Abstract
Endophthalmitis is an infection and inflammation of the interior of the eye that can result in significant vision loss. This infection occurs as a result of the seeding of organisms into the interior of the eye following surgery (postoperative), trauma (post-traumatic) or an infection in another site in the body (endogenous). The general rate of endophthalmitis has remained steady over the past several years. However, the increased use of intraocular injections to treat various degenerative and inflammatory ocular diseases, in addition to the already large and growing number of invasive ocular surgeries, may increase the opportunities in which organisms can gain access to the eye. In most cases of endophthalmitis, useful vision can be retained if proper treatment is instituted. However, in severe cases of bacterial endophthalmitis, blindness often occurs despite treatment. This article summarizes information on endophthalmitis epidemiology, treatment issues and current regimens, and recent experimental and clinical efforts to improve the outcome of severe and blinding forms of bacterial endophthalmitis.
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Learning objectives
• Describe the clinical characteristics of, risk factors for, and prevention of bacterial endophthalmitis
• Examine the role of varying management strategies, including topical, systemic, and intravitreal antibiotics; anti-inflammatory medications; and vitrectomy, in the management of bacterial endophthalmitis
Financial & competing interests disclosure
EDITOR
Elisa ManzottiEditorial Director, Future Science Group, London, UK.
Disclosure:Elisa Manzotti has disclosed no relevant financial relationships.
CME AUTHOR
Laurie Barclay, MDFreelance writer and reviewer, Medscape, LLC.
Disclosure:Laurie Barclay has disclosed no relevant financial relationships.
AUTHORS AND CREDENTIALS
Billy D NovosadDepartments of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, OK, USA.
Disclosure:Billy D Novosad has disclosed that portions of the work presented in this article were supported by US Health Service Grants R01EY01985, the Department of Defense Congressionally Directed Medical Research Program (W81XWH-07-1-0280), Allergan Inc., and an unrestricted grant to the Dean A McGee Eye Institute from Research to Prevent Blindness, Inc.
Michelle C CalleganDepartments of Microbiology and Immunology, and Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA; Dean A McGee Eye Institute, Oklahoma City, OK, USA.
Disclosure:Michelle C. Callegan, PhD, has disclosed that portions of the work presented in this article were supported by US Health Service Grants R01EY01985, the Department of Defense Congressionally Directed Medical Research Program (W81XWH-07-1-0280), Allergan Inc., and an unrestricted grant to the Dean A McGee Eye Institute from Research to Prevent Blindness, Inc.
Endophthalmitis: epidemiology & incidence
Endophthalmitis is an infection that occurs as a result of seeding of organisms into the interior of the eye following surgery (postoperative), trauma (post-traumatic) or an infection elsewhere in the body (endogenous). While the general rate of endophthalmitis has remained somewhat constant over the past several years, the increased use of intravitreal injections for the treatment of various degenerative and inflammatory ocular diseases, as well as the growing number of invasive ocular surgeries, may create a clinical environment in which organisms have a greater opportunity to infect the eye. Endophthalmitis cases can be treated successfully if properly managed, and useful vision can be retained. However, in severe cases of bacterial endophthalmitis, significant vision loss can occur rapidly, despite prompt and proper treatment.
During the last two decades, postoperative endophthalmitis rates have risen. The rates of infection after cataract surgery in the 1990s were 0.1% or 1 in 1000, but increased to 0.2% or 1 in 500 surgeries in the early 2000s Citation[1]. Cataract surgery results in more cases of postoperative endophthalmitis than any other type of ocular surgery Citation[1]. The vast majority of postoperative endophthalmitis cases (48–70%) are caused by coagulase-negative staphylococci. Many other Gram-positive bacteria have also been isolated from postoperative endophthalmitis cases, including streptococci, enterococci and Staphylococcus aureus. Rates of endophthalmitis following traumatic injury are more common, occurring in 3–17% of ocular traumatic events Citation[2–5]. For post-traumatic endophthalmitis, staphylococci other than coagulase-negative staphylococci are the most common cause, followed by Bacillus cereus. B. cereus is ten-times more likely to be isolated from cases of post-traumatic endophthalmitis than from cases of endophthalmitis following surgery Citation[6]. Endogenous endophthalmitis (also known as metastatic endophthalmitis) results from spread of the organism into the eye from an infection elsewhere in the body. Compared with endophthalmitis following trauma or surgery, endogenous endophthalmitis is relatively rare, accounting for only 2–8% of all reported endophthalmitis cases Citation[7–11]. However, endogenous endophthalmitis carries with it the danger of bilateral infection in 15–25% of cases Citation[7]. Fungal organisms account for at least 50% of all endogenous cases, with Candida albicans (75–80% of fungal cases) being the leading causative agent Citation[8,9]. Gram-negative organisms cause 32–37% of all endogenous endophthalmitis cases and typically have poor visual outcomes because these infections are difficult to treat Citation[7].
