Nosocomial acute-onset postoperative endophthalmitis survey. A 10-year review of incidence and outcomes

Acute-onset endophthalmitis after cataract surgery (2000-2004): incidence, clinical settings, and visual acuity outcomes after treatment

PURPOSE

To report the incidence, clinical settings, and visual acuity outcomes of acute-onset endophthalmitis after cataract surgery.

DESIGN

Retrospective, observational case series.

METHODS

Annual cataract surgery statistics were determined by review of electronic surgical records. The clinical and microbiologic records were reviewed of all patients with clinically diagnosed endophthalmitis within 6 weeks after cataract surgery at a single university-affiliated hospital between January 2000 and November 2004. main outcome measures: Operative technique, intraoperative complications, and visual acuity.

RESULTS

The incidence of acute-onset endophthalmitis after cataract surgery was 0.04% (7/15,920) for cataract surgeries of all methods, 0.05% (6/11,462) for cataract surgery by clear cornea phacoemulsification, and 0.02% (1/4,458) for cataract surgery by methods other than clear cornea phacoemulsification (P = .681, Fisher's exact test). Six of seven (86%) cases occurred in the right eye, and all cases were performed by right-handed surgeons through temporal incisions. Five of seven (71%) patients had relative immune compromise. Four of seven (57%) patients had an intraoperative complication: vitreous loss in three patients and iris prolapse in one patient. Two patients had topical placement of lidocaine 2% gel before povidone-iodine preparation. The visual acuity at final follow up was 20/25 or better in four patients and count fingers or worse in three patients.

CONCLUSIONS

The incidence of acute-onset endophthalmitis after temporal clear cornea incision phacoemulsification is low (0.05%). Potential risk factors for endophthalmitis may include intraoperative complications, relative immune compromise, application of lidocaine 2% gel before povidone-iodine preparation, and inferior incision location.

[Postoperative acute endophthalmitis: a prospective study. Clinical presentation, management and prognostic factors]

AIMS

To assess the characteristics and visual outcome of patients with acute postoperative endophthalmitis hospitalized in a referral center.

MATERIALS AND METHODS

All patients suspected of having infectious endophthalmitis were included in this study. All patients were treated with the same protocol including at least intravitreal injection of antibiotics and instillation of fortified antibiotics. Symptoms, visual acuity, and slit lamp examination were recorded before treatment, at the end of hospitalization and during clinical follow-up. Treatments and biological results were also reported. For patients developing infectious endophthalmitis after cataract surgery, intraoperative management such as location of the incision, suture or sutureless incision, and material of the intraocular lens were also noted.

RESULTS

Forty-one patients were included in the study over 32 months (33 patients after cataract surgery). Intraocular inflammation and a decrease in subjective visual acuity were the most frequently reported findings (90% and 94%, respectively). Ocular pain and conjunctiva injection were less frequently reported (47% and 48%, respectively). Symptoms occurred 5 days after the surgery (median); 56% of patients needed a second intravitreal injection of antibiotics. There was a significant increase in visual acuity during and after hospitalization; median final visual acuity was 4.6/10 (0.34 log MAR = 20/43); 30% of patients had less than 20/200, but 44% more than 20/40. In endophthalmitis following cataract surgery, incisions were corneal in all cases and sutured in 62% of cases. Incisions were temporal in 55% of patients.

DISCUSSION

Our results are similar to those previously published for acute endophthalmitis following ocular surgery. Intravitreal antibiotic injection remains the gold standard on the management of acute postoperative endophthalmitis.

Review of sterile, postoperative, anterior segment inflammation following cataract extraction and intraocular lens implantation

PURPOSE

To evaluate unexpected, acute intraocular anterior segment inflammation following uneventful cataract extraction by phacoemulsification and foldable posterior chamber intraocular lens (PCIOL) implantation.

METHODS

This retrospective study evaluated five cases of postoperative inflammation that occurred after cataract extraction with foldable PCIOL implantation. Medical records were reviewed to analyze the unexplained postoperative inflammation.

RESULTS

The five patients who developed inflammatory activity during the postoperative period responded well to corticosteroid treatment. Toxic maculopathy developed in one patient after aggressive antibacterial therapy. Vitrectomy was performed for one patient with prolonged vitreal inflammatory activity.

CONCLUSIONS

Noninfectious endophthalmitis developing upon surgery may be caused by a multifactorial process or an interindividual variable response to a common factor as a hypersensitivity reaction. It should be remembered in inflammatory cases after surgery in order to prevent the toxic, irreversible side effects of bacterial endophthalmitis treatment.

A comparison of intravitreal piperacillin/tazobactam with ceftazidime in experimental Pseudomonas aeruginosa endophthalmitis

In the present study, we aimed at comparing the efficacies of intravitreal piperacillin/tazobactam and ceftazidime applications in the treatment of experimental Pseudomonasaeruginosa endophthalmitis in rabbit eyes. Twenty-four New Zealand white albino rabbits were divided into three groups (n=8 in each), and the right eyes received 0.1 ml intravitreal injections of P. aeruginosa suspension. The left eyes served as uninfected control and were injected with 0.1 ml of saline solution. The right eyes of rabbits in group 1 were treated with intravitreal injection of 250 microg/0.1 ml piperacillin/tazobactam 24 hr after intravitreal inoculation of P. aeruginosa, whereas group 2 eyes received intravitreal 1 mg/0.1 ml ceftazidime. Group 3 eyes received no treatment and served as infected controls. Clinical, microbiological and histopathological evaluations of the eyes in each group were performed on the 1st, 3rd, and 6th day after the inoculation of P. aeruginosa. The mean clinical scores of each group were similar at the first day after P. aeruginosa inoculation (P>0.05). At the 6th day, there was no statistically significant difference in mean clinical scores between group 1 and 2, but mean clinical score of group 3 was significantly higher (P<0.001). Microbiological analysis and histopathological scoring demonstrated no statistically significant difference between group 1 and 2 (for each, P>0.05). Group 3 eyes had a significantly more CFU/ml and higher histopathological score (for each, P<0.001). In conclusion, intravitreal application of 250 microg/0.1 ml piperacillin/tazobactam seems to be effective in the treatment of P. aeruginosa endophthalmitis in rabbits, but is not superior to intravitreal ceftazidime application. Therefore, intravitreal piperacillin/tazobactam may be a useful alternative to ceftazidime for pseudomonal endophthalmitis.

