Bacterial culture after three sterilization methods for cataract surgery

Topical Antiseptics in Minimizing Ocular Surface Bacterial Load Before Ophthalmic Surgery: A Randomized Controlled Trial

PURPOSE

To investigate the reduction of the ocular surface bacterial load induced by 2 commercially available ophthalmic antiseptic formulations, povidone-iodine (PVI) 0.6% and chlorhexidine (CLX) 0.02%, before ocular surgery.

DESIGN

Randomized controlled trial.

METHODS

Seventy adult patients undergoing intraocular surgery (phacoemulsification) were randomized to receive in the index eye PVI (group A) 4 times a day for 3 days or CLX (group B) 4 times a day for 3 days before surgery. The untreated eye was used as control. A conjunctival swab was taken in both eyes before (T0) and after (T1) therapy. Microbial DNA was quantified with real-time polymerase chain reaction (PCR) analysis. The Mick algorithm was used to compare the abundance of each genus/genera against the distribution of abundances from the reference. At T1, patients filled a questionnaire to evaluate therapy-induced symptoms. Primary outcome was the reduction of bacterial DNA at T1 (microbial load), vs control arm, expressed as mean number of real-time PCR cycle times (CTs). Secondary outcomes were taxonomic composition, differential abundance, and therapy-induced ocular symptoms.

RESULTS

The T0-T1 difference in CT was significant in group B, but not in group A (mean [95% CI], 0.99 [0.33] vs 0.26 [0.15], P < .001, and 0.65 [0.3] vs 0.45 [0.41], P = .09, respectively). The taxonomic composition, alpha, and beta diversity remained consistent at all time points in both groups. The rate of patients reporting therapy-induced ocular symptoms and the mean discomfort grade were greater in group A than in group B (97% vs 26% and 4.97±2.48 vs 0.66±1.53, respectively).

CONCLUSIONS

Compared with PVI 0.6%, CLX 0.02% induced a greater reduction of ocular surface bacterial load, with no significant alterations of the taxonomic composition. Moreover, CLX was better tolerated than PVI.

Antimicrobials and antiseptics: Lowering effect on ocular surface bacterial flora - A systematic review

Topical antimicrobials and antiseptics are used perioperatively to reduce the ocular surface bacteria flora (OSBF) that are involved in the development of post-operative infectious complications. However, their effectiveness is still a controversial topic. This systematic review, performed according to the PRISMA guidelines and registered in PROSPERO, aims to provide an overview of the efficacy of the agents currently used in peri-cataract surgery and -intravitreal injections (IVI) in lowering the OSBF. Although effective in lowering OSBF, perioperative topical antimicrobials are associated with the risk of resistance development, with no obvious additional benefit compared with topical antisepsis. Conversely, the effectiveness of topical antiseptics before cataract surgery and IVI is strongly supported. Based on the available evidence, perioperative antimicrobials are not recommended, whereas the perioperative use of antiseptics is strongly recommended as prophylactic treatment for lowering the infection due to OSBF. Post-operative antimicrobials may be considered in eyes at higher risk for infection.

Preoperative Antisepsis with Chlorhexidine Versus Povidone-Iodine for the Prevention of Surgical Site Infection: a Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVE

Chlorhexidine (CH) and povidone-iodine (PI) are the most commonly used preoperative skin antiseptics at present. However, the prevention of the surgical site infection (SSI) and the incidence of skin adverse events do not reach a consistent statement and conclusion. This meta-analysis aimed to evaluate the efficacy of chlorhexidine and povidone-iodine in the prevention of postoperative surgical site infection and the incidence of corresponding skin adverse events.

METHOD

Substantial studies related to "skin antiseptic" and "surgical site infection" were consulted on PUBMED, Web of Science, EMBASE, and CNKI. The primary outcome was the incidence of postoperative SSI. The secondary outcome was associated with skin adverse events. All data were analyzed with Revman 5.3 software.

