Internal Medicine

0521779407-C03 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 20:54

404 Corneal Ulcer

tests

Laboratory

■Corneal scraping for cytology & culture/sensitivities

differential diagnosis

Infectious:

■Bacterial: most common; corneal infections assumed bacterial

unless clinical characteristics or lab studies direct otherwise

■Fungal: consider after trauma, infiltrates feathery edges, satellite

lesions

■Acanthamoeba: extremely painful, history of swimming w/contact

lenses

■Viral: herpes simplex or zoster, may have eyelid vesicles, dendritic

pattern of epithelial staining

Other:

■Corneal abrasion: epithelial defect w/ edema, no stromal opacity

■Corneal scar: stromal opacity w/out epithelial defect, redness, or

pain

■Sterile ulcer: not infectious, culture negative, seen in collagen vas-

cular diseases, neurotropic keratopathy, vernal or atopy, vitamin A

deficiency

■Subepithelial infiltrates: follow viral conjunctivitis, epithelium intact

■Staphylococcal hypersensitivity: peripheral infiltrates, often multi-

ple

■Residual corneal foreign body or rust ring

management

What to Do First

■Corneal scraping for culture & sensitivities: blood & chocolate

agar (bacteria), thioglycolate broth (aerobic & anaerobic bacteria),

Sabouraud medium w/out cyclohexamide (fungi)

■Corneal scraping for cytology: gram & giemsa stains, KOH prep if

fungus suspected

■Swab cultures of palpebral conjunctiva & eyelids if significant dis-

charge

General Measures

■Prompt treatment required if suspicion of bacterial corneal ulcer

■Institute local therapy immediately after cultures

■No systemic antibiotics for bacterial corneal ulcers