Infections nosocomiales endoculaires au CHNO des XV-XX de 2000 à 2002

PURPOSE

Prevention of nosocomial infection is a priority for the Infection Control Committee (ICC). Following their recommendations, the XV-XX National Ophthalmologic Hospital's ICC conducted a survey on cases of infection and we report these results for the 2000-2002 period.

METHODS

During the 2000-2002 period, 21,384 programmed intraocular surgeries were done. Every day, a hygiene coordinator was informed of each bacterial or fungal laboratory test on intraocular samples and for all patients who were hospitalized for endophthalmitis. After data analysis with a referent ICC physician, resulting infection was declared postoperative nosocomial endophthalmitis. For these patients, prophylactic antibiotic use, the surgery report, and bacterial laboratory test results were reviewed.

RESULTS

The overall 3-year incidence of suspected postoperative endophthalmitis after intraocular surgery was 2.0 per 1000 (42 cases). Confirmed microbiological growth was demonstrated in 19 cases (45%). For cataract surgery, the incidence was 1.0 per 1000 for acute-onset culture-proven postoperative endophthalmitis, 0.1 per 1000 for delayed culture-proven postoperative endophthalmitis, 2.1 per 1000 for acute-onset suspected postoperative endophthalmitis and 0.5 per 1000 for delayed suspected postoperative endophthalmitis. Gram-positive cocci were isolated in 77%. Twenty-one patients received systemic prophylactic antibiotics. Bacterial growth was positive in five of these 21 cases. For two cases, organisms were resistant to the prophylactic antibiotics used.

CONCLUSION

Monitoring postoperative nosocomial infection is mandatory to detect incidence variation and evaluate infection control management. Prophylactic antibiotic efficacy remains to be evaluated.

Endophthalmitis following cataract surgery in Sweden: national prospective survey 1999-2001

PURPOSE

To investigate the epidemiology of postoperative endophthalmitis (POE) following cataract surgery in Sweden during a 3-year period, using the framework of the Swedish National Cataract Register.

METHODS

Clinically presumed cases of POE were reported in a prospective survey involving all Swedish ophthalmic surgical units except one. Data on results of the intraocular culture and visual outcome after infection, as well as patient age and gender and various elements of the surgical procedure, were collected.

RESULTS

The nationwide incidence of POE was 0.0595%, representing 112 cases in 188 151 cataract operations. Gram-positive bacteria were the predominant aetiology, with an 84.6% share of culture-positive cases. A significantly decreased risk for POE was found for patients who had received prophylactic intracameral antibiotics (mainly cefuroxime) in comparison with those who had been treated with topical antibiotics only.

CONCLUSIONS

The prevalence of POE after cataract surgery in Sweden is at the lower end of the spectrum of incidence currently reported in the developed world. The administration of intracameral antibiotics may have contributed to these results.

Comparison of Preoperative Conjunctival Bacterial Flora in Patients Undergoing Glaucoma or Cataract Surgery

PURPOSE

To assess differences in conjunctival bacterial flora between patients undergoing glaucoma and cataract surgery.

PATIENTS AND METHODS

A prospective study comparing conjunctival bacterial cultures obtained from 339 patients undergoing either cataract (n = 258) or glaucoma (n = 81) surgery. All cultures were acquired during the preoperative visit, approximately three to seven days prior to surgery. The culture samples were inoculated onto blood and chocolate agar, as well as blood culture broth media. All bacterial isolates were identified and statistical analyses were performed to determine if there were differences in flora between the eyes undergoing cataract versus glaucoma surgery.

RESULTS

Two hundred fifteen of 258 eyes (83%) undergoing cataract surgery were found to have positive bacterial growth, compared with 62 of 81 eyes (77%) of those undergoing glaucoma surgery (P = 0.2246). Coagulase-negative Staphylococci, the most common bacterial isolate, was cultured from 167 eyes (65%) in the cataract group and 42 (52%) in the glaucoma group (P = 0.0514). Among all bacterial isolates, only Corynebacterium species was found to be statistically different between the two patient groups with 92 (36%) and 11 (14%) eyes testing positive in the cataract and glaucoma groups, respectively (P = 0.0003).

CONCLUSIONS

There was no statistically significant difference in the proportion of conjunctival culture samples testing positive for bacterial growth in eyes undergoing glaucoma surgery compared with those undergoing cataract surgery. Glaucoma medications, or their preservatives, do not appear to significantly alter conjunctival flora. Techniques used for endophthalmitis prophylaxis prior to cataract surgery are likely appropriate for glaucoma surgery as well.

Endophthalmitis after pars plana vitrectomy: Incidence, causative organisms, and visual acuity outcomes

PURPOSE

To investigate the incidence, causative organisms, and visual acuity outcomes associated with endophthalmitis after pars plana vitrectomy.

DESIGN

Retrospective, noncomparative, consecutive case series.

METHODS

The medical records were reviewed of all patients who developed acute-onset postoperative endophthalmitis (within 6 weeks of surgery) after pars plana vitrectomy at Bascom Palmer Eye Institute between January 1, 1984 and December 31, 2003.

RESULTS

During the 20-year study interval, the overall incidence rate of postvitrectomy endophthalmitis was 0.039% (6/15,326). Cultured organisms were Staphylococcus aureus (n = 3), Proteus mirabilus (n = 1), and Staphylococcus epidermidis/Pseudomonas aeruginosa (n = 1); one case was culture-negative. Visual acuity after treatment for endophthalmitis ranged from 2/200 to no light perception, with a final vision of light perception or no light perception in four of six (67%) eyes.

CONCLUSION

The incidence of endophthalmitis after pars plana vitrectomy is low but the visual acuity outcomes after treatment are generally poor.

MINIMIZING THE RISK OF ENDOPHTHALMITIS FOLLOWING INTRAVITREOUS INJECTIONS

PURPOSE

To review techniques that are important in preventing endophthalmitis following intravitreous injections based on the available evidence.

METHODS

A review of the literature regarding existing evidence that is relevant to post-injection endophthalmitis prophylaxis.

RESULTS

The available evidence regarding endophthalmitis prophylaxis is largely based on intraocular surgery, particularly cataract surgery. Despite the controversy and the paucity of evidence regarding endophthalmitis prophylaxis for intravitreous injections, it is recommended that povidone-iodine should be used prior to intravitreous injections to minimize or eliminate the presence of ocular surface bacteria. Administration of topical antibiotics may also be considered before and after the intravitreous injections. Strict adherence to aseptic techniques, including the use of an eyelide speculum is also important.