In any type of endophthalmitis, bacteria are introduced into the intraocular environment, encountering a site of immunological inactivity. The intraocular environment is termed an ‘immune-privileged site’, devoid of inflammatory mediators and cells present that would otherwise fight infection Citation[12,13]. In this environment, initial immune responses that would typically handle infection are delayed or absent, providing an optimal growth medium for organisms that reach the area. Eventually, bacteria are recognized and inflammation initiates in an effort to handle the infection. The extent of inflammation in the eye during endophthalmitis has been shown to be organism dependent, with relatively avirulent organisms (e.g., S. epidermidis) causing mild and treatable inflammation, and virulent toxin-producing pathogens (e.g., B. cereus, S. aureus or streptococci) causing severe and intractable inflammation Citation[14–16].
Clinical presentation affects outcome
The course of endophthalmitis, treatment effectiveness and visual outcome can be unpredictable. Clinical presentation of the disease depends, in part, on the relative virulence of the infecting pathogen, the mechanism of introduction into the eye and how quickly treatment is initiated. Other factors that affect the outcome of infection include the patient’s age, how vulnerable the infecting agent is to antibiotic therapy, and the anatomic condition of the eye during infection. Clinical studies have reported that increased time between infection and treatment is associated with a worse visual outcome Citation[7,17–19], but this is not always the case Citation[20]. At presentation, the infecting agent is not typically known, and because treatment must begin immediately, broad-spectrum antibiotics are generally used. Currently, broad-spectrum antibiotic coverage for endophthalmitis includes a two-drug regimen: vancomycin to cover Gram-positive organisms and a third-generation cephalosporin (ceftazidime) to cover Gram-negative organisms. Fluoroquinolones are also considered broad spectrum and readily penetrate the eye, but are at present not considered mainstays for the treatment of endophthalmitis. In addition, the rapid development of fluoroquinolone resistance in ocular isolates may preclude their routine use Citation[21–25].
Regardless of the antibiotic chosen, studies suggest that these drugs must be injected directly into the vitreous for the most direct and effective treatment Citation[24,26,27] because antibiotics may not reach the posterior segment at concentrations great enough or fast enough to be effective when these drugs are administered by systemic, oral or topical routes. The blood–ocular barriers provide a necessary and important obstruction to the penetration of potentially harmful cells, drugs and other toxic substances into the eye, but prevent systemic or topical antibiotics and other useful drugs from reaching the intraocular infection site. Bactericidal antibiotic levels achieved at the site of infection as soon after infection as possible are critical to sterilizing the eye and minimizing intraocular damage and inflammation during severe cases of endophthalmitis.
Therapeutic limitations: the blood–ocular barrier & drug toxicity
The blood–ocular barrier facilitates maintenance of a sterile environment in the interior of the eye, creating an immune-privileged site Citation[12,13,28–30]. Narrow intercellular tight junctions between endothelial cells and the basement membrane impair paracellular transport of hydrophilic compounds, requiring transport via intracellular routes. Tight junctions of the blood–ocular barrier protect the intraocular space from a myriad of compounds but, as stated earlier, also limit the entrance of potentially helpful systemic antimicrobial and anti-inflammatory drugs. This restrictive environment leaves clinicians with few treatment options, the best being circumvention of the blood–ocular barrier by injection of the drugs directly into the intraocular space. However, intraocular injections carry their own risk of vitreous or subretinal hemorrhaging, retinal toxicity, corneal abrasions, central artery occlusion, uveitis or lens opacification Citation[31–35]. The critical factor for clinicians to assess is whether the potential for significant vision loss from infection outweighs the minimal risk of complications from intravitreal injection of antibiotics that would otherwise quickly sterilize the eye.
