A literature review and update on the incidence and microbiology spectrum of postcataract surgery endophthalmitis over past two decades in India

Preferred practice patterns of endophthalmitis management and prevention: A survey among the members of Vitreoretinal Society of India - Study by the VRSI study group

PURPOSE

To assess the preferred practice patterns of endophthalmitis management and prophylaxis among the members of Vitreo Retina Society of India (VRSI).

METHODS

An online questionnaire was circulated among the VRSI members, enquiring details on clinical presentation of endophthalmitis, initial management protocols of acute and chronic endophthalmitis, usage of antibiotics, steroids, and silicone oil (SO) in endophthalmitis, and prophylaxis followed for prevention of endophthalmitis.

RESULTS

A total of 313 (20.2%) responses were obtained. The mean age of the respondents was 43.2 ± 0.5 years, and there was a male predominance (n = 231, 73.8%). Post-cataract surgery endophthalmitis (PCSE) was the most common (n = 273, 87.2%) reported variant, followed by post-traumatic endophthalmitis (PTE) (n=37,11.8%). Over 50% (n = 181, 57.8%) of respondents followed Endophthalmitis Vitrectomy Study (EVS) guidelines for acute PCSE and about 60% (n = 194, 61.9%) would not extrapolate EVS guidelines to other forms of endophthalmitis. A total of 159 (50.8%) respondents preferred using a vitreous/anterior chamber tap with needle, and vitreous biopsy with vitrector was preferred by 117 (37.3%) respondents. Vancomycin-ceftazidime remains the preferred combination of empirical intravitreal antibiotics (IVAs), and 169 (54%) preferred injecting intravitreal steroids along with IVA. About one-fourth (n = 90, 28.8%) of the respondents preferred pars plana vitrectomy as the initial management for PCSE. SO was used mostly in cases with PTE (n = 176, 56.2%). Prophylactic measures to prevent endophthalmitis varied among the respondents.

CONCLUSION

Majority of the Indian vitreoretinal surgeons felt the need for amendment in the EVS guidelines, but would prefer to follow the EVS guidelines for managing endophthalmitis at present.

Long term analysis of microbiological isolates and antibiotic susceptibilities in acute-onset postoperative endophthalmitis: a UK multicentre study

OBJECTIVES

To review the trend of microbial isolates for postoperative endophthalmitis (POE) in the United Kingdom (UK) and determine the sensitivity to current empirical intravitreal antibiotic treatment.

METHODS

We conducted a long term multicentre consecutive case review of POE across 3 geographically distant tertiary eye centres in the UK: Sunderland Eye Infirmary (2000-2022), Oxford Eye Hospital (2016-2022), and Southampton General Hospital (2016-2022). Data on the microbial samples taken and results including sensitivities to antibiotics agents given were collected. Poisson regression was used to analyse microbial trends and outcomes were considered statistically significant at a level of p < 0.05.

RESULTS

179 consecutive eyes of 177 patients with POE met our inclusion criteria. The most common primary procedure was phacoemulsification and IOL insertion followed by intravitreal injections. 104 (58.1%) were culture positive and most were Gram-positive bacteria (85, 81.7%). The microbial trend consistently showed Staphylococcus epidermidis and unspecified coagulase-negative Staphylococci to be the most prevalent pathogens. Poisson regression showed no statistically significant change in any of the bacterial isolates over our study period. Antibiotic sensitivity data was available for 74% of the culture positive samples (77/104). All Gram-positive bacteria (68/68, 100%) and most (8/9, 88.9%) Gram-negative bacteria were sensitive to the empirical antibiotics (Vancomycin and Ceftazidime/Amikacin) given at presentation.

CONCLUSIONS

Most of the bacterial isolates causing POE in the UK are Gram-positive bacteria, and the trend has remained stable over more than two decades. Current empirical treatment with intravitreal Vancomycin and Ceftazidime/Amikacin provides effective broad coverage for the vast majority of cases.

The diagnosis and treatment progress of infectious endophthalmitis

Endophthalmitis is a blinding disease that may lead to permanent vision loss. The diagnosis of endophthalmitis relies on clinical findings. It is crucial to identify causative microorganisms in time for subsequent treatment and saving vision. For a long time, cultures of vitreous and/or aqueous humours have been the gold standard for the diagnosis of endophthalmitis. The development of modern molecular diagnostic techniques has brought new opportunities for identifying pathogens rapidly and improving sensitivity. Intravitreal antibiotic injection has the become standard treatment option for infectious endophthalmitis in clinical practice, however, the role and timing of pars plana vitrectomy remains controversial. Moreover, the development of new drugs for intravitreal injection and posterior segment drug delivery systems is expected to achieve the transition from invasive to non-invasive management. Thus, endophthalmitis is an ophthalmic emergency and timely diagnosis and treatment are crucial for preserving vision.