CONCLUSION

Endophthalmitic can occur following intravitreous injections. Prophylaxis with topical povidone-iodine, and possibly antibiotics, as well as adherence to aseptic technique may minimize the risk of post-injection endophthalmitis.

RISKS OF INTRAVITREOUS INJECTION: A COMPREHENSIVE REVIEW

PURPOSE

To evaluate the prevalence of the most common serious adverse events associated with intravitreous (IVT) injection.

METHODS

A systematic search of the literature via PubMed from 1966 to March 1, 2004, was conducted to identify studies evaluating the safety of IVT injection. Data submitted in New Drug Applications to the U.S. Food and Drug Administration for drugs administered into the vitreous were included where available. Serious adverse events reported in each study were recorded, and risk per eye and risk per injection were calculated for the following serious adverse events: endophthalmitis, retinal detachment, iritis/uveitis, intraocular hemorrhage, ocular hypertension, cataract, and hypotony. Rare complications also were noted.

RESULTS

Data from 14,866 IVT injections in 4,382 eyes were analyzed. There were 38 cases of endophthalmitis (including those reported as pseudoendophthalmitis) for a prevalence of 0.3% per injection and 0.9% per eye. Excluding cases reported specifically as pseudoendophthalmitis, the prevalence of endophthalmitis was 0.2% per injection and 0.5% per eye. Retinal detachment, iritis/uveitis, ocular hypertension, cataract, intraocular hemorrhage, and hypotony were generally associated with IVT injection of specific compounds and were infrequently attributed by the investigators to the injection procedure itself. Retinal vascular occlusions were described rarely in patients after IVT injection, and it was unclear in most cases whether these represented true injection-related complications or chance associations.

CONCLUSION

The risk of serious adverse events reported after IVT injection is low. Nevertheless, careful attention to injection technique and appropriate postinjection monitoring are essential because uncommon injection-related complications may be associated with permanent vision loss.

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.

Prevention of endophthalmitis

PURPOSE

To report the incidence of postoperative endophthalmitis in a series of patients who had cataract surgery with intraocular lens (IOL) implantation and to apply guidelines toward the prevention of postoperative endophthalmitis.

SETTING

The Buzard Eye Institute for Corneal, Refractive and Cataract Surgery, Las Vegas, Nevada, USA.

METHODS

In this prospective institutional study, 5,131 cataract surgery cases with IOL implantation were performed from 1998 to 2002 by 1 surgeon at a single institute. The surgeon used a blue-line incision at the superior location, povidone- iodine prophylaxis, and postoperative injection of subconjunctival antibiotics. The incidence of endophthalmitis in the study was compared with the general incidence in the United States (range 0.07% to 0.13%) and in published studies (range 0.02% to 0.57%).

RESULTS

The 5,131 cases were followed for a mean of 2 years (range 3 months to 4 years). The mean patient age was 69.6 years +/- 10.9 (SD). No case of endophthalmitis occurred. The zero incidence of endophthalmitis was below the general incidence in the United States and in published studies.

CONCLUSIONS

The findings suggest that the absence of postoperative endophthalmitis may be related to 4 factors: povidone-iodine prophylaxis, meticulous draping of the eyes, operative technique (blue-line incision), and postoperative injection of subconjunctival antibiotics.

Three-day application of topical ofloxacin reduces the contamination rate of microsurgical knives in cataract surgery

PURPOSE

To determine the rate of contamination of microsurgical knives during cataract surgery and the benefit of a 3-day versus a 1-hour preoperative application of topical ofloxacin in reducing the contamination rate.

DESIGN

Prospective, randomized controlled trial.

PARTICIPANTS

Seventy-eight eyes of 75 patients were randomly assigned to control (39 eyes) or study groups (39 eyes).

METHODS

All patients from both groups received 0.3% topical ofloxacin 1 hour before surgery, 5% povidone-iodine (PVI) scrub of the periorbital area, and 2 drops of PVI onto the ocular surface preoperatively. The patients in the study group also received ofloxacin 4 times a day for 3 days before surgery.

MAIN OUTCOME MEASURES

Microsurgical knives were placed in blood culture broth media immediately after the incision had been made. The number of positive cultures and types of bacteria isolated were determined.

RESULTS

Ten of 39 knives (26%) in the control group were found to be positive for bacterial growth compared with only 2 of 39 (5%) in the study group (P = 0.028).

CONCLUSIONS

The initial paracentesis incision frequently results in contamination of the microsurgical knife and may serve as a mechanism for introducing bacteria from the ocular surface into the anterior chamber. The application of topical ofloxacin for 3 days before surgery significantly reduces the contamination rate of the microsurgical knives, compared with a preoperative application of ofloxacin given 1 hour before surgery.

Incidence of acute endophthalmitis after triamcinolone-assisted pars plana vitrectomy

PURPOSE

To report the incidence of acute endophthalmitis after triamcinolone acetonide-assisted pars plana vitrectomy (PPV).

DESIGN

A retrospective multicenter interventional case series collected over 23 months.

METHODS

We retrospectively reviewed the charts of all patients who underwent triamcinolone-assisted PPV at seven academic clinical centers or eye hospitals from January 2002 to November 2003.

RESULTS

Of a total of 1,886 cases, only 1 case showed acute endophthalmitis due to Staphylococcus epidermidis (0.053%). No other cases showed any signs of postoperative endophthalmitis.

CONCLUSION

Intraoperative use of triamcinolone during PPV is not a high risk factor for acute endophthalmitis.

Surveillance of endophthalmitis following cataract surgery in the UK

AIMS

To estimate the incidence of acute-onset presumed infectious endophthalmitis (PIE) following cataract surgery in the UK and provide epidemiological data on the presentation, management, microbiology, and outcome of cases of endophthalmitis.

METHODS

Cases were identified prospectively by active surveillance through the British Ophthalmological Surveillance Unit reporting card system, for the 12-month period October 1999 to September 2000 inclusive. Questionnaire data were obtained from ophthalmologists throughout the UK at baseline and 6 months after diagnosis. Under-reporting was estimated by independently contacting units with infection databases.

