Effectiveness of voriconazole and corneal cross-linking on Phialophora verrucosa keratitis: a case report

Abstract

BackgroundWe report a rare case of Phialophora verrucosa fungal keratitis, which required various types of treatment according to the intractable natural history of the disease.Case presentationA 51-year-old Thai man with poorly controlled diabetes received a bamboo branch injury and developed a perforated corneal lesion on his left eye. A pathological study from therapeutic penetrating keratoplasty showed fungal hyphae. This was later identified as Phialophora verrucosa by polymerase chain reaction. This organism was aggressive and recalcitrant because it relapsed with two corneal grafts and was resistant to amphotericin B, natamycin, and itraconazole. However, we found that the efficacy of voriconazole was promising for treating Phialophora verrucosa. We also used corneal cross-linking to establish corneal integrity after the infection was under control.ConclusionsBecause of the chronic nature of Phialophora verrucosa, a patient’s first visit may occur many years after trauma, and sometimes clinical presentation might not appear to indicate fungal infection. Therefore, a high index of suspicion is needed in this situation. Voriconazole showed good results in our case. Instead of using a more invasive keratoplasty, we used corneal cross-linking to strengthen the corneal biomechanics. To the best of our knowledge, this is the first case showing the benefit of corneal cross-linking to improve corneal biomechanics in resolved Phialophora verrucosa keratitis.

Phialophora chinensis fungal keratitis: An initial case report and species identification

“… 6 Taechajongjintana et al showed no response of Phialophora to amphotericin B, natamycin, or itraconazole, but susceptibility to voriconazole. 2 In contrast, Banitt et al reported no activity of voriconazole, fluconazole, or amphotericin against P. verrucosa. 21 Hirst et al only eradicated the Phialophora infection after penetrating keratoplasty due to clinical progression despite aggressive topical and systemic antifungal treatment.…”

“…2 A–G) . After a literature search noted promising results in treating a recalcitrant P. verrucosa keratitis infection with corneal cross-linking (CXL), 2 this was performed for our patient. Following CXL treatment (Dresden protocol), 10 there was a clinical improvement, and topical and oral antifungals were maintained.…”

“…Phialophora are commonly found in tropical areas, and infection most commonly results from a traumatic inoculation. 1 In addition to causing chronic cutaneous and subcutaneous tissue infection, Phialophora have been implicated in mycotic keratitis 2 , 3 , 4 , 5 , 6 and endophthalmitis. 7 , 8 Nearly all Phialophora ocular infections have been attributed to P. verrucosa.…”

Use of corneal cross-linking beyond keratoconus: a systemic literature review

“…Thakur et al (2019) used the Dresden protocol against a fungal "phaco-tunnel" infection which proved successful, but the partial success of intracameral and intrastromal antifungal injections was likely a factor, and early presentation and treatment may also have roles [65]. There are also more cases [45,[66][67][68] with success attributed to PACK-CXL, but CXL protocols were not provided.…”

Antifungal Combination Eye Drops for Fungal Keratitis Treatment

“…Fungal keratitis (FK) is a corneal mycotic infection mainly caused by corneal trauma with contaminated plants or objects [ 1 , 2 ], the misuse of contact lenses [ 3 , 4 ], prolonged use of topical antibiotics or corticosteroids [ 5 ], eye surgeries [ 6 ], or the immunocompromised state of the patient [ 7 , 8 ], among others. FK is a severe disease that can lead to vision loss or even the complete loss of the eye.…”