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

Abstract

Background: We 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 presentation: A 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.

Conclusions: Because 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.

Keywords: Corneal cross-linking; Fungal keratitis; Phialophora verrucosa; Voriconazole.

Fig. 1

Slit lamp photograph of the left eye demonstrating multiple sites of corneal perforation, totally flat anterior chamber, and loss of the amniotic membrane

Fig. 2

Pathologic sections of the diseased cornea demonstrating abnormal organisms with branching hyphae within posterior corneal stroma. a Grocott-Gomori methenamine silver stain. b Periodic acid–Schiff stain

Fig. 3

Slit lamp photograph of the left eye demonstrating the first corneal graft with pigmented endothelial plaques at inferior half

Fig. 4

Clinical photograph of the second corneal graft on second postoperative day demonstrating inferior pigmented endothelial plaque with pigmented keratic precipitates

Fig. 5

Clinical photograph of the second corneal graft after the infection was controlled. a A large persistent epithelial defect with corneal graft perforation at 6 o’clock position. b The same eye after gluing, botulinum toxin injection, and corneal cross-linking

Fig. 6

Timeline. BCL bandage contact lens, AMT amniotic membrane transplantation, ICM intracameral injection, TPK therapeutic penetrating karatoplasty, KOH potassium hydroxide, C/S culture, PCR polymerase chain reaction