Clinical characteristics of endophthalmitis after an injection of intravitreal antivascular endothelial growth factor

Pars plana vitrectomy versus intravitreal antibiotics for endophthalmitis management following intravitreal anti-VEGF agents: A meta-analysis

In this meta-analysis, we aim to compare the efficacy and safety of pars plana vitrectomy (PPV) versus tap-and-inject (TAI) of intravitreal antibiotics for the management of endophthalmitis secondary to intravitreal injections of anti-vascular endothelial growth factor (VEGF) agents. A systematic literature search was conducted on Ovid MEDLINE, EMBASE, and Cochrane Central (January 2005-October 2022). The primary analysis compared initial PPV versus TAI and the secondary analysis examined the efficacy and safety of TAI alone compared to TAI followed by PPV. The quality of non-randomized observational studies was assessed using the Newcastle-Ottawa Scale. The quality of the evidence was assessed for each outcome. A random effects meta-analysis was performed. Weighted mean differences (WMDs) with 95% confidence intervals were reported. Of the 7474 screened studies, nine studies reporting on 153 eyes were included. The change in mean best corrected visual acuity (BCVA) between endophthalmitis presentation and last follow-up did not significantly differ between the initial TAI versus PPV groups (WMD = 0.05 units; 95% CI -0.12 to 0.22; p = 0.59; heterogeneity p = 0.41). The difference in pre- to post-treatment mean BCVA did not significantly differ between eyes that received TAI alone or TAI followed by PPV (WMD = 0.04 units; 95% CI -0.42 to 0.51; p = 0.85; heterogeneity p = 0.74). While the meta-analysis revealed no significant difference in the change in BCVA between PPV and TAI to treat endophthalmitis secondary to anti-VEGF agents, the quality of evidence was low with potential for confounding and selection bias. Further well-designed studies in this setting are needed.

Postintravitreal Injection Endophthalmitis: Incidence, Characteristics, Management, and Outcome

Purpose

Postintravitreal injection (IVI) endophthalmitis is a rare but devastating complication. Herein, we report the incidence ,and clinical and microbiological characteristics, as well as the visual outcome, in IVIs endophthalmitis in two medical centers.

Methods

All patients undergoing intravitreal injections between 1/2018 and 12/2019 in two large medical centers were analyzed for post-IVI endophthalmitis.

Results

Of the total of 51,356 IVIs performed, 23 cases of post-IVI endophthalmitis were diagnosed, yielding an overall incidence of 0.045%. The median interval from IVI to symptoms onset was 2 days (IQR: 1-5). Cultures were positive in 56% of the cases (100% Gram-positive bacteria and 76% coagulase-negative staphylococcus). Parameters associated with higher culture-positive rates included samples taken during vitrectomy, WBC on vitreous smear, the number of IVIs in the 12 months prior to presentation, and the time interval from last IVI to diagnostic sampling. At 6- and 12-month follow-up, the median change in VA (logMAR) was -1.10 (IQR: (-1.32)-(-0.40)) and -1.02 (IQR: (-1.10)-(-0.30)), respectively. Younger age and better BCVA at presentation were associated with better VA outcome, while positive culture result and systemic steroids treatment were each associated with the worse visual outcome. We found no difference in visual outcomes between PPV and TAI as a primary procedure.

Conclusion

Post-IVI endophthalmitis is a rare complication, and most patients do not regain their initial VA. Certain parameters (clinical, microbiological, and therapeutic) may help anticipate the outcome and guide decision making regarding diagnosis and treatment.

Early Vitrectomy with Silicone Oil Tamponade in the Management of Postoperative Endophthalmitis

Background: Early vitrectomy for postsurgical endophthalmitis may improve visual acuity outcomes. Silicone oil as a tamponade has some potential benefits in the management of endophthalmitis. This study aims to evaluate the use of a silicone oil tamponade in the surgical management of endophthalmitis. Material and Methods: All patients with a pars plana vitrectomy with silicone oil tamponade for postsurgical endophthalmitis at the Department of Ophthalmology, University of Bonn, Germany, between 2017 and 2021 were retrospectively reviewed. We included all preoperative data, including BCVA at diagnosis, clinical findings, and symptoms. For every follow-up visit, we looked at BCVA and complications. Results: In total, 82 patients were included in this study. The mean follow-up was 13.1 months (range 1-58 months). An intravitreal injection was the cause in 42 patients (51.2%) and cataract surgery in 29 patients (35.4%). The mean interval between the causing event and the date of onset was 8.8 days (range, 1-59 days). The most prevalent pathogen was Staphylococcus epidermidis in 16 patients (19.5%). In 47 patients (57.3%), no pathogen was found. The initial best-corrected visual acuity was 2.1 logMAR and improved significantly to 1.0 logMAR after six months (p < 0.001) and 1.1 logMAR after 1 year (p < 0.001). In a multivariate analysis, a low BCVA at diagnosis (p = 0.041) was a significant predictor for poor visual acuity outcomes. A total of 17 patients (20.1%) developed postoperative complications. Five patients (6.1%) needed an anterior chamber washout with repeated injections of antibiotics. Two patients (2.4%) had persistent fibrin and were treated with YAG-laser treatment. Three patients (6.7%) developed a retinal detachment. Two patients (2.4%) had persistent corneal decompensation with endothelial cell loss and received perforating keratoplasty. We performed a matched-pair analysis (n = 30, each group n = 15) to compare a silicone oil tamponade with BSS at the end of surgery. The visual acuity outcome showed no significant differences (BCVA after one year: 1.17 logMAR in eyes with silicone oil and 0.90 logMAR in eyes with BSS; p = 0.684). Conclusions: In our study, a vitrectomy with silicone oil tamponade in the surgical management of postoperative endophthalmitis led to a significant improvement in visual acuity and had a low complication rate. Low BCVA at diagnosis was significantly associated with poor visual acuity outcomes. A comparison of silicone oil and BSS at the end of surgery showed similar results.

Differential diagnosis of endophthalmitis after intravitreal drug injection for age related macular degeneration: Sterile vs. infectious

The recent release of brolucizumab and the development of new antiangiogenic molecules as abicipar pegol has increased the interest towards inflammatory complications after intravitreal drug injection. Those drugs are associated to a higher rate of inflammatory adverse events compared to classic drugs. In this context it is essential to differentiate between sterile and infectious cases for a fast and effective treatment. The clinical similarities between infectious and sterile cases, the high rate of culture negative patients and the heterogeneity in the terminology used are obstacles for a correct diagnosis and report of these complications. Sterile cases appear early after the injection, before 48 hours; or 20 days after in brolucizumab-related vasculitis cases. Infectious cases show up around the third day after injection and up to a week after it. A severe visual impairment, severe pain, severe hyperemia, hypopyon and a more severe intraocular inflammatory process are signs of a likely infectious origin. If the cause of the inflammation is uncertain we must follow up the patient closely or "tap and inject" antimicrobial agents in order to prevent the eventual complications of an infectious endophthalmitis. On the other hand, sterile endophthalmitis might be observed in mild cases or treated with steroids according to the severity of the inflammation.

