Abstract
Purpose: :
We found previously (ARVO, 2007 & 2009) that endophthalmitis after strabismus surgery occurs either in children under 7 after medial rectus recession (approx. 1:7160 such operations in NL over 1994-2007), causing enucleation, or in elderly over 65 after previous eye surgery, with more favorable outcome. In a RCT we study the effectiveness of irrigating the conjunctiva with 5% vs. 1.25% povidone-iodine (PI) as additional antiseptic measure. We found a peculiar similarity.
Methods: :
In a multicenter RCT the conjunctiva was irrigated with either 5% or 1.25% PI prior to strabismus surgery in 1-to-5- year-olds. Smears were obtained from (i) conjunctiva after induction of anesthesia, (ii) conjunctiva 5 minutes after PI irrigation, (iii) muscle and cut-off sutures after reattachment and (iv) again from conjunctiva, all for aerobic and anaerobic bacteria. A nose smear (o) was added to (i) during the study, as it had been suggested that reflux from the lacrimal puncta may play a role (John Sloper, Moorfields Eye Hospital). Samples were taken from the conjunctiva with a small standard dissolving Ca-alginate swab (Sanofi-Pasteur). The moistened swab was taken softly via one rotational swipe over conjunctiva or eye muscle without touching the lid or eyelashes, and put into a tube containing Transport Medium 482 CE (Hain Lifescience). To minimize variation in culture techniques, all cultures were analysed in a central laboratory.
Results: :
42 children had been recruited by September 2011, 24 of these had had nose cultures. Randomisation is still coded. Four children carried similar bacteriae in the nose before surgery (o) as on the muscle with cut-off sutures after reattachment (iii), although intermediate conjunctival cultures were either negative (ii) or carried other bacteriae (i). The four concerned coagulase-negative Staphylococcus in 3 cases and Hemophilus sp. in 1 case.
Conclusions: :
The similarity between the bacteriae from the nose at the start of surgery and the bacteriae in the recontaminated surgical field (reattached muscle with cut-off sutures), while these bacteriae were not found in the conjunctiva at the start of surgery, supports the suggestion that reflux may occur from the lacrimal puncta. The lacrimal ducts and sack are not disinfected preoperatively. Reflux may occur especially in children with obstructed ducts, either anatomically or functionally, during a cold for instance. It should be discussed whether surgery should be avoided in children under 6 with discharge from nose or puncta, whether the lacrimal ducts and sack can be disinfected prior to surgery and whether children under 6 should be checked 1-2 days postoperatively after medial rectus recession.
Clinical Trial: :
http://www.clinicaltrials.gov NCT00461656
Keywords: endophthalmitis • strabismus: treatment • bacterial disease