the peripheral cornea (<1.5mm)
*Clear cornea between ulcer and limbus
*Epithelium may stain
*Defined margins
*Mild sectoral hyperemia
*No lid oedema
*If severe, a mild AC reaction
*50% will be asymptomatic
*Possible FB Sensation
*Mild photophobia
*Lacrimation
*General lens intolerance
*Cease lens wear until resolved ~ 2 weeks
*Self-limiting but careful monitoring over first 24-48 hours – MK risk
*Ocular lubricants
*Possible prophylactic antibiotics
*Address any lid margin disease
*Address compliance regime – consider modality
*Advise A and E if they get symptoms of microbial keratitis
*Good prognosis – corneal scar likely
What are the associations of CLPU?
*Greater incidence in extended wear
*inflammatory response
*Related to bacteria but not bacterial infection
*Bacterial contamination, hypoxia
*Tight lens
*Poor hygiene, lid margin disease
What pathogens usually cause fungal keratitis?
What can it be wrongly diagnosed as?
What are the associations?
What are the signs?
What are the symptoms?
What is the management?
Candida sp. Or Fusarium sp.
bacterial keratitis
*Most likely in patients with an immune disorder
*Associated with trauma with vegetative material (hit by tree branch)
*Unilateral
*Hyperemia
*Lacrimation
*Hypopyon
*Lid oedema
-Pain
-Photophobia
-Vision reduction
-FB Sensation
-slower onset than bacterial keratitis
*Cease lens wear
*Emergency Referral
*Topical anti-fungals
*May require a corneal graft
What are the signs of acanthamoeba keratitis?
What are the symptoms of acanthamoeba keratitis?
What is the management?
*Begins as a nonspecific keratitis with infiltrates along the corneal nerves in a radial pattern.
*Ring infiltrate typically appears later in the disease process,
*Same as MK
*Not as much hyperaemia but a lot of pain
*Immediate referral to HES
*May be mistaken for viral infection (Herpes simplex)
*Culture maybe taken
*Treated with broad spectrum antibiotics
*Look closely at lens care (water contact)
What is microbial keratitis?
Infection of the cornea characterized by excavation of the corneal epithelium, Bowman’s layer, and stroma with infiltration and necrosis of tissue