Preventive factors, diagnosis, and management of injection-related endophthalmitis: a literature review

BACKGROUND

Intravitreal medication injections represent the gold standard treatment for a variety of potentially blinding chorioretinal vascular diseases. Despite their excellent safety profile, they are associated with the feared complication of injection-related endophthalmitis (IRE). Though the overall incidence of IRE is low, due to the ever-increasing number of injections being performed, it is a complication that all retina specialists are likely to encounter. This article reviews various factors that could potentially influence the risk of IRE and discusses evidence-based strategies for management.

METHOD

PubMed was searched for keywords "intravitreal injection" and "endophthalmitis" from the period of 1995-2021. Relevant articles were reviewed and selected articles were analyzed with respect to the incidence, potential preventive factors, clinical presentation, microbial profile, management, and outcomes for IRE.

RESULTS

There is strong consensus supporting the use of povidone iodine topical antiseptic, eyelid retraction away from the injection site, and avoiding treatment of eyes with active surface or eyelid disease, but there is less agreement on the use of face masks versus "no-talking" policies and optimal anesthetic technique. Current evidence comparing tap and inject or early vitrectomy for treatment of IRE is inadequate to determine an optimal treatment strategy.

CONCLUSION

Intravitreal injections are sight saving, but even using established prophylactic measures there remains a small but real risk of infectious injection-related complications. Further investigations comparing tap and inject versus vitrectomy may help to establish optimal treatment, although the rarity of IRE makes designing adequately powered prospective trials a difficult task.

TAP AND INJECT VERSUS PARS PLANA VITRECTOMY FOR POSTPROCEDURAL ENDOPHTHALMITIS: A Meta-analysis

PURPOSE

To compare the visual outcomes after prompt pars plana vitrectomy (PPV) with tap biopsy and intravitreal antimicrobial injection to treat postinjection and postsurgery endophthalmitis.

METHODS

The Cochrane Central Register of Controlled Trials, Ovid MEDLINE, and Ovid Embase databases were searched for articles published between January 2010 and November 2020. Two independent reviewers selected articles and extracted data. We analyzed data in RevMan 5.3 and assessed methodological quality using the Cochrane ROBINS-I tool. The mean improvement in visual outcome was compared between PPV and intravitreal antimicrobial injection as a relative risk of improving ≥2 lines and a mean logarithm of the minimal angle of resolution difference in improvement.

RESULTS

Fifteen retrospective case series (1,355 eyes), of which 739 eyes (55%) received intravitreal antimicrobial injection and 616 (45%) received PPV as initial treatment, were included. The overall relative risk of improving 2 or more lines in PPV in comparison with intravitreal antimicrobial injection was 1.04 (95% CI 0.88-1.23; P = 0.61; I2 = 0%) with a mean difference of 0.04 (95% CI -0.18 to 0.27; P = 0.69; I2 = 0%). The results stayed robust when subgroup analysis based on causative procedure for endophthalmitis was performed.

CONCLUSION

Intravitreal antimicrobial injection is noninferior to PPV for the treatment of postcataract operation, postinjection, and post-PPV endophthalmitis.

Drug-related adverse effects of antivascular endothelial growth factor agents

PURPOSE OF REVIEW

Antivascular endothelial growth factor (VEGF) agents have provided historic therapeutic breakthroughs in the treatment of retinal disease. New anti-VEGF agents are emerging for the treatment of retinal vascular diseases. Both systemic and ocular adverse effect need to be understood in managing patients. This review aims to highlight the adverse effects seen with routine use of bevacizumab, ranibizumab and aflibercept, as well as with new medications such as brolucizumab and abicipar.

RECENT FINDINGS

We review the recent findings of intraocular inflammation (IOI) of brolucizumab and abicipar in the context of the efficacy and safety reported with the routine anti-VEGF agents. Specifically, brolucizumab has been reported to cause occlusive retinal vasculitis in the setting of IOI, which has not been seen in other anti-VEGF medications. In addition, abicipar appears to cause IOI at a higher rate of patients than other anti-VEGF agents have previously.

SUMMARY

Newer anti-VEGF agents pose a significant risk of adverse events not seen with routine anti-VEGF agents.

Inflammatory Complications of Intravitreal Anti-VEGF Injections

Intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF) agents is a commonly used therapy for numerous retinal diseases. The most commonly used of these medications are bevacizumab, ranibizumab, aflibercept, and brolucizumab. However, intravitreal administration of these agents is also associated with several inflammatory and non-inflammatory adverse events. The three inflammatory adverse events are sterile intraocular inflammation, brolucizumab-associated retinal vasculitis, and post-injection endophthalmitis. This narrative review summarizes the current literature regarding these conditions, including their epidemiology, presentation, management, outcomes, and pathogenesis. The inflammatory adverse events also share a number of overlapping features, which can make them difficult to discern from one another in a clinical context. This review discusses certain distinguishing features of these conditions that may aid providers in discerning between them and establishing the correct diagnosis.

Patient-Reported Complications after Intravitreal Injection and Their Predictive Factors

Purpose

The intravitreal injection (IVI) of pharmacologic agents is the most commonly performed ocular procedure and is associated with a host of complications. Most IVI-related complications data are derived from randomized controlled clinical trials, which report a high adverse event rate. The nature of these protocol-driven trials limit their applicability to the diverse circumstances seen in routine clinical practice. The goal of this study was to determine the prevalence of patient-reported IVI-related complications, their risk factors, and the manner in which patients sought treatment at a tertiary eye care center.

Design

Retrospective, institutional review board–approved study.

Participants

Forty-four thousand seven hundred thirty-four injections in 5318 unique patients at the Cleveland Clinic Cole Eye Institute from 2012 through 2016.

Methods

Intravitreal injection.

Main Outcome Measures

Complication occurrence within 15 days of injection.

