- Sight-threatening infection.
- Clinical features:
- Present as an acute, rapidly progressive corneal destructive
process or a chronic process.
- Predisposing factors include: corneal epithelial disruption
caused by trauma, contact lens wear, contaminated ocular medications
and impaired immune defense mechanisms.
- Symptoms: foreign body sensation, ocular pain, conjunctival
injection, photophobia, tearing and decreased vision.
- Signs: initial ulceration may progress to stromal infiltrate,
stromal abcess formation and necrosis or anterior segment inflammation.
- May be complicated with intraocular infection.
- Causative organisms include gram-positive cocci (Staphyloccocus
sp. Streptococcus pneumoniae), aerobic gram-negative bacilli (Pseudomonas
aerugenosa, Haemophilus influenzae, Moraxella catarrhalis.), enteric
gram-negative bacilli or colonization of normal skin flora (Staphylococcus
aureus, Streptococcus viridans).
- Work up:
- Corneal scrapings for stains and cultures. Consider additional
studies to rule out fungal, Acanthamoeba or mycobacterial infections
- Antimicrobial susceptibility testing.
- May culture the eyelid and conjunctiva, ophthalmic medication
bottles or tubes, contact lenses, contact lens cases and solutions.
- Broad-spectrum topical antibiotic therapy.
- Fortified subconjunctival or IV antibiotic are indicated if
infection does not respond to initial treatment.
- Topical corticosteroids may be used to prevent scarring.
- Therapeutic surgical penetrating keratoplasty is indicated
when corneal perforation occurs.