Microbial keratitis after penetrating keratoplasty: impact of sutures.

Purpose: To determine the impact of presence or absence of sutures in cases with post-penetrating keratoplasty (PKP) microbial keratitis.

Design: A 10-year retrospective chart review of post-PKP patients admitted with microbial keratitis at the Royal Victorian Eye and Ear Hospital, Melbourne, between January 1998 and December 2008 was undertaken.

Methods: Patients were categorized in 2 groups, "sutures present" and "sutures absent." Main parameters evaluated were clinical and microbiological profile and treatment outcome.

Results: One hundred and twenty-two episodes of microbial keratitis were noted in 101 patients: 71 (58.2%) with sutures present and 51 (41.8%) with sutures absent. Overall, pseudophakic bullous keratopathy was the most common indication for keratoplasty (P=.92). Ocular surface disorder was the commonest risk factor associated with the occurrence of infection in both groups (P=.17). Infections caused by Moraxella sp. (P=.001) were significantly more common in the "sutures absent" group. Surgical interventions were required for 47 episodes (39%), with corneal gluing performed in significantly higher number of cases in the "sutures absent" group (40% vs 15%; P=.05). Multivariate analyses did not reveal any significant associations. Final mean visual acuity outcome was poorer in the "sutures absent" group (logMAR 2.10 ± 0.92 vs 1.76 ± 0.96; P=.04).

Conclusions: Corneal graft infections, in the presence and absence of sutures, share similar indications and risk factors. However, infections caused by indolent microorganisms were more prevalent in grafts without sutures. This group of patients required a higher number of surgical interventions in the form of corneal gluing and the overall visual outcome was poor.