Results

From 2012 through 2016, a total of 44734 injections were performed in 5318 unique patients. Overall, complication rates were low, representing 1.9% of all injections, with 1031 unique complications in 685 patients (12.9%). The most common minor complications, or those not requiring intervention, were irritation (n = 312) and subconjunctival hemorrhage (n = 284). The most common serious complications, or those requiring intervention, were corneal abrasion (n = 46) and iritis (n = 31). Most complications (66%) were managed adequately by a telephone or Epic (Epic Systems Corp., Verona, WI) electronic message encounter only. Importantly, no injection protocol parameter, such as type of anesthesia, preparation, or post-injection medication, increased the risk of a complication. However, a patient’s gender, age, number of previous injections, and provider strongly influenced the risk of patient-reported complications.

Conclusions

Overall, complication rates seen in routine clinical practice were low compared with clinical trial reporting. Providers should feel confident in the safety and administration of IVI during times when follow-up office visits and resources may be limited. When performing an IVI, factors such as a patient’s gender, age, number of previous injections, and provider must be taken into account to ensure the best possible outcomes.

RELATIVE QUIESCENCE OF EXUDATIVE AGE-RELATED MACULAR DEGENERATION AFTER RESOLUTION OF POSTINJECTION ENDOPHTHALMITIS

PURPOSE

To evaluate alterations in treatment burden and course of exudative age-related macular degeneration in patients who contracted endophthalmitis from intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections.

METHODS

Retrospective study at the University of Pittsburgh Medical Center examining frequency of anti-VEGF injections, activity of choroidal neovascularization, and visual acuity before and after endophthalmitis treatment.

RESULTS

Twenty-one patients meeting inclusion criteria were identified, of whom 7 (33%) patients did not restart anti-VEGF treatment 12 months after endophthalmitis because of quiescence of exudative age-related macular degeneration without significant visual acuity loss (P > 0.05). Patients who resumed anti-VEGF treatment exhibited 32% and 38% decreases in injection frequency by 12 and 24 months after endophthalmitis, respectively (P < 0.05). On first optical coherence tomography follow-up, 10 patients exhibited quiescence of choroidal neovascularization activity, although there were no measurable changes in macular thickness (P > 0.05). No differences in post-endophthalmitis exudative age-related macular degeneration progression or treatment burden were observed when factoring adjuvant intravitreal steroid therapy, culture results, nor choroidal neovascularization subtypes.

CONCLUSION

Endophthalmitis resolution is associated with a decrease in choroidal neovascularization activity and a reduction of anti-VEGF treatment burden in patients with exudative age-related macular degeneration.

Impact of antibiotic resistance of pathogens and early vitrectomy on the prognosis of infectious endophthalmitis: a 10-year retrospective study

PURPOSE

Infectious endophthalmitis (IE) is a severe complication that can lead to blindness even with treatment. However, the impact of antibiotic resistance and early vitrectomy on its prognosis has scarcely been documented. This study investigated the impact of antibiotic resistance of pathogen and early vitrectomy on the prognosis of IE.

METHODS

The medical records of 171 patients treated for IE at a tertiary referral center between 2007 and 2016 were retrospectively reviewed and analyzed for etiology, pathogen, drug resistance to vancomycin or third-generation cephalosporins, treatment types and timing, and visual outcomes. Multivariate logistic regression analysis was used to determine significant prognostic factors.

RESULTS

Among 171 eyes, 121 (70.8%) eyes developed IE after intraocular surgery (cataract surgery, 46.3%; intraocular injection, 13.2%), 37 (21.6%) eyes developed IE endogenously, and 9 (5.3%) eyes developed IE after trauma. The major causative pathogens were Staphylococcus aureus (9.4%) and Klebsiella pneumoniae (7.0%). In total, 72.6% of the identified pathogens demonstrated antibiotic resistance. Antibiotic resistance was associated with a worse final vision (P = .027). Visual prognosis was better for eyes treated with early vitrectomy combined with intravitreal antimicrobial injections within 24 h of onset than for eyes that received only intravitreal antimicrobial injections before undergoing delayed vitrectomy (P = .003).

CONCLUSION

Antibiotic resistance of organisms causing IE is one of the most important prognostic factors. Early vitrectomy (i.e., within 24 h) may be helpful for achieving a better visual outcome. Immediate vitrectomy can be recommended, especially in IE cases caused by organisms with resistance to empirically used antibiotics.

POOLED ESTIMATES OF INCIDENCE OF ENDOPHTHALMITIS AFTER INTRAVITREAL INJECTION OF ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR AGENTS WITH AND WITHOUT TOPICAL ANTIBIOTIC PROPHYLAXIS

PURPOSE

To assess the effect of topical antibiotic prophylaxis on postoperative endophthalmitis after intravitreal injection of anti-vascular endothelial growth factor agents.

METHODS

A systematic literature search was performed from inception to March 2016 using PubMed, Medline, Web of Science, Embase, and the Cochrane Library, to identify articles that reported cases of endophthalmitis after intravitreal injection of anti-vascular endothelial growth factor agents. We used a pooled analysis to estimate the incidence of cases of endophthalmitis who developed after injections performed with and without topical antibiotic prophylaxis. We used regression analysis to explore the effects of study characteristics on heterogeneity.

RESULTS

From our search of electronic databases, we identified and screened 4,561 unique records. We judged 60 articles to have reported findings for cohorts of patients who met our inclusion criteria, (12 arms of randomized clinical trials, 11 prospective cohort studies, and 37 retrospective cohort studies), which included 244 cases of endophthalmitis and 639,391 intravitreal injections of anti-vascular endothelial growth factor agents. The final pooled estimate endophthalmitis proportions were 9/10,000 (95% confidence interval, 7/10,000-12/10,000) in the antibiotic-treated group and 3/10,000 (95% confidence interval, 2/10,000-5/10,000) in the untreated group. The estimated incidence of endophthalmitis with topical antibiotic prophylaxis was approximated three times the incidence without prophylaxis. Random effects regression showed that none of the study characteristics significantly affected the effect size in either group.

CONCLUSION

Topical antibiotic after intravitreal injection of anti-vascular endothelial growth factor agents is associated with a higher risk of endophthalmitis.

A Large Outbreak of Fulminant Bacterial Endophthalmitis after Intravitreal Injection of Counterfeit Bevacizumab

PURPOSE

This study reports the findings in a large series of patients with acute bacterial endophthalmitis after intravitreal injection of bevacizumab (IVB) in two eye hospitals.

METHODS

Medical records were reviewed for patients who presented with acute fulminant endophthalmitis in one or two eyes following intravitreal injection of bevacizumab from two separate batches in two eye hospitals.

