Bacterial endophthalmitis after small-incision cataract surgery. effect of incision placement and intraocular lens type

Exogenous Endophthalmitis

PURPOSE

Exogenous endophthalmitis (ExE) results from microbial infection as a complication of ocular surgery, penetrating ocular trauma, and intraocular foreign bodies. We herein review the classification of ExE, etiological agents, differential diagnosis and therapeutic challenges.

METHODS

Narrative Literature Review.

RESULTS

Identification of the causative agent through ocular fluid analysis is central in the diagnostic work-up of ExE. Prompt intravitreal antimicrobial therapy is key to successful management of ExE and vitrectomy is essential in severe cases. In culture-negative cases, and in the presence of specific features, a diagnosis of sterile intraocular inflammation or toxic syndrome should be suspected.

CONCLUSION

Strict adherence to treatment guidelines may improve outcomes of ExE, however the ultimate prognosis, especially in severe cases, may depend more on the virulence of the causative organism and associated ocular complications. Accurate differential diagnosis and effective treatment are crucial elements in the management and prognosis of non-infectious masquerades of ExE.

Incidence, Prophylaxis and Prognosis of Acute Postoperative Endophthalmitis After Cataract Surgery: A Multicenter Retrospective Analysis in Northern China from 2013 to 2019

Objective

To investigate the incidence of acute postoperative endophthalmitis (POE) after cataract surgery in Northern China from 2013 to 2019, evaluate the efficacy of prophylaxis and analyze the predictors of visual prognosis among POE patients.

Methods

The study was conducted as a retrospective multi-center research, with seven hospitals in Northern China enrolled. The diagnosis of acute-onset POE was made on the basis of clinical manifestations within six weeks after initial surgery. By reviewing electronic medical system, the number of cataract surgeries and acute POE cases were recorded to estimate the overall incidence and incidences by different years and hospitals. Perioperative measures for preventing infection in different hospitals were collected. The correlations between unfavorable final vision and potential factors including basic information and clinical characteristics were examined to determine the predictive factors for final visual prognosis.

Results

Of 72,255 cataract surgeries performed during seven years in the seven hospitals, 19 cases developed acute POE, yielding an overall incidence of 0.026%. The average incidence of acute POE among seven hospitals significantly declined annually during the past 7 years (p = 0.021). In Hospital-D, the incidence of acute POE significantly decreased after the application of 0.5% povidone-iodine (PVP-I) for conjunctival washing (p = 0.003). Two hospitals adopting tobramycin in the irrigation solution achieved a significant lower incidence of POE than the other hospitals (p = 0.044). The positive rate of pathogen culture was just 17.6% (3/19). Patients with presenting BCVA of CF or better were more likely to present with unfavorable final vision than those with worse presenting BCVA (p = 0.003).

Conclusion

The overall incidence of acute POE after cataract surgery from 2013 to 2019 in Northern China was 0.026%, and the incidence declined annually over the period. Presenting BCVA could be a significant prognosis factor for predicting the final visual outcomes of acute POE patients.

Experimental evaluation of the injection force exerted in intraocular lens delivery with syringe-type injectors

The process of intraocular lens (IOL) delivery within the capsular bag during cataract surgery is crucial, as the integrity of the IOL, the injector and the ocular structures should be preserved at all times. This study aims to obtain the main parameters that affect the injection force exerted in the ejection of an intraocular lens (IOL) through syringe-type injectors. For that purpose, ejection tests were carried out in vitro, measuring the resistance force throughout the entire delivery process. The effect of IOL material, haptic design, IOL thickest area and ophthalmic viscosurgical device (OVD) was studied by ejecting seven IOLs with four syringe-type injectors of different sizes, 3.0, 2.2 and 1.8 mm. In all injectors, plate hydrophilic IOLs present the lowest resistance forces; hydrated C-loop hydrophobic IOLs present higher forces and the C-loop hydrophobic IOL in dry conditions presents the highest resistance forces. All IOLs could be properly delivered with an injector size of 2.2 mm, making injector sizes of 3.0 mm outdated. The injector size of 1.8 mm damaged several IOLs. IOL material and cartridge nozzle size were the most influential parameters in IOL delivery. IOL thickest area was also relevant but in a lesser extent whereas IOL haptic design was not as relevant.

Clinical Presentations and Management Outcomes of Culture-Proven Mixed Bacterial and Fungal Endophthalmitis

OBJECTIVE

To report the clinical features and management outcomes of mixed fungal and bacterial endophthalmitis.

METHODS

Retrospective, consecutive non-comparative case series. Fifteen eyes of 15 patients were included from January 2009 to December 2019 with culture proven mixed fungal and bacterial endophthalmitis. Demography, clinical presentations, interventions received, and final visual and anatomical outcomes were noted. A favorable anatomic outcome was defined as preservation of the globe, absence of hypotony, attached retina, and absence of active inflammation at the last visit.

RESULTS

The mean age of patients in this series was 34.2 ± 19.6 years (range: 5-61 years). Male preponderance was found in 14 (93.3%). Eight (53.3%) eyes had open globe injury, 5(33.3%) had postoperative endophthalmitis and one (6.6%) each with endogenous endophthalmitis and post-keratitis. Pars plana vitrectomy was done in eight (53.3%) eyes whereas vitreous tap alone was done in seven (46.7%) eyes. Gram positive cocci (n = 11, 73.3%) were the commonest bacterial isolates (n = 7, 46.6%). Staphylococcus aureus (n = 3, 20%) was the most common bacterial isolate. The commonest fungi were filamentous hyaline fungi (n = 5, 33.3%). An unfavorable visual outcome (VA<20/400) was seen in all the eyes. The mean duration of follow-up was 13 ± 18.3 months. Globe salvage was possible only in five (33.3%) eyes. The bacterial isolates were highly sensitive to all of the tested antibiotics.

