Post-cataract Surgery Endophthalmitis Research Articles

Fluorescent amplified fragment length polymorphism (FAFLP) genotyping demonstrates the role of biofilm-producing methicillin-resistant periocular Staphylococcus epidermidis strains in postoperative endophthalmitis

BackgroundAn observational case series was used to study the virulence characteristics and genotypes of paired Staphylococcus epidermidis isolates cultured from intraocular samples and from periocular environment of patients with postcataract surgery endophthalmitis.MethodsEight S. epidermidis isolates were obtained from three patients (2 from patients #1 and 2 and 4 from patient #3) whose vitreous and/or anterior chamber (AC) specimens and preoperative lid/conjunctiva samples were culture positive. Cultures were identified by API-Staph phenotypic identification system and genotypically characterized by Fluorescent Amplified Fragment Length Polymorphism (FAFLP) and checked for their antimicrobial susceptibility. The isolates were tested for biofilm-production and methicillin-resistance (MR) by PCR amplification of icaAB and mecA gene respectively.ResultsFour out of eight S. epidermidis strains showed multiple drug resistance (MDR). All the eight strains were PCR positive for mecA gene whereas seven out of eight strains were positive for icaAB genes. In all three patients FAFLP typing established vitreous isolates of S. epidermidis strains to be indistinguishable from the strains isolated from the patient's conjunctival swabs. However, from patient number three there was one isolate (1030b from lid swab), which appeared to be nonpathogenic and ancestral having minor but significant differences from other three strains from the same patient. This strain also lacked icaAB gene. In silico analysis indicated possible evolution of other strains from this strain in the patient.ConclusionMethicillin-resistant biofilm positive S. epidermidis strains colonizing the conjunctiva and eyelid were responsible for postoperative endophthalmitis (POE).

High-resolution genotyping of Pseudomonas aeruginosa strains linked to acute post cataract surgery endophthalmitis outbreaks in India

BackgroundInvestigation of two independent outbreaks of post cataract surgery endophthalmitis identified the reservoir of epidemic strains of P. aeruginosa.MethodsPatient isolates cultured from vitreous fluid of all the nine cases and from the peripheral devices of phacoemulsification machine were subjected to high-resolution Fluorescent Amplified Fragment Length Polymorphism (FAFLP) analysis.ResultsFAFLP based genotyping of the isolates confirmed nosocomial transmission. Although biochemical characterization and antibiotic susceptibility profiles grouped all the isolates together, FAFLP based genotyping revealed that, all the outbreak isolates were derived from 2 different strains, with independent origins. One group of isolates was traced to phacoprobe and the second one to the internal tubing system of the phacoemulsification machine used in cataract surgery. In silico analysis indicated possible evolution in both the clusters of P. aeruginosa isolates due to genetic polymorphisms. The polymorphisms were mapped to gene products (cell envelope, outer membrane proteins) possibly having significant role in pathogenesis.ConclusionThe present study is probably the first one to apply FAFLP typing successfully to investigate outbreaks of postoperative endophthalmitis (POE) in an ophthalmic setting, which was able to identify the source, and helped to make rational decisions on sterilization procedures that halted more cases of infection in these hospitals.

Cohort study of 27 cases of endophthalmitis at a single institution

This retrospective cohort study identified potential risk factors associated with post-cataract surgery endophthalmitis. A 10% sampling of all patients operated on for cataract surgery between January 1, 1996 and December 31, 2002 were compared with 27 cases of bacterial endophthalmitis that occurred during the same period at the same institution. In a multivariate regression analysis, the factors found to be statistically associated with endophthalmitis, in decreasing order of significance, were (1) wound leak on the first postoperative day, (2) capsular or zonular surgical complication, (3) topical antibiotic started on the day after surgery instead of on the day of surgery, (4) use of ciprofloxacin instead of ofloxacin topically after surgery, (5) not patching after surgery, and (6) not placing a collagen shield soaked in antibiotic.

The effect of cataract surgery on ocular levels of topical moxifloxacin

To investigate the effect of cataract surgery on the concentration of moxifloxacin in aqueous and vitreous humor after topical application. Prospective laboratory intervention using a rabbit model. Following topical administration of 0.5% moxifloxacin, 60 minutes before surgery and immediately post cataract surgery, aqueous and vitreous humor were sampled at 30, 60, and 120 minutes postsurgery. Moxifloxacin concentrations were determined by high-pressure liquid chromatography (HPLC). Mean tissue concentrations obtained in surgical eyes were compared with concentrations obtained in nonsurgical eyes. The potential effectiveness of moxifloxacin in providing prophylaxis against intracameral bacterial inoculation was investigated by comparing antibiotic concentrations to minimum inhibitory concentration (median MIC90) values for Staphylococcus aureus and Staphylococcus epidermidis. In surgical eyes, mean moxifloxacin concentrations in aqueous were 13.9, 16.2, and 12.2 microg/ml versus 25.3, 32.6, and 15.7 microg/ml in nonoperated eyes at 30, 60, and 120 minutes, respectively. No statistically significant differences were found between surgical and nonsurgical eyes. In surgical eyes, mean moxifloxacin concentrations in vitreous were 66.8, 66.6, and 400.2 ng/ml versus 43.1, 199.8, and 54.4 ng/ml in nonoperated eyes at 30, 60, and 120 minutes, respectively. These differences were not statistically significant. There were no statistically significant differences in the penetration of topical moxifloxacin in eyes undergoing cataract surgery compared with unoperated eyes. A multiple-drop schedule of moxifloxacin produced aqueous concentrations that were well above the MICs of even resistant strains of the most common organisms implicated in postcataract surgery endophthalmitis.