RESULTS

Twenty-eight eyes of 21 patients presented with acute endophthalmitis 12-48 hours after IVB injection. Cultures from the eyes and the vials were positive for E. coli and Citrobacter, each in one of the hospitals. All patients were initially treated with topical, intravitreal, and systemic antibiotics. Twenty-four eyes underwent pars plana vitrectomy. Best corrected visual acuity (BCVA) was 1.27 ± 0.89 logMAR before IVB injecti,on which decreased to 2.80 ± 0.45 LogMAR after presentation of endophthalmitis and 2.12 ± 0.97 logMAR three months after IVB injection. Final visual acuity was found to be no light perception in four eyes.

CONCLUSIONS

This large outbreak of E.coli and Citrobacter endophthalmitis occurred after intravitreal injection of counterfeit bevacizumab. Visual outcomes were very poor.

Comparative safety and tolerability of anti-VEGF therapy in age-related macular degeneration

Neovascular age-related macular degeneration (NVAMD) is one of the leading causes of blindness. Over the last decade, the treatment of NVAMD has been revolutionized by the development of intravitreal anti-vascular endothelial growth factor (VEGF) therapies. Several anti-VEGF medications are used for the treatment of NVAMD. The safety and tolerability of these medications deserve review given the high prevalence of NVAMD and the significant utilization of these medications. Numerous large randomized clinical trials have not shown any definitive differential safety relative to ocular or systemic safety of these medications. Intravitreal anti-VEGF therapy does appear to impact systemic VEGF levels, but the implications of these changes remain unclear. One unique safety concern relates drug compounding and the potential risks of contamination, specifically for bevacizumab. Continued surveillance for systemic safety concerns, particularly for rare events, is merited. Overall, these medications are well tolerated and effective in the treatment of NVAMD.

Endophthalmitis After Intravitreal Injections: Incidence, Presentation, Management, and Visual Outcome

PURPOSE

To report the incidence and characteristics of endophthalmitis after intravitreal injections of anti-vascular endothelial growth factor agents or corticosteroids and to describe the clinical and bacteriologic characteristics, management, and outcome of these eyes with acute endophthalmitis in France.

DESIGN

Retrospective, nationwide multicenter case series.

METHODS

From January 2, 2008 to June 30, 2013, a total of 316,576 intravitreal injections from 25 French ophthalmic centers were included. For each center, the number of intravitreal injections was determined using billing codes and the injection protocol was recorded. A registry and hospital records were reviewed to identify patients treated for endophthalmitis after injection during the same time period. The main outcome measures were the incidence of clinical endophthalmitis and visual acuity of endophthalmitis cases.

RESULTS

During the study period, 65 cases of presumed endophthalmitis were found, giving an overall incidence of 0.021% (2.1 in 10,000 injections) (95% confidence interval [CI], 0.016%-0.026%). The median number of days from injection to presentation was 4 [1-26] days. The most common symptom was vision loss. Bacterial identification was achieved in 43.4%. The most frequent pathogens were gram-positive bacteria (91.3%), including coagulase-negative Staphylococcus in 78.3%. Neither the interval between injection and presentation for endophthalmitis nor the clinical signs differentiated culture-positive from culture-negative cases. In multivariate analysis, the use of a disposable conjunctival mould assist device and the use of prophylaxis with an antibiotic or antiseptic were significantly associated with an increased incidence of endophthalmitis (P = .001). The majority of patients had worse visual acuity after 3 months of follow-up when compared with acuity before endophthalmitis.

CONCLUSIONS

The incidence of presumed endophthalmitis after intravitreal injections of anti-vascular endothelial growth factors or corticosteroids was low and the prognosis poor. Prevention and management remain challenging. It remains to be determined whether the findings of this study are relevant for other countries using different techniques for intravitreal injections.

Safety study of 38,503 intravitreal ranibizumab injections performed mainly by physicians in training and nurses in a hospital setting

PURPOSE

To evaluate and to compare the safety of intravitreal ranibizumab injections performed by physicians and nurses at a single large hospital clinic in Denmark during 5 years.

DESIGN

Retrospective, interventional, non-comparative study.

METHODS

SETTING

All eyes that underwent a protocolized ranibizumab injection procedure performed in an operating room mainly by nurses and physicians in their first year of ophthalmology training.

STUDY POPULATION

A total of 4623 eyes in 3679 patients with subretinal neovascularization secondary to a variety of retinal diseases, mainly neovascular AMD treated with intravitreal therapy (IVT) at the Glostrup Hospital from January 1, 2007 to December 31, 2011 with a mean follow-up of 12.2 months (95% confidence interval: 11.9-12.6).

MAIN OUTCOME MEASURES

Frequency of endophthalmitis, traumatic cataract, intraocular haemorrhage and retinal detachment from 2007 to 2012.

RESULTS

Overall, 38,503 intravitreal ranibizumab injections were performed in 4623 eyes. Injections were performed by nurses (32.5%), ophthalmology residents (61.3%) and vitreoretinal surgeons (6.2%). Severe complications to treatment were observed in 17 eyes: Endophthalmitis (14 eyes, 0.36 ‰ of injections whereof seven cases were culture-positive), anterior uveitis (one eye, 0.026 ‰), traumatic cataract (one eye, 0.026 ‰) and rhegmatogenous retinal detachment (one eye, 0.026 ‰). Retinal pigment epithelial tears were registered in 14 eyes in 14 subjects within the first year of treatment with ranibizumab. Of the 14 cases of endophthalmitis, seven occurred within a period of 5 weeks in 2010 when occasionally abnormal needle outflow resistance prompted the needle replacement in the operating room. No drug-related adverse events were recorded.

CONCLUSIONS

Intravitreal ranibizumab injection performed by nurses and physicians without preinjection topical antibiotics was associated with a rate of injection-related adverse events of 0.44 ‰.

Endophthalmitis: state of the art

Endophthalmitis is an uncommon diagnosis but can have devastating visual outcomes. Endophthalmitis may be endogenous or exogenous. Exogenous endophthalmitis is caused by introduction of pathogens through mechanisms such as ocular surgery, open-globe trauma, and intravitreal injections. Endogenous endophthalmitis occurs as a result of hematogenous spread of bacteria or fungi into the eye. These categories of endophthalmitis have different risk factors and causative pathogens, and thus require different diagnostic, prevention, and treatment strategies. Novel diagnostic techniques such as real-time polymerase chain reaction (RT-PCR) have been reported to provide improved diagnostic results over traditional culture techniques and may have a more expanded role in the future. While the role of povidone-iodine in prophylaxis of postoperative endophthalmitis is established, there remains controversy with regard to the effectiveness of other measures, including prophylactic antibiotics. The Endophthalmitis Vitrectomy Study (EVS) has provided us with valuable treatment guidelines. However, these guidelines cannot be directly applied to all categories of endophthalmitis, highlighting the need for continued research into attaining improved treatment outcomes.