CONCLUSION

Mixed fungal and bacterial endophthalmitis occur commonly in a setting of open-globe trauma. The presence of fungus concurrently leads to a very poor management outcome even if the bacterial isolate sensitivity is good.

Optimization of femtosecond laser-constructed clear corneal wound sealability for cataract surgery

PURPOSE

To compare the sealability of femtosecond laser (FSL)-assisted corneal incisions (CIs) with that of triplanar manual (M)-CIs and to determine FSL wound parameters minimizing leakage.

SETTING

Private practice.

DESIGN

Phase IV, single-surgeon, retrospective cohort study.

METHODS

One eye per patient was included. Two groups defined by the main wound (FSL-CI or M-CI) were compared for leakage, inferred by placement of a suture at the end of surgery. Leakage in FSL-CIs was analyzed as a function of customizable wound parameters: anterior plane depth (APD), posterior plane depth (PPD), anterior side-cut angle (ASCA), and posterior side-cut angle (PSCA). The risk of leakage of FSL-CIs with optimal and nonoptimal parameters was further compared with that of M-CIs.

RESULTS

A total of 1100 eyes (757 [68.8%] FSL-CI; 343 [31.2%] M-CI) were included. Wound leakage occurred in 133 FSL-CI (17.6%) and 30 M-CI eyes (8.7%) (P < .001). FSL wound parameters associated with the lowest risk of leakage were 60% APD, 70% PPD, 120 degrees ASCA, and 70 degrees PSCA. FSL-CIs constructed with at least 3 optimal parameters (60% APD, 70% PPD, and 120 degrees ASCA) had a similar risk of leakage to M-CIs (odds ratio [OR], 1.1; 95% CI, 0.5-2.3). FSL-CIs with suboptimal parameters had twice the risk of leakage of M-CIs (OR, 2.0; 95% CI, 1.1-3.8).

CONCLUSIONS

Overall, FSL-CIs leaked more than M-CIs. However, FSL-CIs with optimized wound profiles had an equivalent risk of leakage to M-CIs. Wound parameter customization is an asset of FSL technology that allows optimization of FSL-CI sealability.

Surveillance of post-cataract endophthalmitis at a tertiary referral center: a 10-year critical evaluation

BACKGROUND

Acute post-cataract endophthalmitis (APE) is a rare complication potentially causing irreversible visual loss. A 10-year study of APE was conducted to determine its incidence, microbiological spectra and antibiotic resistance profile of APE-related pathogens at a major tertiary referral center in Brazil.

METHODS

APE cases reported between January 2010 and December 2019 were included. Phacoemulsification and extracapsular cataract techniques were eligible; combined procedures, traumatic and congenital cataract were excluded. Vitreous samples were cultured and antimicrobial resistance was compared for the periods of 2010-2014 and 2015-2019. The results were analyzed with Fisher's exact test.

RESULTS

Our sample consisted of 40,491 cataract surgeries and 51 (0.126%) APE cases. Culture was positive in 35 cases (71.4%), of which 31 (88.6%) Gram-positive, 3 (8.6%) Gram-negative, and 1 (2.9%) fungal. The most frequently isolated organism was Staphylococcus epidermidis (n = 17/35, 48.6%), followed by Staphylococcus aureus (n = 4/35, 11.4%). From 2010-2014 to 2015-2019, antimicrobial resistance increased against moxifloxacin (11.1-54.5%, p = 0.07), ciprofloxacin (54.5-72.7%, p = 0.659) and oxacillin (66.7-93.3%, p = 0.13).

CONCLUSIONS

The observed incidence and microbial spectra were compatible with previous studies. A trend towards growing moxifloxacin and ciprofloxacin resistance was observed. Surveillance remains crucial to prevent treatment failure from antimicrobial resistance.

Modified manual small incision cataract surgery technique for phacoemulsification-trained surgeons

Purpose:

To present the technique and outcomes of a modified manual small incision cataract surgery designed for the phacoemulsification surgeons who are learning to perform manual small incision cataract surgery.

Methods:

This was a retrospective, single-centred, comparative study. We included all the patients who underwent the modified manual small incision cataract surgery for visually significant cataract at Singapore National Eye Centre. All surgeries were performed by either a senior phaco-trained surgeon (M.A.) who had performed more than 500 manual small incision cataract surgery or a junior phaco-trained surgeon (D.C.) who had performed around 500 phacoemulsification but never performed any manual small incision cataract surgery. The main modification of this technique lies in the creation of an additional phaco-like main wound at 90° to the scleral tunnel wound, with most surgical steps performed through this additional wound. The outcomes were analysed and compared between the senior and junior surgeons. The main outcome measures were visual outcome and major intraoperative complications such as posterior capsular rupture and zonular dialysis.

Results:

A total of 132 cases were included; 102 (77.3%) and 30 (22.7%) cases were performed by the senior and junior surgeons, respectively. Pre-operatively, 85.6% eyes had best-corrected visual acuity of counting fingers or worse. Postoperatively, the visual outcome at 1 month was similar between the senior and junior surgeons, with 68.7% eyes achieving a best-corrected visual acuity of ⩾6/12 (p = 0.17). No posterior capsular rupture, zonular dialysis or endophthalmitis was observed during the study period.

Conclusions:

This modified technique may serve as a useful transition technique for the phaco-trained surgeons to develop skills in manual small incision cataract surgery, with demonstrable good visual outcome and safety.

