Corneal abrasions in contact lens wearers may have sight threatening consequences. Contact lenses can compromise the corneal epithelium and act as pathogenic vectors, facilitating the development of bacterial keratitis. Most corneal abrasions heal quickly when treated with topical antibiotics, which act as lubricants and antimicrobial agents. However, in contact lens wearers there may be rapid progression to corneal scarring or even perforation.

Two patients with contact lens related corneal abrasions, who were initially treated with topical fusidic acid or chloramphenicol, have presented with corneal stromal abscesses. The abscesses developed 12 hours and three days respectively after diagnosis of simple corneal abrasion. Visual acuity was perception of light and hand movements. Both required admission for intensive topical fortified guttae gentamicin and guttae cephalosporin.

Pseudomonas aeruginosa and proteus were grown, which were resistant to chloramphenicol and fusidic acid. Best corrected visual acuities were 2/60 and 6/36 after resolution of the infections; one patient has proceeded to corneal grafting.

A 15 year study of resistance in bacterial isolates from corneal scrapings found that 30.4% of isolates were resistant to chloramphenicol¹ (54% of Gram negative organisms), with a significant increase in resistance during this period. Once microbial keratitis is established, a combination of topical fortified aminoglycoside and cephalosporin or fluoroquinolone is indicated²; no trend for increasing resistance to these antibiotics was observed in the aforementioned study.¹

Contact lenses are the most important risk factor for the development of bacterial keratitis.³ In the emergency department, a history of contact lens wear should be sought, with urgent review of worsening abrasions. We advise that all contact lens related red eyes should be referred to the ophthalmology department, as clinical signs may initially be subtle and corneal scraping may be warranted. Timely commencement of guttae ofloxacin with the first sign of infection, may greatly reduce the chance of poor outcome.

Contributors

Shauna Quinn treated the second patient, reviewed the literature and wrote the paper. Jeffrey Kwartz treated both patients and contributed to the discussion of core ideas. He was the supervisor and is the guarantor.