The challenge of determining aqueous contamination rate in anterior segment intraocular surgery.
OBJECTIVE
To determine aqueous contamination rate in anterior segment intraocular surgery using two different techniques of obtaining aqueous fluid and to assess whether a 3-day application of topical 0.3% ofloxacin reduces this contamination rate compared with a 1-hour application.


METHODS
Randomized clinical trial.


METHODS
One hundred and thirty-three eyes of 130 patients undergoing anterior segment intraocular surgery were randomized to either control (64 eyes received topical ofloxacin 1 hour before surgery) or study groups (69 eyes received topical ofloxacin four times a day for 3 days before surgery in addition to 1 hour preoperatively). Eyes in both groups received a periorbital iodine scrub and two drops of topical 5% iodine. Aqueous fluid was obtained at the beginning and conclusion of surgery using a cannula passed through a paracentesis or a needle passed through clear cornea. The aqueous, cannula, and needles were inoculated in blood culture media broth and bacterial growth was identified.


RESULTS
Overall, eight of 89 aqueous samples (9%) obtained using a cannula at the beginning of surgery were culture-positive. Similarly, six of 41 aqueous samples (15%) obtained through a needle through clear cornea at the beginning of surgery showed contamination. At the conclusion of surgery, nine of 112 samples (8%) showed positive cultures. There was no difference in the aqueous contamination rates between the control and study groups.


CONCLUSIONS
Despite the use of a needle to obtain aqueous fluid at the beginning of surgery before creating a paracentesis, the aqueous contamination rate remained higher than that found at the conclusion of surgery. A 3-day application of topical ofloxacin before surgery did not reduce the anterior chamber aqueous contamination rate relative to a 1-hour application.
Ta
Christopher N
CN
Department of Ophthalmology, School of Medicine, Stanford University, Stanford, California 94304, USA.
Egbert
Peter R
PR
Singh
Kuldev
K
Blumenkranz
Mark S
MS
de Kaspar
Herminia Miño
HM
D000869:Anterior Eye Segment / Q000601:surgery*; D000890:Anti-Infective Agents / Q000008:administration & dosage; D001082:Aqueous Humor / Q000382:microbiology*; D001419:Bacteria / Q000302:isolation & purification; D002404:Catheterization / Q000379:methods; D015818:Eye Infections, Bacterial / Q000382:microbiology* / Q000517:prevention & control; D006801:Humans; D015242:Ofloxacin / Q000008:administration & dosage; D009883:Ophthalmic Solutions; D018918:Phacoemulsification; D011446:Prospective Studies; D013530:Surgical Wound Infection / Q000382:microbiology* / Q000517:prevention & control
D000890:Anti-Infective Agents; D009883:Ophthalmic Solutions; D015242:Ofloxacin