Application of a Novel Film Sealant Technology for Penetrating Corneal Wounds: An Ex-Vivo Study

Aim: To compare the burst pressures of corneal wounds closed with a laser-activated, chitosan-based thin film adhesive against self-seal, sutures and cyanoacrylate. Methods: 2, 4 or 6 mm penetrating corneal wounds were created on 100 freshly enucleated bovine eyes. The wounds were closed using a laser-activated chitosan adhesive (n = 30), self-sealed (control) (n = 30), sutures (n = 20) or cyanoacrylate glue (Histoacryl®) (n = 20). The corneoscleral rim was dissected and mounted onto a custom burst pressure testing chamber. Water was pumped into the chamber at 9ml/hr. The fluid pressure prior to wound leakage was recorded as the ‘burst pressure’. Results: The burst pressure for the 2, 4 and 6 mm wounds were 239.2 mmHg (SD = ±102.4), 181.7 mmHg (SD = ±72.8) and 77.4 mmHg (SD = ±37.4) (p < 0.00001), respectively, for chitosan adhesive. Burst pressure was 36.4 mmHg (SD = ±14.7), 4.8 mmHg (SD = ±4.9) and 2.7 mmHg (SD = ±1.3) (p < 0.00001), respectively, for the self-sealed group. For 4 and 6mm wounds, burst pressures with sutures were 33.0 mmHg (SD = ±19) and 23.5 mmHg (SD = ±17.4) (p = 0.0087), respectively. For cyanoacrylate, burst pressures for 2 and 4 mm wounds were 698 mmHg (SD = ±240.3) and 494.3 mmHg (SD = ±324.6) (p = 0.020087), respectively. Conclusion: This laser-activated chitosan-based adhesive sealed bovine corneal wounds up to 6 mm in length. Burst pressure was higher for the adhesive than sutured or self-sealed wounds, but lower than for cyanoacrylate.

Endophthalmitis after Cataract Surgery in Korea: A Nationwide Study Evaluating Incidence and Risk Factors in a Korean Population

PURPOSE

To assess the nationwide rate of acute postoperative endophthalmitis (APE) after cataract extraction in Korea and to evaluate potential risk factors thereof.

MATERIALS AND METHODS

Nationwide insurance claims data from July 2014 to June 2017 were reviewed. All patients with phacoemulsification or extracapsular/intracapsular cataract extraction were included. Exclusion criteria were combined glaucoma surgery or total vitrectomy or when the patient had a history of intraocular foreign body.

RESULTS

In total, 1505103 cases (982203 patients) were included. APE developed in 953 cases (938 patients) with an overall incidence of 0.063%. After adjusting for possible confounding factors, male sex [odds ratio (OR) 1.42; 95% confidence interval (CI) 1.25-1.61; p<0.001], primary clinical setting, operations performed in non-major cities, usage of sutures (OR 2.82; 95% CI 2.13-3.74; p<0.001), anterior vitrectomy (OR 8.71; 95% CI 6.71-11.32; p<0.001), aphakic cataract surgery (OR 1.52; 95% CI 1.03-2.22; p=0.033), hypertension (OR 1.40; 95% CI 1.18-1.66; p<0.001), diabetes (OR 1.59; 95% CI 1.31-1.93; p<0.001), and chronic renal failure (OR 1.28; 95% CI 1.01-1.62; p=0.039) were found to be related to APE development.

CONCLUSION

The incidence of APE after cataract extraction was consistent with reports from other studies. Additional research is needed to determine the relationship of newly found risk factors, such as hypertension, primary clinical setting, chronic renal failure, and usage of suturing, with APE development.

Risk factors for endophthalmitis after cataract surgery in diabetic patients: a case control study

AIM

To identify risk factors associated with post-cataract surgery endophthalmitis (PCE) in type 2 diabetic patients.

METHODS

A hospital-based retrospective case-control study was conducted on 194 type 2 diabetic patients undergoing cataract surgery in Rajavithi Hospital from January 2007 to December 2015. Fifteen patients with PCE were included as the case group and 179 patients without PCE were included as the control group. Potential factors associated with PCE among both groups including demographics, pre-operative characteristics, surgical settings and complications, were statistically analyzed using Chi-square testing and a logistic regression model.

RESULTS

Within the case group, 53% were females and the median age was 68y. Univariate analysis of pre-operative characteristics, surgical settings and complications revealed that recent pre-operative fasting plasma glucose, insulin therapy, presence of diabetic retinopathy, and severe non-proliferative or proliferative diabetic retinopathy were significantly associated with PCE. In a multivariate analysis adjusting for blood glucose level, insulin treatment was the only significant factor associated with an increased risk of PCE (OR 3.9, 95%CI 1.0-15.0, P=0.04) compared to patients without insulin treatment. The most common causative organisms were gram-positive bacteria (89%). Staphylococcus species represented the most common group (67%). Median best corrected visual acuity at 1-month and 3-month follow-up was equal at 0.7 logMAR (20/100).

CONCLUSION

The authors identify insulin treatment as the only risk factor associated with endophthalmitis after cataract surgery in type 2 diabetic patients. Further studies with serum levels of pre-operative glycated hemoglobin (HbA_1c) and post-operative fasting plasma glucose level are essential to truly demonstrate the role of peri-operative glycemic markers as a risk factor for PCE.

Change in Nationwide Incidence of Post-Cataract Surgery Endophthalmitis: Korean Cohort Study from 2002 to 2013

Purpose: To investigate the change in nationwide incidence of endophthalmitis following cataract surgery in Korea from 2002 to 2013. Methods: From a national sample cohort (n = 1 025 340), cases of postoperative endophthalmitis between 2002 and 2013 were identified. Results: From 70,719 cases of cataract surgery, 49 incidents of endophthalmitis were reported, yielding an incidence of 0.069% (95% confidence interval [CI], 0.051-0.092%). Overall, the endophthalmitis incidence decreased from 0.103% in 2002-2005 to 0.045% in 2010-2013, corresponding to an annually decreasing time-trend (0.902, 95% CI, 0.827-0.984). In diabetic patients, however, the incidence was 0.128% and did not change (time trend, 1.015; 95% CI, 0.828-1.245). Conclusions: This study revealed the incidence of endophthalmitis decreased during a 12-year period, but remained constant in diabetic patients.

