Empiric antibacterial therapy
›Initial regimen selection by severity
›Mild to moderate suspected bacterial keratitis
›Fourth-generation fluoroquinolone monotherapy
›Moxifloxacin 0.5% ophthalmic
›Initiate 1 drop every 1 hour while awake
›If severe pain or high-risk features, initiate every 1 hour around the clock
›Gatifloxacin 0.5% ophthalmic
›Initiate 1 drop every 1 hour while awake
›If high risk, initiate every 1 hour around the clock
›Severe ulcer or sight-threatening features
›Fortified dual therapy
›Fortified tobramycin ophthalmic 14 mg/mL
›Initiate 1 drop every 1 hour alternating with second agent
›If fulminant, loading dose every 5 to 15 minutes for 1 hour then hourly
›Fortified cefazolin ophthalmic 50 mg/mL
›Initiate 1 drop every 1 hour alternating with aminoglycoside
›If gram negative concern, consider ceftazidime substitute per ophthalmology
›MRSA risk or poor response
›Fortified vancomycin ophthalmic per ophthalmology
›Dosing typically hourly initially
›Sensitivity-guided continuation
›Evidence notes for antibiotic choices
›Fluoroquinolone monotherapy and fortified combinations as common effective options
›Comparative effectiveness differences small across many regimens
›Time to healing varies by regimen in evidence synthesis
›AAO Preferred Practice Pattern support for culture in high-risk ulcers
Targeted pathogen pathways
›Herpes simplex keratitis suspicion
›Antiviral therapy
›Ganciclovir 0.15% gel
›Initiate 1 drop 5 times daily
›Taper per ophthalmology after epithelial healing
›Acyclovir PO 400 mg
›Initiate 5 times daily
›Duration per ophthalmology
›Steroid avoidance in epithelial HSV
›Ophthalmology-directed only
›Fungal keratitis suspicion
›Natamycin 5% ophthalmic
›Initiate 1 drop every 1 hour while awake
›Prolonged course expectation
›Voriconazole ophthalmic or PO per ophthalmology
›Escalation when natamycin nonresponse
›Acanthamoeba keratitis suspicion
›Biguanide therapy per ophthalmology
›PHMB 0.02%
›Initiate hourly initially
›Prolonged taper over months typical
›Chlorhexidine 0.02%
›Initiate hourly initially
›Combination strategy common
Adjunctive therapy and comfort
›Cycloplegia for pain and photophobia
›Cyclopentolate 1% ophthalmic
›Initiate 1 drop 2 to 3 times daily
›Atropine 1% ophthalmic
›Initiate 1 drop once to twice daily for severe spasm per ophthalmology
›Systemic analgesia
›Acetaminophen
›Dosing per age and weight
›NSAID oral if no contraindications
›Avoid topical NSAID when epithelial defect large
›Corneal melt mitigation adjuncts
›Doxycycline PO 100 mg
›Initiate twice daily when significant thinning or melt risk per ophthalmology
›Vitamin C supplementation per ophthalmology
›Collagen support rationale
Steroids and contraindications
›Topical corticosteroids
›Avoid initiation in ED without ophthalmology
›Risk of worsening undiagnosed fungal or HSV disease
›Adjunctive steroid evidence mixed
›Requires specialist selection and timing
›Contact lens precautions
›No contact lens wear until ophthalmology clearance
›Discard current lenses and case
Evidence levels and guideline framing
›Guideline alignment
›AAO Preferred Practice Pattern for bacterial keratitis as primary reference
›ACEP Level C style consensus mapping for ED actions
›Immediate topical antibiotic therapy for suspected microbial keratitis
›Urgent ophthalmology for high-risk features
›Class recommendation mapping
›Class I
›Immediate topical antimicrobial therapy when microbial keratitis suspected
›Same-day ophthalmology for central or severe ulcers
›Class IIa
›Corneal cultures for high-risk ulcers before antibiotics when feasible without delay
›Class IIb
›Adjunctive systemic agents for melt risk per specialist