[Perioperative risk of infection in cataract surgery]

The presence of bacteria during cataract surgery was studied on 71 consecutive patients. Lid and conjunctival smears were cultured 24 hours preoperatively. Additional conjunctival smears were harvested in the operating room before and after conjunctival disinfection by oxycyanate. Moreover, the whole irrigation fluid was collected under sterile condition and examined microbiologically. 24 hours preoperatively 61 of 71 patients had positive cultures of their lids and/or conjunctivae. 8 of them showed growth of pathogenous bacteria (7 staphylococcus aureus, 1 proteus mirabilis). In the operating room before oxycyanate disinfection 5 patients were positive for staphylococcus aureus and 13 for coagulase negative staphylococci (none for proteus species). After oxycyanate disinfection 4 residual conjunctival smears showed bacterial growth when cultured (3 coagulase negative staphylococci, 1 proteus mirabilis). 22 of 71 collected irrigation fluids content few numbers of bacteria. One was positive for proteus mirabilis, 3 for staphylococci. The patient showing growth of proteus after oxycyanate disinfection and one of the patients with staphylococcus aureus positive irrigation fluid did not show this kind of micro-organism in any smear before. The authors conclude that preoperative cultures do not give real security about the presence or absence of bacteria during the operation.