Clinical and ex vivo laboratory comparison of the self-sealing properties and dimensional stability between the femtosecond laser and manual clear corneal incisions

PURPOSE

To compare the self-sealing features and dimensional stability between the femtosecond laser (FL) and manual knife corneal incision.

METHODS

For the clinical study, 29 consecutive eyes from 29 patients and 28 eyes from 28 patients who underwent cataract surgery with FL corneal incision and manual knife incision, respectively, were enrolled. Immediately after cataract surgery, the self-sealing features of the corneal incisions were evaluated. Scanning electron microscopy (SEM) images were obtained. For the experimental study, clear corneal incisions with a knife or FL with different energy settings (3, 6 and 9 μJ) were created in fresh porcine eyes, followed by a stress test. The incision width was measured before and after the stress test.

RESULTS

In the clinical study, the knife group had a higher self-sealing score (0.60 ± 0.49 points) than the FL group (0.17 ± 0.38 points). In the experimental study, the deformation rate in the knife incision (5.04 ± 1.93) was significantly lower than that in the FL with any energy. The deformation rate in the 9 μJ (12.98 ± 2.76) was significantly higher than in the 3 μJ (8.54 ± 2.38) and 6 μJ (8.82 ± 2.85) FL energies. Scanning electron microscopy (SEM) images revealed that the corneal stromal surface of the knife incision was smoother than that of the FL. Higher energy FL showed more irregular surfaces.

CONCLUSION

Higher FL energy tended to widen a clear corneal incision when mechanical stress was applied. The histological differences at the inner tunnel surface may cause differences in wound stability of the corneal incision.

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.

Prevention and management of postoperative endophthalmitis: A case-based approach

Endophthalmitis following intraocular surgery is a disastrous complication and can lead to poor visual outcomes and loss of globe integrity. It should be differentiated from toxic anterior segment syndrome (TASS) where management differs drastically. This article presents basic knowledge about postoperative endophthalmitis and describes nine different real–world scenarios ranging from TASS to milder forms of endophthalmitis responding to intravitreal antibiotics alone and more complicated forms associated with corneal involvement, fungal endophthalmitis and cases requiring intraocular lens removal, radical vitrectomy with hyaloid peeling, base dissection, and silicone oil. A case-based approach is followed where practical considerations have been adopted with each case such that it facilitates the readers’ ability to apply theoretical knowledge to real-life clinical situations.

Factors to be Considered when Performing Cataract Surgery in Patients Unable to Recline Flat

PURPOSE

Although phacoemulsification is routinely performed with the patient in a supine position, certain locomotor deformities and other severe ailments can lead to the inability of the patient to recline flat.

METHODS

The present article surveys publications and summarizes our own experience regarding positioning techniques during cataract surgery on patients unable to adopt a supine position.

RESULTS

The successful and effective performance of cataract surgery by phacoemulsification depend on the comfortable positioning of both the patient and the surgeon. In order to achieve the highest possible success rate in phacoemulsification surgery, optimal positioning of the patient and the operating microscope are essential. There are other features of pivotal importance, including the construction of the operating table, the anesthesia technique, and the surgical approach.

CONCLUSIONS

Surgeons often have to rely on their own imagination and experience in finding optimal positioning in order to perform effective and successful phacoemulsification surgery.

Endophthalmitis after cataract surgery: epidemiology, risk factors, and evidence on protection

PURPOSE OF REVIEW

After publication of the results of the European Society of Cataract and Refractive Surgery (ESCRS) study, there is a lot of enthusiasm for using intracameral antibiotics for the prevention of postcataract endophthalmitis. However, despite level 1 evidence, the practice has not been adopted universally. The aim of this review is to present a summary of the articles published in the last 18 months on this topic.

RECENT FINDINGS

The published literature highlights that the incidence rate of endophthalmitis declined after 2007. Simultaneously, there is a rising trend for using intracameral injection of antibiotics at the conclusion of cataract surgery. Although various drugs have been used for this purpose, nearly all provide comparable protection. Industry has started manufacturing formulations for commercial availability of intracameral injection. Innovations are also ongoing to use intraocular lens for drug delivery and developing other intraocular drug delivery devices.

SUMMARY

Endophthalmitis prevention is at an interesting crossroad. Although there is hesitation the intracameral injection of antibiotics is increasingly being adopted by physicians, which is likely to grow further with commercial availability of formulations. However, it will be important to be cautious and report all adverse reactions associated with this practice.

Post-clear corneal phacoemulsification endophthalmitis: profile and management outcomes at a tertiary eye care center in western India

Background

Infectious endophthalmitis is a serious sight threatening intraocular inflammation that results from exogenous or endogenous spread of organisms into the eye.A retrospective case series to study the profile of endophthalmitis following clear corneal phacoemulsification in western India between years 2008 and 2014 was held in the National Institute of Ophthalmology, Pune, India. Cases of endophthalmitis post-clear corneal phacoemulsification were reviewed pertaining to demography, clinical history, surgeon experience, surgical complications, time of onset following surgery, duration between onset of symptoms and presentation to the center, presenting visual acuity and at follow-ups, slit-lamp examination and ultrasound findings, vitreous tap culture results, treatment, and final functional and anatomical outcomes.

