Session: Poster session C

Randomised controlled trial of 5% vs. 1.25% povidone-iodine preoperative conjunctival rinsing: no difference but many contaminated reattached eye muscles

Herb SIMONSZ¹, Marietta SWART-VAN DEN BERG², Laurentius VAN RIJN³, Martha TJON⁶, Nicoline SCHALIJ-DELFOS², Li BING^4,5

¹Erasmus University Medical Center, Rotterdam, Netherlands
²Leiden University Medical Center, Leiden, Netherlands
³Amsterdam University Medical Center, Amsterdam, Netherlands
⁴Ludwig-Maximilians-University, Munich, Germany
⁵Yangpu Hospital, Tongji University, Shanghai, China
⁶Eye Hospital, Rotterdam, Netherlands

Introduction: Our previous study of 26 patients with endophthalmitis after strabismus surgery doi:10.1111/aos.14446 showed that most cases occur in children aged 6 or less, exclusively after medial rectus recession. One issue discussed was the optimal concentration of Povidone-Iodine (PI) for antisepsis.

Methods: In four academic clinics in Amsterdam, Leiden and Rotterdam the onjunctiva was irrigated with 1.25% or 5% PI prior surgery. PI 10% was diluted 2x or 8x by the anesthiologist prior surgery according to a blinded randomisation table. Smears were obtained for aerobic and anaerobic bacteria with moistened dissolving Ca-alginate swabs from nose and conjunctiva before PI irrigation, from conjunctiva 5 minutes after PI irrigation, from reattached medial rectus muscles (RMR), and from conjunctiva after its closure (CC). Specimens were inoculated and cultivated onto blood/chocolate agars and in thioglycolate broth for 3-5 days.

Results: 70 Children were included. Case #20-70 had nose cultures. Case #53-70 had lacrimal sack compression added to PI irrigation. No statistically significant difference was found between 1.25% and 5% PI.Bacteria were found on RMR in 7, on CC in another 2, of 19 cases without nose cultures. Bacteria were found on RMR in 9, on CC in another 5, of 33 cases with nose cultures; in 9 of these 9+5=14 cases, the bacteriae in the nose and on RMR or CC were the same. In some cases where nose and RMR bacteria were the same, the conjunctiva had contained other bacteria before surgery. Bacteria were found on RMR in 3, on CC in 0, of 18 cases with lacrimal sack compression added tot PI irrigation.

Conclusions: RCT

In 44.2% of the first 52 cases, bacteriae were found on RMR or CC. Of the 33 cases of these that had nose cultures, 64.3% of 14 cases with bacteria on RMR or CC carried the same bacteria in the nose. Of the 18 cases with lacrimal sack compression added to PI irrigation only 16.7% had bacteriae on RMR and none on CC.