When should steroid drops be started in the treatment of a corneal ulcer?

Timing of Steroid Drop Initiation in Corneal Ulcer Treatment

Topical corticosteroid therapy should be added to the treatment regimen following at least 2 to 3 days of progressive improvement with topical antibiotic treatment, typically after identification of the pathogen and after fungal infection has been ruled out. 1

Evidence-Based Approach to Steroid Initiation

The timing of steroid drop initiation in corneal ulcer treatment requires careful consideration of both potential benefits and risks:

Initial Management

1. Begin with appropriate topical antibiotic therapy based on clinical presentation
2. Obtain corneal cultures before initiating antibiotics when possible
3. Monitor clinical response for at least 48 hours
4. If patient is already on topical steroids at presentation, reduce or eliminate them until infection is controlled 1

When to Start Steroids

• Timing: After 2-3 days of antibiotic therapy showing progressive improvement 1
• Prerequisites before starting steroids:
  • Identification of causative organism (when possible)
  • Evidence of epithelial defect healing and/or ulcer consolidation
  • Fungal infection has been ruled out
  • No evidence of Nocardia infection (poor outcomes with steroids) 1

Patient Selection Factors

Steroids may be particularly beneficial in:

• Corneal ulcers with central involvement compromising the visual axis 1
• More severe cases (ulcers covering central 4mm pupil or vision of counting fingers or worse) 1
• Pseudomonas keratitis 1, 2
• Non-Nocardia bacterial ulcers 2, 3

Monitoring and Follow-up

After initiating steroid therapy:

• Examine patient within 1-2 days of starting steroids 1
• Monitor intraocular pressure (IOP) regularly 1, 4
• Use minimum amount of steroid required to control inflammation 1
• Discuss risks of long-term steroid therapy (cataract, glaucoma) with patient 1, 4

Important Cautions and Contraindications

Avoid Steroids In:

• Nocardia keratitis (associated with poor visual outcomes) 1, 3
• Fungal keratitis (may increase risk of requiring penetrating keratoplasty) 1
• Mpox-related corneal ulcers (may lead to worsening infection) 5
• Uncontrolled infection without appropriate antibiotic coverage 4

Potential Complications:

• Recurrence of infection
• Local immunosuppression
• Inhibition of collagen synthesis (risk of corneal melting)
• Increased intraocular pressure
• Risk of infectious crystalline keratopathy with chronic use 1

Clinical Decision Algorithm

1. Start appropriate antibiotic therapy based on clinical presentation and cultures
2. Monitor for clinical improvement for 2-3 days
3. If improving and pathogen identified (not Nocardia or fungal):
   • Consider adding steroids if central cornea involved or severe presentation
   • Use minimum effective dose
4. If not improving after 48 hours:
   • Modify antibiotic therapy based on culture results
   • Defer steroid initiation
5. Follow up within 1-2 days after starting steroids
6. Continue monitoring for adverse effects and clinical response

The Steroids for Corneal Ulcers Trial (SCUT) found that earlier administration of steroids (within 2-3 days) resulted in better visual outcomes than later administration (after 4 or more days), with approximately 1-line better visual acuity at 3 months compared to placebo 1, 2.