Optimizing the antisepsis protocol: Effectiveness of 3 povidone-iodine 1.0% applications versus a single application of povidone-iodine 5.0

In vivo assessment of antimicrobial activity and toxicity of repeated 1% povidone-iodine applications vs a single 5% povidone-iodine application

PURPOSE

To demonstrate the noninferiority in antimicrobial effectiveness of thrice-repeated applications of 1% povidone-iodine (PI) compared with a single application of 5% PI on the ocular surface in vivo and to evaluate potential toxicity of PI to the corneal epithelium.

SETTING

Department of Ophthalmology, Shaare Zedek Medical Center, Jerusalem, Israel.

DESIGN

Prospective, randomized, double-blind study.

METHODS

Patients randomly received either a single application of 5% PI or repeated irrigations of 1% PI on the ocular surface preoperatively. Bacterial colony counts were quantitatively analyzed by taking standardized conjunctival swabs before and after irrigation, and differences in bacterial colony counts were compared between the 2 groups. The presence of superficial punctate keratopathy was evaluated in all patients by the National Eye Institute grading system.

RESULTS

The study comprised 102 eyes of 102 patients. Both 1% and 5% PI yielded a marked decrease in bacterial colonies compared with before application ( P < .001). The repeated application of 1% PI showed a significantly lower bacterial count compared with the single application of 5% PI ( P < .05) and resulted in significantly less damage to the corneal epithelium compared with a single 5% PI application ( P < .001).

CONCLUSIONS

Preoperative repeated applications of 1% PI effectively eradicated ocular surface bacteria equal to that of 5% PI with a less deleterious effect on the corneal epithelium. Our findings suggest that 1% PI may be a promising alternative to 5% PI.

Using 2% PVPI topical solution for serial intravitreous injections and ocular surface findings: a case control study

BACKGROUND

The use of povidone-iodine for ocular surface asepsis is widespread for intravitreal injections. They became frequent procedures, leading to serial exposure of patients' eyes to iodinated solutions. In this study, we investigate the changes in the ocular surface in patients submitted to repeated use of povidine for intravitreal injection of anti-VEGF asepsis, analyzing Ocular Surface Disease Index, non-invasive break up time, blinking quality, lipid layer, meniscus height and osmolarity.

METHODS

This case-control study included 34 individuals (68 eyes), 14 males, 20 females aged 48 to 94. Inclusion criteria were individuals who received application of 2% povidone-iodine eyedrops for intravitreal injections treatment with the non-treated contralateral eye used as control. Ocular surface examinations were performed at a single occasion. A pre-intravitreal injection asepsis protocol with povidone-iodine was applied. All statistical analysis was performed using the STATA® 18.0 Software and a p-value = 0.05 was considered as the statistical significance value in all tests.

RESULTS

The median number of IVIs in treated eyes was 12 (range 6-20). The results in treated eyes compared with untreated eyes were respectively : median OSDI 16 (IQR 6-39) and 12.5 (IQR 8-39) (p = 0.380); mean NIBUT 10.30 (SD ± 2.62) and 10.78 (SD ± 2.92) ( s, p = 0.476); median blinking quality 100 (IQR 100) and 100 (IQR 100 ) (%, p = 0.188); median lipid layer 87 (IQR 77-90) and 86 (IQR 74-100) (nm, p = 0.451); median meniscus height 0.22 (IQR 0.19-0,31) and 0.24 (IQR 0.20-0.27) (mm, p = 0.862), median Meibomian gland atrophy 33 (IQR 24-45) and 31.5 (IQR 25-39) (%, p = 0.524); and mean osmolarity 306.6 (SD ± 21.13) and 313.8 (SD ± 29) (mOsm, p = 0.297). There was no statistically significant relationship between the repetitive use of 2% iodinated solution and signs or symptoms compatible with dry eye syndrome in this group of patients.

CONCLUSIONS

The findings suggest that 2% povidone iodine is a safe and efficacious agent for ocular surface antisepsis during intravitreal injections, not leading to substantial ocular surface modifications. This conclusion supports the continued use of povidone iodine in routine ophthalmic procedures without increased risk of inducing dry eye syndrome.

