Prospective study to determine the penetration of iodide into the anterior chamber following preoperative application of topical 1.25% povidone-iodine.
BACKGROUND
Povidone-iodine is currently the agent of choice for pre-operative antisepsis in ophthalmology. Due to experimental and analytical constraints, iodine absorption into the anterior chamber (AC) has not yet been studied. However, knowledge of the details of iodine transfer into the aqueous humor (AH) is critical for risk assessment of local and/or systemic side effects


METHODS
Following a 2-min antisepsis with 1.25% povidone-iodine, the AC of eligible cataract patients was penetrated with a 26-gauge cannula prior to any other intraocular manipulation. To distinguish between the iodine absorbed into the AC and that remaining in the hypodermic delivery syringe, we studied three different groups of specimens: (i) AH from the AC (n=19); (ii) Ringer's solution aspirated through the cannula after penetration into and immediate withdrawal from the AC without subsequent decontamination (n=8); and (iii) Ringer's solution aspirated through the cannula after penetration into and immediate withdrawal from the AC, and subsequent decontamination of its outer surface (n=5). Patients with pre-operative epithelial defects were excluded from the study. To measure iodine absorption, iodide levels in samples were determined chromatographically (ion-pair chromatography) and electrochemically (gold electrode).


RESULTS
There was no difference (P=0.815) between detectable amounts of iodide in groups I and II (median: 24.0 microg/dl and 28.9 microg/dl, respectively). Only group III (median: 5.2 microg/dl) showed a statistically significant lower level of iodide than did groups I or II (P=0.019 and P=0.011, respectively).


CONCLUSIONS
A healthy ocular surface behaves as a barrier to the penetration of iodine into the AC. Any detectable iodide in the AH after antisepsis should therefore be considered harmless.
Hansmann
Fabian
F
University Eye Hospital, Ratzeburger Allee 160, 23538, Luebeck, Germany.
Below
Harald
H
Kramer
Axel
A
Müller
Gerald
G
Geerling
Gerd
G
D000042:Absorption; D000891:Anti-Infective Agents, Local / Q000493:pharmacokinetics*; D000985:Antisepsis / Q000379:methods; D001082:Aqueous Humor / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D004563:Electrochemistry; D006801:Humans; D018918:Phacoemulsification; D011206:Povidone-Iodine / Q000493:pharmacokinetics*; D011446:Prospective Studies; D014018:Tissue Distribution
D000891:Anti-Infective Agents, Local; D011206:Povidone-Iodine