Endophthalmitis after intravitreal injection: decreasing incidence and clinical outcome-8-year results from a tertiary ophthalmic referral center

PURPOSE

To report the incidence, clinical features, microbiologic culture results, management and visual outcome of patients with endophthalmitis after intravitreal injections (IVTs).

METHODS

This retrospective chart review included all patients receiving IVTs between January 2005 and July 2012. Cases of suspected and confirmed endophthalmitis after IVT were identified and reviewed.

RESULTS

A total of 20,179 IVTs were perfomed during the study period. Six cases of supected endophthalmitis were identified clinically (0.03%), of which 3 were culture positive (0.015%). The risk of culture-positive post-IVT endophthalmitis was 2/8,882 (0.023%) in the 2005 to 2008 period and 1/11,297 (0.009%) in the period 2009 to 2012. Symptoms developed within the first 3 days after IVT in 4 of the 6 patients and visual acuity was reduced to hand motion in 4 of the 6 patients. Microbiologic specimens were positive on 3 of the 6 cases (coagulase-negative Staphylococcus, n = 2; Staphylococcus aureus, n = 1). Mean visual acuity before patients with endophthalmitis was 20/100, whereas mean final visual acuity at last follow-up was 20/200.

CONCLUSION

The incidence of endophthalmitis after IVT was low with no cases because of Streptococcus species in the present setting using povidone-iodine in the preoperative disinfection of the conjunctival sac. Therefore, adherence to standardized protocols including the use of povidone-iodine when performing IVTs is recommended.

Resistance of ocular flora to gatifloxacin in patients undergoing intravitreal injections

OBJECTIVE

To compare gatifloxacin resistance in a population of ophthalmology patients who had received intravitreal injections (IVIs) with prophylactic topical gatifloxacin use to resistance in a similar population of patients who had not received IVI.

DESIGN

Nested case-control study.

PARTICIPANTS

Fifty eyes of 50 patients who received prior IVI were enrolled, as were 50 control eyes.

METHODS

Each patient had a conjunctival swab performed on the study eye, which underwent microbial identification and testing for gatifloxacin resistance using the ellipsoid test to determine a minimum inhibitory concentration (MIC) value for each isolate. The primary outcome was susceptibility to gatifloxacin, as measured by the MIC of each isolate.

RESULTS

A total of 111 bacterial isolates were obtained from 60 eyes; the remainder was culture negative. There were no significant differences in bacterial species or culture positivity rate between case and control eyes (50% in cases vs. 66% in controls, p = 0.16). The most common organism was coagulase-negative staphylococcus, comprising 64% of all isolates. Resistance to gatifloxacin was observed in 76% of the bacterial isolates and 38% of patients in the case group, as compared with 3% of bacterial isolates and 4% of patients in the control group, a result that was statistically significant (p = 0.0002 and 0.0008, respectively). The mean gatifloxacin MIC was also significantly higher in the case group.

CONCLUSIONS

Topical gatifloxacin prophylaxis in those who receive IVI is associated with an increased rate of gatifloxacin resistance among conjunctival isolates.

Meta-analysis of infectious endophthalmitis after intravitreal injection of anti-vascular endothelial growth factor agents

BACKGROUND AND OBJECTIVE

To investigate the rate of endophthalmitis after intravitreal injection of anti-vascular endothelial growth factor (VEGF) agents, the spectrum of causative organisms, and associated visual acuity outcomes.

PATIENTS AND METHODS

PubMed articles containing the keywords "endophthalmitis" and "intravitreal" between January 2005 and May 2012 were identified and reviewed. Inclusion criteria included article in English, more than 100 intravitreal anti-VEGF injections, and report of adverse events including endophthalmitis after intravitreal injection.

RESULTS

Forty-three articles were analyzed. Endophthalmitis occurred after 197 of 350,535 intravitreal anti-VEGF injections (0.056%). The most common organisms isolated were coagulase-negative Staphylococcus (38.24%) and Streptococcus species (29.41%).

CONCLUSION

The reported rate of endophthalmitis after intravitreal anti-VEGF injection is low. Coagulase-negative Staphylococcus and Streptococcus species were the most frequent causative organisms. Streptococcus species represent the causative organism of endophthalmitis after intravitreal VEGF injections at a higher rate than rates reported in the literature for endophthalmitis following most incisional intraocular surgeries. Among patients with endophthalmitis after intravitreal anti-VEGF injection, endophthalmitis caused by Streptococcus species is associated with poorer visual acuity outcomes than endophthalmitis caused by coagulase-negative Staphylococcus and culture-negative cases.

Pars plana vitrectomy in the management of patients diagnosed with endophthalmitis following intravitreal anti-vascular endothelial growth factor injection

PURPOSE

To evaluate the possible benefit of pars plana vitrectomy in the treatment of patients with endophthalmitis following antivascular endothelial growth factor (VEGF) injection.

METHOD

The authors retrospectively reviewed the medical records of all patients in their practice with a diagnosis of endophthalmitis from January 1, 2007, through December 31, 2011. Only those with a clinical presentation consistent with endophthalmitis after intravitreal anti-VEGF injection were included. Clinical data that were collected and recorded included visual acuities and the method of initial and subsequent treatment of endophthalmitis following anti-VEGF injection: tap and injection of intravitreal antibiotics (TAP) and tap and inject with subsequent pars plana vitrectomy (VIT).

RESULTS

The authors identified 23 patients meeting criteria. Nineteen patients had received bevacizumab and four patients had received ranibizumab. The median time from last injection to presentation was 4 days (range, 1-18 days) with a median follow-up of 15 months (range, 5-48 months) after being diagnosed of endophthalmitis. Nine patients had positive cultures. The median baseline visual acuity (preendophthalmitis) was 20/70 (range, 20/25 to counting fingers at 2 ft) with a median presenting visual acuity of counting fingers at 1 ft (range, 20/50 to light perception vision). Overall, 90% (9/10) of the patients in TAP only group regained visual acuity within 1 line or better of baseline versus 46% (6 of 13) in the TAP and VIT group. Only one of the patients treated with TAP alone suffered more than one line of visual acuity loss.

CONCLUSION

Patients diagnosed with endophthalmitis after anti-VEGF intravitreal injection who underwent TAP regained baseline visual acuity more often than those who underwent TAP and VIT. This study did not support a benefit for VIT in all patients, rather only in those cases who warranted it because of worsening clinical course. The study suggests that TAP is a viable primary intervention for endophthalmitis after anti-VEGF injection.

