Author: Marco Pastore (Italy)
Co-authors: Lorenzo Belfanti, Riccardo Merli, Gabriella Cirigliano, Daniele Tognetto
To assess the antimicrobial activity of the antiseptic ophthalmic solution with preservative-free 0.6% povidone-iodine as a prophylactic treatment in eyes scheduled for intravitreal treatments, and to compare its efficacy to the untreated fellow eye used as the control group.
Eye Clinic, Department of Medical, Surgical Sciences and Health, University of Trieste, and Microbiology Unit, University Hospital of Trieste.
Prospective cohort analysis in which 208 patients received preservative-free 0.6% povidone-iodine eye drops (IODIM®, Medivis, Catania, Italy) three times a day for three days before the intravitreal injection. Before and after the prophylactic treatment, a conjunctival swab was collected from both the study eye and the untreated contralateral eye, used as control. The swab was inoculated on different culture media and the colony-forming units were counted. Bacteria and fungi were identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-ToF-MS, VITEK® MS Plus).
A statistically significant decrease (p<0.001) of the bacterial growth from conjunctival swab cultures was found in the study group, with an eradication rate of 82%. The most commonly isolated pathogen at each time point and in both groups was coagulase-negative Staphylococci, isolated in 84% of the positive cultures. Other bacteria identified in order of frequency were staphylococci aureus and other gram-positive bacteria. 8 (3.9%) out of 208 patients who underwent 0.6% PI eye drops treatment experienced conjunctival hyperemia with light serous conjunctival discharge in 3 eyes (1.4%).
This large independent study conducted on two-hundred and eight eyes provides evidence about the effectiveness of 0.6% povidone-iodine eye drops in reducing the conjunctival bacterial load in eyes scheduled for intravitreal treatment while also showing a good safety profile.