Results

Of 60 cases, 34 were operated in the tertiary center and 26 were referred. The incidence of endophthalmitis post clear corneal phacoemulsification performed at the tertiary center was 0.17%. Mean time delay between onset of symptoms and presentation to the tertiary care center was 2.6 days. Fifty percent cases were culture +ve, of which 80% were Gram +ve and 20% were Gram −ve, no fungal isolates. Coagulase –ve staphylococcus was the most common causative organism; rare isolates included Sphingomonas paucimobilis and Streptococcus mitis. Twenty-six eyes underwent primary vitrectomy. Mean presenting visual acuity was 2.14 ± 0.07 logMAR units which improved to logMAR 0.98 ± 0.12 at final follow-up. Presenting VA was >20/200 in 13.3% and <HM in 60% cases. 66.7% of eyes had visual improvement; 26.7% cases achieved VA 20/40 at final follow-up. Gram +ve and culture –ve cases, better presenting VA, and less time delay between onset and presentation had a favorable visual outcome.

Conclusions

The shift of the clinico-microbiological spectrum of endophthalmitis could be due to change in surgical technique to clear corneal phacoemulsification. Predictors of good visual outcome include good presenting visual acuity, early presentation to the center, culture negativity, and coagulase negative organisms.

Electronic supplementary material

The online version of this article (doi:10.1186/s12348-016-0115-y) contains supplementary material, which is available to authorized users.

Bacterial endophthalmitis: 10-year review of the culture and sensitivity patterns of bacterial isolates

OBJECTIVE

To examine the spectrum and sensitivity patterns of bacterial isolates derived from all culture-positive aqueous and vitreous samples submitted for culture and sensitivity analysis at our institution over a 10-year period.

DESIGN

Retrospective cohort study.

PARTICIPANTS

A total of 368 culture-positive aqueous and vitreous samples from 265 patients were reviewed.

METHODS

Over a decade extending from January 2000 through December 2009, all culture-positive aqueous and vitreous specimens at our institution were identified. Isolated bacterial pathogens and their in vitro antibiotic sensitivities were analyzed.

RESULTS

Approximately 86.4% of patients had positive cultures for either staphylococci (Staphylococcus aureus and coagulase-negative staphylococci [CNS]) or streptococci. Gram-negative bacteria were isolated in only 9.8% of patients. From 2000 to 2004, 81.2% and 55.9% of CNS isolates were sensitive to ciprofloxacin and cefazolin, respectively, compared with 41.2% and 23.5% of isolates in the last 5 years. Over the study period, ceftazidime retained 100% efficacy against the gram-negative isolates tested. Vancomycin was 99.6% effective against the gram-positive isolates tested.

CONCLUSIONS

The microbiology of pathogens in endophthalmitis is evolving, with an increase in streptococcal isolates and a decrease in CNS. The apparent lack of efficacy of conventionally used antibiotics and the emergence of increasingly resistant strains of bacteria may have significant implications in the management of bacterial endophthalmitis.

Safety Profile of Stromal Hydration of Clear Corneal Incisions with Cefuroxime in the Mouse Model

PURPOSE

The use of sutureless clear corneal incisions (CCIs) for phacoemulsification is an established surgical technique, but the dynamic morphology of the wound and poor construction can lead to an increased risk of postoperative endophthalmitis. Stromal hydration with balanced salt solution (BSS) can improve the self-sealing status. Intracameral cefuroxime has reduced endophthalmitis rates. This study investigates the safety profile of stromal hydration with cefuroxime, as sequestering antibiotic at the wound may potentially provide added protection against infection.

METHODS

MF-1 mice underwent bilateral CCI, followed by stromal hydration with 5 μL of 10 mg/mL cefuroxime, cefuroxime-texas red conjugate (for detection using confocal microscopy), or BSS. Corneas were harvested from 1 h to 12 weeks postoperatively; gross morphology, histology, and apoptotic cell death levels were investigated to determine the safety profile. Bactericidal activity of cefuroxime was assayed using homogenized whole cornea following stromal hydration at 1 h, 24 h, and day 7 against gram-negative Escherichia coli.

RESULTS

Cefuroxime stromal hydration did not alter corneal morphology, with no evidence of corneal scarring or vascularization. Corneal histology and levels of apoptosis were minimal and comparable to the BSS groups up to 12 weeks. Confocal microscopy detected cefuroxime-texas red up to 1 week surrounding the corneal wound. Whole corneal tissue homogenates displayed bactericidal activity up to 24 h postoperatively.

CONCLUSIONS

Stromal hydration of CCI with cefuroxime is safe in mouse corneas. A reservoir of antibiotic at the wound can potentially act as a barrier of defense against infection following cataract and associated ocular surgery.

Microencapsulation of rifampicin for the prevention of endophthalmitis: In vitro release studies and antibacterial assessment

Rifampicin encapsulated microparticles were designed for intraocular injection after cataract surgery to prevent postoperative endophthalmitis. Microparticles were formulated by emulsification diffusion method using poly(lactic acid-co-glycolic acid) (PLGA) as polymer in order to propose a new form of rifampicin that overcome its limitations in intraocular delivery. Depending on processing formulation, different types of microparticles were prepared, characterized and evaluated by in vitro release studies. Two types of microparticles were selected to get a burst release of rifampicin, to reach minimal inhibitory concentrations to inhibit 90% of Staphylococcus epidermidis mainly involved in postoperative endophthalmitis, combined with a sustained release to maintain rifampicin concentration over 24h. The antibacterial activity and antiadhesive property on intraocular lenses were evaluated on S. epidermidis. Microparticles, with a rapid rifampicin release profile, showed an effect towards bacteria development similar to free rifampicin over 48h. However, slow-release profile microparticles exhibited a similar antibacterial effect during the first 24h, and were able to destroy all the S epidermidis in the medium after 30h. The association of the two formulations allowed obtaining interesting antibacterial profile. Moreover, rifampicin-loaded microparticles have shown a very efficient anti-adherent effect of S. epidermidis on intraocular lenses at 24h. These results propose rifampicin microparticles as suitable for antibioprophylaxis of the postoperative endophthalmitis.