Microbiological Profile of Post-cataract Surgery Endophthalmitis with Usage of Prophylactic Intracameral Moxifloxacin

PURPOSE

To study the effect of prophylactic intracameral moxifloxacin (ICM) on microbiological profile and antimicrobial sensitivity of culture-proven postoperative endophthalmitis (POE).

METHODS

This study evaluated culture-proven POE diagnosed within 6 weeks of cataract surgery over two periods, period-1 (January 2010-March 2015) and period-2 (April 2015-December 2019), before and after introduction of prophylactic ICM, respectively.

RESULTS

In period-1, 100 cases of culture-positive POE were reported (1 in 4879, 0.02%), while 20 cases (1 in 24635, 0.004%) were reported in period-2 (5-fold reduction, p < .001). The cumulative culture positivity rate decreased from 27.6% to 17.1% (1.6-fold) . Coagulase-negative Staphylococci (CoNS) were significantly reduced (p = .005).

CONCLUSIONS

ICM reduced the incidence of culture-proven POE, CoNS in particular. In future, POE caused by rarer pathogens may become more prevalent due to reduction in the rate of commoner and more virulent pathogens with use of intracameral antibiotics. The moxifloxacin sensitivity of CONS did not show change with the use of ICM. Studies with larger population of POE will be more helpful to understand the trend better.

Antibiotic susceptibility in Endophthalmitis Management Study and intravitreal antibiotic practice trend in India-EMS Report #5

AIM

Analyze antibiotic susceptibility in the Endophthalmitis Management Study (EMS) and compare it with the current intravitreal antibiotic practice trend of members of the Vitreoretinal Society of India (VRSI) practicing in India.

METHODS

The microbiology work-up of undiluted vitreous included microscopy, culture-susceptibility, polymerase chain reaction (PCR), and next-generation sequencing (NGS). VRSI members were invited to the survey. The EMS conventional culture-susceptibility (PCR and NGS excluded) results were compared vis-a-vis gram-positive cocci (GPC), gram-negative bacilli (GNB), and less commonly used antibiotics with the current recommended intravitreal antibiotics. p < 0.05 was considered significant.

RESULTS

Culture and positivity (culture + PCR/NGS) positivity was 28.8% and 56.1%, respectively. GPC was most susceptible to cefazolin, linezolid, and vancomycin; GNB was most susceptible to amikacin, ceftazidime, colistin, and imipenem. There was no susceptibility difference between cefazolin and vancomycin (p = 0.999) and between ceftazidime and imipenem (p = 1.0). Colistin was superior to ceftazidime (p = 0.047) against GNB. The GNB resistant to amikacin (n = 14) were equally susceptible to ceftazidime and colistin; resistant to ceftazidime (n = 16) were susceptible to colistin; and resistant to colistin (n = 7) were susceptible to ceftazidime. The preference of VRSI members (n = 231) practicing in India was a vancomycin-ceftazidime combination (82%), vancomycin for GPC (94%), ceftazidime for GNB (61%), and voriconazole for fungi (74%).

CONCLUSION

In EMS, GPC had good susceptibility to vancomycin; GNB had good susceptibility to ceftazidime and colistin. Given the lower resistance of colistin, a vancomycin-colistin combination could be an alternative empiric treatment in post-cataract endophthalmitis in India.

Tap and inject of intravitreal antibiotics versus pars plana vitrectomy for post-cataract surgery endophthalmitis: a meta-analysis

BACKGROUND

The efficacy and safety of initial tap and inject (T/I) compared with pars plana vitrectomy (PPV) for acute postoperative bacterial endophthalmitis following cataract surgery is unclear. Understanding the comparative safety and efficacy of initial T/I and initial PPV can provide context for treatment decision making in this setting.

METHODS

A systematic literature search was performed on Ovid MEDLINE, EMBASE, and the Cochrane Library from January 1990 to January 2021. Comparative studies reporting on final best-corrected visual acuity (BCVA) following initial T/I or PPV in patients with infectious endophthalmitis secondary to cataract surgery were included. Cochrane's Risk of Bias in Non-Randomized Studies of Interventions (ROBINS-I) was used to evaluate the risk of bias, and GRADE criteria were used to assess certainty of evidence. A random-effects model was used for meta-analysis.

RESULTS

Seven nonrandomized studies reporting on 188 eyes at baseline were included in this meta-analysis. Initial T/I achieved a significantly better BCVA at last study observation than initial PPV (weighted mean difference [WMD] = -0.61 logMAR; 95% CI, -1.19 to -0.03; p = 0.04; I2 = 89%; n = 7 studies; GRADE = very low). The incidence of enucleation was similar between initial T/I and initial PPV (risk ratio [RR] = 0.73; 95% CI, 0.09-6.25; p = 0.78; I2 = 4%; n = 2 studies; GRADE = very low). The risk of retinal detachment was similar between treatment modalities (RR = 0.29; 95% CI, 0.01-5.94; p = 0.42; I2 = 52%; n = 2 studies; GRADE = very low).