RESULTS

Data were available on 213 patients at baseline and 201 patients at follow-up. The minimum estimated incidence of PIE was 0.086 per 100 cataract extractions and the corrected incidence was 0.14 per 100 cataract extractions. For the management of PIE, 96% of patients received intravitreal, 30% subconjunctival, 65% oral, and 17% intravenous antibiotics. In all, 17% of patients received intravitreal steroid. From the intraocular samples taken for microbiological analysis, 56% were culture positive. At follow-up, 48% of patients achieved visual acuity of 6/12 or better and 66% achieved better than 6/60. 13% of patients were unable to perceive light or had evisceration of the globe.

CONCLUSIONS

The incidence of PIE after cataract surgery in the UK is comparable to that of other studies. Approximately 50% of patients achieved a visual acuity close to the driving standard.

Reducing the risk of postoperative endophthalmitis

Recent literature suggests that the incidence of postoperative endophthalmitis is variable and may be on the rise. This article reviews established perioperative preventative measures, and discusses some possible causes of postoperative endophthalmitis that may be insufficiently addressed by current risk reduction techniques. This article also considers future measures for reducing the risk of postoperative endophthalmitis.

An in vivo study comparing the ocular absorption of levofloxacin and ciprofloxacin prior to phacoemulsification

PURPOSE

To compare aqueous humor concentrations of levofloxacin vs ciprofloxacin when used as prophylactic medications before phacoemulsification.

DESIGN

Patients (n = 93) were randomly assigned to receive either 0.5% levofloxacin (Quixin) or 0.3% ciprofloxacin (Ciloxan) using one of the following dosing regimens: (A) 1 to 2 drops four times a day for 2 days preoperatively; (B) 5 doses (1 to 2 drops) delivered every 10 minutes in the hour immediately preceding surgery; or (C) the combination of A and B.

METHODS

Aqueous samples (0.1 ml) were obtained immediately before surgery, and drug concentrations were measured using high performance liquid chromatography/mass spectrometry.

RESULTS

The mean concentration of levofloxacin in the aqueous humor was significantly greater than that of ciprofloxacin in all treatment groups (P <.001): 284.8 vs 67.4 microg/ml (regimen A); 1,135.6 vs 185.6 microg/ml (regimen B); and 1,618.6 vs 241.5 (regimen C). Dosing regimen B delivered significantly more drug to the aqueous humor than regimen A for both levofloxacin (P < or =.001) and ciprofloxacin (P =.004). Dosing regimen C delivered significantly more drug to the aqueous humor than regimen B for levofloxacin (P =.05) but not for ciprofloxacin (P =.384).

CONCLUSIONS

Although the concentration of active drug in levofloxacin is approximately 1.7-fold higher than that in ciprofloxacin, the aqueous concentration of levofloxacin after topical administration was four to seven times greater than ciprofloxacin; these differences were statistically significant. With dosing regimens B and C, levofloxacin concentrations in the aqueous humor were above the MIC90 for most common ocular pathogens, including Staphylococcus and Streptococcus species. Ciprofloxacin did not reach such concentrations in any treatment group.

Imaging and investigating the effects of incision angle of clear corneal cataract surgery with optical coherence tomography

Effects of incision angle in construction of clear corneal cataract incision are studied with optical coherence tomography (OCT). A stable incision angle range is found to be existent for single-planed, clear corneal cataract incisions. When well pressurized, incision angles within this stable range result in well-apposed incision edges that resist gapping while incision angles falling outside this range have a larger tendency for wound leakage. It is also shown that a two-planed incision can effectively expand the stable range. For incision angles outside the stable range, the farther the incision angle is away from stable range, the larger the gap between incision wound edges when well pressurized. These findings emphasize the significance of incision construction to the self-sealing property of clear corneal cataract incisions. Finally, we demonstrate that OCT could be an effective modality for imaging and monitoring corneal surgery.

Endophthalmitis caused by Pseudomonas aeruginosa

OBJECTIVE

To investigate the clinical settings and treatment outcomes for endophthalmitis caused by Pseudomonas aeruginosa.

DESIGN

Retrospective, noncomparative, consecutive case series.

METHODS

The medical records were reviewed of all patients treated for P. aeruginosa endophthalmitis at a single institution between January 1, 1987, and December 31, 2001.

MAIN OUTCOME MEASURES

Final visual acuity and rate of enucleation or evisceration.

RESULTS

The study included 28 eyes of 28 patients with a median age of 75 years (range, 5-93 years). The clinical setting of endophthalmitis included: cataract surgery (n = 9), corneal ulcer (n = 7), penetrating keratoplasty (n = 5), bleb associated (n = 2), glaucoma drainage implant (n = 2), pars plana vitrectomy (n = 1), iris cyst removal (n = 1), and trauma (n = 1). In acute-onset postoperative cases (n = 10), the median interval between surgery and presentation with endophthalmitis was 4 days (range, 1-26 days). The median duration of symptoms was 1 day, and all patients were treated on the day of diagnosis. Eleven patients (39%) had hand motions or better vision in the infected eye at the time of initial diagnosis. Because of no light perception visual acuity, necrosis of cornea and sclera, and intractable pain, 7 eyes (25%) underwent evisceration or enucleation as initial treatment; of the remaining 21 eyes, intravitreal antibiotics were administered in all cases and intravitreal dexamethasone was administered in 15 cases (71%). Pars plana vitrectomy was performed in 12 patients (43%). The organism was sensitive to the initial antibiotics administered in all but 2 cases. Final visual acuity was 5/200 or better in 2 of 28 eyes (7%). Nineteen patients (68%) had a final visual acuity outcome of no light perception, and no patient achieved a final visual acuity of better than 20/400. Overall, 18 of the 28 eyes (64%) were either eviscerated or enucleated.

CONCLUSIONS

Endophthalmitis caused by P. aeruginosa is associated with poor visual outcomes despite prompt treatment with intravitreal antibiotics to which the organisms were sensitive.

Risk factors for antibiotic-resistant conjunctival bacterial flora in patients undergoing intraocular surgery

BACKGROUND

The purpose of this study was to determine if patients with certain risk factors are more likely to harbor conjunctival bacterial flora resistant to multiple antibiotics.

METHODS

In this prospective study, detailed medical history and slit-lamp examination were performed on all patients prior to intraocular surgery. Patients with local risk factors were defined as those with chronic blepharitis, conjunctivitis or discharge. Those with systemic risk factors were patients with diabetes, autoimmune, immunodeficient or skin disorders, asthma and those taking immunosuppressant medications. Conjunctival cultures were obtained prior to preoperative antibiotics and povidone-iodine. Bacteria isolated were identified and antibiotic susceptibility was determined. Bacteria resistant to five or more antibiotics were defined as multi-resistant (MR).