Wound Integrity of 2.0 mm Transconjunctival Single-Plane Sclerocorneal Incision: A Comparison between a Motorized Injector with/without Pause Time and a Manual Injector

Purpose. To compare the final incision size and wound structure after the intraocular lens implantation from 2.0 mm transconjunctival single-plane sclerocorneal incision (TSSI) between the use of a motorized injector at first speed and the use of a manual injector. Methods. Patients were divided into three groups as follows: Group A, a manual injector, Group B, a motorized injector with 0.5 s pause time, and Group C, a motorized injector without pause time. The change in incision size and anterior segment optical coherence tomography findings of the wound structure were analyzed. Results. 110 eyes were enrolled (Group A: 40, Group B: 30, and Group C: 40). The averaged change in incision size (mm) was 0.08, 0.01, and 0.03 in Groups A, B, and C, respectively (p < 0.001). The incision enlargement in Group A was statistically larger compared with other groups (p < 0.01). Descemet's membrane detachments were seen in 26, 9, and 27 eyes one day after the surgery in Groups A, B, and C, respectively (p = 0.001). The rate of Descemet's membrane detachment in Group B was significantly lower than other groups (p < 0.01). Conclusions. The use of a motorized injector by fastest setting with 0.5 s pause time is the best for less wound damage in 2.0 mm TSSI.

Staphylococcus aureus and its Bearing on Ophthalmic Disease

PURPOSE

To review antibiotic resistance associated with S. aureus endophthalmitis and the virulence of S. aureus.

METHODS

Review of the current and prospective approaches for treating S. aureus endophthalmitis.

RESULTS

Bacterial endophthalmitis remains to be a major threat for vision. S. aureus endophthalmitis specifically, carries a poor visual prognosis making early diagnosis and treatment crucial. Methicillin resistant Staphylococcus aureus (MRSA) endophthalmitis represents a significant number of S. aureus endophthalmitis cases. MRSA with reduced susceptibility to glycopeptide antibiotics such as vancomycin (vancomycin intermediate S. aureus, VISA) have also emerged in the ocular infections, and there has been a rise in S. aureus resistance to new and old generation fluoroquinolones that are commonly used for prophylaxis after intravitreal injections and intraocular surgeries.

CONCLUSIONS

With the rise in the number of penetrating procedures in the ophthalmology practice and the parallel rise in antibiotic resistance, prophylaxis and awareness of the antimicrobial resistance profiles remain crucial and the identification of novel antimicrobials is essential.

Antibiotic prevention of postcataract endophthalmitis: a systematic review and meta-analysis

Endophthalmitis is one of the most feared complications after cataract surgery. The aim of this systematic review was to evaluate the effect of intracameral and topical antibiotics on the prevention of endophthalmitis after cataract surgery. A systematic literature review in the MEDLINE, CINAHL, Cochrane Library and EMBASE databases revealed one randomized trial and 17 observational studies concerning the prophylactic effect of intracameral antibiotic administration on the rate of endophthalmitis after cataract surgery. The effect of topical antibiotics on endophthalmitis rate was reported by one randomized trial and one observational study. The quality and design of the included studies were analysed using the Cochrane risk of bias tool. The quality of the evidence was evaluated using the GRADE approach. We found high-to-moderate quality evidence for a marked reduction in the risk of endophthalmitis with the use of intracameral antibiotic administration of cefazolin, cefuroxime and moxifloxacin, whereas no effect was found with the use of topical antibiotics or intracameral vancomycin. Endophthalmitis occurred on average in one of 2855 surgeries when intracameral antibiotics were used compared to one of 485 surgeries when intracameral antibiotics were not used. The relative risk (95% CI) of endophthalmitis was reduced to 0.12 (0.08; 0.18) when intracameral antibiotics were used. The difference was highly significant (p < 0.00001). Intracameral antibiotic therapy is the best choice for preventing endophthalmitis after cataract surgery. We did not find evidence to conclude that topical antibiotic therapy prevents endophthalmitis.

An 8-year retrospective study of cataract surgery and postoperative endophthalmitis: injectable intraocular lenses may reduce the incidence of postoperative endophthalmitis

BACKGROUND/AIMS

Postoperative endophthalmitis (POE) is a rare but potentially devastating complication of modern cataract surgery. We examine whether the use of injectable intraocular lenses (IOLs) is associated with a lower rate of POE after cataract surgery compared with forceps-inserted foldable IOLs.

METHODS

A single-centre retrospective cohort study of 25 410 cataract operations was performed over an 8-year period when standard practice in cataract surgery changed from the use of forceps-inserted foldable IOLs to injectable IOLs. Cases of POE were identified and the rates compared between the two groups.

RESULTS

Twelve cases of POE were identified in the study period. The rate of POE was significantly lower in the injectable IOL group compared with the forceps-inserted foldable IOL group (0.008% vs 0.081%, p=0.008). This difference remained significant when controlling for posterior capsular rupture and lens material.

CONCLUSIONS

This study, the largest of its kind to date, supports the use of injectable IOLs over forceps-inserted foldable IOLs as a significant measure in reducing the risk of POE.

Study of fluid ingress through clear corneal incisions following phacoemulsification with or without the use of a hydrogel ocular bandage: a prospective comparative randomised study

PURPOSE

To assess the use of a hydrogel ocular bandage (HOB) on clear corneal incisions in phacoemulsification cataract surgery and determine whether HOB reduces ocular surface contaminants ingress after routine surgery.