CONCLUSIONS

The quality of evidence in this setting is limited. T/I had a significantly better BCVA at last study observation than initial PPV. Safety profiles were similar between T/I and PPV.

Early Vitrectomy: An Effective Treatment for Acute Postcataract Surgery Endophthalmitis

Background

Endophthalmitis is a rare but a high morbid complication after cataract surgery, and a gold standard treatment is not recommended yet. In this study, we aim to evaluate the effect of early vitrectomy on the visual acuity of patients with postcataract endophthalmitis.

Materials and Methods

This study was a single-arm clinical trial on 27 patients with postcataract surgery endophthalmitis. Early vitrectomy was the intervention. Visual acuity as the primary outcome was evaluated and compared at baseline, at discharge, and 1 and 3 months after the intervention.

Results

From 27 patients who included in our study, six patients gain favorable visual acuity of 5/10 and above (success rate = 22%), and four of them have no improvement in their visual acuity. Retinal detachment was reported as a complication in just one case. Negative culture was a predictor for success in terms of visual acuity after the surgery. All patients who gain favorable results, presented in the first 15 days after the cataract surgery.

Conclusion

The result of our study showed that, considering complete, early vitrectomy for the treatment of postcataract surgery endophthalmitis, especially for those who presented in the first 15 days of cataract surgery and for those who have negative culture is promising.

Comparison of different endophthalmitis prophylactic measures in cataract surgery - An analysis of 2.4 lakh cases

Purpose

To compare different endophthalmitis prophylaxis methods adopted in cataract surgery (manual small-incision cataract surgery and phacoemulsification) between the years 2013 and 2021 in the community eye care section of a tertiary eye care hospital in South India and report their outcomes.

Methods

All cataract surgeries performed from January 2013 to December 2021 (2,46,874 surgeries) at a single center were included in this retrospective study. The different endophthalmitis rates with each regimen were analyzed and evaluated.

Results

70,081 surgeries were performed from January 2013 to February 2015, where Tobramycin was added to Balanced Salt Solution (BSS) (Group A). From March 2015 to January 2017, 63,245 surgeries were performed when intracameral Moxifloxacin was given (Group B). From February 2017 to December 2021, 1,13,548 surgeries were performed were Amikacin was added to BSS (Group C). In total, 42 cases of postoperative endophthalmitis were reported during the study period (0.02%). There was no significant difference in the endophthalmitis rates between groups A and B (P = 0.4152); however, there was a significant decrease in endophthalmitis rates in group C when compared with group A (P = 0.04) and group B (P = 0.006).

Conclusion

There was a significant reduction in the rates of endophthalmitis following the addition of amikacin in irrigating BSS. Nocardia was one of the predominant organisms isolated from these endophthalmitis patients. This is the first single-center study to report a comparative analysis of different endophthalmitis prophylactic measures in a community eye care set up with a high incidence of Nocardia endophthalmitis prevented with amikacin in BSS irrigating solution.

Emerging antimicrobial resistance and need for antimicrobial stewardship for ocular infections in India: A narrative review

Patients with ocular infections are at increased risk of vision impairment and may require immediate medical care to preserve their vision. Management of ocular bacterial infections has evolved in recent years and includes a pragmatic selection of broad-spectrum antibiotics based on the causative bacteria. Nevertheless, the treatment of bacterial ocular infections is increasingly becoming a challenge, as the causative bacterium acquires resistance to antibiotics through intrinsic and acquired methods. From an Indian perspective, along with the challenges of antibiotic resistance, there are other factors such as lack of knowledge on epidemiology, and lack of data on local susceptibility patterns of ocular pathogens that have significant impact on the management of ocular infections. This narrative review summarizes the available knowledge on prescribing antibiotics for five common ocular infections in India. It further highlights the significance of the understanding of antimicrobial susceptibility patterns across India as a cornerstone to promote rational use of ocular antibiotics. This review indicates that large-scale antimicrobial resistance surveillance studies can facilitate the synchronization of ophthalmic antimicrobial prescription policies with local antibiotic resistance patterns. Further, establishment of an antimicrobial stewardship program in ophthalmology can potentially increase the efficacy of diagnostic tools, and implement earlier adoption of effective antibiotics. Overall, this review provides consolidated information and key considerations for treatment decision-making of common ocular infections in India.

Factors associated with postoperative visual outcome in acute endophthalmitis after cataract surgery-a cross-sectional, analytical study

PURPOSE

To identify predictors of visual outcome in patients with acute endophthalmitis following cataract surgery.

METHODS

This cross-sectional study included consecutive patients with acute endophthalmitis following cataract surgery at our tertiary care center between January 2017 and June 2018. Baseline demographic details, surgical details, and treatment offered were extracted from the medical record, and patients were followed for 3 months after diagnosis and treatment for endophthalmitis. A good outcome was defined as visual acuity of greater than 6/12; a poor outcome, visual acuity of less than 6/60 on 3-month follow-up. The factors associated with these outcomes were analyzed.