RESULTS

Among the 207 patients enrolled in the study, 73 patients had local risk factors. Of these patients, 32 patients (44%) carried MR organisms, compared to 32 of the 134 patients (24%) without local risk factors (P=0.0049). Thirty-two of 71 patients (45%) with systemic risk factors harbored MR organisms, compared to 32 of 136 patients (24%) without systemic risk factors (P=0.0025). Seventeen of 93 patients (18%) who had neither local nor systemic risk factors had MR organisms on their conjunctiva. In contrast, 17 of the 30 patients (57%) with both local and systemic risk factors (57%) carried MR bacteria (P=0.0001).

CONCLUSION

Patients with local and/or systemic risk factors are more likely to harbor MR organisms. This may be one mechanism for the reported increased risk of postoperative endophthalmitis in this group of patients.

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 post-cataract 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 (chi(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 (chi(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 post-cataract surgery endophthalmitis when compared with scleral tunnel incisions.

Postoperative endophthalmitis: establishment and results of a national registry

PURPOSE

To determine the incidence, clinical presentation, etiology, and outcomes of postoperative endophthalmitis in Norway and to explore the potential of and establish a platform for improving diagnostics, prophylaxis, and treatment of postoperative endophthalmitis.

SETTING

All ophthalmic surgical units and relevant microbiology laboratories in Norway.

METHODS

A national registry of cases of postoperative endophthalmitis was established in 1996. All ophthalmic surgery units in Norway were asked to return forms including preoperative, perioperative, and postoperative data for each case of endophthalmitis occurring between January 1996 and December 1998 after any intraocular surgery irrespective of the time between the surgery and the onset of endophthalmitis symptoms. All microbiology laboratories in Norway were asked to return questionnaires regarding their routine handling procedures of eye specimens in cases of endophthalmitis.

RESULTS

From 1996 to 1998, 111 suspected endophthalmitis cases were reported, all after cataract surgery. Eighty cases were culture positive, 75 with gram-positive bacteria, 4 with gram-negative bacteria, and 1 with Candida albicans. Depending on the definition, the incidence of postoperative endophthalmitis was between 0.11% and 0.16%. Thirteen percent of cases had "delayed" endophthalmitis. Twenty-nine percent of eyes had an outcome of permanent amaurosis or light perception visual acuity; 56% (47/84) retained or improved their categorized visual acuity in the affected eye compared to preoperatively. Positive bacterial growth was associated with a worse visual outcome (P =.008). The degree of inflammation when endophthalmitis was diagnosed and the visual outcomes were worse in cases with growth of streptococci than in cases with growth of staphylococci (P =.009 and P<.001, respectively). The questionnaire to the microbiology laboratories revealed a lack of consensus on how to handle the specimens.

CONCLUSIONS

Postoperative endophthalmitis remains a serious complication of intraocular surgery, although the prognosis depends greatly on the microbe isolated. Common guidelines should be established regarding clinical and microbiological diagnosis and treatment. Further improvement of the registry would make it a suitable platform for evaluating prophylactic treatments.

A 10 year retrospective survey of cataract surgery and endophthalmitis in a single eye unit: injectable lenses lower the incidence of endophthalmitis

AIM

To study the incidence of endophthalmitis following cataract surgery over a 10 year period, and to examine ways in which this may be related to changes in surgical technique.

METHODS

All cases of endophthalmitis occurring over a 10 year period within a single ophthalmic unit in the United Kingdom were reviewed, and possible risk factors identified.

RESULTS

During the study period, as the technique of extracapsular cataract surgery was replaced by phacoemulsification, there was a commensurate reduction in the incidence of endophthalmitis. Injectable IOLs were associated with the lowest risk of postoperative endophthalmitis (0.028%).

CONCLUSIONS

Injectable intraocular lenses do not make contact with the ocular surface and this may result in the observed lower rate of endophthalmitis. This, and the ease with which they can be inserted through small incisions, support their use as the first line method of lens insertion.

Trends in cataract surgery and postoperative endophthalmitis in Western Australia (1980-1998): the Endophthalmitis Population Study of Western Australia

OBJECTIVES

Postoperative endophthalmitis results from an intraocular infection and usually occurs following cataract surgery. It has significant morbidity and causes severe visual impairment or blindness of the eye. The aim of this study was to assess the trends in the incidence rates of cataract surgery and postoperative endophthalmitis in Western Australia for the period 1980-1998.

METHODS

The Western Australian Record Linkage Project was used to link the morbidity records for all patients treated for cataract surgery in Western Australia in 1980-1998. Patient records were selected using the international classification for diagnosis and procedure codes pertaining to cataract surgery and postoperative endophthalmitis. All cases of postoperative endophthalmitis were validated by case-note review. The separate databases of the Royal Perth Hospital microbiology and anaesthetic departments as well as the vitreo-retinal surgeon logbooks were used to cross-validate the hospital morbidity database. Trends in the incidence rates of cataract surgery and postoperative endophthalmitis were assessed by Poisson regression.

RESULTS

There were 94,653 cataract procedures performed for 63,007 patients in Western Australia during the 19-year period. The majority (88%) of cataract procedures performed were in patients aged 60 years or older. Postoperative endophthalmitis developed in 188 patients, with serious visual impairment occurring in 70.6% of patients for whom visual acuity data was available at presentation. The incidence rate of cataract surgery increased more than three-fold from 1981 (102 per 100,000 person years) to 1998 (345 per 100,000 person years), mainly due to the increase in extracapsular cataract extraction during the 1980s and phacoemulsification extraction from 1990 onwards. In contrast, the average annual incidence rate of postoperative endophthalmitis remained relatively unchanged at around 2 per 1000 cataract procedures over the same period.

CONCLUSION

Cataract surgery is becoming more prevalent in the elderly as the life expectancy of the population increases. There has been a dramatic shift in surgical practice during the last 30 years with small-incision phacoemulsification being the predominant method of intervention used since 1990. Despite changes in surgical practice the incidence rate of postoperative endophthalmitis has remained the same.

Residual debris as a potential cause of postphacoemulsification endophthalmitis

AIM

To examine residual debris within sterilised instruments prior to cataract surgery.

