Therapeutic Penetrating Keratoplasty In A Rare Case Of Corneal Abscess With Capnocytophaga Gingivalis: A Case Report.

To report a rare case of Capnocytophaga gingivalis necrotizing keratitis, which was managed with an urgent therapeutic penetrating keratoplasty, and a video demonstration of surgical steps for a large-diameter therapeutic corneal graft.

Capnocytophaga Gingivalis is an anaerobic fastidious gram-negative bacillus and has been reported as a causative agent of periodontitis, dental abscess, and necrotizing ulcerative gingivitis. Keratitis is rare, albeit an aggressive ocular infection, often associated with diffuse corneal involvement, extensive keratomalacia, and a poor prognosis.

 81-year-old male patient who was first seen three months ago in our eye clinic. He gave a past history of left eyelid papilloma, which was treated in 2016 with surgical excision and later with proton beam therapy for a recurrence. Then, the eye started to develop further problems, for which he underwent a tube shunt procedure for glaucoma and limbal epithelial transplant. He developed a post-operative infection, after which his cornea deteriorated.

He was diagnosed with a scarred, vascularized cornea, along with ocular surface features suggestive of possible recurrent papilloma. He was treated with alternate cycles of topical mitomycin C and prednisolone. He underwent an extensive evaluation of his left eye to determine the visual potential and was likely to be listed for a left corneal biopsy and/or limbal stem cell transplantation with keratoplasty. He was followed up on two weeks later and was doing well with the therapy.

Six weeks later, he returned to our clinic with a left-eye total corneal abscess with impending perforation. He gave a preceding history of tooth infection and was waiting for dental extraction. His corneal scraping culture came positive for Capnocytophaga gingivalis. He underwent an urgent therapeutic penetrating keratoplasty along with the removal of a hypermature brown shrunken cataract. One month post-op, his eye is settling  well with no signs of infection. However, the histology of the excised cornea shows intraepithelial neoplasia.

With promt intensive antibiotics and therapeutic keratoplasty, we have managed to salvage, which, in most cases of infection with this bacterial strain, has ended in enucleation.