Methicillin-Resistant Staphylococcus aureus Keratitis: Initial Treatment, Risk Factors, Clinical Features, and Treatment Outcomes

Am J Ophthalmol. 2020 Jun:214:119-126. doi: 10.1016/j.ajo.2020.03.017. Epub 2020 Mar 21.

Abstract

Purpose: To analyze the clinical characteristics, management choices, and outcomes of cases of methicillin-resistant Staphylococcus aureus (MRSA) keratitis.

Design: Retrospective interventional case series.

Methods: Fifty-two culture-proven (52 eyes) cases of MRSA keratitis diagnosed and treated at the University of Pittsburgh Medical Center were identified and reviewed.

Results: The mean age was 66.6 ± 19.2 years with a median follow-up time of 147 days. The most prevalent risk factors included a history of ocular surgery (62.5%), topical corticosteroid use (35.4%), and dry eye syndrome (37.5%). There was a high burden of systemic disease (95.8%). The average presenting logarithm of minimal angle of resolution visual acuity was 1.7 ± 0.8 and the average final logarithm of minimal angle of resolution visual acuity was 1.2 + 1.0. Initial antibiotic treatment varied, with 20.8% receiving moxifloxacin alone, 20.8% receiving fortified cefazolin and fortified tobramycin together, and 12.5% receiving fortified vancomycin and fortified tobramycin, although other antibiotics were used during treatment if warranted. Surgical management was often required as 17.3% of eyes perforated: 13.5% required tarsorrhaphy, 5.8% required penetrating keratoplasty, and 1 eye was enucleated. When patients treated with fourth-generation fluoroquinolones were compared with those treated with fortified vancomycin, no difference in final visual acuity, treatment duration, or need for surgery was found.

Conclusion: MRSA causes fulminant keratitis often requiring surgical management with poor visual acuity outcomes. Poor ocular surface, topical corticosteroid use, previous ocular surgery, and/or a high burden of systemic disease were identified as common risk factors. Patients treated with fluoroquinolones in our study had comparable outcomes to those treated with fortified vancomycin; however, those treated with fortified vancomycin tended to have more severe ulcers at presentation.

MeSH terms

  • Administration, Ophthalmic
  • Adult
  • Aged
  • Aged, 80 and over
  • Anti-Bacterial Agents / therapeutic use*
  • Cefazolin / therapeutic use
  • Corneal Ulcer / diagnosis
  • Corneal Ulcer / drug therapy*
  • Corneal Ulcer / microbiology
  • Drug Combinations
  • Eye Infections, Bacterial / diagnosis
  • Eye Infections, Bacterial / drug therapy*
  • Eye Infections, Bacterial / microbiology
  • Female
  • Humans
  • Male
  • Methicillin-Resistant Staphylococcus aureus / isolation & purification*
  • Middle Aged
  • Moxifloxacin / therapeutic use
  • Ophthalmic Solutions
  • Retrospective Studies
  • Risk Factors
  • Staphylococcal Infections / diagnosis
  • Staphylococcal Infections / drug therapy*
  • Staphylococcal Infections / microbiology
  • Tobramycin / therapeutic use
  • Treatment Outcome
  • Vancomycin / therapeutic use

Substances

  • Anti-Bacterial Agents
  • Drug Combinations
  • Ophthalmic Solutions
  • Vancomycin
  • Cefazolin
  • Moxifloxacin
  • Tobramycin