RESULTS

A total of 60 patients were included, of whom 32 (53%) had good visual outcome, and 11 (18%) had poor visual outcome. On univariate analysis, factors associated with good outcome were younger age at surgery, male sex, diabetes, absence of hypopyon, and absence of fibrillary membrane over the intraocular lens (IOL). Poor visual acuity at presentation, inability to visualize the optic disc on indirect ophthalmoscopy, and negative microbiological culture were associated with poor visual outcome. Stepwise logistic regression analysis showed that absent hypopyon (OR = 19.50; 95% CI, 2.87-132.14) and absent fibrillary membrane over the IOL (OR =15.0; 95% CI, 2.34-96.89) were independent factors for good visual outcome. Negative microbiological culture (OR = 18.67; 95% CI, 2.32-150.13) was the only independent factor associated with poor visual outcome.

CONCLUSIONS

The clinical findings at presentation and microbiological profile play an important role in determining the outcome in patients with acute post-cataract surgery endophthalmitis.

Fungi of the human eye: Culture to mycobiome

The focus of the current review is multi-fold and compares the diversity and abundance of fungi on the ocular surface by the conventional culture-based method with the more sensitive, high throughput, culture-independent NGS method. The aim is to highlight the existence of a core ocular mycobiome and explore the transition of the ocular fungal microbiota from the normal eye to the diseased eye. PubMed, Google Scholar and Medline were used to search for publications and reviews related to cultivable fungi and the mycobiome of the normal and diseased eye. The conventional cultivable approach and the NGS approach confirm that the eye has its own mycobiome and several confounding factors (age, gender, ethnicity etc.) influence the mycobiome. Further, dysbiosis in the mycobiome appears to be associated with ocular diseases and thus impacts the health of the human eye. Considering that the mycobiome of the eye is influenced by several confounding factors and also varies with respect to the disease status of the eye there is a need to extensively explore the mycobiome under different physiological conditions, different ethnicities, geographical regions etc. Such studies would unravel the diversity and abundance of the mycobiomes and contribute to our understanding of ocular health. Research focused on ocular mycobiomes may eventually help to build a targeted and individualized treatment.

All India Ophthalmological Society (AIOS) Task Force guidelines to prevent intraocular infections and cluster outbreaks after cataract surgery

Infectious endophthalmitis is a serious and vision-threatening complication of commonly performed intraocular surgeries such as cataract surgery. The occurrence of endophthalmitis can result in severe damage to the uveal and other ocular tissues even among patients undergoing an uncomplicated surgical procedure. If the infections result from common factors such as surgical supplies, operative or operation theater-related risks, there can be a cluster outbreak of toxic anterior segment syndrome (TASS) or infectious endophthalmitis, leading to several patients having an undesirable outcome. Since prevention of intraocular infections is of paramount importance to ophthalmic surgeons, the All India Ophthalmological Society (AIOS) has taken the lead in the formation of a National Task Force to help ophthalmic surgeons apply certain universal precautions in their clinical practice. The Task Force has prepared a handy checklist and evidence-based guidelines to minimize the risk of infectious endophthalmitis following cataract surgery.

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

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

Effect of Lockdown and Unlock Following COVID-19 on the Presentation of Patients With Endophthalmitis at a Tertiary Eye Center Over One Year

Introduction Endophthalmitis is an emergency where patients need immediate intervention to salvage both vision and the globe. Regular follow-up care and close monitoring of the status of the patient are crucial in determining the final outcomes of the treatment. While there is ample literature on the epidemiology and demography of endophthalmitis across the globe, no information exists on the effect of the coronavirus disease 2019 (COVID-19) pandemic on the presentation patterns of endophthalmitis. Objectives To describe the impact of the lockdown and unlock phases of the COVID-19 pandemic on the presentation of endophthalmitis at a tertiary eye care center in India. Methods This cross-sectional hospital-based study included 1,253 patients presenting between March 25, 2017, and March 31, 2021. The data on the patients diagnosed with endophthalmitis in one or both eyes presenting during the lockdown and unlock phases were compared with the respective time periods in the previous three years before COVID-19. Results The patient numbers dropped to 42.18% (27/64) of pre-COVID-19 volumes during the lockdown phase. There was a near-complete recovery of the outpatient numbers to 85.71% (26/30) of pre-COVID-19 volumes by March 2021. This gradual incremental trend was seen in etiology due to post-surgery (88%) and endogenous (159%) infections while post-traumatic (67%) and post-infection (0%) infections were lower than pre-COVID-19 volumes by March 2021. There was a slight increase in the proportion of patients with acute endophthalmitis (88.93% vs 86.20%; p=0.76) presenting during the COVID-19 phase as compared to the pre-COVID-19 phase. The proportion of patients requiring inter-state travel showed complete recovery to 107% of pre-COVID-19 distribution by March 2021. Conclusion The first year of the COVID-19 pandemic saw a decline of over half the number of patients with endophthalmitis accessing eye care services. There was an increase in the presentation of endogenous endophthalmitis and a decrease in post-traumatic forms. Patients requiring inter-state travel recovered during the unlock phase.