METHODS

In this prospective randomized controlled study, thirty eyes of patients undergoing uneventful phacoemulsification were recruited consecutively and randomly assigned to have a HOB applied to the corneal incision at the end of the surgery or not. At the end of the surgery, trypan blue (TRB) was instilled on the ocular surface, aqueous fluid was aspirated from the anterior chamber (AC) and its optical density was measured using ultraviolet spectrophotometry. The corneal incisions were examined postoperatively using anterior segment optical coherence tomography. Main outcome measures were concentration of TRB in the AC, corneal incision architecture, intraocular pressure (IOP) and Seidel test.

RESULTS

All incisions were Seidel negative. The mean IOP in the immediate postoperative period was 18.1 ± 5.48 mmHg for the intervention group and 16.9 ± 5.7 mmHg for the control group (p > 0.05). No architectural differences of the incisions between the two groups were noted. The total mean length of the three-step corneal incisions in the two groups was 2261.2 ± 96.92 μm and 2263 ± 119.75 μm, respectively (p > 0.05). No trace of TRB was detected in any of the samples.

CONCLUSION

Proper surgical wound construction without the use of a HOB is efficient in preventing the ingress of fluid through the main corneal incision postoperatively.

Corneal astigmatism change and wavefront aberration evaluation after cataract surgery: "Single" versus "paired opposite" clear corneal incisions

Background:

Correcting the pre-existing astigmatism is an optimal goal in cataract surgery. The aim of this study is to compare the astigmatic correcting effect of a single regular 3.2 mm clear corneal incision (CCI) with paired opposite CCI in cataract patients and effect of these incisions on optical aberrations using the wavefront quantitative analysis.

Materials and Methods:

This was a randomized controlled trial study undertaken in an ophthalmology referral center on 50 patients planned for cataract surgery who were randomized to either single 3.2 mm CCI or paired opposite CCI group. Post-operative evaluation was performed at 12 weeks and included refraction, keratometery, corneal topography and wavefront analysis. Corneal astigmatism and post-operative values were compared in two groups.

Results:

The mean pre-operative corneal astigmatism was 2.58 ± 1.03 D in the single incision group and 2.70 ± 0.94 D in the paired opposite incisions group. After 12 weeks of surgery, the corneal astigmatism was reached to 2.15 ± 0.82 D in single incision group and 1.63 ± 1.21 in the paired opposite incisions group. There was a statistically significant difference in two arms of treatment regarding to surgically induced astigmatism after 3 months. The mean post-operative total and higher order aberrations and values were not significantly different in two groups.

Conclusion:

The results of our study showed that paired opposite incisions is an effective procedure for reducing pre-existing corneal astigmatism in cataract surgery. Paired incisions did not show any beneficial effect regarding wavefront aberrations compared with conventional single incision method.

Clear corneal incision in cataract surgery

Since the introduction of sutureless clear corneal cataract incisions, the procedure has gained increasing popularity worldwide because it offers several advantages over the traditional sutured scleral tunnels and limbal incisions. Some of these benefits include lack of conjunctival trauma, less discomfort and bleeding, absence of suture-induced astigmatism, and faster visual rehabilitation. However, an increasing incidence of postoperative endophthalmitis after clear corneal cataract surgery has been reported. Different authors have shown a significant increase up to 15-fold in the incidence of endophthalmitis following clear corneal incision compared to scleral tunnels. The aim of this report is to review the advantages and disadvantages of clear corneal incisions in cataract surgery, emphasizing on wound construction recommendations based on published literature.

Architectural analysis of clear corneal incision techniques in cataract surgery using Fourier-domain OCT

BACKGROUND AND OBJECTIVE

To compare the architecture of single plane self-sealing clear corneal incision (SP-CCI) and shallow grooved self-sealing clear corneal incision (SG-CCI) after cataract surgery using Fourier-domain optical coherence tomography (FD-OCT).

PATIENTS AND METHODS

An FD-OCT system with a corneal adaptor module was used to image the corneal incisions in radial sections in 44 eyes. A line scan pattern was used to measure the corneal incision, positioning the caliper mark perpendicular to the limbus. Measurements were performed immediately after cataract surgery and at postoperative days 1, 7, and 30. Incisions were analyzed regarding length, location, angle, architecture, and anatomic imperfections.

RESULTS

All incisions were located superiorly (temporal, 24 eyes; nasal, 20 eyes). The mean SG-CCI length (20 eyes) was 1.79 ± 0.31 mm (range: 0.93-2.64 mm) and the mean incision angle was 37 ± 7 degrees (range: 24-34 degrees). The mean SP-CCI length (22 eyes) was 1.64 ± 0.22 mm (range: 1.25-2.36 mm) and the mean incision angle was 38.5 ± 5 degrees (range: 27-52 degrees) (P < .05). Anatomic imperfections were observed at postoperative day 1 in 19 eyes for SP-CCI and 14 eyes for SG-CCI. No patient presented endophthalmitis during 30 days of follow-up.

CONCLUSION

Epithelial imperfection at the corneal incision site was observed in more than 36% of the wounds (36% in SP-CCI and 45% in SG-CCI) at postoperative day 1 with spontaneous resolution. SG-CCI had the greatest length and lowest angle of corneal incision. Reduced incision length and inappropriate construction may determine risk factors for wound architectural imperfections. Further studies including more patients with an architectural analysis of clear corneal incisions are needed to confirm these preliminary results.

Risk factors for acute endophthalmitis following cataract surgery: a systematic review and meta-analysis

Background

Acute endophthalmitis is one of the most serious complications of cataract surgery and often results in severe visual impairment. Several risk factors for acute postoperative endophthalmitis (POE) following cataract surgery have been reported but the level of evidence and strength of association is varied. The purpose of this study was to critically appraise published reports on and to summarize clinical risk factors associated with acute POE which could be easily assessed by ophthalmologists for the introduction and implementation of preventive measure.

