What is the likely diagnosis and recommended management for a patient with a week‑old left corneal abrasion from eye rubbing, persistent discomfort despite preservative‑free artificial tears?

Likely Diagnosis: Non-Healing Corneal Abrasion with Risk of Secondary Infection

This patient requires immediate escalation to topical fluoroquinolone antibiotic drops (moxifloxacin 0.5% or gatifloxacin 0.5%) four times daily, as the one-week duration without improvement indicates treatment failure and significantly increases the risk of bacterial keratitis. 1, 2

Critical Assessment Required Immediately

The persistent discomfort after one week despite lubricant drops is a red flag that demands:

• Fluorescein staining examination under cobalt-blue light to confirm the abrasion is still present and assess for signs of infection (infiltrate, suppuration, or stromal involvement) 1, 3
• Evaluation for incomplete eyelid closure during sleep, which significantly impairs corneal epithelial healing 1, 4
• Assessment for contact lens wear history (even if not currently wearing), as this dramatically increases Pseudomonas keratitis risk 1, 2
• Examination for corneal infiltrate, which would indicate progression to bacterial keratitis requiring urgent ophthalmology referral 1, 2

Why Lubricant Drops Alone Are Insufficient

Preservative-free artificial tears provide symptomatic relief but do not prevent bacterial infection, which is the primary concern in any corneal abrasion. 1, 4 The American Academy of Ophthalmology mandates that all patients with corneal abrasions receive topical broad-spectrum antibiotic drops started within 24 hours of injury to prevent bacterial keratitis and ulceration. 1, 2 This patient is already one week out—well beyond the optimal 24-hour window—making antibiotic prophylaxis even more critical now. 1, 2

Immediate Management Algorithm

Step 1: Initiate Antibiotic Coverage NOW

• Prescribe fluoroquinolone drops (moxifloxacin 0.5% or gatifloxacin 0.5%) four times daily until complete epithelial healing is confirmed 1, 2
• Fluoroquinolones are preferred because they achieve superior corneal tissue penetration and provide broad-spectrum coverage against both gram-positive and gram-negative organisms 1, 4
• If the patient has ANY history of contact lens wear, mandatory antipseudomonal fluoroquinolone coverage is required due to dramatically increased Pseudomonas keratitis risk 1, 2

Step 2: Pain Management

• Over-the-counter oral acetaminophen or NSAIDs for residual discomfort 1, 2
• Topical NSAIDs (ketorolac 0.5%) can significantly reduce pain at 24 and 48 hours and decrease oral analgesia use by 53% 5, 6

Step 3: Address Healing Impairment

• Evaluate for inadequate blinking or incomplete eyelid closure during sleep, which significantly impairs healing 1, 4
• Consider placement of a bandage contact lens for persistent epithelial defects that fail to re-epithelialize, but ONLY with concurrent topical prophylactic broad-spectrum antibiotic to decrease infection risk 7, 1
• If a bandage contact lens is used, patients must be informed of infectious keratitis risk and instructed to contact you immediately if redness, pain, or increased photophobia develops 7

Critical Red Flags Requiring IMMEDIATE Ophthalmology Referral

Obtain emergent ophthalmology consultation if ANY of the following are present:

• Central infiltrate >2 mm 1, 2
• Significant stromal involvement or corneal melting 1, 2
• Corneal infiltrate with suppuration, necrosis, or feathery margins suggesting bacterial keratitis 1, 2
• Increasing pain, purulent discharge, or vision changes despite treatment 1, 2
• Irregular pupil after trauma 1, 2
• Eye bleeding or loss of vision 1, 2

What NOT to Do (Common Pitfalls)

• Do NOT continue lubricant drops alone—this patient needs antibiotics 1, 4
• Do NOT patch the eye—patching does not improve pain, may delay healing, and increases infection risk 1, 2, 3
• Do NOT use combination steroid-antibiotic drops as initial therapy—steroids delay healing and increase infection risk 1, 2
• Do NOT use topical corticosteroids initially; they should only be added after 2-3 days of antibiotic-only therapy if bacterial infection is controlled 1, 2
• Do NOT allow the patient to rub the eye, as this worsens the injury and causes further corneal damage 1, 4

Follow-Up Protocol

• Re-evaluate within 24 hours to assess healing and detect early infection 1, 2
• Regular follow-up is necessary to monitor healing and detect early signs of infection 1, 4
• Patient education is essential: instruct on infection warning signs (increasing pain, discharge, vision changes) and the need for prompt ophthalmologic care if these develop 1, 2

Special Considerations for This Patient

Given the one-week duration without improvement, consider:

• Underlying conditions such as diabetes or Parkinson's disease, which affect healing 4
• Chronic ocular surface disease (severe dry eye, entropion, lagophthalmos), which requires enhanced vigilance 1, 2
• Prior corneal surgery, which significantly increases infection risk 1, 2

Treatment Escalation if Bacterial Keratitis Develops

If the abrasion progresses to bacterial keratitis with deep stromal involvement, central location, infiltrate >2 mm, hypopyon, or corneal stromal loss:

• Obtain cultures before antibiotic initiation 1
• Initiate loading dose every 5-15 minutes, then hourly dosing 1, 2
• Consider fortified antibiotics (tobramycin 1.5% + cefazolin 10%) for severe cases 1, 4
• Fourth-generation fluoroquinolones have demonstrated at least equivalent efficacy to fortified combination therapy 1, 4, 2

Important Caveat

Chronic prophylactic antibiotic use promotes resistant organisms and should only be used for finite treatment periods during the healing phase. 1, 2 Increasing resistance of MRSA and Pseudomonas to fluoroquinolones has been documented, highlighting the need for judicious use. 4, 2 However, in this patient with a week-old non-healing abrasion, the risk of bacterial keratitis far outweighs concerns about antibiotic resistance.