Bacterial Keratitis

Publication Date: February 11, 2024
Last Updated: February 16, 2024


The majority of community-acquired cases of bacterial keratitis that are small noncentral ulcers resolve with topical empiric therapy. However, smears and/or cultures are specifically indicated in certain circumstances. (, , )

Contact lens wear is the number-one risk factor for microbial keratitis in the United States. Overnight wear (including orthokeratology) is a major risk factor for infection. In many other parts of the world trauma is the leading risk factor for bacterial keratitis. (, , )

Topical antibiotics should be prescribed to prevent acute infection in patients with a corneal abrasion who wear contact lenses or suffered trauma. In these patients, patching the eye early on is not advised because these increase the risk of secondary bacterial keratitis.

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When treating microbial keratitis, corticosteroids may be considered after 48 hours of antibiotic therapy when the causative organism is identified and/or the infection has responded to therapy. Corticosteroids should be avoided in cases of suspected Acanthamoeba, Nocardia, or fungus. The efficacy of the therapeutic regimen is judged primarily by the clinical response. In Pseudomonas and other gram-negative keratitis, there may be increased inflammatory signs during the first 24 to 48 hours despite appropriate therapy. (, , )

Froom 2005 to 2015 there was increased resistance of methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa to topical fluoroquinolones. (, , )

Recommendation Grading



Bacterial Keratitis

Authoring Organization

Publication Month/Year

February 11, 2024

Last Updated Month/Year

February 19, 2024

Document Type


External Publication Status


Country of Publication


Document Objectives

Recognize and reduce risk factors that predispose patients to bacterial infection of the cornea. Establish the diagnosis of bacterial keratitis and differentiate it from other causes of keratitis. Utilize appropriate diagnostic tests. Select appropriate therapy to resolve the keratitis. Relieve pain. Establish appropriate follow-up. Prevent complications such as medication toxicity, intraocular infection, cataract, corneal perforation, and loss of vision due to corneal scarring. Educate patients and their families about treatment and ways to reduce risk factors in the future.

Inclusion Criteria

Female, Male, Adolescent, Adult, Child, Older adult

Health Care Settings

Ambulatory, Emergency care, Operating and recovery room, Outpatient

Intended Users

Optometrist, nurse, nurse practitioner, physician, physician assistant


Diagnosis, Management

Diseases/Conditions (MeSH)

D003316 - Corneal Diseases, D007634 - Keratitis, D020795 - Photophobia


blurred vision, Bacterial Keratitis, Pseudomonas aeruginosa

Source Citation

Rhee MK, Ahmad S, Amescua G, Cheung AY, Choi DS, Jhanji V, Lin A, Mian SI, Viriya ET, Mah FS, Varu DM; American Academy of Ophthalmology Preferred Practice Pattern Cornea/External Disease Panel. Bacterial Keratitis Preferred Practice Pattern®. Ophthalmology. 2024 Feb 12:S0161-6420(24)00007-1. doi: 10.1016/j.ophtha.2023.12.035. Epub ahead of print. PMID: 38349295.

Supplemental Methodology Resources

Data Supplement


Number of Source Documents
Literature Search Start Date
March 3, 2022
Literature Search End Date
June 7, 2023