Very helpful drugs can sometimes be toxic and damaging to the sensitive structures of the retina Citation[36,37]. The sensitive nature of photoreceptor cells and other retinal cells limits the drugs and concentrations that can be used for treatment Citation[36–38]. Amikacin or low-dose gentamicin at doses of 0.4 mg have been reported to cause macular infarction Citation[36,38]. Owing to the potential toxicity of aminoglycosides, ceftazidime has been a preferred choice for Gram-negative cases of endophthalmitis due to its lack of toxicity Citation[7,36]. The unique challenges presented by the blood–ocular barrier and the potential for intraocular drug toxicity requires careful consideration in determining the most effective treatment regimens for salvaging vision while reducing treatment risks during endophthalmitis.
The danger of systemic infections
As stated earlier, endogenous endophthalmitis is relatively rare, comprising only a small percentage of all types of endophthalmitis Citation[9,11]. In the West, the majority of endogenous endophthalmitis cases are fungal in origin, with Candida being the primary infecting agent, while S. aureus is the most common bacterial cause among several different types of bacteria Citation[8,11,39,40].
Underlying risk factors associated with an immunocompromised state are highly associated with cases of endogenous endophthalmitis, with only a limited number of the cases reported in otherwise healthy individuals Citation[11,41,42]. The risk factors themselves are broad and range from underlying diabetes mellitus to infection with HIV Citation[8,11,39,40,43]. Jackson et al. reported that 56% of patients with endogenous bacterial endophthalmitis also had an underlying immunocompromise Citation[7]. Of those immunocompromised patients, many were diabetic. Type 2 diabetes is the most common underlying condition in endogenous endophthalmitis patients, especially those with secondary Klebsiella pneumoniae liver abscesses Citation[7]. Prolonged intravenous drug use and immunosuppressive treatment have also been associated with endogenous endophthalmitis cases Citation[7].
Patients with systemic fungemia, specifically candidemia, have a reported mortality rate of 77%, suggesting that the progression of infection into the eye may be a mortality indicator in systemically ill patients with endogenous Candida endophthalmitis Citation[44]. Noting the potential for endogenous endophthlamitis in those patients with bacteremia or fungemia is critical in preventing ocular sequelae of systemic infection. In patients with endogenous endophthalmitis, initial ocular changes may not be addressed until a complaint of ocular pain or vision loss, because the systemic infection is the main priority Citation[11,40]. Shankar et al. concluded that endogenous endophthalmitis in healthy individuals leads to a poor visual outcome Citation[44]. Okada et al. demonstrated that 78% of patients with endogenous endophthalmitis had a final visual acuity of 20/400 or worse Citation[8]. Schiedler et al. reported the number of final visual acuities of 20/400 or worse at 50% Citation[11], while Jackson et al. reported the number of patients with 20/20 vision after endogenous endophthalmitis at only 5% Citation[7]. Despite improvements in the drugs used for treating such infections, the visual outcome of endogenous endophthalmitis has not improved over the past 55 years Citation[7,45].
Current treatment regimens for endophthalmitis
Antibiotics
As stated earlier, current treatment regimens for bacterial endophthalmitis include direct intravitreal injections of vancomycin (1.0 mg/0.1 ml) and ceftazidime (2.2 mg/0.1 ml) for broad-spectrum coverage of Gram-positive and Gram-negative organisms, respectively. Systemic antibiotics are administered for cases of endogenous endophthalmitis. At present, vancomycin has 99% susceptibility against all Gram-positive organisms causing endophthalmitis Citation[19,25,46]. Recent reports have emerged regarding endophthalmitis cases caused by vancomycin-resistant EnterococcusCitation[47,48]. The potential effectiveness of commonly used antibiotics can be variable owing to the development of resistance. Sensitivities of Gram-negative ocular isolates to ceftazidime, a third-generation cephalosporin, were reported to be 100% Citation[25]. However, Han et al. reported a series of Gram-negative endophthalmitis cases in which 89% of patients were successfully treated, but the remaining 11% were infected with Gram-negative bacteria resistant to both amikacin and ceftazidime Citation[49]. Structural improvements made to the cephalosporin drug class have improved the efficacy of these drugs against Gram-negative organisms. Second-generation (cefoxitin, cefamandole, cefotetan) and third-generation (ceftriaxone, ceftazidime, moxolactam) cephalosporins have superior activity against Gram-negative bacteria, but decreased activity against Gram-positive bacteria Citation[50]. Intravitreal ceftazidime has been reported to be safer than aminoglycosides, with toxicity observed only when ceftazidime was administered at high dosages Citation[38,51]. A recent clinical report demonstrated that the risk of endophthalmitis was reduced by 93% when the second-generation cephalosporine cefuroxime was used as an intracameral prophylactic injected prior to surgery Citation[52]. Synergy between antibiotic combinations is important to consider, especially for a rapidly blinding infection such as endophthalmitis. Vancomycin/amikacin and vancomycin/ceftazidime are synergistic in combination. However, Roth and Flynn suggested that synergy in antibiotic combinations may not be as important for endophthalmitis due to the high levels of the individual drugs injected at the site of infection Citation[53].