Bacterial Burden Declines But Neutrophil Infiltration and Ocular Tissue Damage Persist in Experimental Staphylococcus epidermidis Endophthalmitis

Coagulase-negative staphylococci (CoNS), including Staphylococcus (S) epidermidis, are responsible for ~70% of all post-surgical endophthalmitis, a potentially blinding eye infection. However, the pathobiology of CoNS endophthalmitis is limited to epidemiological and clinical case studies with few experimental studies. Here, we report both in vitro and in vivo models to study the pathobiology of S. epidermidis endophthalmitis in mice. We found that S. epidermidis is rapidly cleared from mouse eyes, and a relatively higher dose (i.e., 107 CFU/eye) was needed to cause endophthalmitis. Our time-course study revealed that bacterial load peaked at 24 h post-infection followed by a gradual decline up to 72 h. A similar time-dependent decrease in levels of inflammatory mediators and Toll-like receptor (TLR) expression was also observed. In contrast, neutrophil infiltration continued to increase up to 72 h coinciding with significant retinal tissue damage and loss of visual function. In vitro, S. epidermidis induced the activation of various inflammatory signaling pathways (i.e., NF-kB, ERK, and P38) and the production of both cytokines and chemokines in mouse BMDMs, human RPE, and retinal Muller glia. Altogether, we show that bacterial burden is reduced in S. epidermidis endophthalmitis, while tissue damage and visual function loss continue. Thus, our study provides new insights into the pathogenesis of CoNS endophthalmitis.

Acute postoperative endophthalmitis after resurgery following primary cataract surgery: 9 years experience from a tertiary eyecare center

PURPOSE

To report the incidence, risk factors, and visual outcomes of acute postoperative endophthalmitis in patients undergoing resurgery after cataract surgery.

SETTING

Tertiary eye hospital in southern India.

DESIGN

Retrospective, clinical registry.

METHODS

Medical records of patients were retrospectively reviewed from January 2010 to December 2018. Incidence, risk factors, causative organisms, management, and outcomes were studied. Patients who underwent resurgery within 6 weeks of primary cataract surgery and developed endophthalmitis within 6 weeks of resurgery were included.

RESULTS

A total of 5705 patients (0.64%) underwent resurgery. Of 5705 resurgeries, 11 patients (0.19%) developed postoperative endophthalmitis. The incidence of endophthalmitis was higher in the eyes having a breach in the posterior capsule than the eyes with no breach in the posterior capsule (10/1277 [0.78%] vs 1/4428 [0.02%]). Among the 11 patients, secondary intraocular lens (IOL) implantation was the most common indication for resurgery (9/11 [82%]) after which endophthalmitis occurred. Three (27.3%) of the 11 patients were culture-positive. Nine (82%) of 11 patients were managed with a vitreous tap along with intravitreal antibiotics and steroid injections. After treatment, 80% of the patients achieved a visual acuity of 6/18 or greater (logMAR 0.5, P value < .05). None of the eyes developed phthisis bulbi.

CONCLUSIONS

Eyes having a breach in the posterior capsule requiring vitrectomy and taken for resurgery as secondary IOL implantation were having an increased risk for endophthalmitis. The posttreatment visual outcomes were favorable.

Aging, But Not Sex and Genetic Diversity, Impacts the Pathobiology of Bacterial Endophthalmitis

Purpose

Age, sex, and genetics are important biological variables in determining an individual's susceptibility or response to infectious agents; however, their role has not been evaluated in intraocular infections. In this study, we comprehensively examined the impact of these host biological factors in the pathogenesis of experimental bacterial endophthalmitis.

Methods

Endophthalmitis was induced by intravitreal injection of bacteria (Staphylococcusaureus) in the eyes of male and female C57BL/6 mice of different ages: group I (young, 6–8 weeks), group II (mid-age, 18–20 weeks), and group III (old, 1 year). Highly heterogeneous outbred J:DO mice were used for genetic diversity analysis. Eyes were subjected to clinical examination, retinal function testing using electroretinography (ERG), histopathological analysis (hematoxylin and eosin staining), and bacterial burden estimation. The levels of inflammatory mediators were measured using qPCR and ELISA, and the infiltration of neutrophils was determined by flow cytometry.

Results

Both inbred C57BL/6 and diversity outbred (J:DO) mice were equally susceptible to S. aureus endophthalmitis, as evidenced by a time-dependent increase in clinical scores, bacterial burden, intraocular inflammation, and retinal tissue damage, in addition to decreased retinal function. However, no significant differences were observed in disease severity and innate responses in male versus female mice. Older mice (group III) exhibited higher clinical scores coinciding with increased bacterial proliferation and intraocular inflammation, resulting in enhanced disease severity. Moreover, bone-marrow-derived macrophages from old mice exhibited reduced phagocytic activity but increased inflammatory response toward S. aureus challenge.