Methods

A systematic review and meta-analysis of observational studies was performed. Six databases were searched with no limits on the year or language of publication. Study-specific odds ratios (Ors) or relative risk (RR) of each risk factor were pooled using a random effect model.

Results

A total of 6 686 169 participants with 8 963 endophthalmitis in 42 studies were analyzed. Of the nine risk factors identified in our systematic review and meta-analysis, extra- or intracapsular cataract extraction, a clear corneal incision, without intracameral cefazolin (1 mg in 0.1 ml solution), without intracameral cefuroxime (1 mg in 0.1 ml solution), post capsular rupture, silicone intraocular lenses and intraoperative complications were found strongly associated with acute endophthalmitis. Other significant factors with a lower strength of association (risk estimates generally 1.5 or less) were male gender and old age (85 years and older).

Conclusions

Our study provides summary data on the risk factors for acute POE. Identifying patients at high risk of this sight-threatening eye disease is important from both the public health and clinical perspectives as this would facilitate detection of disease before the onset of irreversible visual loss enabling earlier intervention.

Development of a novel disposable lid speculum with a drape

Purpose

To evaluate the clinical use of a newly-developed disposable lid speculum with a drape.

Methods

LiDrape® is a cylindrical device that consists of two flexible rings of polyacetal resin with a transparent elastic silicone sheet attached to the rings. The novel device holds the eyelids between the rings, and a hole in the center of the device provides a surgical field. We used the novel device in cataract surgery (75 eyes), glaucoma surgery (eleven eyes), vitrectomy (ten eyes), and intravitreal injection (six eyes) and evaluated its clinical efficacy.

Results

The LiDrape was easy to attach and detach. The novel device was not detached from the eye during surgery. No eyelashes or secretions from the meibomian glands were seen in the surgical field, and the drape provided a sufficient surgical field.

Conclusions

The LiDrape functions as a lid speculum as well as a drape. Our results showed that the novel device is useful for ocular surgeries.

Management strategies to reduce risk of postoperative infections

Postoperative infections, although rare, are still of great concern to the ophthalmologist. The incidence of post-cataract endophthalmitis is low, with a range of .28 per 1,000 to 2.99 per 1000. In addition to intraoperative considerations such as poor wound construction, vitreous loss, topical anesthesia, and prolonged surgical time, other risk factors include preoperative factors such as a diseased ocular surface and systemic immunosuppression. Potential methods of reducing risk of endophthalmitis after anterior segment surgery are discussed and available literature is summarized.

Sutured clear corneal incision: wound apposition and permeability to bacterial-sized particles

PURPOSE

To determine the effects of single radial or horizontal suture placement in 2-step clear corneal incision (CCI) wound apposition and permeability to particles of India ink.

METHODS

Five fresh human globes were included. Two 25-gauge needles connected to a saline solution bag and to a digital manometer were inserted through the limbus, 120 degrees apart from each other. Four 2-step CCIs (2.75 mm wide and 3 mm length) were constructed in each cornea. Incisions were divided into 3 groups: single radial suture (SRS), single horizontal suture (SHS), and unsutured group. Optical coherence tomography (OCT) was performed before and after suture placement. With a preset 10 mm Hg intraocular pressure (IOP), India ink was applied to the incision site and a standardized sudden IOP fluctuation was induced. OCT and superficial images were recorded before and after suture placement. India ink inflow and internal and external CCI gapping were outlined and measured by planimeter.

RESULTS

The area and linear distance of India ink inflow after pressure challenge in all study groups were higher when compared with pre-pressure measurements; however, this increase was significant in the SRS and SHS groups (P < 0.05). Additionally, SRS placement significantly increased inner wound gapping (P = 0.018), and SHS significantly widened outer wound gape (P = 0.02).

CONCLUSIONS

Well-constructed unsutured 2-step CCI seems to be more efficient at preventing bacterial-sized particles inflow during sudden changes in IOP, and it seems to offer better wound apposition as assessed by OCT.

[Efficacy of topical 0.3% ciprofloxacin application in reducing the conjunctival biota of patients undergoing cataract extraction]

OBJECTIVE

To determine the efficacy of topical 0.3% ciprofloxacin in reducing conjunctival biota in patients undergoing cataract surgery.

PATIENTS AND METHODS

Experimental, prospective, randomized, controlled and single-blind study. Forty-six eyes of 46 patients were randomized into 2 groups, the study group (n=23) received topical 0.3% ciprofloxacin one day before surgery for six times, and on the day of the surgery one drop every 15minutes starting one hour before surgery until 3 doses were completed. The control group (n=23) did not receive any antibiotics. For both groups for the surgical field 10% povidone-iodine was applied. Samples from the conjunctiva were taken at four different times and then cultured on solid media (chocolate agar, blood agar) and enrichment broth (thioglycolate). The aqueous humor samples were also cultured in thioglycolate. The presence of bacteria was identified quantitatively and qualitatively, and the frequency of contamination was measured by considering the presence of bacteria in liquid and solid culture media. The number of colony forming units (CFU) was counted in the solid culture medium.

RESULTS

Positive cultures were obtained in 82.6% and 78.2% of the patients in the study and control groups, respectively, before the administration of 0.3% ciprofloxacin. The administration of 0.3% ciprofloxacin significantly reduced the CFU compared to the control group (P<.05). Immediately after the use of povidone-iodine, the proportion of patients with a positive culture decreased to 21.7% in the study group, and 8.7% in the control group. At the end of the surgery, this percentage was 26% and 30.4%, respectively. The most common isolated pathogen was negative-coagulase Staphylococcus (66.7%).

CONCLUSION

The administration of 0.3% ciprofloxacin reduces conjunctival bacterial load in the preoperative period. However, it was unable to eradicate the bacteria completely. The administration of povidone-iodine reduced conjunctival biota in 50%-70% of patients undergoing cataract surgery.