Prevention of postoperative infections in ophthalmic surgery.

Postoperative endophthalmitis is a serious, vision-threatening complication of intraocular surgery. Better instrumentation, surgical techniques, prophylactic antibiotics and better understanding of asepsis have significantly reduced the incidence of this complication. Postoperative endophthalmitis may occur as an isolated event or as a cluster infection. Topical antibiotics, preoperative periocular preparation with povidone-iodine combined with a sterile operating room protocol significantly reduce the incidence of isolated postoperative endophthalmitis. The role of antibiotics in the irrigating fluid and subconjunctival antibiotics remains controversial. Cluster infections on the other hand are more likely to occur due to the use of contaminated fluids/viscoelastics or a breach in operating room asepsis. Prevention of postoperative endophthalmitis requires strict adherence to operating room norms, with all involved personnel discharging their assigned roles faithfully.

Bacterial adherence to polymethylmethacrylate posterior chamber intra ocular lenses.

PURPOSE: Bacterial adherence to intraocular lenses (IOLs) has been incriminated in the pathogenesis of postoperative endophthalmitis. Staphylococcus epidermidis is the most common organism isolated. We studied the in-vitro adhesion of Staphylococcus epidermidis to Polymethylmethacrylate (PMMA) IOLs and the effect of duration of exposure to adherence. METHODS: Two groups of 10 IOLs each were incubated in Staphylococcus epidermidis suspension for 2 minutes and 20 minutes respectively. Adhesion of bacterial cells was determined by counting the number of viable bacteria attached to IOLs. RESULTS: The mean bacterial adherence with 2 minutes incubation was 12,889 +/- 7,150 bacteria/ IOL and with 20 minutes incubation was 84,226 +/- 35,024 bacteria/IOL (P< 0.01). CONCLUSION: Our results show that Staphylococcus epidermidis adheres to PMMA IOLs in vitro and the degree of adherence is less for shorter duration of exposure. We conclude that viable bacteria irreversibly adherent to IOLs may play a role in the pathogenesis of postoperative endophthalmitis. Shorter duration of operative manipulation and exposure to contaminating sources may decrease the chances of postoperative endophthalmitis.