Paecilomyces Fungal Keratitis: Combining Multiple Strategies to Improve the Outcome of Severe, Pesticide-Associated Fungal Keratitis

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Paecilomyces Fungal Keratitis Combining Multiple
Strategies to Improve the Outcome of Severe,
Pesticide-Associated Fungal Keratitis

• Jonathan Etter, MD, Matthew Caldwell, MD,
  Christopher Boehlke, MD, Anthony Kuo, MD, Brad
  Feldman, MD and Alan N. Carlson, MD
• Dept. of Ophthalmology, Duke University Medical
  Center, Durham, NC
• Authors have no financial interest.
• This poster describes technology used in a
  compassionate and off-label capacity.

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Purpose

• We report the development of severe
  Paecilomyces keratitis in two patients who came
  in close contact with an pesticide containing
  this organism, leading to rapid and severe
  progression of fungal keratitis. In one patient,
  we appeared to improve the clinical course by
  using the femtosecond laser (IntraLaseTM FS
  laser, Advanced Medical Optics, Inc., Santa Ana,
  CA) to create a strategically placed lamellar
  keratectomy in an attempt to facilitate the
  penetration and effectiveness of topical
  antifungal medication. Despite this initial
  improvement, both patients required therapeutic
  penetratrating keratoplasty (PK) to manage the
  aggressive course commonly associated with this
  highly resistant organism.

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Patient 1
A 60 yo woman presented with a corneal
infiltrate. After negative scrapings a corneal
biopsy was performed that identified the
causative organism as Paecilomyces lilicanus. The
infiltrate worsened despite aggressive antifungal
treatment. Vision was hand motion. Numerous
surgical options were discussed, including
penetrating keratoplasty. Femtosecond-assisted
superficial keratectomy was offered as a
compassionate treatment in an attempt to reduce
the infectious load and allow for better exposure
to topical antifungal medications.
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Femtosecond Keratectomy, Step 1

• The femtosecond laser (IntraLase) was used to
  create a 6 mm diameter flap with a thickness of
  100 microns. A raster pattern was used with an
  energy of 1.0 millijoules. The flap was
  completely removed and pathology confirmed a high
  density of fungal organism.

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Femtosecond Keratectomy, Step 2

• Once the flap was removed and the plaque was
  exposed, a Maloney blade and forceps were used to
  dissect the infectious core away from the
  underlying stroma. One drop each of voriconazole,
  amphotericin, chlorhexadine and polyhexamethaline
  biguanide (PHMB) were applied directly to the
  excision site.

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Follow-up Visits
Five Weeks Later
Seven Weeks Later

• Five weeks after femtosecond keratectomy, there
  was decreased injection and a smaller infiltrate.
  At 7 weeks after the procedure, the infiltrate
  continued to evolve into a scar, the hypopyon
  resolved and vision improved to 20/60.

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Two Months Later
PAS stain of Paecilomyces plaque removed from
our patient during femstosecond-assisted
treatment.

• After two months of stability, following taper of
  antifungal drops, the patient demonstrated
  evidence of a mild flare of her infection on
  exam. We were able to perform Penetrating
  keratoplasty under much improved circumstances
  (ie. with much less inflammation present)
  compared to when the patient initially presented.
  Currently, the patient is doing well without
  evidence of recurrence.

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Patient 2
Corneal perforation in the second patient
presenting with Paecilomyces keratitis.

• A second patient presented the same week as
  Patient 1. This patient also noted a recent
  exposure to commercial pesticides and presented
  with Paecilomyces keratitis. The patients
  infection evolved into a corneal perforation
  within 48 hours. Emergent penetrating
  keratoplasty was performed. Currently, this
  patient is also doing well without any evidence
  of infection after corneal transplant.

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Paecilomyces
Right Image from www.moldtestingma.com

• Paecilomyces is a filamentous fungus found in
  soil and decaying plants. It is used in some
  pesticides because of its ability to kill
  nematodes. Paecilomyces rarely causes infection
  in immunocompetent humans however, corneal
  infection is often devastating and extremely
  difficult to treat medically as the organism is
  often resistant to antifungal medication.

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Results
Patient 2 after penetrating keratoplasty.

• The laser-created keratectomy performed in one of
  our patients appeared to improve the clinical
  course initially, presumably by removing organism
  and improving contact between the remaining
  infection and topical treatment. Both patients
  however, underwent penetrating keratoplasty to
  manage this aggressive infection.

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Conclusion

• We recommend stronger labeling and education
  regarding the risks of severe fungal infection
  associated with pesticide contact. Combining
  multiple medical and surgical strategies may be
  needed to eradicate aggressive infection and in
  one of our cases, lamellar keratectomy using the
  femtosecond laser appeared to provide substantial
  benefit in temporarily stabilizing aggressive
  fungal keratitis.