Effects of Contamination of Bottles of Zymar and Vigamox with Candida albicans on Incidence of PostL

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Effects of Contamination of Bottles of Zymar and
Vigamox with Candida albicans on Incidence of
Post-LASIK Corneal Flap Infection

• Ralph Chu, MDChu Vision InstituteEdina,
  Minnesota

This study was supported by an unrestricted
educational grant from Allergan, Inc. Poster
presented at American Society of Cataract and
Refractive Surgery (ASCRS) Symposium March
17-22, 2006 San Francisco, CA. This poster
addresses off label uses of Zymar and Vigamox.
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Purpose

• To compareclinical outcomes in
  rabbitspost-LASIK when administered Zymar
  (gatifloxacin 0.3 preserved with benzalkonium
  chloride (BAK) 0.005) or Vigamox (moxifloxacin
  0.5 without BAK) through bottlespreviously
  inoculated withCandida albicans

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Methods

• Twelve New Zealand White rabbits underwent
  aLASIK-type procedure A corneal flap was
  created using a trephine and an 8-mm blade at a
  depth of 125 to 150 µM
• Animals were assigned randomly to receive
  ophthalmic solutions of either gatifloxacin 0.3
  with BAK 0.005 (Zymar Allergan Inc. Irvine,
  CA n 6) or moxifloxacin 0.5 (Vigamox Alcon
  Inc. Ft. Worth, TX n 6)
• The bottles of ophthalmic solutions were
  previously inoculated to contain 3.7 105
  colony-forming units/mLof C albicans
• A single drop of inoculated antibiotic solution
  was placed under the flap, which was then replaced

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Methods

• Rabbits were checked twice daily for up to 5 days
  by a masked observer to identify signs of ocular
  infection, including inflammation, redness, flap
  slippage, andpawing by the rabbit
• Animals were sacrificed when eyes displayed
  clinicalsigns of infection or at day 5,
  whichever came first
• After the animal was sacrificed, the corneal flap
  was excised
• BSS-wetted Dacron swabs were wiped on the
  underside of the excised flap and across the
  cornea stroma
• The swabs were then streaked across Sabouraud
  plates and then placed in thioglycolate broth
  with dextrose, both of which were incubated at
  20C to 25C for 5 days

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Results Four of the Six Rabbits (67) Treated
With Vigamox Tested Positive for C Albicans by
Day 5
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Results Of the Four Vigamox-treated Rabbits
That Tested Positive for C Albicans, Three (50
Of 6 Total) Showed Clinical Signs of Infection,
Including Inflammation, Excess Tearing,
Discomfort, and Redness
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Results None of the Six Rabbits (0) Treated
With Zymar Tested Positive for C Albicans or
Showed Any Clinical Signs of Infection
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Conclusion
The results of this study demonstrate that
potential exists for the development of infection
after LASIK surgery fromyeast-contaminated
Vigamox bottles and possibly other ophthalmic
solutions not preserved with BAK