METHODS

(i) Flushings from 32 sets of phacoemulsification instruments, sterilised according to hospital routine protocols, were taken preoperatively and analysed by scanning electron microscopy (SEM). (ii) A total of 16 sets of flushings from a different institute were collected-with separation of samples collected from phacoemulsification and those from irrigation-aspiration (IA) instruments-and analysed in the same way. (iii) A total of 15 sets of flushings were collected from instruments where an automated flushing system was used prior to sterilisation.

RESULTS

(i)In the first study, 62% were clean, 16% were moderately contaminated and 22% were severely contaminated. Various contaminants were identified including lens capsule and cells, man-made fibres, squamous cells, bacteria, fungal elements, diatoms, red blood cells and proteinaceous material. (ii) In the second study, the results were similar and contamination of both phacoemulsification and IA instruments was shown. (iii) The third study showed that although a decrease in contamination followed automated flushing, contamination was not completely eliminated.

CONCLUSIONS

Although all equipment had been sterilised, pyrogenic material was still present. These findings emphasise the importance of meticulous cleaning of all surgical equipment in which biological debris can remain.

Topical anaesthesia: a risk factor for post-cataract-extraction endophthalmitis?

PURPOSE

To investigate if the incidence of postoperative endophthalmitis in temporal clear corneal cataract surgery is influenced by the use of topical anaesthesia compared to retrobulbar anaesthesia.

METHODS

A retrospective study was conducted of one surgeon's cataract surgery between October 1997 and October 2001.

RESULTS

Between October 1997 and May 2000, there were 633 cataract extractions performed with 219 patients operated under topical anaesthesia and 414 under retro-bulbar injection. The selection criteria were that surgically easier cases underwent topical anaesthesia. There were five patients who suffered postoperative endophthalmitis in their first week, of which four cases were under topical anaesthesia. This was shown to be borderline significance of P = 0.05 using the Fischer exact 2-tailed test. There was a complicated case, operated under retrobulbar anaesthesia, who had a low-grade endophthalmitis in the second postoperative week. The four topical cases and the case from the second week all grew Staphylococcus epidermidis. The retrobulbar case developing endophthalmitis in the first week grew alpha haemolytic Streptococcus. After May 2000, there was a change to performing all cataract surgery under retrobulbar anaesthesia and the next 453 cases had no incidence of endophthalmitis.

CONCLUSION

Topical anaesthesia techniques in temporal clear corneal cataract extraction may be a factor in endophthalmitis.

Glaucoma-filtering bleb infections

PURPOSE OF REVIEW

To present a review of the current literature regarding the management of glaucoma-filtering bleb infections.

RECENT FINDINGS

With the increased use of intraoperative antifibrotic (eg, mitomycin and fluorouracil) as an adjunct to standard trabeculectomy, an increased incidence is seen of late-onset filtering bleb-related infections. These infections range from infections localized to the bleb (blebitis) to endophthalmitis. Risk factors for bleb-related infections include an inferior or nasally located bleb; presence of a high bleb or blepharitis; development of a late-onset bleb leak; use of antifibrotic agents; chronic antibiotic use; and performance of a trabeculectomy alone versus a combined procedure.

SUMMARY

The optimal treatment for bleb-related infections is evolving, but consensus is that a high degree of vigilance and aggressive treatment are key to minimizing the potentially blinding nature of this complication. It is important to note that those glaucoma procedures that provide the lowest intraocular pressure are often those that predispose to bleb-related infections.

Bacterial adhesion to rigid and foldable posterior chamber intraocular lenses: in vitro study

PURPOSE

To determine the in vitro bacterial adherence to intraocular lenses (IOLs) routinely used at 1 center.

SETTING

University Hospital of Vienna, Vienna, Austria.

METHODS

Four types of rigid IOLs (hydrophobic poly[methyl methacrylate] [PMMA] and hydrophilic heparin-surface-modified PMMA) and 5 types of foldable intraocular lenses (hydrophobic silicone, hydrophobic acrylic, and hydrophilic acrylic) were used in the experiment. Under standardized conditions, the IOLs were contaminated with 2 strains of Staphylococcus epidermidis. A sonication method and impression method were used for quantification. The mean bacterial density per lens type (colony forming units/mm(2)) was compared.

RESULTS

With both germs and both quantification methods, more bacteria was found on hydrophobic lenses than on IOLs with hydrophilic surfaces (P =.001). The Alcon AcrySof and Askin UV80F IOLs had the greatest and the Corneal Acrygel and Bausch & Lomb Hydroview IOLs the least affinity to these microorganisms.

CONCLUSION

The data suggest that hydrophilic IOLs can help reduce the rate of postoperative endophthalmitis as a result of their surface properties.

Evaluating outpatient versus inpatient costs in endophthalmitis management

PURPOSE

To assess the cost savings that would result from 1) implementing the treatment guidelines of the Endophthalmitis Vitrectomy Study (EVS) and 2) performing procedures on an outpatient rather than an inpatient basis, and to compare the savings to the cost of conducting the EVS.

METHODS

The coding algorithms for four endophthalmitis treatment groups were obtained from Patient Financial Services at the Anne Bates Leach Eye Hospital (ABLEH) and national Medicare averages were consulted for reimbursements in 2000 dollars. The four groups were: 1) inpatient pars plana vitrectomy (PPV) with intravenous antibiotics; 2) outpatient PPV; 3) inpatient vitreous tap with intravenous antibiotics; and 4) outpatient vitreous tap. Physician reimbursements were calculated using International Classification of Diseases-9 (ICD-9) diagnoses and Current Procedural Terminology (CPT) codes. Facility reimbursements were calculated using ICD-9 diagnoses and Diagnosis-Related Group codes for inpatient procedures versus Ambulatory Payment Classification codes for outpatient procedures. The annual savings in reimbursements were estimated for a range of annual incidence rates of endophthalmitis assuming ABLEH financial data across all patients in the United States, and the savings into the future as well as the total expenses of conducting the EVS from 1989 to 1995 were summed in 2000 dollars using a net present value analysis based on the Bureau of Labor Statistics consumer price indices.

RESULTS

Facility reimbursements are significantly higher for procedures performed on an inpatient compared to an outpatient basis (P < 0.001). Treating endophthalmitis according to the EVS guidelines on an outpatient basis would be associated with an estimated $1.5 to $7.8 million reduction in reimbursements per year. The cost of the EVS in 2000 dollars was $4.0 million.

CONCLUSIONS

Implementing the treatment guidelines of the EVS on an outpatient basis may result in significant cost savings--savings that may cover the entire cost of the EVS in 3 years.

