Impact of changes in antibiotic prophylaxis on postoperative endophthalmitis in a Spanish hospital

This study aims to assess whether changes in antibiotic prophylaxis used in cataract surgery in the La Mancha Centro General Hospital, Spain, were associated with a reduced incidence of postoperative endophthalmitis (POE).

The hospital employed two different antibiotic prophylaxis regimens during two clearly differentiated periods. In the first period (January 2000 to April 2003), subconjunctival injections of gentamicin were used while in the second (May 2003 to December 2008), vancomycin and gentamicin were added to the irrigating solution. During both periods, povidone iodine was used at the site of surgery and aminoglycoside eye drops were administered postoperatively. A Poisson regression model was used to evaluate the relationship between the incidence rate of endophthalmitis and variables such as time trends, seasonality, and change in antibiotic prophylaxis regimen.

During the period between 2000 and 2008, 26 cases of POE were detected after 14,285 operations for an incidence rate (IR) of 1.8 cases per 1000 procedures (95% confidence interval 1.2-2.7 cases out of 1000 procedures). In the period prior to the change in prophylaxis, 23 cases were detected (IR 4.5 cases/1000 procedures) while only three cases were observed in the period after the change (IR 0.3 cases/1000 procedures). A total of 84% of the microorganisms isolated were gram-positive, and all were sensitive to vancomycin.

The change in antibiotic prophylaxis regimen for cataract surgery was associated with a relevant and significant decrease in the incidence of POE.