Local and systemic complications after intravitreal administration of anti-vascular endothelial growth factor agents in the treatment of different ocular diseases: a five-year retrospective study

PURPOSE

To observe the frequency of complications in patients undergoing intravitreal anti-VEGF injections for different ocular diseases in a five-year period.

MATERIALS AND METHODS

Charts of patients receiving intravitreal anti-VEGF were retrospectively reviewed. Out of 1173 eyes, 762 were treated with bevacizumab, 382 with ranibizumab, and 29 with pegaptanib. Data recorded included demographic information, clinical findings, total injections received, and info about the onset of adverse effects.

RESULTS

12.86% of the eyes treated with bevacizumab presented side-effects, while ratings in the ranibizumab and pegaptanib groups were 15.97% and 20.69%, respectively. Odds ratios calculated comparing incidences after each anti-VEGF are 0.78 (bevacizumab versus ranibizumab, p = 0.152), 0.57 (bevacizumab versus pegaptanib, p = 0.227), and 0.73 (ranibizumab versus pegaptanib, p = 0.508). A total of 185 complications were detected (62.16% after bevacizumab). Ocular side-effects registered were 40 cases of sustained intraocular pression (IOP) elevation, one infectious uveitis, one retinal detachment, and one sub-retinal hemorrhage. Other cases were related to transient IOP elevation immediately after injection. Systemic complications registered were one case of nausea, one episode of chest pain with acute vision loss, and one case of acute blood hypertension.

CONCLUSIONS

The majority of significant complications occurred in patients receiving multiple bevacizumab administrations. However, results may be affected by the difference in the utilization amount for each drug. AMD patients were the most represented, probably due to greater indication to treatment.

Acute endophthalmitis after intravitreal injection and preventive effect of preoperative topical antibiotics

PURPOSE

To evaluate the incidence, causative organism, clinical features, and visual outcome of acute endophthalmitis following intravitreal injection and to report the clinical outcome of patients receiving preinjection antibiotics for the prevention of endophthalmitis.

METHODS

For all intravitreal triamcinolone acetonide, bevacizumab, ranibizumab, and C3F8 gas injections performed in our outpatient clinic between June 2008 and November 2012, the number of injections, indications, types of administered drugs, and methods of injection were investigated. A retrospective chart review was performed comparing patients with self-administration of antibiotic eye drops for 3 days before injection (n=8649 injections), and patients those who received no pretreatment with antibiotics (n=8683 injections). Cases of suspected endophthalmitis after intravitreal injection during this period were identified and reviewed retrospectively.

RESULTS

The total number of intravitreal injections was 17,332. The incidence of acute endophthalmitis for all intravitreal injections was 0.000% (0/849) for triamcinolone acetonide, 0.022% (2/9,125) for bevacizumab, 0.000% (0/7,061) for ranibizumab, and 0.337% (1/297) for C3F8 gas injections. The overall rate of intravitreal injection-related endophthalmitis with the use of topical antibiotics given 3 days before injection was no less statistically significant compared with that of no antibiotics. Staphylococcus species was confirmed in the bacterial culture of one eye with acute endophthalmitis. After early vitrectomy and intravitreal antibiotic injection, one eye maintained vision, but the other eye developed phthisis.

CONCLUSIONS

All 3 endophthalmitis patients had not taken prophylactic preinjection topical antibiotics, but the difference in the rates of endophthalmitis between those who received a multiday course of preinjection antibiotics and those who did not was not statistically significant. The rate of endophthalmitis after intravitreal injection using aseptic techniques in the clinical practice setting is similar with or without the use of preinjection antibiotics. Preinjection antibiotic use confers no additional benefit in the treatment of endophthalmitis compared to without preinjection antibiotics.

Adverse events and complications associated with intravitreal injection of anti-VEGF agents: a review of literature

Intravitreal injection of anti-vascular endothelial growth factor (VEGF) agents is increasingly used for the treatment of a wide variety of retinal diseases, including age-related macular degeneration, diabetic retinopathy and retinal vascular occlusions, and retinopathy of prematurity. Despite encouraging results in halting the disease and improving the vision, intravitreal injection of anti-VEGF agents may be associated with systemic adverse events and devastating ocular complications. In this review, we provide an overview of safety data for intravitreal injection of common anti-VEGF agents.

Ocular and systemic safety of bevacizumab and ranibizumab in patients with neovascular age-related macular degeneration

PURPOSE OF REVIEW

This study reviews differences in both ocular and systemic safety between intravitreal bevacizumab and ranibizumab in the setting of neovascular age-related macular degeneration.

RECENT FINDINGS

Serious adverse events associated with either bevacizumab or ranibizumab injections are generally rare. However, acute intraocular inflammation (AII) tends to occur more frequently following bevacizumab injection. Systemic absorption of bevacizumab is greater than with ranibizumab, and many studies have shown an increased risk of systemic adverse events in patients receiving bevacizumab compared with those receiving ranibizumab.

SUMMARY

Although rare, adverse events with off-label use of bevacizumab are more common than with ranibizumab. Continued study into long-term safety of the two agents is warranted.

The impact of short-term topical gatifloxacin and moxifloxacin on bacterial injection after hypodermic needle passage through human conjunctiva

PURPOSE

To determine the bacterial contamination rate of a 27-gauge needle bore during conjunctival penetration in donor eye bank eyes and the effect of short-term use of topical 0.3% gatifloxacin and 0.5% moxifloxacin.

METHODS

One hundred consecutive human donors had 10 conjunctival penetrations per 10 syringes per eye before antibiotic placement; this was repeated 15 min after antibiotic use. Samples were cultured by expressing 0.3 mL of saline through the needle. Positive cultures were speciated.

RESULTS

There were 1,033 positive cultures (25.8% of all cultures); 568 (28.4%) pre-antibiotics, 249 (24.9%) after gatifloxacin (P=0.04, compared to the pre-antibiotic rate), and 216 (21.6%) after moxifloxacin (P<0.001). The most common organism was Staphylococcus epidermidis [334 positive cultures (8.4%)]. No antibiotic effect was seen on this or other organisms except S. aureus [4.6% pre-antibiotic, 2.8% after gatifloxacin (P=0.02), and 1.8% after moxifloxacin (P<0.001)] and other Staphylococcus species [5.3% pre-antibiotic, 3.6% after gatifloxacin (P=0.04), and 3.2% after moxifloxacin (P=0.01)].

CONCLUSIONS

Transconjunctival penetration often results in needle bore contamination; bacteria are included in an injected solution. Fifteen minutes of exposure to 2 topical antibiotics had a minimal effect on bacterial contamination and no significant effect on many common pathogens.

