Sir,

We thank Dr Nestel1 for his interest in our study.2 We found some associations between the pathogenic conjunctival bacteria and the systemic co-morbidities of patients undergoing cataract surgery, which was the main purpose of the study. Among these associations, we found that enterococci prevalence is associated with age and diabetes. Owing to the current wide use of intracameral cefuroxime for the cataract surgery prophylaxis,3, 4 we introduced the example of the postoperative endophthalmitis (PE) caused by enterococci for illustrating the implications of our findings in the management of patients carrying conjunctival bacteria resistant to a particular prophylaxis, such as the enterococci to cefuroxime, as Dr Nestel pointed. The systemic co-morbidities associations with other bacteria (for instance multi-resistant Staphylococcus) could also help in choosing a prophylaxis.

The answers to other comments are as follows:

  • In the study design, polymyxin B plus trimethoprim eye drops is an empirical prophylaxis for all patients, except those having conjunctival pathogen bacteria resistant to these antibiotics, such as enterococci. We try not to increase the resistance to first-line antibiotic treatments.

  • The occurrence of four PE cases in the first year of the study period2 was before using intracameral cefuroxime. This fact could point to streptococci as the most likely cause, as there was no case of Streptococci-PE in the ESCRS groups treated with cefuroxime,5 and no others prophylactic measures had changed in our study.

  • The oral antibiotic for patients with conjunctival enterococci was chosen in accordance with their susceptibility tests;6 quinolones being the first choice, if possible.

  • Finally, the ‘potential’ risk of intraocular contamination by enterococci, in patients over 85 years, was calculated with respect to the conjunctival enterococci prevalence of patients younger than 86 years (Supplementary Table 3).2 This information is extended in Table 1.

    Table 1 Increasing potential risk of intraoperative contamination by enterococci according to age in patients operated on for cataract
    Full size table