Bacteriology and cefuroxime resistance in endophthalmitis following cataract surgery before and after the introduction of prophylactic intracameral cefuroxime: a retrospective single-centre study.

BACKGROUND

Intracameral cefuroxime as prophylaxis against postoperative endophthalmitis (POE) following cataract surgery was introduced in 1996 at St Erik Eye Hospital. Soon after the introduction of intracameral cefuroxime, the rate of POE fell dramatically and a shift in the aetiology was noticed.

AIM

To analyse bacteriology and susceptibility to cefuroxime before and after the introduction of intracameral cefuroxime.

METHODS

All culture-proven cases of endophthalmitis at St Erik Eye Hospital after cataract surgery performed over a 20-year period were included in a retrospective observational study.

FINDINGS

Sixty-two cases of endophthalmitis occurred in 34,390 (0.18%) cataract surgeries before the introduction of intracameral cefuroxime (Period 1), while 33 cases occurred in 75,144 (0.044%) operations after the introduction of intracameral cefuroxime (Period 2), showing a significant difference between the periods (P < 0.001). The incidence of coagulase-negative staphylococci (1/1400 vs 1/15,000; P < 0.001), Staphylococcus aureus (1/2000 vs 1/30,000; P < 0.001), streptococci other than enterococci (1/2500 vs 1/25,000; P < 0.001) and Propionibacterium acnes (1/16,000 vs 0/75,000; P = 0.04) fell sharply in Period 2. Cefuroxime-sensitive strains became less frequent in Period 2 (P < 0.001). Enterococci became the predominant species, albeit not significantly (P = 0.13), whereas the rate of cefuroxime-resistant strains almost reached significance (P = 0.05) in Period 2.

CONCLUSIONS

Intracameral cefuroxime leads to a reduction of the rate of endophthalmitis after cataract surgery, and brings about a shift in pathogens from cefuroxime-sensitive to cefuroxime-resistant organisms.