Study of the Acute Effects of Povidone-Iodine on Conjunctival Bacterial Flora

The ocular surface bacterial contamination and its management in the prophylaxis of post cataract surgery endophthalmitis

Objective: To investigate the recent pieces of evidence regarding the bacterial ocular surface contamination and its treatment in the prophylaxis of post-cataract surgery endophthalmitis. Methods: We conducted a literature research on the topic of interest and selected the most relevant data. Results: The studies reported a relatively high rate of positive conjunctival culture and the most frequently isolated organism was Coagulase negative Staphylococcus, which is also the most common etiological agent of the postoperative endophthalmitis. The bacterial ocular surface load is influenced by age, climate, associated diseases, topical and systemic medication. The use of povidone-iodine alone or in association with levofloxacin eyedrops as prophylactic method is effective in reducing the conjunctival bacterial contamination and consequently decreases the incidence of postoperative endophthalmitis. Conclusions: Based on the current pieces of evidence, adequate treatment of the bacterial ocular surface contamination prior to cataract surgery seems to be effective in preventing endophthalmitis after cataract surgery. Abbreviations: EU = European Union, Spp. = Species, HIV = Human Immunodeficiency Virus.

Topical proparacaine eye drops to improve the experience of patients undergoing intravitreal injections: A randomized controlled trial

PURPOSE

We sought to evaluate whether additional topical anesthetic, specifically proparacaine 0.5%, improved patient experience with intravitreal injections without hindering antisepsis.

METHODS

A prospective, randomized controlled trial was conducted including 36 eyes of 36 patients undergoing intravitreal injections. Patients were randomized to treatment with additional topical proparacaine 0.5% versus control after undergoing informed consent. All patients prior to intravitreal injection underwent conjunctival culture after one drop of topical proparacaine 0.5% was placed. Half of patients then received an additional drop of proparacaine and then underwent a second conjunctival culture. The other half of patients had a drop of povidone iodine and then a second conjunctival culture. Intravitreal injection followed conjunctival cultures. To evaluate their experience, patients were provided with a survey.

RESULTS

In total, 36 patients were enrolled in the study. Three of 36 (8.3%) patients had positive conjunctival cultures after proparacaine eye drops alone. One of 17 (5.8%) patients had a positive conjunctival culture after a second drop of proparacaine. One of 19 (5.3%) patients had a positive culture after proparacaine and povidone iodine. By noninferiority analysis, proparacaine was inferior to povidone iodine (p = .28). Patient experience surveys did not differ between groups.

CONCLUSION

Patient perception did not significantly differ whether or not additional proparacaine drops were used prior to intravitreal injection in a randomized controlled trial. While proparacaine has some antiseptic properties, these were found to be inferior to those of povidone iodine. Therefore, while povidone iodine is essential for antisepsis, additional proparacaine drops should not interfere with antisepsis.

The effect of recurrent povidone-iodine usage on conjunctival flora in diabetic patients undergoing intravitreal injections

PURPOSE

The purpose was to evaluate the change in the microbiological profile of diabetic patients undergoing intravitreal injections for diabetic macular edema.

METHODS

Patients were included in this prospective study when referred for the first time for intravitreal injection to treat diabetic macular edema. For each patient, conjunctival cultures were taken from the lower fornix of each eye prior to the povidone-iodine application and the intravitreal injection. An additional culture was taken from the treated eye 20 min after the injection. The same culture protocol was used for the two following injections of these patients. A later conjunctival culture was also taken a month after the last injection.

RESULTS

Twenty-one eyes of 21 patients were included. The mean duration of diabetes was 13.7 ± 7.9 years. Prior to the first intravitreal injection, 33% of cultures were positive. Prior to the third intravitreal injection, 26% of cultures were positive (p = 0.63), and 1 month after the last injection, 18% of cultures were positive (p = 0.495). The mean HbA1C was 8.1% ± 1.7%. HbA1C of patients with positive cultures was 8.0% ± 1.1% at the first intravitreal injection and 8.2% ± 1.0% at the third intravitreal injection. This was compared with HBA1C in eyes with negative cultures: 7.4% ± 1.2% (p = 0.45) and 7.1% ± 1.0% (p = 0.14), respectively.