A Critical Analysis Of The Management Of Acute Postcataract Surgery Endophthalmitis In The Gambia

Objectives: To report the pattern of presentation and the outcome of management of postcataract surgery endophthalmitis at the Royal Victoria Hospital (RVH), Banjul, The Gambia, and to critically analyse the methods employed. Methods: The records of four consecutive cases of acute endophthalmitis following cataract surgery, seen over a one-year period (October 2000 to September 2001) at the eye unit of RVH, Banjul, were analysed. Results: Early diagnosis of endophthalmitis, based on clinical signs only, was made within the first 14 post-operative days in all 4 patients (3 females and l male aged between 50 and 60 years.) Prompt treatment with a variety of broad spectrum systemic, topical and subconjunctival antibiotics was administered to each patient. Despite this treatment, vision was eventually lost in all the eyes. Conclusion: Because of the poor outcome of the treatment of these patients, one may conclude that the current management of acute postcataract surgery endophthalmitis in the Gambia does not seem to be effective. A new evidence-based management protocol is proposed using the results of the Endophthalmitis Vitrectomy Study (EVS) as a guide. Nigerian Jnl Ophthalmology Vol.11(2) 2003: 80-85

Relationship of Echographic Findings With Visual Outcomes in Post-Cataract Surgery Endophthalmitis

Preoperative ultrasonography in postoperative endophthalmitis was correlated with outcome following vitrectomy. Final visual acuity <20/400 in 14% of eyes with mild/moderate vitreous opacities vs. 67% with dense vitreous opacities. More virulent isolates were found in 67% of eyes with dense opacities vs. 9% with mild/moderate opacities. Dense vitreous debris on ultrasonography was associated with infection by virulent organisms and poorer outcome.

Case-control study of endophthalmitis after cataract surgery comparing scleral tunnel and clear corneal wounds

Purpose To study the possible association between clear corneal incision with or without placement of a suture during cataract extraction and postoperative endophthalmitis. Design Retrospective, comparative, case-controlled study. Methods Thirty-eight patients treated for culture-positive, acute postcataract surgery endophthalmitis, and 371 randomly selected control patients who underwent uncomplicated cataract surgery in the referring community were studied. Incision type and use of suture during cataract surgery of endophthalmitis patients were compared with the controls. The data were analyzed using logistic regression methods. Results Of the 38 patients with endophthalmitis, 17 patients (45%) had clear corneal incisions and 21 patients (55%) had a scleral tunnel incision. In 371 controls, 76 patients (20%) had clear corneal incisions and 295 patients (80%) had scleral tunnel incisions. Clear corneal incision was associated with a threefold greater risk of endophthalmitis than was scleral tunnel incision (Odds Ratio, 3.36, 95% Confidence Interval = 1.67 to 6.78). The type of incision was significant (χ 2 = 11.53, P = .0007); a clear corneal incision was more frequently associated with endophthalmitis. A subgroup analysis revealed that the presence or absence of a suture was not significant (χ 2 = 1.31, P = .2524). Conclusions In this retrospective, case-controlled study, clear corneal incisions were found to be a statistically significant risk factor for acute postcataract surgery endophthalmitis when compared with scleral tunnel incisions.

Endophthalmitis following cataract surgery in Sweden. The 1998 national prospective survey.

To investigate the morbidity of postoperative endophthalmitis (POE) following cataract surgery in Sweden in 1998. Clinically presumed cases of POE were reported in a prospective survey in which all Swedish ophthalmic surgical units except one had agreed to participate. Data on intraocular cultures and visual outcomes at 3 months after infection were supplied. Surgical cases that became infected were identified in the Swedish National Cataract Register, thereby enabling screening for various putative risk factors. The nationwide incidence of POE amounted to 58 cases out of 54 666 cataract operations, or 0.1% of surgical cases. The predominant aetiology was gram-positive bacteria, which comprised 57% of the material. Acrylic intraocular lenses were found to decrease the risk of POE significantly in comparison to hydrogel and polymethylmethacrylate lenses. The incidence of POE after cataract surgery in Sweden is similar to that currently reported elsewhere in the developed world. We hope that continued registration of cases of POE in Sweden will shed light on the possible influences of various prophylactic measures and different intraocular lens materials on the development of postoperative infection.

Épidémiologie des infections nosocomiales après opération de la cataracte et rôle du CLIN dans la prévention

Despite of a low incidence (3 for 1,000), post-cataract surgery endophthalmitis remains a serious complication with a poor prognosis. The nosocomial definition is almost always present despite the endogenous origin; the latter is associated with the risk prone operative procedure, and the presence of numerous normal flora on skin and conjunctiva. Within this context, the incriminated bacteria are coagulase-negative Staphylococcus. Micro-outbreaks of postoperative Pseudomonas aeruginosa endophthalmitis have an exogenous origin. In order to prevent these nosocomial infections, the role of the "infection control committee" and the operational hygiene team is very important: 1) survey of new infectious cases and of the hospital environment; 2) infection control measures about pre and intra operative preparation of the patient; 3) operating room maintenance.