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[Comparative study of gentamycin and povidone-iodine on eliminating the conjunctival bacteria]
Ming-hua Shi1, Nan Hu, Huai-jin Guan
1Department of Ophthalmology, Affiliated Hospital of Nantong University, Nantong 226001, China.
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.
Insights
Gentamycin, 0.5% povidone-iodine, and 5.0% povidone-iodine demonstrate similar efficacy in reducing conjunctival bacteria and preventing aqueous humor contamination during ocular surgery. All tested agents were found to be safe for conjunctival sac irrigation.
Area of Science:
- Ophthalmology
- Microbiology
- Surgical Infection Prevention
Background:
- Bacterial contamination of the conjunctival sac and anterior chamber poses a risk for intraocular infections following surgery.
- Effective preoperative antisepsis is crucial for minimizing microbial load and preventing surgical site infections.
Purpose of the Study:
- To compare the efficacy of gentamycin, 0.5% povidone-iodine, and 5.0% povidone-iodine in reducing positive conjunctival bacterial cultures.
- To assess the impact of these agents on preventing aqueous humor contamination.
- To evaluate the safety and adverse effects of the tested antimicrobial agents.
Main Methods:
- A randomized comparative study involving 300 patients undergoing ocular surgery.
- Patients were assigned to receive topical gentamycin, 0.5% povidone-iodine, or 5.0% povidone-iodine irrigation of the conjunctival sac prior to surgery.
- Conjunctival cultures and anterior chamber aspirates were collected at various time points to determine bacterial presence and identify microorganisms.
Main Results:
- No statistically significant difference was observed in the rate of positive conjunctival cultures among the three groups before or after irrigation and at the end of surgery.
- The average rate of anterior aqueous contamination was 4.9%, with no significant variations between the gentamycin, 0.5% povidone-iodine, and 5.0% povidone-iodine groups.
- All tested agents showed comparable effectiveness in reducing bacterial load.
Conclusions:
- Gentamycin, 0.5% povidone-iodine, and 5.0% povidone-iodine are safe for conjunctival sac irrigation.
- These agents exhibit similar efficacy in reducing bacteria in the conjunctival sac, suggesting comparable effectiveness in preoperative antisepsis for ocular procedures.
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