Paecilomyces Fungal Keratitis Combining Multiple Strategies to Improve

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.

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 (Intra. Lase. TM 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.

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.

Femtosecond Keratectomy, Step 1: The femtosecond laser (Intra. Lase) 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.

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.

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.

Two Months Later PAS stain of Paecilomyces plaque removed from our patient during femstosecondassisted 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.

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 patient’s 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.

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.

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.

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.