Residual debris as a potential cause of postphacoemulsification endophthalmitis

Clinical features of endophthalmitis clusters after cataract surgery and practical recommendations to mitigate risk: systematic review

Intraocular transmission of exogenous pathogens in cataract surgery can lead to endophthalmitis. This review evaluates the features of endophthalmitis clusters secondary to pathogen transmission in cataract surgery. Articles reporting on pathogen transmission in cataract surgery were identified via searches of Ovid MEDLINE, EMBASE, and Cochrane CENTRAL, and a total of 268 eyes from 24 studies were included. The most common source of infectious transmission was attributed to a contaminated intraocular solution (ie, irrigation solution, viscoelastic, or diluted antibiotic; n = 10). Visual acuity at presentation with infectious features was 1.89 logMAR (range: 1.35 to 2.58; ∼counting fingers) and 1.33 logMAR (range: 0.04 to 3.00; Snellen: ∼20/430) at last follow-up. Patients with diabetes had worse outcomes compared with patients without diabetes. The most frequently isolated pathogen from the infectious sources was Pseudomonas sp. (50.0%). This review highlights the various routes of pathogen transmission during cataract surgery and summarizes recommendations for the detection, prevention, and management of endophthalmitis clusters.

An investigation on the current patterns of using consumables and sterilizing accessories in phacoemulsification in China

PURPOSE

To survey the routine application of consumables and sterilized accessories of phacoemulsification in mainland China.

METHODS

This was a cross-sectional questionnaire-based study. A questionnaire link was sent to Chinese ophthalmologists via the most widely used social communication tool (WeChat platform).

RESULTS

A total of 815 questionnaires were determined to be valid and were included in the final analysis. The majority of respondents were from Guangdong, Shandong, Zhejiang, Hebei, and Henan provinces. A number of hospitals (48.22%) reused the fluidics management system (FMS) after sterilization. Among the hospitals using disposable FMS, 38.03% reused tubing after sterilization. Most respondents' hospitals (70.43%) sterilized the handpiece for each operation. Only 38.77% of the respondents' hospitals adopted irrigation fluid antibiotics and/or intracameral antibiotics intraoperatively. Greater single usage of FMS was significantly associated with higher provincial gross domestic product (GDP), government hospitals, provincial hospitals, and disposable tubing (P < 0.05). The adoption of irrigation fluid/intracameral antibiotics was correlated with the financial type of the hospital, the daily volume of phacoemulsification, and the usage of silicone tubing (P < 0.05).

CONCLUSIONS

The results show a wide variation in the application of consumables and the sterilization of accessories in phacoemulsification in mainland China. Only half of the hospitals adopted interfusion/intracameral antibiotic prophylaxis, despite its efficacy having been confirmed. These data revealed potential safety issues of the sterilization of phacoemulsification instruments and the risk of intraocular infection.

Prophylaxis against Infection in Cataract Surgery: A Survey of Routine Practice

PURPOSE

To survey the routine practice of consultant ophthalmic surgeons in the United Kingdom in preventing postoperative endophthalmitis following cataract surgery.

METHODS

This is a cross-sectional questionnaire-based study. A questionnaire was sent to consultant ophthalmic surgeons in university teaching hospital ophthalmology departments in the United Kingdom.

RESULTS

Questionnaires were sent to 391 consultant ophthalmic surgeons in 36 ophthalmology departments. The response rate was 55.0% (215 responses). Eleven (5.1%) did not perform cataract surgery routinely. Of the remaining 204 respondents, all performed phacoemulsification as routine. A total of 28 (13.7%) reported a 0% rate of postoperative infective endophthalmitis. Preoperative topical antibiotics were routinely prescribed by 12 respondents (5.9%). The most common immediately preoperative measure was the usage of povidone iodine (203 respondents, 99.5%). A total of 19 (9.3%) used an antibiotic infusion during surgery. Postoperative subconjunctival antibiotics were given by 138 (67.6%), most commonly cefuroxime. A total of 33 (16.2%) administered postoperative intracameral antibiotics. A total of 141 (69.1%) prescribed topical antibiotics after surgery, most commonly neomycin. None gave systemic antibiotics routinely pre-or postoperatively.

CONCLUSIONS

The results show a wide variation of prophylactic measures used in the United Kingdom. The routine practices adopted reflect personal preferences, and were not necessarily evidence-based. Further prospective studies are required to provide evidence for the efficacy of these prophylaxis techniques.

Alcohol fixation of bacteria to surgical instruments increases cleaning difficulty and may contribute to sterilization inefficacy

BACKGROUND

Alcohol is frequently inappropriately used on surgical instruments to reduce bacterial contamination, but fixes protein to stainless steel. Here we compare the effect of air drying, prolonged soaking in water, and alcohol treatment on cleaning difficulty of contaminated forceps.

