[Comparative study of gentamycin and povidone-iodine on eliminating the conjunctival bacteria].
OBJECTIVE
To study the efficacy of gentamycin, 0.5% povidone-iodine and 5.0% povidone-iodine in eliminating rate of positive conjunctival bacteria cultures and aqueous humor contamination, and to observe their adverse effects.


METHODS
It was a comparative study. Three hundred patients (300 eyes) were randomized to three groups: gentamycin group, 0.5% povidone-iodine group and 5.0% povidone-iodine group. All patients received 1-day (6 times) topical application of 0.3% ofloxacin before surgery. Approximately 5 minutes before surgery, the conjunctival sac was irrigated with 5 - 8 ml gentamycin, 0.5% povidone-iodine or 5.0% povidone-iodine, correspondingly. Conjunctival cultures were obtained at the following time points: before receiving any topical medications; after application of 1-day topical 0.3% ofloxacin, before irrigating the conjunctival sac; immediately before surgery approximately 5 minutes after conjunctival sac irrigation and at the end of the surgery. Anterior chamber aspirates were obtained at the beginning of the surgery. Bacteria isolated were identified and antibiotic susceptibility was determined. The rate of positive conjunctival cultures among each group was compared and significance of the difference was tested with the Pearson chi-square test.


RESULTS
Rate of positive conjunctival cultures before the conjunctival irrigation was 79.7%, 76.6% and 77.8% in the gentamycin group, 0.5% povidone-iodine group and 5.0% povidone-iodine group, respectively. The difference between these three groups was not statistically significant (chi2 = 0.28, P = 0.86). At the end of surgery, the rate of positive conjunctival cultures in these three groups was 11.7%, 8.3% and 6.3%, respectively. The difference between these three groups was also not statistically significant (chi2 = 1.74, P = 0.41). The average rate of anterior aqueous contamination was 4.9% and there was no significant difference among these three groups (P > 0.05).


CONCLUSIONS
Both 0.5% povidone-iodine and 5.0% povidone-iodine using for irrigating conjunctival sac are safe. Gentamycin, 0.5% povidone-iodine and 5.0% povidone-iodine have similar effects on the reduction of the bacteria in conjunctival sac.
Shi
Ming-hua
MH
Department of Ophthalmology, Affiliated Hospital of Nantong University, Nantong 226001, China.
Hu
Nan
N
Guan
Huai-jin
HJ
Ye
Ying-jia
YJ
Chen
Mao-sheng
MS
Yu
Chang-tai
CT
D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D019072:Antibiotic Prophylaxis; D015169:Colony Count, Microbial; D003228:Conjunctiva / Q000382:microbiology*; D015818:Eye Infections, Bacterial / Q000382:microbiology / Q000517:prevention & control*; D005260:Female; D005839:Gentamicins / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011206:Povidone-Iodine / Q000627:therapeutic use*
D000900:Anti-Bacterial Agents; D005839:Gentamicins; D011206:Povidone-Iodine