CONCLUSION

Repeated intravitreal injection for diabetic macular edema with application of povidone-iodine 5% in diabetic patients did not lead to a significant change in the percentage of positive conjunctival cultures. Patients with higher HbA1C had a slight, non-statistically significant trend for positive cultures.

Preoperative topical liposomal ozone dispersion to reduce bacterial colonization in conjunctival sac and periocular skin: Preliminary study in dogs

Prophylaxis represents a keystone to reduce periocular skin and ocular conjunctiva bacterial load before surgical procedures. Despite many prophylactic agents are available the preferred perioperative ocular surface antimicrobial is still unknown. The purpose of this study was to assess the effectiveness of preoperative liposomal ozone dispersion in reducing bacterial colonization from the conjunctival sac and periocular skin in dogs, in comparison with povidone-iodine and fluoroquinolone. Twenty-two owned dogs consisting with 44 eyes in total scheduled for ophthalmic surgical procedure were enrolled for the study and divided in four groups receiving either ozone dispersion or povidone iodine in eyelid and conjunctiva, fluoroquinolone or placebo. A swab was taken before and after the antisepsis protocol evaluating total microbial count, coagulase positive and negative staphylococci. Statistical analysis revealed a significant decrease in colony forming units (CFU) for total microbial count, coagulase positive and negative staphylococci both for liposomal ozone dispersion and povidone iodine. No statistical differences were detected in median CFU for both one-day placebo and fluoroquinolone preoperative prophylactic topical therapy. The results of this preliminary study demonstrate that liposomal ozone-dispersion is as effective as povidone iodine to reduce preoperative bacterial load in ocular surface.

EMA and EFSA Joint Scientific Opinion on measures to reduce the need to use antimicrobial agents in animal husbandry in the European Union, and the resulting impacts on food safety (RONAFA)

EFSA and EMA have jointly reviewed measures taken in the EU to reduce the need for and use of antimicrobials in food-producing animals, and the resultant impacts on antimicrobial resistance (AMR). Reduction strategies have been implemented successfully in some Member States. Such strategies include national reduction targets, benchmarking of antimicrobial use, controls on prescribing and restrictions on use of specific critically important antimicrobials, together with improvements to animal husbandry and disease prevention and control measures. Due to the multiplicity of factors contributing to AMR, the impact of any single measure is difficult to quantify, although there is evidence of an association between reduction in antimicrobial use and reduced AMR. To minimise antimicrobial use, a multifaceted integrated approach should be implemented, adapted to local circumstances. Recommended options (non-prioritised) include: development of national strategies; harmonised systems for monitoring antimicrobial use and AMR development; establishing national targets for antimicrobial use reduction; use of on-farm health plans; increasing the responsibility of veterinarians for antimicrobial prescribing; training, education and raising public awareness; increasing the availability of rapid and reliable diagnostics; improving husbandry and management procedures for disease prevention and control; rethinking livestock production systems to reduce inherent disease risk. A limited number of studies provide robust evidence of alternatives to antimicrobials that positively influence health parameters. Possible alternatives include probiotics and prebiotics, competitive exclusion, bacteriophages, immunomodulators, organic acids and teat sealants. Development of a legislative framework that permits the use of specific products as alternatives should be considered. Further research to evaluate the potential of alternative farming systems on reducing AMR is also recommended. Animals suffering from bacterial infections should only be treated with antimicrobials based on veterinary diagnosis and prescription. Options should be reviewed to phase out most preventive use of antimicrobials and to reduce and refine metaphylaxis by applying recognised alternative measures.