Evaluation of the Possible Influence of Povidone Iodine (PVI) Solution and Polyhexanide (PHMB) on Wound Healing in Corneal Epithelial Regeneration

This study investigates the possible toxic effects of the preoperative antiseptic substances povidone iodine (PVI) and polyhexanide (PHMB; Serasept® 2) on wound healing in ophthalmology. To assess this impact, human telomerase-immortalized corneal epithelial (hTCEpi) cells and human telomerase-immortalized conjunctival epithelial (hCjE) cells were exposed to 1% and 5% PVI or 0.04% PHMB for different periods to evaluate the cytotoxicity of these two antiseptics. Furthermore, the toxicity of these antiseptics was investigated in a human tissue-specific corneal epithelial construct and porcine eye culture model. The results reveal the high cytotoxicity of PVI and PHMB in the hTCEpi and hCjE in monolayer cell culture models, independent of the incubation time and concentration of these substances. However, after hTCEpi cell differentiation into a tissue-specific corneal epithelial construct, contact with these antiseptics for the relevant preoperative time did not alter cPARP1 or Ki67 expression. Furthermore, the wound-healing process in the porcine cornea was not significantly influenced after incubation with these antiseptics. In summary, corneal and conjunctival epithelial cell lines are very sensitive to PVI and PHMB, whereas no significant alterations were found in intact tissue-specific corneal epithelial constructs or porcine corneas. Therefore, we could not identify PVI and PHMB as reasons for postoperative eye irritation.

Chlorhexidine and other alternatives for povidone-iodine in ophthalmic surgery: review of comparative studies

Povidone-iodine (PVI) is a universally accepted antiseptic agent used in ophthalmic surgery. Insufficient antisepsis in patients with self-reported allergies to iodine has led to devastating complications. The aim of this study was to review the current evidence for alternatives to PVI in ocular surgery. Aqueous chlorhexidine has been used as a primary antiseptic agent in Sweden for several years and has proven efficiency and safety; in a study of a large series of intravitreal injections in Australia, the endophthalmitis rates were similar to those after the use of PVI. The evidence related to using other disinfectants such as picloxydine, hypochlorous acid solution, and polyhexanide is scarce. Single studies have shown lower patient discomfort after conjunctival lavage with chlorhexidine or hypochlorous acid than with PVI. No evidence was found to suggest changing from PVI to other antiseptic agents. Disinfectant solutions other than PVI or chlorhexidine will require further investigations to show their utility in ocular surgery.

Low-concentration povidone-iodine for the prevention of intraocular infections in ophthalmic surgery

PURPOSE OF REVIEW

Endophthamitis following intraocular surgery is rare using current antiseptic techniques, such as single application of 5% povidone-iodine to the ocular surface and adjuvant topical or intracameral antibiotics. Challenges remain, however, including increased multidrug-resistant bacterial endophthalmitis, increased fungal endophthalmitis, and the low but nonzero endophthalmitis rate attributable to the typical bacteria that colonize the ocular surface.

RECENT FINDINGS

Povidone-iodine has a wide spectrum of activity, including activity against novel pathogens, such as SARS-CoV-2. Povidone-iodine alternatives, such as hypochlorous acid can have significantly less efficacy in vitro against endophthalmitis isolates. Repetitive application of dilute povidone-iodine has an excellent safety profile and strong evidence base for efficacy.

SUMMARY

Povidone-iodine is widely available, inexpensive, and commonly used by ophthalmologists. The repetitive application of dilute povidone-iodine is a well studied, well tolerated, and efficacious way to transiently sterilize the ocular surface during intraocular surgery. Additional benefits include activity against multidrug-resistant bacteria, fungi, and lack of inducible resistance.

Effect of topical povidone-iodine 10% plus levofloxacin 0.5% 1 hour before cataract surgery in eliminating perioperative conjunctival flora: randomized clinical trial

PURPOSE

To evaluate the effect of a single administration of topical povidone-iodine (PVI) 10% plus levofloxacin 0.5% at 1 hour before cataract surgery on perioperative elimination rate of conjunctival flora.

SETTING

Poostchi Ophthalmology Research Center, Shiraz, Iran.

DESIGN

Randomized controlled trial.

METHOD

Patients who required cataract surgery were randomly assigned to 1 of 2 groups: intervention (administration of PVI 10% plus levofloxacin 0.5% at 1 hour preoperatively) or control. The patients in both groups received PVI just before the operation. Conjunctival cultures were obtained using thioglycollate broth at 4 timepoints: T1, before intervention; T2, before the second application of PVI; T3, 3 minutes after the second administration of PVI; and T4, just postoperatively.