Rate of serious adverse effects in a series of bevacizumab and ranibizumab injections

OBJECTIVE

To compare the rate of serious ocular and systemic adverse effects of intravitreal bevacizumab and ranibizumab in the treatment of a variety of eye diseases.

DESIGN

Retrospective chart review.

PARTICIPANTS

Consecutive series of intravitreal injections of bevacizumab (n = 693) and ranibizumab (n = 891).

METHODS

Medical records of all patients receiving injections in the series were retrieved. We considered the rate of both serious ocular adverse effects (e.g., acute intraocular inflammation, infectious endophthalmitis, retinal detachment, vitreous hemorrhage) and of arterial thromboembolic events that occurred within 1 month of injection.

RESULTS

Subjects who received bevacizumab were 12 times more likely to develop severe intraocular inflammation following each injection than were those who received ranibizumab (OR = 11.71; 95% CI 1.5-93). The 1 case of acute intraocular inflammation following ranibizumab injection was mild and not associated with vision loss. No other serious ocular complications were noted. A trend was also noted toward an increased risk for arterial thromboembolic events in patients receiving bevacizumab, although the confidence interval was wide (OR = 4.26; 95% CI 0.44-41).

CONCLUSIONS

Significant concern still exists regarding the safety of off-label use of intravitreal bevacizumab. Patients receiving bevacizumab should be counselled regarding a possible increased risk for serious adverse events.

Suspected bacterial endophthalmitis following intravitreal anti-VEGF injection: case series and literature review

AIM

To report an up-to-date overview of all patients reported in the literature with suspected bacterial endophthalmitis following anti-VEGF injection. Secondly, to identify specific symptoms and signs to differentiate between infectious and noninfectious endophthalmitis.

METHODS

A Pubmed search retrieved 12 retrospective case series which had included a total of 118 patients with suspected bacterial endophthalmitis after anti-VEGF injection. Data of 15 patients from the Rotterdam Eye Hospital were added. Patients were divided into three groups: those who did not receive intravitreal antibiotics (group A), patients who received intravitreal antibiotics with biopsy-negative cultures (group B) and those with biopsy-positive cultures (group C).

RESULTS

The median time between anti-VEGF injection and presentation with suspected bacterial endophthalmitis was 1 day in group A compared to 3 days in groups B and C. At presentation, patients of group A had a better median visual acuity (logMAR 1.0) compared to those in groups B and C (logMAR 2.1 and 2.5, respectively).

CONCLUSION

This study suggests that patients presenting with a visual acuity of 20/200 (logMAR 1.0) or less and later than 24 h after injection are more likely to have bacterial endophthalmitis. To prevent undertreatment in these patients, the threshold to proceed to vitreous biopsy and empirical intravitreous antibiotics should be low.

Incidence of endophthalmitis and use of antibiotic prophylaxis after intravitreal injections

PURPOSE

To report the incidence of endophthalmitis in association with different antibiotic prophylaxis strategies after intravitreal injections of anti-vascular endothelial growth factors and triamcinolone acetonide.

DESIGN

Retrospective, comparative case series.

PARTICIPANTS

Fifteen thousand eight hundred ninety-five intravitreal injections (9453 ranibizumab, 5386 bevacizumab, 935 triamcinolone acetonide, 121 pegaptanib sodium) were reviewed for 2465 patients between January 5, 2005, and August 31, 2010. The number of injections was determined from billing code and patient records.

METHODS

The indications for injection included age-related macular degeneration, diabetic macular edema, central and branch retinal vein occlusion, and miscellaneous causes. Three strategies of topical antibiotic prophylaxis were used by the respective surgeons: (1) antibiotics given for 5 days after each injection, (2) antibiotics given immediately after each injection, and (3) no antibiotics given.

MAIN OUTCOME MEASURES

The primary outcome measures were the incidence of culture-positive endophthalmitis and culture-negative cases of suspected endophthalmitis.

RESULTS

Nine eyes of 9 patients with suspected endophthalmitis after injection were identified. Three of the 9 cases had culture-positive results. The overall incidence of endophthalmitis was 9 in 15 895. The incidence of culture-negative cases of suspected endophthalmitis and culture-proven endophthalmitis after injection was 6 in 15 895 and 3 in 15 895, respectively. Taking into account both culture-positive endophthalmitis and culture-negative cases of suspected endophthalmitis, the incidence per injection was 5 in 8259 for patients who were given antibiotics for 5 days after injection, 2 in 2370 for those who received antibiotics immediately after each injection, and 2 in 5266 who received no antibiotics. However, if considering culture-proven endophthalmitis alone, the use of topical antibiotics, given immediately or for 5 days after injection, showed lower rates of endophthalmitis compared with those without postinjection antibiotics. The risk of endophthalmitis after intravitreal injection varied among agents that were used. Among the 9 cases of clinically suspected endophthalmitis, regardless of prophylactic strategies used, the incidence of endophthalmitis per injection was 2 in 935 for triamcinolone acetonide, 3 in 9453 for ranibizumab, and 4 in 5386 for bevacizumab.

CONCLUSIONS

The overall rate of intravitreal injection-related endophthalmitis is greater with the use of topical antibiotics, given immediately or for 5 days after the injection, compared with no antibiotics.

Endophthalmitis after intravitreal vascular [corrected] endothelial growth factor antagonists: a six-year experience at a university referral center

PURPOSE

To assess the rate of infectious endophthalmitis and to describe the clinical and microbiological features of eyes that develop clinically suspected endophthalmitis after an intravitreal injection of vascular endothelial growth factor antagonists.

METHODS

The medical records of patients undergoing intravitreal injections of anti-vascular endothelial growth factor agents from January 1, 2005, through December 31, 2010, at a single university referral center and associated satellite clinics were retrospectively analyzed to determine the rate of infectious endophthalmitis after intravitreal anti-vascular endothelial growth factor injections.

RESULTS

Twelve cases (11 patients) of clinically suspected endophthalmitis were identified after a total of 60,322 injections (0.02%; 95% confidence interval, 0.0114%-0.0348%). Of the 12 cases, 11 presented within 3 days of the injection. Of the 7 culture-positive cases, 5 were because of Streptococcus species. In 4 of the 5 Streptococcus cases, final visual acuity was hand motions or worse. The rate of clinically suspected endophthalmitis was 0.018% after bevacizumab and 0.027% after ranibizumab injections.

CONCLUSION

A very low rate of endophthalmitis after intravitreal injections of anti-vascular endothelial growth factor agents was observed. Patients typically presented within 3 days of injection. Streptococcus species was the most common bacteria isolated, and it was generally associated with poor visual outcomes.

Endophthalmitis following intravitreal injections

BACKGROUND

To report the clinical features, culture results, management and visual outcome of patients with endophthalmitis following intravitreal injections.

