Cornea pathologic response

 

defects/repair

fibrosis/vascularization

edema/cysts

inflammation/immune response

deposits

proliferation

 

infectious crystalline keratopathy (ICK)

adjacent to suture tracks

little/no adjacent inflammation early on

lesion appearance likely due to architecture of stroma allowing for crystalline appearance and spread

 

assoc with: pk, topical steroid use, ctl wear, presumed hsv

also assoc with: corneal relaxing incisions, topical anesthetic abuse, acanthamoeba infection, epithelial defect, post-LASIK infections

 

caused by:

strep viridans (42%), coag-neg staph, fungus

pathogens gain access to stroma via suture track

preceding topical steroid use inhibits inflammatory response

 

inflam response also inhibited by exopolysaccharide production by streptococci, biofilm surrounds and isolates bacteria

both mechs block complement pathway, dec inflam response

 

ddx:

corneal dystrophy, lipid keratopathy, localized fb, calcium deposition

 

diag:

corneal scraping, culture, especially suture material, corneal biopsy

 

therapy:

topical abx (diff penetration), consider continuing steroid use (withdrawal may lead to inflammatory response)

 

outcome:

50% require repeat PK

alternatively,  expect slow resolution over months without surgical intervention

 

conclusions:

ick has unique clinical presentation, often with min early inflam

diagnostic challenge due to depth and appearance of lesion

therapeutic challenge due to depth of lesions, often requires PK