What is the treatment for keratitis in the eye?

Treatment of Keratitis in the Eye

For bacterial keratitis, the most effective treatment is topical fluoroquinolones (moxifloxacin 0.5%) or fortified antibiotics (vancomycin + ceftazidime) administered frequently, with the specific regimen determined by the severity and location of the infection. 1, 2

Treatment Algorithm Based on Type of Keratitis

Bacterial Keratitis

1. Initial Empiric Treatment:

   • For central or severe keratitis (deep stromal involvement, infiltrate >2mm with suppuration, or hypopyon):

     • Loading dose: Apply drops every 5-15 minutes initially
     • Maintenance: Apply hourly
     • Consider fortified antibiotics (cefazolin 5% + tobramycin 1.3%) 1, 2

   • For non-severe/peripheral keratitis:

     • Fluoroquinolone monotherapy: Moxifloxacin 0.5% or gatifloxacin 0.3% every 1-2 hours 1, 2
     • Alternative options: Ciprofloxacin 0.3%, ofloxacin 0.3%, or levofloxacin 1.5% 1

2. Specific Pathogen Considerations:

   • MRSA: Vancomycin (fortified) 1
   • Multidrug-resistant Pseudomonas: Colistin 0.19% 1
   • Moraxella: Requires prolonged treatment (average 41.9 days) 1

Fungal Keratitis

• First-line treatment: Natamycin 5% ophthalmic suspension 3, 4
• Apply every 1-2 hours initially, then taper as clinical improvement occurs

Herpetic Keratitis

• First-line treatment: Ganciclovir 0.15% ophthalmic gel 5
• Dosing: 1 drop 5 times daily until corneal ulcer heals, then 1 drop 3 times daily for 7 days 5

Acanthamoeba Keratitis

• Polyhexamethylene biguanide or chlorhexidine 4

Adjunctive Treatments

1. Pain Management:

   • Cycloplegic agents to decrease pain from inflammation and prevent synechiae formation 1, 2
   • Oral analgesics (acetaminophen, NSAIDs) 2
   • Topical NSAIDs for pain relief 2

2. Supportive Care:

   • Preservative-free lubricants every two hours to maintain corneal moisture 2

Monitoring and Follow-up

1. Reassessment Schedule:

   • Every 24 hours until improvement is noted 2
   • Look for: reduced pain, decreased discharge, lessened eyelid edema, and reduced conjunctival injection 2

2. Treatment Modification:

   • Consider changing therapy if no improvement within 48 hours 2
   • For bacterial keratitis, treatment should continue until complete healing 1, 2

Special Considerations

1. Contact Lens Wearers:

   • Avoid pressure patching and bandage contact lenses due to higher risk of secondary infection 1
   • Discontinue contact lens wear during treatment 5

2. Resistance Concerns:

   • Increasing resistance to fluoroquinolones has been reported, particularly in MRSA 1
   • Fourth-generation fluoroquinolones (moxifloxacin, gatifloxacin) have better gram-positive coverage than earlier generations 1, 6

3. Severe Cases:

   • Consider subconjunctival antibiotics for imminent scleral spread or perforation 1
   • Systemic antibiotics rarely needed except for gonococcal keratitis or when infection extends to adjacent tissues 1

When to Refer to Ophthalmology

• Immediate referral (same day) for suspected bacterial keratitis or serious ocular infection 2
• For minor corneal abrasions without signs of infection, refer within 24 hours 2

Treatment Efficacy

Recent evidence suggests that vancomycin + ceftazidime combination therapy, moxifloxacin monotherapy, and cefazolin + tobramycin combination therapy may be the most effective treatments for bacterial keratitis in terms of healing time 6. However, fluoroquinolones generally cause less ocular discomfort and chemical conjunctivitis compared to aminoglycoside-cephalosporin combinations 7.