Skip to Main Content

1. BACTERIAL KERATITIS

Risk factors for bacterial keratitis include contact lens wear—especially overnight wear—and corneal trauma, including refractive surgery. The pathogens most commonly isolated are staphylococci, including MRSA; streptococci; and Pseudomonas aeruginosa, Moraxella species, and other gram-negative bacilli. The cornea has an epithelial defect and an underlying opacity. Hypopyon may be present (eFigure 7–22). Topical fluoroquinolones, such as levofloxacin 0.5%, ofloxacin 0.3%, norfloxacin 0.3%, or ciprofloxacin 0.3%, are commonly used as first-line agents as long as local prevalence of resistant organisms is low (Table 7–2). For severe central ulcers, diagnostic scrapings can be sent for Gram stain and culture. Treatment may include compounded high-concentration topical antibiotic drops applied hourly day and night for at least the first 48 hours. Fourth-generation fluoroquinolones (moxifloxacin 0.5% and gatifloxacin 0.3%) are also frequently used in this setting. Although early adjunctive topical corticosteroid therapy may improve visual outcome, it should be prescribed only by an ophthalmologist.

eFigure 7–22.

Central corneal ulcer and hypopyon due to Pseudomonas keratitis. (Used with permission from Ahmed Al-Maskari and Daniel F P Larkin.)

When to Refer

Any patient with suspected bacterial keratitis must be referred emergently to an ophthalmologist.

+
Fernandes  M  et al. Extensively and pan-drug resistant Pseudomonas aeruginosa keratitis: clinical features, risk factors, and outcome. Graefes Arch Clin Exp Ophthalmol. 2016 Feb;254(2):315–22.
[PubMed: 26537122]
+
Herretes  S  et al. Topical corticosteroids as adjunctive therapy for bacterial keratitis. Cochrane Database Syst Rev. 2014 Oct 16;10:CD005430.
[PubMed: 25321340]
+
Jin  H  et al. Evolving risk factors and antibiotic sensitivity patterns for microbial keratitis at a large county hospital. Br J Ophthalmol. 2017 Nov;101(11):1483–7.
[PubMed: 28336675]
+
Lin  A  et al; American Academy of Ophthalmology Preferred Practice Pattern Cornea and External Disease Panel. Bacterial Preferred Practice Pattern®. Ophthalmology. 2019 Jan;126(1):P1–P55.
[PubMed: 30366799]
+
Marasini  S  et al. Clinical and microbiological profile of Pseudomonas aeruginosa keratitis admitted to a New Zealand tertiary centre. Clin Exp Ophthalmol. 2018 May;46(4):441–4.
[PubMed: 29053206]
+
Peng  MY  et al. Bacterial keratitis: isolated organisms and antibiotic resistance patterns in San Francisco. Cornea. 2018 Jan;37(1):84–7.
[PubMed: 29053557]
+
Tam  ALC  et al. Bacterial keratitis in Toronto: a 16-year review of the microorganisms isolated and the resistance patterns observed. Cornea. 2017 Dec;36(12):1528–34.
[PubMed: 28938380]

2. HERPES SIMPLEX KERATITIS

Primary ocular herpes simplex virus infection may manifest as lid, conjunctival, or corneal ulceration (eFigure 7–23). The ability of the virus to colonize the trigeminal ganglion leads to recurrences that may be precipitated by fever, excessive exposure to sunlight, or immunodeficiency. Herpetic corneal disease is typically unilateral but can be seen bilaterally in the setting of atopy or immunocompromise. The dendritic (branching) corneal ulcer is ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.