Purpose
To assess the risk factors for harboring oxacillin-resistant Staphylococcus species on the ocular surface in a cohort of patients undergoing cataract surgery.
Methods
Conjunctival cultures were obtained from patients undergoing cataract surgery on the day of surgery before the instillation of any ophthalmic medications. Patients also answered a questionnaire about risk factors that might lead to having oxacillin-resistant Staphylococcus organisms. The demographic and questionnaire risk factors tested against having oxacillin-resistant organisms were: 1) age, 2) gender, 3) race, 4) recent antibiotic usage, 5) recent hospitalization, and 6) exposure to health-care or institutional settings. Multivariate logistic regression analysis was performed.
Results
183 eyes were cultured. 27 eyes showed no growth. 128 eyes revealed Staphylococcus organisms of which 70 eyes (54.7%) had oxacillin-resistant organisms. Of these 128 subjects, 19 had incomplete questionnaires; therefore a total of 109 subjects were utilized for risk-factor analysis. Of the six risk factors, only prior antibiotic usage was significantly associated with having oxacillin-resistant organisms (OR 8.2; 95% CI 2.2—30.5; p = 0.002). The rest of the risk factors were not significantly associated: age (p = 0.06), gender (p = 0.33), race (p = 0.34), hospitalization (p = 0.94), and institutional settings (p = 0.10).
Conclusions
While the non-ophthalmic literature has put forth various risk factors for patients to harbor oxacillin-resistant organisms, in our cohort of patients undergoing cataract surgery, only antibiotic usage in the preceding 30 days prior to surgery was significantly associated with having oxacillin-resistant organisms on the ocular surface. This finding is of importance to ophthalmic surgeons when considering peri-operative antibiotic prophylaxis.
Keywords: 433 bacterial disease •
464 clinical (human) or epidemiologic studies: risk factor assessment •
720 Staphylococcus