Abstract
Purpose: :
Although it is very important to assess the risk of post-operative infection after corneal transplantation, there are few previous reports about conjunctival contamination of cadaver donor. So, we analyzed microbiologically the contamination of conjunctiva and corneoscleral rim of cadaver donor for corneal transplantation to predict post operative endophthalmitis.
Methods: :
A retrospective review of the culture results of 98 cadaver donor conjunctival swabs (female: 17 patients, 33 eyes; male: 34 patients, 65 eyes; mean age : 76.4±12.9 (standard deviation) years.), which underwent removal of corneoscleral loaves at Nagasaki eye bank from August 2007 to October 2008. We studied the detection rate of bacteria, the variety of detected bacteria, interval from death to harvest in hours, and age of donors, comparing before (group 1) and after (group 2) disinfecting with gentamycin.
Results: :
Microbial growth was found in 60/98 (61.2%) conjunctival swabs collected from group 1 eyes and in 36/98 (36.7%) of those obtained from group 2 (p=0.0006). Isolated microorganisms included coagulase-negative Staphylococcus (30.6% vs 23.4%, group 1 vs group 2, respectively), Corynebacterium (18.4% vs 8.2%), Staphylococcus aureus (11.2% vs 8.2%), Brahamella catarrhalis β-lactamase(+) (6.1% vs 2.0%). The detection rate of bacteria is significantly higher, the interval from death to harvest is longer than 10 hours in both group 1 and group 2. The mean age of culture positive donors (74.1±13.6years) was younger than culture negative (79.8±10.8years) in group 1 (p=0.024). We performed 22 operations of corneal transplantation at Nagasaki University Hospital. Of 22 corneal grafts, 2 (9.1%) had a positive donor rim culture and none had a positive medium (OptisolTM-GS). The isolated microorganisms of corneal grafts matched with that of conjunctiva after disinfection. In our cases we had not experienced endophthalmitis.
Conclusions: :
From the findings of this study, it is recommended to perform removal of corneoscleral loaves after disinfection with appropriate antibiotics, as early as possible to prevent endophthalmitis. The isolated microorganisms from corneal grafts and conjunctiva after disinfection were similar, so the information from conjunctival swab culture after disinfection may be useful to treat post-operative infection after corneal transplantation.
Keywords: bacterial disease • conjunctiva • cornea: storage