RESULTS

A total of 30 studies were included, including 29,006 participants. This study revealed that chlorhexidine was superior to povidone-iodine in the prevention of postoperative SSI (risk ratio [RR], 0.65; 95% confidence interval [CI], 0.55-0.77; p < 0.00001, I² = 57%). Further subgroup analysis showed that chlorhexidine was superior to povidone-iodine in the prevention of postoperative SSI in clean surgery (risk ratio [RR], 0.81; 95% confidence interval [CI], 0.67-0.98; p = 0.03), I² = 28%) and clean-contaminated surgery (risk ratio [RR], 0.58; 95% confidence interval [CI], 0.47-0.73; p < 0.00001, I² = 43%). However, there was no statistically significant difference in the incidence of skin adverse events between CH and PI groups.

CONCLUSION

Chlorhexidine was superior to povidone-iodine in preventing postoperative SSI, especially for the clean-contaminated surgery. However, there was no statistically significant difference in the incidence of skin adverse events between CH and PI groups.

Comparison of the Effects of Povidone-Iodine 5%, Polyhexamethylene Biguanide, and Chlorhexidine as a Preoperative Antiseptic in Endophthalmitis Prophylaxis in Patients Undergoing Phacoemulsification Cataract Surgery

Background:

This study aims to compare the efficacy and toxicity of povidone-iodine (PI) 5%, polyhexamethylene biguanide (PHMB) 0.02%, and chlorhexidine 0.02% in patients undergoing phacoemulsification cataract surgery.

Materials and Methods:

This single-center, randomized study was done on 330 patients who referred to Feiz hospital in Isfahan and scheduled for cataract surgery. They were assigned randomly to 1 of 3 groups of 110 eyes who received 1 drop of PI 5% in group 1, 1 drop of PHMB 0.02% in group 2 and 1 drop of chlorhexidine 0.02% in group 3. Pre-operative Cultures samples were obtained without any topical application and it was repeated 5 min after use of antiseptic solutions. Cultures were obtained from the inferior conjunctival fornix, using sterile culture swabs while avoiding contact to the eyelids and lashes.

Results:

The numbers of colony-forming units (CFUs) did not differ significantly among the three groups (P = 0.149 and P = 0.260, respectively). After the intervention, CFUs numbers in the three groups were decreased with a significant difference in both blood and chocolate agars (P = 0.304 and P = 0.136, respectively). Of the 317 eyes, 108 (34.1%) showed no bacterial growth in the pre-preparation period, which was similar in the three groups. Staphylococcus epidermidis was the most common isolated bacteria. Conjunctival injection was significantly different among studied groups (P = 0.0001), five patients in iodine group had severe conjunctival injection and no one in the other group. SPE was significantly fewer in chlorhexidine group than PHMB and iodine groups (P = 0.0001).

Conclusion:

Pretreatment with 5% Povidone-Iodine (PVI) for at least 15 min or repeated applications over 10 min is effective in the reduction of conjunctival organisms, and results in less postoperative endophthalmitis.

Pathogens in the Meibomian gland and conjunctival sac: microbiome of normal subjects and patients with Meibomian gland dysfunction

Objective

To explore the composition of the ocular microbiome in normal subjects and patients with Meibomian gland dysfunction (MGD).

Subjects and methods

Seventy subjects (140 eyes) were enrolled in our study. Signs of dry eye were evaluated and bacterial species in the conjunctival sac (CS) and Meibomian gland (MG) secretions were then identified by 16S rRNA gene sequencing. Additionally, 17 subjects (34 eyes) were further evaluated to determine differences in the microbiomes in the surface and deep layers of MG using a segmental secretion analysis.

