What is the recommended management for a contact lens wearer who develops a contact‑lens‑associated keratitis?

Management of Contact Lens-Associated Keratitis

Immediately remove the contact lens after thorough handwashing, discontinue all lens wear until complete corneal healing is confirmed by an ophthalmologist, and initiate topical fluoroquinolone monotherapy (moxifloxacin 0.5%, levofloxacin 1.5%, or ciprofloxacin 0.3%) every 1-2 hours while awake for small, non-central ulcers—but escalate to fortified antibiotics for large, central infiltrates or those with hypopyon. 1, 2

Immediate Actions

Lens Removal Protocol

• Perform meticulous hand hygiene with soap and water, dry completely with a lint-free method, then gently remove the lens without using any water, saliva, or non-sterile fluid. 3
• Never rinse the removed lens with tap water, bottled water, or homemade saline—only sterile commercial contact lens solution may be used, though the lens should be discarded if infection is confirmed. 1, 3
• Do not patch the eye after lens removal, as patching dramatically increases the risk of bacterial keratitis progression. 2

Urgent Ophthalmology Evaluation Triggers

• Moderate to severe ocular pain, purulent discharge, unilateral presentation, photophobia, or recent water exposure (swimming, showering, hot tubs) while wearing contacts all warrant same-day ophthalmologic assessment. 3, 4
• Unilateral pain is particularly concerning for infectious keratitis rather than simple irritation, especially with water exposure history suggesting possible Acanthamoeba keratitis. 4, 2

Antibiotic Treatment Algorithm

For Small, Non-Central Ulcers

• Initiate fluoroquinolone monotherapy with moxifloxacin 0.5%, levofloxacin 1.5%, or ciprofloxacin 0.3% applied every 1-2 hours while awake initially, then taper based on clinical response. 2
• Reassess within 24 hours to evaluate treatment response and detect early treatment failure. 2

For Large, Central, or Severe Ulcers

• Escalate immediately to fortified antibiotics when infiltrates are large, centrally located, or accompanied by hypopyon. 2
• Fortified cefazolin 50 mg/ml (for gram-positive coverage) combined with fortified tobramycin or gentamicin 14 mg/ml (for gram-negative coverage) represents the standard dual-therapy approach. 1
• Preparation: Add 9.2 ml artificial tears to 1 g cefazolin powder, dissolve, then mix 5 ml of this solution with 5 ml artificial tears; for tobramycin/gentamicin, withdraw 2 ml from injectable 40 mg/ml vial and add to 5 ml ophthalmic solution bottle. 1

Adjunctive Therapy

• Add cyclopentolate 1% or homatropine 5% three times daily to decrease synechiae formation and reduce pain from anterior segment inflammation. 2
• Avoid topical corticosteroids initially, as they delay healing and increase infection risk; reserve for later inflammatory management only after infection control is established. 2

Microbiological Workup

• Obtain corneal scrapings for smears (Gram stain, Giemsa) and culture (blood agar, chocolate agar, Sabouraud agar) before starting antibiotics in all sight-threatening cases. 2
• Bacterial pathogens account for 90% of contact lens-associated keratitis, with Pseudomonas aeruginosa being the leading cause, followed by Acanthamoeba (especially with water exposure) and fungi in severe cases. 5, 6

When to Escalate Further

• Consider systemic antibiotics (oral fluoroquinolones) when scleral extension, intraocular extension, or systemic infection is present. 2
• Emergency corneal transplantation may be required in 20-30% of fungal and Acanthamoebic infections that fail medical management. 5

Critical Prevention Education for Future Lens Use

Water Avoidance (Non-Negotiable)

• Never swim, shower, use hot tubs, bathe, or wash hair while wearing contact lenses, as water exposure—particularly swimming and showering—is strongly associated with Acanthamoeba keratitis development. 1
• Overnight wear increases corneal infection risk fivefold compared to daily wear, even with lenses approved for extended wear; even occasional overnight wear carries significant risk and should be strongly discouraged. 1

Lens Care Hygiene

• Replace contact lens cases at least every 3 months, as cases are a major source of lens contamination and persistent microbial colonization. 1
• Use only fresh disinfecting solution each time; never "top off" old solution with new, as this practice perpetuates contamination. 1
• Hydrogen peroxide systems may be superior to preserved disinfecting solutions in reducing pathogen binding and providing cysticidal disinfection, though they require more complex care regimens. 1

Common Pitfalls to Avoid

• Waiting for symptoms to improve without professional evaluation allows rapid progression to permanent vision loss, as contact lens-associated keratitis can advance quickly. 3
• Resuming lens wear after redness resolves without corneal examination by an eye care professional leads to recurrence and chronic complications. 3, 4
• Using ocular ointments as primary therapy results in poor corneal penetration and inadequate treatment. 2
• Patient self-reported compliance with hygiene practices is unreliable—studies show only 34% of patients who believe they are compliant actually exhibit good lens care practices, despite 86% reporting compliance. 1

Follow-Up After Resolution

• Review contact lens fit, type, wearing schedule, and care regimen comprehensively; consider switching to daily disposable lenses, high DK/T ratio silicone-hydrogel materials, or reducing daily wearing time. 4
• Discuss alternative vision correction methods such as spectacles or refractive surgery, as recurrent keratitis risk remains elevated in contact lens wearers. 4
• Schedule regular examinations every 1-2 years to monitor ocular health, lens fit, and reinforce proper hygiene practices. 1