METHODS

Haltsted-mosquito forceps were contaminated with only Staphylococcus aureus. Instruments were air-dried for 10 (control), 75, or 240 minutes, soaked in water, or air dried then treated with ethanol or isopropanol for 10 seconds. All instruments were prewashed for 15 minutes. Forceps contaminated with blood and S aureus or Pseudomonas aeruginosa were dried and then sprayed or wiped with ethanol, and prewashed. Bacterial viability and soiling were determined by standard plate culture and crystal violet staining, respectively.

RESULTS

Soaking or spraying instruments with alcohol significantly reduced viable bacterial numbers, but significantly increased soil attached to forceps, as did air drying. Wiping instruments with alcohol had little effect on bacterial viability, but increased cleaning difficulty. Soaking in water for 75 or 240 minutes increased cleaning difficulty perhaps due to bacterial attachment to forceps.

CONCLUSIONS

Treating contaminated instruments with alcohol, allowing them to dry, or allowing them to soak in water for prolonged periods increases cleaning difficulty and should be discouraged.

An outbreak of surgical site infections following craniotomy procedures associated with a change in the ultrasonic surgical aspirator decontamination process

We investigated an outbreak of surgical site infections that occurred in a tertiary care hospital in Quebec, Canada. This investigation revealed that a change in the sterilization process of the ultrasonic surgical aspirator may have caused this outbreak. It emphasizes the fact that the complex designs of surgical power tools may restrict access to cleaning and sterilization agents. Health care professionals should review manufacturers' assembly/disassembly instructions and sterilization/decontamination procedures before use of such tools.

Biofouling of surgical power tools during routine use

Surgical power tools (SPTs) are frequently used in many surgical specialties such as dentistry, orthopaedics, ophthalmology, neurology, and podiatry. They have complex designs that may restrict access to cleaning and sterilization agents and frequently become contaminated with microbial and tissue residues following use. Due to these challenges, surgical power tools can be considered the weak link in the decontamination cycle and present a potential for iatrogenic transmission of infection. We aimed to review the existing literature on the decontamination of surgical power tools and associated iatrogenic transmission of infection. A search of the medical literature was performed using Ovid online using the following databases: Ovid Medline 1950-2014, Embase 1980-2014, and EBM Reviews Full Text--Cochrane DSR, ACP Journal Club, and Dare. Despite challenges to decontamination processes, reported episodes of iatrogenic infection directly linked to SPTs appear rare. This may reflect a true picture but more likely represents incomplete reporting, failure to investigate power tools, or lack of surveillance linking surgical site infections (SSIs) to power tools. Healthcare professionals should be aware of the complexities associated with the decontamination of different SPTs, and should review manufacturers' reprocessing instructions prior to purchase. More clarity is required in the manufacturers' validation of these reprocessing instructions. This particularly applies to the emerging surgical robot systems that present extreme challenges to decontamination between uses. Investigation of cross-infection incidents or SSI surveillance should include an element of assessment of SPT decontamination to further elucidate the contribution of SPTs to skin and soft tissue infections.

Fibres found in the eye during and after phacoemulsification cataract surgery

PURPOSE

Fibres are regularly found within the delivery cartridge (DC) and in the anterior chamber (AC) during phacoemulsification cataract surgery (PCS) and postoperatively. The purpose of this study was to identify their frequency and possible significance.

SETTING

Dedicated ophthalmic day surgery.

DESIGN

Prospective, consecutive, single-surgeon, cohort study.

METHODS

In 639 eyes undergoing PCS, the presence of fibres was documented in or on both the DC and in the AC intraoperatively, and in the AC postoperatively. The intraoperative method of fibre removal was documented. Corrected distance visual acuity (CDVA) was recorded preoperatively, and at day 1, week 1, and week 4 postoperatively. The incidence of clinical cystoid macular oedema (CMO) and endophthalmitis in the retained fibre subcohort was compared with that of the non-fibre subcohort.

RESULTS

A total of 5.2% of the operated eyes had a fibre or fibres in or on the DC, which in all cases was removed with forceps intraoperatively. A total of 14.6% of operated eyes had a fibre or fibres in the AC intraoperatively; these were removed by irrigation/aspiration. Postoperatively, five eyes (0.78%) had a fibre in the AC. There was no significant difference in postoperative CDVA between the fibre and non-fibre subcohorts (P=0.26), and no clinically significant CMO or endophthalmitis in either subcohort.

CONCLUSIONS

Most fibres seen on the DC or in the eye are sterile and non-inflammatory. However, there have been reports of endophthalmitis attributed to retained fibres. In this study, there were no complications attributable to the fibres, but their removal may minimise any adverse potential.