RESULTS

The study comprised 142 patients. The comparative rates of positive cultures in the intervention vs control groups were as follows: T1 (70.4% vs 73.2%, P = .709); T2 (15.5% vs 71.8%, P < .001); T3 (7.0% vs 19.7%, P = .027); and T4 (5.6% vs 4.2%, P = .698). Coagulase-negative Staphylococci was the most common isolated microorganism.

CONCLUSIONS

Results showed that a single adjuvant application of PVI 10% plus levofloxacin 0.5% eyedrops at 1 hour before operation leads to a further increase in the rate of sterile conjunctiva just preoperatively.

Review, analysis, and education of antiseptic related ocular injury in the surgical settings

Preoperative skin antiseptic preparation is the gold standard for prevention of surgical infection. However, improper use of antiseptics may lead to severe ocular damage. Currently, the most common surgical antiseptics can be divided into aqueous-based and alcohol-based disinfectants, with chlorhexidine and iodine/iodophors being the two major components. Chlorhexidine has a persistent antimicrobial effect and is resistant to neutralization by blood or organic products in surgical wounds. Nevertheless, due to its toxicity to the ears, meninges, and eyes, application of chlorhexidine should be prohibited in these surgical fields. Iodine/iodophor is better tolerated by the ocular surface and is the recommended antiseptic for ophthalmic or head and neck surgeries close to the periocular area. Alcohol is less pricey and has a rapid antiseptic effect, though its desiccating effect and flammability restrict the use in mucosal or laser surgeries. The single or combined use of these antiseptics may inadvertently induce severe ocular damage, especially during time-consuming head and neck surgeries with prone, hyperextension, or lateral tilt positions, or surgeries under general anesthesia. Apart from the choice of antiseptics, appropriate selection and attachment of bio-occlusive dressings are key to avoiding antiseptic-related ocular injuries. In this review, we provided a comprehensive summary of the characteristics of antiseptics used in surgical settings and the possible mechanisms and outcomes of antiseptic-related ocular injuries. The prevention, diagnosis, and acute management of these complications were also discussed.

Effectiveness of 0.66% Povidone-Iodine Eye Drops on Ocular Surface Flora before Cataract Surgery: A Nationwide Microbiological Study

A multicenter, nonrandomized, prospective, controlled study was conducted to evaluate, as perioperative prophylactic treatment, the anti-infective effectiveness of 0.66% povidone-iodine eye drops (IODIM^®) against the bacterial flora of the conjunctival surface of patients who undergo cataract surgery. Eye drops containing 0.66% povidone-iodine were applied to the eye undergoing cataract surgery; the untreated contralateral eye was used as control. One hundred and twenty patients set to receive unilateral cataract surgery were enrolled in 5 Italian Ophthalmology Centers and pretreated for three days with 0.66% povidone-iodine eye drops. The contralateral eye, used as control, was left untreated. Conjunctival swabs of both eyes were collected at the baseline visit and after three days of treatment, just before the cataract surgery. A qualitative and quantitative microbiological analysis of bacterial presence was evaluated by means of bacterial culture, followed by identification. Methicillin resistance determination was also performed on staphylococci isolates. Bacterial load before and after treatment of the eye candidate for cataract surgery was evaluated and compared to the untreated eye. A reduction or no regrowth on the culture media of the bacterial load was observed in 100% of the study subjects. A great heterogenicity of bacterial species was found. The 0.66% povidone-iodine eye drops, used for three days prior to cataract surgery, were effective in reducing the conjunctival bacterial load. The 0.66% povidone-iodine eye drops (IODIM^®) might represent a valid perioperative prophylactic antiseptic adjuvant treatment to protect the ocular surface from microbial contamination in preparation of the surgical procedure.

Repurposing 0.5% povidone iodine solution in otorhinolaryngology practice in Covid 19 pandemic

SARS CoV 2 is very much homologous in structure to SARS CoV. Review of literature suggests the in-vitro virucidal action of povidone iodine in SARS CoV and MERS. The oropharynx and nasopharynx are target sites of SARS CoV 2. A significant proportion of COVID 19 sufferers are asymptomatic, but shedding these viral particles, PVP-I has been shown to be a safe therapy when used as a mouthwash or taken nasally or used during ophthalmic surgeries.

