Infectious Corneal Disorders Flashcards
what G+ bacteria are implicated in infectious keratitis
staph aureus & strep pyogenes
what G- bacteria are implicated in infectious keratitis
pseudomonas aeruginosa & neiserria gonorrhea
what does staph require to cause an infectious keratitis
significant corneal epithelium compromise
how does neiserria gonorrhea cause an infectious keratitis
it can penetrate intact corneal epithelium
what viruses are implicated in infectious keratitis
herpes simplex & herpes zoster
what fungi are implicated in infectious keratitis
aspergillus, fusarium & candida
what parasites are implicated in infectious keratitis
acanthamoeba
when pain = presentation of infectious keratitis, what organism causes the infection
bacterial & viral
when pain < presentation of infectious keratitis, what organism causes the infection
fungal
when pain»_space; initial presentation of infectious keratitis, what organism causes the infection
acanthamoeba
what are the common signs of infectious keratitis
- conjunctival hyperemia
- anterior chamber inflammation
- large epithelial ulceration overlying corneal infiltrate
what is the major risk factor for infectious keratitis & why
CL wear
- corneal epithelial hypoxia
- bacterial adherence to lens surface
what are other risk factors for developing an infectious keratitis
- trauma
- ocular surface diseases
- immunosuppression (HIV/AIDS, diabetes)
corneal infiltrates are
leukocyte infiltration into corneal stroma
is a hypersensitivity reaction to an antigen an infectious or non-infectious corneal infiltrate
non-infectious
when the immune system is directly battling an infectious organism, is that a infectious or non-infectious corneal infiltrate
infectious
corneal infiltrates: infectious or non-infectious
- larger & solitary
infectious
corneal infiltrates: infectious vs. non-infectious
- peripheral/scattered
non-infectious
corneal infiltrates: infectious vs. non-infectious
- overlying epithelial defect stains well w/ NaFl
infectious
corneal infiltrates: infectious vs. non-infectious
- anterior chamber inflammation
infectious
corneal infiltrates: infectious vs. non-infectious
- commonly unilateral
infectious
corneal infiltrates: infectious vs. non-infectious
- milder level of discomfort
non-infectious
corneal infiltrates: infectious vs. non-infectious
- injected “angry” eye
infectious
when should a corneal culture be performed
- when ulcer does not respond to aggressive therapy
- a large, central ulcer is present
- case history & clinical presentation point away from the common organisms