NOV 06, 2007
A randomized equivalency trial comparing 2.5% povidone-iodine eye drops with ophthalmic chloramphenicol for preventing neonatal conjunctivitis in a trachoma endemic area in southern Mexico demonstrates the anti-microbial agents are similarly effective.
However, the risk of Ctrachomatis conjunctivitiswas increased in neonates receiving povidone-iodine (relativerisk = 1.99 (95% CI, 1.07 to 3.71), log-rank p = 0.029).
This may be explained bychanges in conjunctival bacterial flora following the use ofa broad spectrum antimicrobial agent. Another possible explanationis that the effectiveness of povidone-iodine may decrease because of achange in its bactericidal properties during its manufactureand storage, or because of unidentified environmental factorsspecific to the region where it was used. Although povidone-iodine hasbeen widely used to reduce the risk of infection, some studieshave failed to demonstrate its efficacy in controlling particulareye infections.
The prevention of neonatal conjunctivitis isa complex task that cannot be achieved by a single mandatoryprophylaxis. Several prospective studies have shown that motherto infant transmission of Ctrachomatis cannot be completelyeliminated with the most common antimicrobial agents currentlyprescribed for preventing neonatal conjunctivitis, such as silvernitrate, erythromycin, or tetracycline ophthalmic ointment,neither is a double application approach capable of reducingthe incidence.