Ocular Microbiology and Immunology Group
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2017 OMIG Abstract 11

Diphtheroids as a corneal pathogen in chronic ocular surface disease
Grace Shih, Deborah S. Jacobs, Hajirah Saeed
Massachusetts Eye and Ear Infirmary, Boston, Massachusetts

Purpose: To characterize the presentation and natural history of diphtheroid keratitis

Methods: Retrospective medical record review.

Results: Four cases of culture proven diphtheroid keratitis were identified: Case 1: 59 year old M with acute Stevens-Johnson syndrome (SJS) 5 years earlier, with persistent epithelial defect that progressed to melting and perforation; Case 2: 70 year old M with acute SJS 6 months earlier and persistent epithelial defect with thinning; Case 3: 42 year old F with history of SJS over 20 years earlier, with epithelial defect, thinning, and focal opacity in the right eye (R), and 8 months later, epithelial defect and hypopyon in the left eye (L). Clinical findings and images were notable for lack of infiltrate typically associated with microbial infection. Diphtheroids were identified as the predominant organism in the initial culture of all 4 cases of keratitis. Speciation revealed Case 1: Corynebacterium glucuronolyticum, Case 2: Corynebacterium amycolatum, Case 3R: Corynebacterium striatum and Case 3L: Corynebacterium amycolatum, No sensitivities were recorded for the first case. All other cases were sensitive to vancomycin, and Case 2 and 3L were also sensitive to clindamycin and tetracycline. Case 3L was additionally sensitive to penicillin. Case 1 was stabilized with penetrating keratoplasty, amniotic membrane grafting, tarsorraphy, and postoperative moxifloxacin. The latter three cases healed with arrest of thinning on topical vancomycin. The focal opacity in Case 3R eye cleared over months. Retrospective review reveals associated risk factors of topical steroid use, SJS with keratinization, and PROSE treatment with overnight wear in all cases, as well as recent therapeutic soft lens (Cases 1, 2), prophylactic antibiotic use (Case1, 2, 3L: moxifloxacin; Case 1: gatifloxacin; Case 3R: ciprofloxacin), and systemic immune compromise (Case 1: Type II DM; Case 3: treatment of secondary chondrosarcoma of lung).

Conclusions: In contrast with other gram positive bacteria, diphtheroid corneal infections present in more indolent fashion. These cases exhibited persistent epithelial defects with gradual thinning and minimal injection, discharge, opacity or infiltrate. Clinicians should consider culture of a persistent epithelial defect in patients with multiple risk factors for infection, even in the absence of infiltration. Diphtheroids should be treated if they are identified as the dominant organism. Recognition and treatment of Corynebacteria spp. as opportunistic pathogens can lead to favorable outcomes in cases of seemingly sterile ulceration during the chronic phase of Stevens-Johnson syndrome.

2017 Agenda and Abstracts | < Previous Next >