Prospective randomized comparison of 3-day versus 1-hour preoperative ofloxacin prophylaxis for cataract surgery

PURPOSE

To determine the efficacy of reducing conjunctival bacterial flora with topical ofloxacin when given for 3 days compared with 1 hour before surgery.

DESIGN

Prospective, randomized, controlled trial.

PARTICIPANTS

Ninety-two eyes from 89 patients were randomized to a control group (48 eyes) or study group (44 eyes).

METHODS

All patients from both groups received topical ofloxacin 0.3% 1 hour before surgery and a 5% povidone iodine scrub of the periorbital area before surgery. The patients in the study group received additional ofloxacin four times daily for 3 days before surgery.

MAIN OUTCOME MEASURES

Conjunctival cultures were obtained at five separate time points and were inoculated in solid and liquid culture media. The presence of bacteria was determined, quantified, and identified.

RESULTS

Forty-two percent of eyes in the control group had positive conjunctival culture immediately before surgery, compared with 19% of eyes in the study group (P < 0.05). Immediately after surgery, 34% and 14% of eyes had positive cultures in the control and study groups, respectively (P < 0.05). Quantitatively, fewer bacteria were isolated from eyes in the study group compared with those in the control group for culture samples that were obtained both before povidone iodine scrub and at the conclusion of surgery (P </= 0.05).

CONCLUSIONS

The application of topical ofloxacin for 3 days before surgery appears to be more effective in eliminating bacteria from the conjunctiva than an application of ofloxacin 1 hour before surgery.

A comparison of endophthalmitis after phacoemulsification or extracapsular cataract extraction in a socio-economically deprived environment: a retrospective analysis of 2446 patients

PURPOSE

To assess which cataract operation technique involves least risk of postoperative endophthalmitis, when performed in a population living in poor hygiene conditions.

METHODS

This retrospective clinical study evaluated 2446 cases at the Eye Clinic of the Komotini General Hospital, Greece, between January 1998 and January 2001.

RESULTS

Endophthalmitis arose in 12/1055 patients (1.13%) after extracapsular cataract extraction (ECCE) and in 8/1391 after phacoemulsification (0.57%). The mean time to onset of endophthalmitis was 23 and 73 days respectively after phacoemulsification and ECCE. This difference was statistically significant.

CONCLUSIONS

Endophthalmitis develops considerably later after ECCE than phacoemulsification. Thus it would appear that hygiene conditions have a stronger effect in patients operated with the ECCE technique. In order to reduce the risk of endophthalmitis after cataract extraction in patients living in substandard conditions, phacoemulsification is proposed as preferable to ECCE.

Prophylactic intracameral cefuroxime. Efficacy in preventing endophthalmitis after cataract surgery

PURPOSE

To evaluate the efficacy of prophylactic intracameral cefuroxime in preventing endophthalmitis in cataract surgery.

SETTING

Department of Ophthalmology, St. Eriks Hospital, Stockholm, Sweden.

METHODS

In a noncontrolled retrospective observational study, all cases of recorded postoperative endophthalmitis were related to the total number of uncombined cataract procedures from January 1996 to December 2000.

RESULTS

Twenty cases of postoperative endophthalmitis occurred in 32180 procedures, yielding an overall rate of 0.06%. Cefuroxime-resistant organisms accounted for 12 of 13 culture-positive cases, and enterococci were the most common etiology.

CONCLUSIONS

Intracameral cefuroxime 1 mg appeared to effectively inhibit sensitive bacterial strains and was associated with a low frequency of postoperative endophthalmitis. The causative organisms of future incidents of postoperative endophthalmitis will determine whether the present protocol must be reappraised.

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

PURPOSE

To investigate the morbidity of postoperative endophthalmitis (POE) following cataract surgery in Sweden in 1998.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Epidemic endophthalmitis after cataract surgery

PURPOSE

We analyzed the results of pars plana vitrectomy in group of patients with a view to establishing risk factors, optimal therapy, surgical technique and the best timing of the pars plana vitrectomy.

METHODS

Eight patients presented features of bacterial endophthalmitis within two days of cataract extraction. We examined the relations between visual outcome and the identity of infecting species, optimal therapy, surgical technique and vitrectomy timing.

RESULTS

Pseudomonas aeruginosa was a pathogenic microbe. Unfortunately the source of infection was not found. The long-term (9-12 months) results are not good. Final visual acuity of all eight patients oscillated between 20/200 and no light perception. Three patients were first treated with intravitreal ATB application and vitrectomy followed with 36 hours lateney. Their final VA was no light perception in two patients and hand motion in one. The outcome was better in five patients operated immediately after the onset of endophthalmitis. Final visual acuity in this group was between hand motion and 20/200.

CONCLUSIONS

Visual prognosis in cases of endophthalmitis is closely related to the type of infecting organism, the visual acuity at presentation, and the speed of progression of inflammatory signs. The need for prompt vitrectomy as the only chance of retaining at least basic visual functions is fully demonstrated.

Immunology of Staphylococcal biofilm infections in the eye: new tools to study biofilm endophthalmitis

Endophthalmitis is an important disease of the eye that is most frequently caused by postoperative and post-traumatic introduction of bacteria into the posterior segment of the eye. In the case of severe infections, visual acuity is greatly damaged or completely lost. Much work has focused on the ability of planktonic bacteria to cause infection and ocular damage while little work has focused on chronic infections in endophthalmitis mediated by the formation of bacterial biofilms on the surface of the lens. This review focuses on the interaction of Staphylococcus aureus and Staphylococcus epidermidis lens-associated biofilms in endophthalmitis. Additionally, this review highlights some relevant biofilm-immune system interactions and outlines a new in vivo mouse model to explore biofilm-related infections in endophthalmitis.

Bacterial contamination of the anterior chamber during phacoemulsification cataract surgery

PURPOSE

To determine the incidence of bacterial contamination of the anterior chamber after phacoemulsification cataract surgery with intraocular lens (IOL) implantation.

SETTING

Department of Ophthalmology, Royal Prince Alfred Hospital, Sydney, Australia.

METHODS

Ninety-eight consecutive eyes of 96 patients having phacoemulsification cataract surgery with IOL implantation were included in this prospective study. Two intraoperative anterior chamber aspirates were obtained from each patient, 1 taken at the start and the other at the conclusion of surgery. In addition, preoperative and postoperative conjunctival swabs were acquired. The 4 specimens were cultured using direct culturing techniques under aerobic and anaerobic conditions for 14 days. No preoperative antibiotics were used.