Conclusions

Age, but not sex, is an important biological variable in bacterial endophthalmitis. Identification of pathways underlying altered innate immunity and impaired bacterial clearance in aging eyes could provide new insights into the pathobiology of intraocular infections in elderly patients.

Endophthalmitis prophylaxis study. Report 1: Intracameral cefuroxime and moxifloxacin prophylaxis for the prevention of postcataract endophthalmitis in rural India

Purpose:

Intracameral antibiotics are known to reduce the incidence of acute endophthalmitis. Various drugs are available for intracameral use. This prospective study was carried out to compare the efficacies of intracameral cefuroxime and moxifloxacin prophylaxis in reducing the incidence of acute endophthalmitis after cataract surgery in rural India.

Methods:

This was a prospective, nonrandomized, comparative, interventional study. Between October 2016 and March 2018, 15 eye care facilities spread over four Indian states were preselected to use either of the intracameral antibiotics, cefuroxime or moxifloxacin, following cataract surgery (phacoemulsification or manual small incision cataract surgery, SICS). The main outcome measure was the occurrence of acute clinical endophthalmitis within six weeks of the surgery. This was compared with the earlier rate of endophthalmitis in the same locations.

Results:

The study was done in 42,466 eyes. Of the total, 42.2% received intracameral cefuroxime and 57.8% received intracameral moxifloxacin. SICS was performed more often. Clinical acute endophthalmitis occurred in 15 eyes. This accounted to a 72.22% reduction, from the earlier 0.126% to 0.035%, of postcataract surgery acute endophthalmitis. The reduction in the incidence of endophthalmitis after intracameral cefuroxime was 0.017% and that after intracameral moxifloxacin was 0.049%. With either intracameral antibiotics, the reduction in incidence was statistically significant (P < 0.001), but not between the molecules. Intracameral cefuroxime showed 66.67% reduction and intracameral moxifloxacin showed 74.74% reduction.

Conclusion:

A 3.6-fold decrease in postcataract surgery endophthalmitis was observed upon the use of intracameral antibiotics in rural India. Both intracameral cefuroxime and moxifloxacin proved efficacious.

Microbes of the human eye: Microbiome, antimicrobial resistance and biofilm formation

BACKGROUND

The review focuses on the bacteria associated with the human eye using the dual approach of detecting cultivable bacteria and the total microbiome using next generation sequencing. The purpose of this review was to highlight the connection between antimicrobial resistance and biofilm formation in ocular bacteria.

METHODS

Pubmed was used as the source to catalogue culturable bacteria and ocular microbiomes associated with the normal eyes and those with ocular diseases, to ascertain the emergence of anti-microbial resistance with special reference to biofilm formation.

RESULTS

This review highlights the genetic strategies used by microorganisms to evade the lethal effects of anti-microbial agents by tracing the connections between candidate genes and biofilm formation.

CONCLUSION

The eye has its own microbiome which needs to be extensively studied under different physiological conditions; data on eye microbiomes of people from different ethnicities, geographical regions etc. are also needed to understand how these microbiomes affect ocular health.

Identification of Bacterial and Fungal Pathogens by rDNA Gene Barcoding in Vitreous Fluids of Endophthalmitis Patients

Purpose: To identify the bacterial and fungal pathogens in ocular samples of clinically suspected endophthalmitis patients by conventional culture methods and 16S and 28S rDNA gene sequencing respectively. Methods: A total of 88 patients with clinically suspected endophthalmitis were included in this study. Under sterile operating conditions, a vitreous fluid (0.1-0.2 ml) was obtained by pars plana vitrectomy procedure. The samples were processed for conventional microbiology methods and PCR. PCR targeting 16S rDNA gene for bacteria and 28S rDNA gene for fungus were performed individually using the MightyAmp DNA Polymerase Ver. 2 (TaKaRa China) kit. The PCR amplified samples were sequenced and aligned using CLUSTAL-W tool. The phylogenetic tree was constructed by Neighborhood joining along with the reference sequences downloaded from NCBI database using MEGA X software. Results: 67 Post-operative, 12 Endogenous and 9 traumatic endophthalmitis patients were included as study subjects. By the direct culturing bacterial growth was observed in 17 samples and fungal growth in three samples. PCR was positive for all the culture positive samples, in addition 14 were positive in culture negative samples. The predominant species identified in gram-positive bacteria were Staphylococcus spp., and Pseudomonas spp. in the gram-negative group. Both PCR and culture identified only three samples positive for fungal pathogens which were identified as Aspergillus fumigatus, Candida albicans, and Exerohilum rostratum. Conclusions: PCR based molecular diagnosis is more sensitive than the conventional gold standard culture methods in endophthalmitis. Bacterial pathogens were found to be the predominant in causing endophthalmitis than fungal pathogens.

