Corneal Ulceration (Suspected Infectious Keratitis) Initial Management
Corneal ulceration with an epithelial defect should be treated as an ocular emergency with immediate antimicrobial therapy while diagnostic sampling is arranged. [1] Management recommendations for suspected bacterial keratitis include stopping contact lens wear, initiating intensive topical antibiotics, obtaining cultures, and using cycloplegia for pain control. [2] Adjunctive topical corticosteroids are not routinely used at presentation because outcomes can be worse in certain bacterial subgroups and trials have not shown clear benefit overall. [3]
Diagnostic Evaluation and Sampling
When corneal ulceration is present, corneal cultures should be obtained for culture and sensitivity before or immediately after starting empiric therapy. [2] Diagnostic sampling should include conjunctival and corneal swabs when bacterial keratitis is otherwise presumed. [2]
Medication Selection Algorithm
Empiric therapy should target both Gram-positive and Gram-negative organisms when the etiology is not yet identified. [1]
- Fluoroquinolone monotherapy (including ofloxacin 0.3% or other fluoroquinolones) can be used as an empiric first-line option for suspected bacterial keratitis. [1]
- Fortified dual topical antibiotic therapy can be used as an empiric first-line option for suspected bacterial keratitis. [1]
- Antiviral therapy is indicated when herpes simplex dendritic ulceration is present, using ganciclovir ointment with ophthalmology follow-up within 72 hours. [2]
- Antifungal therapy should be considered when fungal keratitis is suspected, with topical amphotericin listed as an example of antifungal treatment. [2]
- Acanthamoeba-directed therapy should be considered when Acanthamoeba is suspected, with specific PCR testing arranged in the diagnostic workup. [2]
Empiric Dosing and Intensive Topical Antibiotic Therapy
A guideline-based regimen for bacterial keratitis includes:
- Ofloxacin 0.3% ophthalmic drops hourly (day and night) for corneal ulcers smaller than 1 mm. [2]
- Chloramphenicol ointment at night for corneal ulcers smaller than 1 mm. [2]
- Gentamicin 1.5% plus cefuroxime 5% drops hourly for at least 48 hours (day and night) for corneal ulcers larger than 1 mm. [2]
Monotherapy Versus Combination Therapy
Empiric management of suspected bacterial keratitis is described as either fluoroquinolone monotherapy or fortified cefazolin plus tobramycin in major practice guidance. [1] A local bacterial-keratitis guideline provides structured regimen choices based on ulcer size, using ofloxacin with nighttime chloramphenicol for smaller ulcers and fortified dual therapy for larger ulcers. [2]
Pain Control and Anti-Inflammatory Considerations
Cycloplegia is recommended in some corneal ulcer pathways to control pain and reduce ciliary spasm. [2] Adjunctive topical corticosteroids are supported by trial evidence showing no significant improvement in primary outcomes overall after the defined lead-in period of antibiotic therapy. [4] In SCUT subgroup analyses, corticosteroids were associated with worse infiltrate or scar outcomes in Nocardia ulcers, with a reported mean increase in 3-month infiltrate or scar size in that subgroup. [5]
Initiation Thresholds and Admission Criteria
Admission is recommended in the presence of severity or high-risk features, including:
- Corneal ulcer larger than 2 mm. [2]
- Central ulcer. [2]
- Hypopyon. [2]
- Impending corneal perforation. [2]
- Limbal or scleral involvement. [2]
- Likely poor compliance. [2]
Follow-Up and Diagnostic Escalation
Small ulcers may be reviewed within about 1 week, with earlier review when clinical concern exists. [2] A diagnostic workup should include urgent Gram stain and culture plates, with virology PCR and Acanthamoeba PCR included in one bacterial keratitis pathway. [2]
Quantified Evidence on Corticosteroid Adjuncts
SCUT evaluated 1.0% prednisolone sodium phosphate versus placebo as adjunctive therapy after at least 48 hours of topical moxifloxacin in culture-positive bacterial corneal ulcers. [4] At 12 months, the prespecified analysis showed no significant difference in best spectacle-corrected visual acuity or scar size by treatment group overall in the reported secondary outcomes paper. [4]
Common Pitfalls to Avoid
Topical corticosteroids should not be used empirically at presentation for suspected bacterial corneal ulcers because randomized trial data show lack of clear overall benefit and potential harm in Nocardia-associated disease. [3] Contact lens wear should be stopped when corneal ulceration is present. [2]