METHODS

Retrospective review of all patients with suspected endophthalmitis after intravitreal injections treated with intravitreal antibiotics (teicoplanin and ciprofloxacin) at a referral centre between January 2003 and December 2010.

RESULTS

Nineteen cases that had aqueous or vitreous biopsy were identified. Nine had negative culture. Ten had positive culture; Staphylococcus species in 4/10, Streptococcus species in 4/10, E. coli in 1/10 and gram-negative bacilli in 1/10. Symptoms developed within the first 48 hours in all. One of ten culture-positive cases had no pain on presentation, while 5/9 patients with negative culture reported pain. Initial treatment consisted of intravitreal antibiotics in all cases, 6/19 cases required a second intravitreal antibiotic injection, 4/19 underwent vitrectomy as secondary therapy. At the last follow up, 7/19 patients had visual acuity of 6/18 or better, 9/19 had visual acuity of 6/60 or worse.

CONCLUSION

The overall numbers of patients with endophthalmitis following intravitreal injections has risen dramatically over the past years. In contrast to earlier reports of multicentre studies, outcome of patients is relatively poor in the current treatment settings. We did not find clinical features useful in identifying cases with negative culture.

Outcomes and risk factors associated with endophthalmitis after intravitreal injection of anti-vascular endothelial growth factor agents

OBJECTIVE

To describe outcomes of and risk factors for endophthalmitis after intravitreal anti-vascular endothelial growth factor (VEGF) injection.

DESIGN

Single-center, consecutive, case series and retrospective case-control study.

PARTICIPANTS

Between January 1, 2009, and May 31, 2010, 16 vitreoretinal surgeons administered a total of 27 736 injections. During this period, 23 cases of presumed infectious endophthalmitis occurred. Each surgeon used his own preferred injection technique.

INTERVENTION

Vitreous or aqueous tap, or both, with intravitreal antibiotic injection and subsequent topical antibiotic and steroid drops.

MAIN OUTCOME MEASURES

Visual acuity, bladed lid speculum use, conjunctival displacement, hemisphere of injection, bevacizumab versus ranibizumab, and infectious organism.

RESULTS

Seven of 23 cases had positive culture results; 3 grew coagulase-negative Staphylococcus. All cases had pain and vitritis on average 3.4 days (range, 1-6 days) after injection, with no difference between culture-positive and culture-negative groups. Eighteen (78%) of 23 cases had a hypopyon. Fifteen of 23 cases returned to baseline vision (±2 lines) within 3 months. Neither lid speculum use (0.10% vs. 0.066% in the no-use group; P = 0.27), conjunctival displacement (0.11% vs. 0.076% in the no-displacement group; P = 0.43), hemisphere of injection (0.11% superior vs. 0.079% inferior; P = 0.56), or bevacizumab versus ranibizumab (0.11% vs. 0.066%; P = 0.21) affected risk. Analysis of only culture-positive results yielded similar results. There was no statistically significant difference between the proportion of culture-negative cases after bevacizumab injection (83%) versus ranibizumab injection (55%; P = 0.13).

CONCLUSIONS

Most patients in whom presumed infectious endophthalmitis develop after anti-VEGF injection regained baseline vision after treatment. Bladed lid speculum use, conjunctival displacement, hemisphere of injection, and type of anti-VEGF agent did not affect risk. No difference in culture-negative endophthalmitis rates was detected after bevacizumab versus ranibizumab injection. Neither the presence of pain, vitritis, decreased vision, hypopyon, nor the interval between injection and development of symptoms differentiate culture-positive from culture-negative cases. Because a subgroup of patients had poor outcomes, a low threshold for vitreous tap with intravitreal antibiotic injection may be warranted.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Trans-Chalcone prevents VEGF expression and retinal neovascularization in the ischemic retina

Retinal neovascularization (RNV) is a critical pathological event and a major cause of blindness. Vascular inflammation and oxidative stress have been shown to play a key role in the induction and progression of RNV. Trans-Chalcone-derived flavonoids have been previously shown to be negative modulators of oxidative stress and inflammatory responses as well as tumor angiogenesis. In this study, we characterized the effects of the flavonoid trans-Chalcone in preventing RNV in a model of ischemic retinopathy. Ischemic retinopathy was induced in neonatal mice subjected to oxygen-induced retinopathy. Trans-Chalcone was administered intra-peritoneum at the dose of 25 mg/kg/day. Vascular density was assessed by morphometric analysis of flat mounted retinas stained with Texas red-Isolectin B4. Western blotting analysis was conducted to determine protein levels of vascular endothelial growth factor (VEGF), inter-cellular adhesion molecule 1 (ICAM-1) and the transcriptional activators' signal transducer and activator of transcription 3 (STAT3) and nuclear factor kappa beta (NF-κB). Treatment with trans-Chalcone significantly inhibited RNV in the ischemic retina, as shown by decreased number of neovascular tufts. Trans-Chalcone also blocked ischemia-induced VEGF and ICAM-1 expression and this effect correlated with inhibition of activated STAT3 and NF-κB. Our results show that trans-Chalcone effectively prevents RNV in the murine retina thus suggesting that Chalcone-derived flavonoids may be beneficial in preventing pathological neovascularization in the ischemic retina.

Bevasiranib for the treatment of wet, age-related macular degeneration

Age- related Macular Degeneration (AMD) is the leading cause of severe visual impairment in people 65 years and older in industrialized nations. Exudative, or “wet”, AMD is a late form of AMD (as distinguished from atrophic, so-called dry, AMD) and is responsible for over 60% of all cases of blindness due to AMD. It is widely accepted that vascular endothelial growth factor (VEGF) is a key component in the pathogenesis of choroidal neo-vascularization (CNV), which is a precursor to wet AMD. The current gold-standard for treating wet AMD is the monoclonal antibody fragment ranibizumab (trade name Lucentis), which targets VEGF. Other agents used to treat wet AMD include pegaptanib (Macugen), bevacizumab (Avastin; off-label use), and several other experimental agents. The advent of small interfering RNA (siRNA) has presented a whole new approach to inhibiting VEGF. This article reviews the status of a novel siRNA-based therapeutic, bevasiranib, for the treatment of wet AMD. Bevasiranib is believed to work by down regulating VEGF production in the retina. Studies in human cell-lines and animal models have shown that VEGF siRNAs are effective in inhibiting VEGF production. Although there is a lack of sufficient published data on human studies supporting the use of bevasiranib for wet AMD, available data indicates that due to its unique mechanism of action, bevasiranib might hold some promise as a primary or adjunct treatment for wet AMD.