Exogenous Fungal Endophthalmitis: Clues to Aspergillus Aetiology with a Pharmacological Perspective

Exogenous fungal endophthalmitis (EXFE) represents a rare complication after penetrating ocular trauma of previously unresolved keratitis or iatrogenic infections, following intraocular surgery such as cataract surgery. The usual latency period between intraocular inoculation and presentation of symptoms from fungal endophthalmitis is several weeks to months as delayed-onset endophthalmitis. Aspergillus spp., is the most common causative mould pathogen implicated in this ocular infection and early diagnosis and prompt antimicrobial treatment, concomitantly in most cases with expert surgical attention, reduce unfavorable complications and increase the possibility of eye function preservation. Topical, intravitreal and systemic antifungal molecules are the mainstay of a medical approach to the disease and azoles, polyenes and in particular cases echinocandins are the pharmacological classes most commonly used in clinical practice. This review discusses pharmacokinetics and pharmacodynamic of antifungal agents in their principal modes of administration with a focus on their ability to achieve high drug concentration in the vitreous and ocular tissues.

Characterization of Pseudomonas aeruginosa isolates from patients with endophthalmitis using conventional microbiologic techniques and whole genome sequencing

Purpose

To demonstrate antibiotic susceptibility and genomic virulence factor profiles of Pseudomonas aeruginosa isolates from patients with culture-confirmed endophthalmitis.

Methods

Clinical isolates from patients diagnosed with pseudomonas endophthalmitis were included. Laboratory antibiotic susceptibility testing and whole genome sequencing was performed on all isolates.

Results

In the current study, 8 patients had vitreous culture-confirmed endophthalmitis due to P. aeruginosa. All isolates were multi-drug resistant but sensitive to ceftazidime and each fluoroquinolone tested. Whole genome sequencing revealed a total of 179 unique genes. The most common type of virulence genes included those involved in adherence and the secretion system. Seven of 8 (88%) isolates were of the cytoinvasive phenotype (exoST) and no isolates contained exoU.

Conclusions

P. aeruginosa associated endophthalmitis is often multi-drug resistant and demonstrates a variety of virulence factors with those involved in adherence and the secretion system being the most common.

Toll-like receptors in acute post-cataract surgery endophthalmitis

OBJECTIVE

To evaluate the expression of toll-like receptor 2 (TLR2) and toll-like receptor 4 (TLR4) on CD14 + cells in vitreous and blood of post-cataract surgery acute endophthalmitis.

DESIGN

This prospective case-control pilot study enrolled 16 patients of post-cataract surgery endophthalmitis. All the cases were subjected to 23 G pars plana vitrectomy (PPV). Ten patients undergoing 23 G PPV for non-infectious conditions were taken as controls.

METHODS

23 G PPV was performed, and three undiluted vitreous samples were collected in heparinized syringes from the cases and the controls. Simultaneous venous blood sample was taken, and flow cytometry was performed to detect the expression of TLR2 and TLR4 in vitreous and blood samples. The vitreous and blood samples were incubated with fluorescein isothicyanate (FITC) conjugated anti-TLR2 monoclonal antibody Alexafluor (AX) 647 and anti-TLR4 monoclonal antibody phycoerythrin. Data acquisition was done on a pre-calibrated flow cytometer. TLR analysis of the acquired flow cytometry data was then performed. Mean channel fluorescence intensity (MFI) derived from fluorescence histogram was used to study the level of cell surface TLR expression. MFI was calculated as a ratio and recorded as the MFI of the TLR2 or -4 antibody divided by the MFI of the isotype-matched negative control antibody. Core vitrectomy was done as per the comfort of the surgeon, and intravitreal antibiotics vancomycin (1 mg/0.1 ml) and ceftazidime (2.25 mg/0.1 ml) were injected. The cytological examination was done on vitreous and blood sample.

STATISTICAL ANALYSIS

The median TLR 2 and TLR4 values between cases and controls were compared by Mann-Whitney U test. Spearman's rank correlation test was used to assess the correlation between TLR expression and disease activity.

RESULTS

Vitreous cytology evaluation showed the presence of neutrophils (81.25%, n = 13), monocytes (68.75%, n = 11) and lymphocytes (62.50%, n = 10). The level of expression of TLR2 in vitreous showed a statistically significant correlation with an increase in the time interval of cataract surgery and intervention for endophthalmitis (p < 0.05), but the same was not observed for TLR4. A drift toward higher level of expression of TLR2 and TLR4 in vitreous was observed in patients with poor outcome.

CONCLUSION

TLR2 levels increase with the delay in presentation; thus, TLR2 ligands in vitreous could serve as a good target for the treatment of endophthalmitis.