AIMS

MATERIALS AND METHODS: 0.5% PVP-I solution is prepared from commercially available 10% PVP-I solution. Patients were instructed to put 0.5% PVP-I drops in nose and rinse mouth with gargle prior examinations for 30 s. For endoscopic procedure (nasal and throat) nasal douching and gargling to be started one day prior. Douching and rinsing to be repeated just before procedures. Nasal packing with 0.5% PVP-I along with 4% xylocaine/adrenaline solution, tolerability and any allergic reaction noted.

RESULTS

The patient and health care workers tolerated the 0.5%. No allergy was noted.

CONCLUSION

We propose the use of 0.5% PVP-I in healthcare workers and their patients to minimise the risk of spread of the disease in addition to the recommended PPE.

Response to correspondence from Koerner and colleagues concerning our paper entitled: The effect of diluting povidone-iodine on bacterial growth associated with speech

Clinicians adopt varying strategies for antisepsis with PI, which to this day remains efficient, economical and effective. Clinicians should prudently consider effective PI application, and we thank Koerner and Grzybowski for encouraging debate and raising the profile of this issue.

Povidone-iodine pharmacokinetics and study design

Dr. Gnanasekaran et al. reported the bactericidal activity of various concentrations of povidone iodine (PI) solution in an agar plate experiment of respiratory flora. The study design and the pharmacokinetic properties of PI solution ensured that dilute PI would not be effective in this study. These results may not replicate the typical clinical situation and are significantly different than a previously reported agar plate experiment, again owing to subtle but very significant differences in methodology.

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.

In vitro bactericidal activity of 0.6% povidone-iodine eye drops formulation

PURPOSE

To evaluate the bactericidal activity of a diluted povidone-iodine formulation (0.6%) in comparison with the most used 5% povidone-iodine solution ophthalmic preparation.

METHODS

In vitro bactericidal activity comparison between 0.6% povidone-iodine versus 5% povidone-iodine formulations, against these bacteria: Staphylococcus aureus ATCC 25923, Staphylococcus aureus ATCC 43300, Staphylococcus epidermidis ATCC 12228, linezolid-resistant Staphylococcus epidermidis α99 strain, a clinical isolate, Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922.

RESULTS

About 0.6% povidone-iodine formulation was demonstrated to be faster than 5% povidone-iodine preparation in killing Gram-positive as well as Gram-negative bacteria. Against a linezolid-resistant methicillin-resistant Staphylococcus epidermidis strain, 0.6% povidone-iodine formulation showed the best antiseptic efficacy requirement of 3-log₁₀ reduction in bacterial load, if compared with the 5% povidone-iodine formulation.

CONCLUSION

Our investigation has demonstrated that the more diluted 0.6% preparation was more rapidly bactericidal than the 5% povidone-iodine formulation, most probably due to the fact that dilution from 5% to 0.6% increases the amount of free iodine. While our finding must be confirmed by in vivo clinical studies, this fact constitutes an intriguing news for what concerns the use of povidone-iodine eye drops in the ocular surface treatment before intravitreal injections as well as ophthalmic surgery.

Antiseptic effect of low-concentration povidone-iodine applied with a depot device in the conjunctiva before cataract surgery

Purpose

Examine the antiseptic effect of long-term low-concentration (0.3%) povidone-iodine (PI) before cataract surgery.

Setting

St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway.

Design

Single-armed prospective clinical study.

Methods

Repeated measure of preoperative conjunctival samples from 51 participants were obtained the day before surgery (T1), the day of surgery after treatment with ophthalmic NSAID (T2), and after additional treatment with low-concentration PI (T3) given by placing a pledget soaked in a mix of eye-drops in fornix inferior for 20 min.

Results

Before surgery, and before any type of treatment (T1), bacterial growth (≥5 BC) in the conjunctiva was identified in 36 (66.7%) of the participants. After treatment with ophthalmic NSAID (T2), and after additional treatment with low-concentration PI (T3), bacteria were identified in 31 (60.8%) and 12 (23.4%) participants, respectively. All except one of the participants with a measurable change from T2 to T3 (n = 31, 60.8% of total sample), experienced a decrease in number of bacterial colonies (BC) after treatment with low-concentration PI (96.8 vs. 3.2%, p < 0.001). A complete removal of bacteria was seen in 20 (n = 31, 64,5%) of the colonized participants after treatment with PI.

Conclusions

Preoperative treatment with long-term, low-concentration PI applied via a depot device in fornix inferior, seem to be an easy and effective way to reduce the number of BC in the conjunctiva.

