Internal and external contamination of donor corneas before in situ excision: bacterial risk factors in 93 donors.
BACKGROUND
Most studies of corneal donor contamination concentrate on postenucleation contamination of the eyeball. The purpose of the present study was to evaluate the relative contamination of in situ excised corneal tissue and relevance to final success or rejection by recipients of the corneal grafts.


METHODS
Ninety-three donors underwent anterior chamber puncture (ACP) and corneal epithelium scarification (CS) before and after disinfection with 5% povidone-iodine. Following in situ excision, corneas were preserved in culture medium at +35 degrees C. Morphological and bacteriological assessment was carried out after culture, and recipients were followed up over a 2-year period.


RESULTS
Samples taken by ACP, CS before disinfection, CS after disinfection and a culture medium sample were contaminated by bacteria in, respectively, 8 (8.6%), 23 (24.7%) 4 (4.3%) and 5 (5.4%) donors. Contamination of aqueous humor was significantly associated with age, death-to-sample time and premortem systemic infection. Contamination of epithelium significantly increased culture medium contamination.


CONCLUSIONS
External bacteria on donor cornea are mainly skin bacteria (especially Staphylococcus) and can be partially eliminated by a povidone-iodine wash. Internal bacteria are mainly gut bacteria and may be due to perimortem bacteriemia. However, bacterial infection at the time of death appears to have no effect on the incidence of endophthalmitis in recipients and should no longer prevent use of such corneal tissue in grafts.
Robert
Pierre-Yves
PY
Service d'ophtalmologie, CHRU Dupuytren, 2 avenue Martin Luther King, 87042 Limoges Cedex, France.
Camezind
Philippe
P
Drouet
Mireille
M
Ploy
Marie-Cécile
MC
Adenis
Jean-Paul
JP
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001082:Aqueous Humor / Q000382:microbiology*; D001419:Bacteria / Q000302:isolation & purification*; D003315:Cornea; D016039:Corneal Transplantation; D003470:Culture Media; D004203:Disinfection / Q000379:methods; D009877:Endophthalmitis / Q000382:microbiology; D019573:Epithelium, Corneal / Q000382:microbiology*; D005260:Female; D006084:Graft Rejection / Q000382:microbiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011206:Povidone-Iodine; D012307:Risk Factors; D012590:Sclera / Q000382:microbiology*; D014019:Tissue Donors; D014021:Tissue Preservation
D003470:Culture Media; D011206:Povidone-Iodine