Medical and surgical management of Pasteurella canis infectious keratitis

INTRODUCTION We describe a case of refractory Pasteurella Canis keratitis that initially failed antimicrobial treatment but was successfully treated with a conjunctival flap followed by a penetrating keratoplasty. CASE DISCUSSION A 70-year-old male had persistent corneal edema related to previous herpes zoster keratouveitis with visual acuity of 20/400. An endothelial keratoplasty was performed with improvement in vision to 20/25. Several months after this surgery the patient developed a corneal infiltrate and cultures grew Pasturella canis. The infection persisted despite topical treatment with broad spectrum fortified vancomycin, tobramycin and fluoroquinolones. A conjunctival flap combined with corneal cryotherapy was performed to help mitigate symptoms and to allow the ulcer to heal. A penetrating keratoplasty was done several months later. DISCUSSION The patient achieved pain relief immediately after the flap was placed. Medications were tapered off in the following few months after the procedure. A penetrating keratoplasty was performed 4 months later. The patient has remained almost entirely symptom free, and the graft remained clear one year after surgery. CONCLUSIONS A keratitis caused by Pasteurella canis that is resistant to medical therapy can be treated successfully with a conjunctival flap and cryotherapy followed by a penetrating keratoplasty.