Eye Ointment for Cat Scratch
For a cat scratch injury to the eye, apply a broad-spectrum topical antibiotic ointment such as erythromycin or bacitracin to prevent bacterial keratitis, and ensure urgent ophthalmology evaluation within 24 hours.
Immediate Management
A cat scratch to the eye represents a high-risk corneal trauma that requires prophylactic antibiotic coverage. The 2024 Bacterial Keratitis Preferred Practice Pattern explicitly states that topical antibiotics should be prescribed to prevent acute bacterial keratitis in patients presenting with corneal abrasion following trauma 1. This strategy prevents both bacterial and fungal infection.
Recommended Antibiotic Ointments
First-line options include:
- Erythromycin 0.5% ophthalmic ointment - This is the standard prophylactic agent used in ophthalmology 2
- Bacitracin ophthalmic ointment - Equally effective for prophylaxis 3
Apply the ointment to the affected eye 3-4 times daily for 5-7 days, or as directed by the ophthalmologist.
Critical Considerations for Cat Scratch Injuries
Why This Injury Is High-Risk
Cat scratches carry specific infectious risks beyond typical corneal abrasions:
Bartonella henselae (Cat Scratch Disease) - While systemic cat scratch disease typically presents with lymphadenopathy, ocular involvement can cause severe complications including panuveitis, neuroretinitis, and vision-threatening inflammation 4. If ocular cat scratch disease develops, azithromycin is the treatment of choice: 500 mg on day 1, then 250 mg daily for 4 additional days (for patients >45 kg) 5.
Polymicrobial contamination - Cat claws harbor multiple bacterial species that can cause rapid-onset keratitis.
Deep corneal penetration - Cat scratches often create deeper wounds than other types of trauma.
Mandatory Ophthalmology Referral
Urgent ophthalmology evaluation is non-negotiable for several reasons:
- Assessment of corneal integrity using fluorescein staining to determine extent of epithelial loss 6
- Evaluation for globe penetration or deeper injury
- Monitoring for development of infectious keratitis over the first 48-72 hours
- Detection of early signs of cat scratch disease ocular involvement
The ophthalmologist should examine within 24 hours and re-evaluate at 48 hours if symptoms worsen (increased pain, photophobia, or vision changes) 1.
Red Flags Requiring Immediate Emergency Evaluation
Seek immediate emergency ophthalmology care if any of these develop:
- Worsening pain after initial improvement
- Increasing redness or discharge
- Vision loss or blurring
- Severe photophobia
- White or cloudy appearance of the cornea
- Hypopyon (layered white material in anterior chamber)
Common Pitfalls to Avoid
Do not use topical corticosteroids initially - Steroids are contraindicated in the acute phase of suspected infectious keratitis and can worsen outcomes if infection is present 1. They should only be added after at least 2-3 days of progressive improvement with antibiotics and after fungal infection has been ruled out 1.
Do not assume "it's just a scratch" - The prophylactic antibiotic approach is evidence-based and has been shown to prevent ulceration following corneal abrasion 1. The economic and visual morbidity costs of missing early bacterial keratitis far outweigh the minimal risks of short-term prophylactic antibiotics.
Avoid fluoroquinolone drops for simple prophylaxis - Reserve these for established keratitis to prevent resistance development. Ointment formulations (erythromycin, bacitracin) provide better corneal contact time and are preferred for prophylaxis 3.
Patient Education Points
Instruct the patient to:
- Apply ointment as prescribed even if symptoms improve
- Avoid rubbing the eye
- Watch for warning signs of infection (listed above)
- Keep follow-up appointments even if feeling better
- Avoid contact lens wear until fully healed and cleared by ophthalmology