RESULTS

The incidence of intraoperative anterior chamber contamination was 0% (95% confidence interval, 0%-3.7%) as all intraoperative anterior chamber samples proved culture negative. Sixty-five percent of the preoperative conjunctival swabs were positive for growth, with corynebacteria, coagulase-negative staphylococci, and Propionibacterium acnes being the most frequently cultured organisms. Sixteen percent of the postoperative conjunctival swabs were positive for growth, with corynebacteria and coagulase-negative staphylococci being the most common bacteria. One patient developed culture-positive postoperative endophthalmitis; using pulsed-field gel electrophoresis for further typing, the implicated Staphylococcus epidermidis was indistinguishable from that isolated from the patient's preoperative conjunctival swab.

CONCLUSIONS

The bacterial contamination rate of the anterior chamber after phacoemulsification and IOL implantation was extremely low. Additional findings support the conjunctiva as being a primary source of bacteria causing postoperative endophthalmitis as well as the ability of povidone-iodine to reduce the conjunctival bacterial load.

Occlusive scrub suits in operating theaters during cataract surgery: effect on airborne contamination

The effect of wearing occlusive scrub suits on bacterial contamination of air was studied during cataract operations. All personnel regularly wore cotton scrub suits. During the intervention period, all wore occlusive scrub suits, which, compared with cotton scrub suits, were associated with more than a 50% reduction in the load of airborne bacteria during operations.

Effect of vancomycin on Staphylococcus epidermidis adherence to poly(methyl methacrylate) intraocular lenses

PURPOSE

To study the adherence of Staphylococcus epidermidis in variable loads (10(8) cfu/mL and 10(3) cfu/mL) to poly(methyl methacrylate) (PMMA) intraocular lenses (IOLs) and to evaluate the effect of vancomycin treatment on S epidermidis adherence to the IOL.

SETTING

L.V. Prasad Eye Institute, Hyderabad, India.

METHODS

The study was designed in 2 parts. Phase I: Twelve PMMA IOLs were soaked in a solution of S epidermidis, randomized to 10(8) cfu/mL or 10(3) cfu/mL. They were rinsed or rinsed and vortexed and cultured. Phase II: Twelve IOLs were treated with vancomycin (10 mg/mL), randomized to before and after treatment with S epidermidis.

RESULTS

Staphylococcus epidermidis adhered to all portions of the IOL with 10(8) cfu/mL and 10(3) cfu/mL bacterial loads. Treatment with vancomycin reduced S epidermidis adherence.

CONCLUSION

Pretreatment of an IOL with vancomycin or a suitable antibiotic agent appears to reduce bacterial adherence to the IOL. Placement of a sustained-release device that could release an antibiotic agent over a specific period, reducing the incidence of postcataract endophthalmitis, should be studied.

Postoperative endophthalmitis

Postoperative endophthalmitis is a rare, albeit serious, complication of cataract surgery. Over the years, preoperative and operative measures, such as lid hygiene, appropriate surgical draping, and improved surgical technique, have all decreased the incidence of postoperative endophthalmitis. Commonly used prophylactic measures include preoperative topical, intracameral, and postoperative topical antibiotics. Since the landmark study done by the endophthalmitis vitrectomy study group, treatment has usually consisted of intravitreal antibiotics with or without pars plana vitrectomy (depending on the patient population). In this review, we have focused on advances in the field of endophthalmitis within the last year. These include articles examining treatment and complications of diabetic patients and those with retinal detachments, bacterial adherence to lenses, prophylactic measures, and addition of steroids to conventional treatments of endophthalmitis.

Bacterial endophthalmitis: epidemiology, therapeutics, and bacterium-host interactions

Endophthalmitis is a severe inflammation of the interior of the eye caused by the introduction of contaminating microorganisms following trauma, surgery, or hematogenous spread from a distant infection site. Despite appropriate therapeutic intervention, bacterial endophthalmitis frequently results in visual loss, if not loss of the eye itself. Although the pathogenicity of bacterial endophthalmitis has historically been linked with toxin production during infection, a paucity of information exists as to the exact mechanisms of retinal toxicity and the triggers for induction of the intraocular immune response. Recently, research has begun to examine the bacterial and host molecular and cellular events that contribute to ocular damage during endophthalmitis. This review focuses on the causative agents and therapeutic challenges of bacterial endophthalmitis and provides current data from the analysis of the role of bacterial virulence factors and host inflammatory interactions in the pathogenesis of eye infections. Based on these and related studies, a hypothetical model for the molecular pathogenesis of bacterial endophthalmitis is proposed. Identifying and understanding the basic mechanisms of these bacterium-host interactions will provide the foundation for which novel, information-based therapeutic agents are developed in order to prevent vision loss during endophthalmitis.

Endophthalmitis in the western Sydney region: a case-control study

BACKGROUND

A retrospective case-control study was conducted to investigate risk factors for endophthalmitis following routine intraocular surgery.

METHODS

A review was performed of consecutive cases of endophthalmitis from three teaching hospitals in the western Sydney region and matched controls from the same institutions between 1996 and 1998.

RESULTS

There were 31 cases and 66 controls. Eighty procedures were phacoemulsification, 15 conventional extracapsular cataract extraction, and two were penetrating keratoplasties. Of the 80 patients who had phacoemulsification surgery, 50 had a clear corneal incision, and 26 had a scleral incision (four were unknown). Logistic regression showed an increased risk of endophthalmitis with surgical complications (P = 0.002) and clear cornea temporal incisions (P = 0.007). Risk of endophthalmitis was reduced with use of subconjunctival injections (P = 0.008). The yield for the Gram stain was 47% and for culture was 67%. Anterior chamber tap in addition to vitreous biopsy alone did not increase the yield for microorganism (P = 0.78). Mean visual acuity on presentation was hand movement with 13 patients (50%) showing visual improvement following intravitreal injections of antibiotics (P = 0.003). Visual prognosis did not correlate with presenting visual acuity but appeared to be better in those who grew Staphylococcus epidermidis or were culture negative.

CONCLUSIONS

Although this study is unable to draw definite conclusions regarding risk of endophthalmitis in clear corneal temporal cataract surgery, sufficient data suggest the importance of incision type and location. Surgical complication is an important risk factor for endophthalmitis. Use of subconjunctival antibiotic injections at the conclusion of the procedure is recommended.