Penicillium on the Iris! An Unusual Presentation and Cause of Postoperative Anterior Uveitis

Intraocular fungal infections may not present solely as postoperative anterior uveitis or as a focal anterior segment lesion. The present study describes a 50-year-old woman with well-controlled diabetes who presented with postoperative anterior uveitis three months after uncomplicated cataract surgery. A fuzzy lesion was observed on her iris. The patient underwent an anterior chamber wash and removal of the lesion, followed by intracameral treatment with voriconazole. Culture of the lesion showed that it was a species of Penicillium. The patient has remained stable after treatment. Three aspects of this case were unusual: a fungal lesion of unusual etiology and location, inflammation restricted to the anterior segment despite a fungal background, and the excellent response to treatment with a very favorable outcome.

Trends in microbiological spectrum of endophthalmitis at a single tertiary care ophthalmic hospital in India: a review of 25 years

PURPOSE

To determine trends in the microbial spectrum of endophthalmitis over the past 25 years and to review its antibiotic susceptibility patterns over the last 10 years.

METHODS

Microbiology records of culture-positive endophthalmitis cases from 1991 to 2015 were reviewed. Additionally, data between 2005 and 2015 was also analyzed for trends in antibiotic susceptibility.

RESULTS

Of the total of 9278 patients, 3319 (35.7%) were culture positive and included bacteria (2840/3319, 85.56%), fungi (387/3319, 11.66%), and mixed cultures (92/3319, 2.7%). Gram-positive bacteria accounted for 67.68% (1922/2840) of the total bacteria seen, with the most prevalent pathogen being Streptococcus pneumoniae and Staphylococcus epidermidis. Among the gram-negative organisms Pseudomonas aeruginosa was the most prevalent while. Aspergillus flavus was the most common fungus isolated and Candida sp. accounted for 6.9% of the total fungi isolated. There was no significant change in the trends of bacteria isolated during the study period. Overall susceptibility patterns showed that gram-positive bacteria were most susceptible to vancomycin (96%) and fluoroquinolones (89%). The resistance to ceftazidime increased from 31% in 2005 to 62% in 2015 (P = 0.006) and amikacin decreased from 36% in 2005 to 33% in 2015 (P = 0.782). Although a significant trend (P < 0.001) toward increasing microbial resistance against cephalosporins and fluoroquinolones was observed, decreasing microbial resistance against glycopeptides and aminoglycosides was also detected.

CONCLUSION

The spectrum of pathogens causing endophthalmitis at our institute remained similar over the study period. These findings impact the empiric treatment and choice of antibiotics in patients with endophthalmitis.

Recommendations for an expert team investigating a case of cluster endophthalmitis

Occurrence of postoperative cluster endophthalmitis is a nightmare for the operating surgeon, the involved hospital, and the patients. Due to its multifactorial etiology, surveillance of such an event is extremely important to identify the causative factor and to prevent recurrences in future. For surveillance, a team of ophthalmologists and microbiologists is often appointed by the local health department, and it is imperative that this team investigates thoroughly, reports appropriately safeguarding the interests of all, and also suggests remedial measures for future. Much literature is available on postoperative endophthalmitis and sterilization and disinfection protocols, but to the best of our knowledge, there is none to guide the surveillance team regarding the conduct of the entire process of investigation in the case of such unfortunate incidents. Through this article, we have made an attempt to formulate recommendations for expert teams investigating cases of postoperative cluster endophthalmitis.

Antibiotic prophylaxis practice patterns for cataract surgery in India - Results from an online survey

Purpose:

The aim of this study is to assess the current antibiotic prophylaxis practice patterns for cataract surgery in India.

Methods:

This was a questionnaire-based E-survey carried out at a tertiary eye care center in India. An E-mail invitation to complete an online 20 point questionnaire survey was sent to all members of the All India Ophthalmological Society with valid E-mail addresses using a digital E-mail service. Duplicate entries were prevented.

Results:

Out of 1228 total respondents (8.2%) who completed the survey 38% reported using routine intracameral (IC) antibiotic prophylaxis. Another 7% place antibiotics in the irrigating solution. Of those using IC antibiotic prophylaxis, 91% adopted this practice within the past 2 years; 92% are using moxifloxacin with 56% using a commercially available moxifloxacin formulation. Those predominantly performing phacoemulsification (43% vs. 25% performing mostly manual small incision cataract surgery, P < 0.001) and more than 500 cataract surgeries annually (45% vs. 33%, P < 0.001) reported greater use of IC moxifloxacin. Self-reported endophthalmitis rates were statistically significantly greater in those not using IC antibiotics (0.045% vs. 0.036, P = 0.04). Although a majority of respondents believe that IC antibiotics are an important option (54%) and that it is important to have a commercially available solution (68%), many believe that other antibiotic prophylaxis methods are sufficient (31%).

Conclusion:

IC antibiotic prophylaxis for cataract surgery has sharply increased in India. In contrast to the West, intraocular moxifloxacin, which is commercially available in India, is preferred by the vast majority of users.