Results

The positive bacterial isolation rate was markedly higher in MG secretions than in the CS. The bacterial composition of the control and mild group was simple, whereas the composition of bacteria was more complex as the severity of MGD increased. The positive bacterial isolation rate and number of bacterial types were significantly higher in the severe MGD group than those in the control, mild and moderate MGD groups. Corynebacterium macginleyi was only detected in the severe MGD group, with an isolation rate of up to 26.3%. Furthermore, a new grading system for bacterial severity of MGD was proposed and the severity of MGD appeared to be positively correlated with a higher grade of bacterial severity. The segmental secretion analysis showed severe MGD had a significantly higher incidence of bacterial discordance rate.

Conclusion

The severity of MGD was positively correlated with a higher isolation rate, a greater number of bacterial species, and a higher grade of bacterial severity, which implied that MGD might be correlated with bacterial changes. This study provided some basis for the indications of antibiotic in clinical practice.

Preoperative skin antisepsis with chlorhexidine gluconate versus povidone-iodine: a prospective analysis of 6959 consecutive spinal surgery patients

OBJECTIVE The aim of this study was to determine the efficacy of 2 common preoperative surgical skin antiseptic agents, ChloraPrep and Betadine, in the reduction of postoperative surgical site infection (SSI) in spinal surgery procedures. METHODS Two preoperative surgical skin antiseptic agents-ChloraPrep (2% chlorhexidine gluconate and 70% isopropyl alcohol) and Betadine (7.5% povidone-iodine solution)-were prospectively compared across 2 consecutive time periods for all consecutive adult neurosurgical spine patients. The primary end point was the incidence of SSI. RESULTS A total of 6959 consecutive spinal surgery patients were identified from July 1, 2011, through August 31, 2015, with 4495 (64.6%) and 2464 (35.4%) patients treated at facilities 1 and 2, respectively. Sixty-nine (0.992%) SSIs were observed. There was no significant difference in the incidence of infection between patients prepared with Betadine (33 [1.036%] of 3185) and those prepared with ChloraPrep (36 [0.954%] of 3774; p = 0.728). Neither was there a significant difference in the incidence of infection in the patients treated at facility 1 (52 [1.157%] of 4495) versus facility 2 (17 [0.690%] of 2464; p = 0.06). Among the patients with SSI, the most common indication was degenerative disease (48 [69.6%] of 69). Fifty-one (74%) patients with SSI had undergone instrumented fusions in the index operation, and 38 (55%) patients with SSI had undergone revision surgeries. The incidence of SSI for minimally invasive and open surgery was 0.226% (2 of 885 cases) and 1.103% (67 of 6074 cases), respectively. CONCLUSIONS The choice of either ChloraPrep or Betadine for preoperative skin antisepsis in spinal surgery had no significant impact on the incidence of postoperative SSI.

Povidone-iodine 3-minute exposure time is viable in preparation for cataract surgery

PURPOSE

Povidone-iodine (PI) is widely used to reduce the preoperative conjunctival bacterial load. This study aimed to evaluate the employment of PI 10% in an attempt to sterilize the ocular surface prior to cataract surgery, and to show that PI could be left in contact for 3 minutes. The viability of this exposure time in clinical practice, associated adverse events, and visual outcomes were documented.

METHODS

In this prospective cohort study, phacoemulsification cataract surgery was performed in 604 patients by a single surgeon. Preoperative preparation was undertaken with PI 10%, applied to the cornea, conjunctival sac, eyelids, and periorbital skin with sterile cotton gauze. Povidone-iodine was then flushed onto the ocular surface. Operating room staff timed the precise duration of exposure. After the 3-minute preparation, the lids were thoroughly dried with fresh dry gauze.

RESULTS

The median PI exposure time was 3.17 minutes, with an interquartile range of 0.25. All cases were followed up postoperatively at 1 day, 1 week, and 1 month. There were no complications attributable to PI. Visual outcomes were satisfactory.

CONCLUSIONS

Implementation of a preoperative prophylaxis protocol that used PI 10% with a 3-minute exposure time can be performed in clinical practice. The 3-minute exposure time had no adverse sequelae.