Povidone-iodine concentration and dosing in cataract surgery

Iodine has been recognized as an effective bactericide since the 1800s, and povidone-iodine (PI) solution has been applied to the ocular surface and periocular skin since the 1980s to prevent endophthalmitis in cataract surgery. In vitro, PI solution kills bacteria quickly at dilute concentrations (0.05%-1.0%). In many instances, PI kills bacteria more quickly at these dilute concentrations than more conventional (5%-10%) concentrations. This is due to greater availability of diatomic free iodine in dilute solution, the bactericidal component of PI. The toxicity of PI, both in vitro and clinically, has been shown to be related to concentration. Current American Academy of Ophthalmology and the European Society of Cataract and Refractive Surgeons recommendations regarding PI use suggest using 5% PI before surgery. An alternative dosing strategy uses dilute PI repetitively throughout cataract surgery (0.25% every 30 seconds). We review the povidone-iodine literature with attention to basic science and use of dilute PI.

The use of povidone-iodine in ophthalmology

PURPOSE OF REVIEW

Povidone-iodine (PVI) is a disinfectant and antiseptic agent used for preoperative preparation of the skin and mucous membranes, as well as for the treatment of contaminated wounds. Currently regimens for prophylaxis against postsurgical endophthalmitis are being modified, including a total withdrawal of antibiotics in intravitreal injections. The aim of this study was to evaluate the use of PVI in ophthalmology.

RECENT FINDINGS

As a result of its broad spectrum of microbicidal activity, PVI is routinely used in ophthalmic surgery. However, various protocols are applied worldwide and within different procedures. Additional indications include prophylaxis against ophthalmia neonatorum, acute conjunctivitis, adenoviral conjunctivitis, bacterial keratitis or corneal ulcer, endophthalmitis, giant fornix syndrome, and antimicrobial prophylaxis in patients with Boston type I keratoprosthesis.

SUMMARY

Despite the introduction of new antiseptics in surgery, PVI is still the preeminent antiseptic measure in ophthalmology. Its use is economically reasonable. There have been no reports of resistance to PVI or anaphylaxis with topical ophthalmic use. Furthermore, it does not induce resistance or cross-grztance to antibiotics. With these advantages the range of indications for topical use of antibiotics might decrease, with PVI as the sole perioperative antiseptic measure. Additional studies are required to assess the optimal timing, concentration and exposure time within different ophthalmic procedures.

Comparative efficacy of two different topical povidone-iodine 5% regimens in reducing conjunctival bacterial flora: A randomized parallel double-masked clinical trial

INTRODUCTION

The increasing prevalence of multi-resistant bacteria is a major public health concern. Infections acquired during ophthalmic surgery are devastating. The purpose of the current study is to compare the proportion of eyes with negative bacterial cultures on all tested media after 1 versus 3 sequential drops of povidone-iodine (PI) 5% into the inferior conjunctival fornix.

METHODS

Patients were randomly assigned to receive 1 (PI group) drop (at time 28 minutes) or 3 (PI plus group) sequential drops (at time 0, 20 minutes and 28 minutes) of PI 5% into the inferior conjunctival sac of one randomly selected eye. A swab culture was obtained from the inferior conjunctival fornix 5 minutes before and 30 minutes after time 0. Central corneal thickness (CCT) was measured shortly before time 0 and shortly after time 30. Conjunctival swabs were incubated aerobically in enriched Thioglycolate liquid medium (meat broth) and in three solid culture media (chocolate agar, trypticase soy agar with 5% sheep blood, and Sabouraud agar).

RESULTS

There was no significant difference in the proportion of negative cultures after intervention between groups (p = 0.1638). Also in the PI group (n = 59), the proportion of eyes with negative cultures after PI (79.7%) did not differ significantly from baseline (76.3%; p = 0.7539). However in the PI plus group (n = 61), the proportion of eyes with all negative cultures after PI (85.3%) was significantly higher than before PI (70.5%) (p = 0.0177). There was no significant difference in mean CCT before and after the intervention in both groups.

CONCLUSION

Instillation of 3 sequential drops of PI was associated with a significant increase in the proportion of eyes with all negative cultures, while instillation of a single drop of PI was not associated with a significant increase in the proportion of negative cultures. Further study is warranted to determine whether the difference between the PI administration regimens is also associated with differences in the rates of postoperative ocular infections.