Ophthalmic viscoelastic devices as a cleaning challenge

Common practice when validating the cleaning of medical devices is to employ clinically relevant test soils as a challenge to the cleaning process. During use, medical devices may come into contact with a variety of materials that are difficult to clean. One example of this is the use of ophthalmic viscoelastic devices (OVDs) in cataract surgery. This study evaluated the effectiveness of a procedure for cleaning the lumens of a phacoemulsification handpiece using two different OVDs as test soils. The results of this study demonstrate that effective cleaning of the aspiration and irrigation lumens of a phacoemulsification handpiece may be achieved if the manufacturer's recommended cleaning procedures are followed.

Quantitative assessment of anterior chamber inflammation in patients with retained presumed intraocular cotton fiber after phacoemulsification

PURPOSE

To evaluate anterior chamber inflammation in eyes with retained presumed intraocular cotton fibers after small-incision cataract surgery.

METHODS

Fourteen patients with retained presumed intraocular cotton fibers after phacoemulsification were evaluated for anterior chamber inflammation. The control group consisted of 15 patients with no postoperative intraocular cotton fibers. An aqueous flare meter was used to evaluate anterior chamber reaction 1 day, 1 week, and 1 month postoperatively.

RESULTS

Retained cotton fibers were detected in the anterior chamber in 6 cases, and in the corneal incision site, extending into the anterior chamber, in 8 cases. The mean flare values at each postoperative visit were statistically similar between two groups.

CONCLUSIONS

Following cataract surgery, retained presumed intraocular cotton fibers did not cause any additional inflammation in the eye within the short term. In contrast to other intraocular foreign bodies, which may cause severe inflammation, retained intraocular cotton fibers seem to be well tolerated following cataract surgery.

Outbreak of Ochrobactrum anthropi endophthalmitis following cataract surgery

Postoperative endophthalmitis often progresses to significant visual impairment. This paper describes an outbreak of Ochrobactrum anthropi endophthalmitis following cataract surgery, and propose a new sterilization protocol to minimize the risk of further cases. Medical records of patients with O. anthropi endophthalmitis or with suggestive clinical findings during the outbreak were reviewed. Seven cases of O. anthropi pseudophakic endophthalmitis were confirmed between 24 July and 10 November 2010. The most probable cause of the outbreak of Ochrobactrum anthropi endophthalmitis was contamination of the tubing of the phaco-emulsification machine. Following introduction of a new sterilization protocol, no further cases occurred in over 1000 subsequent procedures.

Retained presumed intraocular cotton fiber after cataract operation: long-term follow-up with in vivo confocal microscopy

PURPOSE

To evaluate the long-term clinical outcomes in eyes with retained presumed intraocular cotton fibers after cataract surgery.

SETTING

Hong Kong Eye Hospital, Hong Kong, The People's Republic of China.

METHODS

A retrospective review of 19 eyes with retained presumed intraocular cotton fibers after cataract surgery was performed. Outcome measures were fiber-related complications. In vivo confocal microscopy was performed in eyes with entrapped cotton fibers at the wound site.

RESULTS

The duration of retained presumed cotton fibers ranged from 5 to 110 months (mean 42.3 months). No complications were noted in any of these eyes, including endophthalmitis, persistent uveitis, or corneal endothelial cell loss. In vivo confocal microscopy in eyes with entrapped fibers at the wound site showed normal corneal endothelium morphology with no keratocyte activation or inflammatory response.

CONCLUSIONS

Retained presumed fibers after cataract operations are more common than anticipated. In contrast to other organic foreign bodies, these retained fibers appear to be well tolerated. Conservative treatment can be adopted for these fibers as these pose minimal toxicity to the eye.

A model for the management of an atypical endophthalmitis outbreak

PURPOSE OF STUDY

To present a model for the assessment, investigation, and management of an atypical outbreak of infectious endophthalmitis of indeterminate aetiology.

METHODS

A published statistical model was used to determine when the case-load constituted an outbreak. Intraocular surgery was discontinued and a multidisciplinary infection control team was formed aimed at identifying potential causative factors among the following categories: environment around theatre, preoperative preparation, intraoperative theatre practices, intraoperative surgical practices, postoperative practices, equipment maintenance guidelines, cleaning/sterilization practices, and microbiological screening.

RESULTS

Five cases of postoperative endophthalmitis developed following uncomplicated phacoemulsification cataract surgery by different surgeons over a 7-month period. Despite full investigation no single focus of infection could be determined. Four out of five cases were culture positive. Three grew Streptococcus viridans of different strains. The fourth culture grew Staphylococcus aureus. In the absence of a single causative factor, it was postulated the combined effect of multiple potential factors may have led to an increased bacterial load and subsequent infection rate. Improved practices were initiated including new cleaning protocols to combat the build-up of debris on phacoemulsification instruments. Cataract surgery was resumed with 3-monthly microbiological monitoring. There have been no further cases in the 12 months following the changes.

CONCLUSION

Outbreaks of endophthalmitis typically present over a short time period and could often be attributed to a single infective cause. We present our experience of detecting and managing this cluster and recommend a 'ground-up' multidisciplinary model to manage future outbreaks of this devastating condition.