The fluoroquinolone class of antibiotics shows good potential for the treatment of bacterial endophthalmitis. Third-generation (levofloxacin) and fourth-generation (gatifloxacin, moxifloxacin) fluoroquinolones have enhanced and broad-spectrum activity against most ocular pathogens, especially Gram-positive bacteria. Compared with second- and third-generation fluoroquinolones, the fourth-generation fluorquinolones have demonstrated high efficacy in killing Gram-positive and -negative organisms Citation[54–56]. Although these drugs exhibit superior killing against common ocular pathogens Citation[57,58], resistance to these antibiotics is on the rise Citation[21–25]. The increased emergence of multidrug-resistant staphylococci or other resistant organisms may eventually increase the frequency of treatment failures.
Fluoroquinolones have been shown to penetrate readily into the eye, making these antibiotics candidates for the treatment of intraocular infections. However, topical prophylactic use of fluoroquinolones for surgery and for potential use in treatment of postoperative endophthalmitis are controversial. Data from clinical and experimental studies on the penetrative ability of the various fluoroquinolones varies widely, owing primarily to differences in dosing schedules. This variation makes drawing solid conclusions difficult. Results vary on the topical dosing regimens necessary to achieve concentrations greater than the MIC90 for most ocular pathogens Citation[59–61]. Of the fourth-generation fluorquinolones, moxifloxacin was shown to readily penetrate into the eye after topical administration, resulting in concentrations greater than that of gatifloxacin Citation[61]. Studies have shown that topical moxifloxacin effectively treated or prevented experimental staphylococcal endophthalmitis Citation[62–64], suggesting that topical moxifloxacin may have reached the interior of the eye at sufficient levels to be effective in these models. As stated earlier, when administered systematically, most antibiotics do not reach clinically acceptable levels in the vitreous because of blood–ocular barrier impermeability. Results also differ as to the efficacy of orally administered fourth-generation fluoroquinolones in delivering adequate bactericidal concentrations to the vitreous Citation[65–67]. Gatifloxacin for systemic use is no longer available due to potential associations with dysglycemia Citation[68].
The ability of fluoroquinolones to cross the blood–ocular barrier without direct intravitreal injection makes these drugs invaluable in the appropriate situations. Fluoroquinolones are most commonly administered as topical drops for ocular surface infections, so their use for endophthalmitis would be considered ‘off-label’. Experimental studies have documented their safety and efficacy in killing intraocular organisms following intravitreal injection Citation[69–74]. Considering these results collectively, intravitreal administration of these and other antibiotics appears to be a very effective choice of treatment for intraocular infections, especially when adequate bactericidal concentrations are needed immediately at the site of infection.
Anti-inflammatory drugs
Inflammation, typically necessary to clear infections, may cause damage to the retina. Intravitreal administration of bacterial wall components induces significant intraocular inflammation, but only a mild and recoverable loss in retinal function Citation[75–78]. Because the intraocular inflammatory response has the potential to cause collateral intraocular damage, arresting the immune response with intravitreal steroids may serve as an adjunct to antibiotic therapy. Clinical and experimental studies on the value of intravitreal corticosteroids have been controversial and generally conflict on the benefit of these drugs for use in endophthalmitis. Most clinical and experimental reports agree that the corticosteroid dexamethasone is not toxic to the retina when intravitreally injected Citation[72,79–82]. However, clinical reports conflict on whether intravitreal dexamethasone is helpful Citation[82,83] or of little use Citation[84,85] as an adjunct to antibiotic therapy for bacterial endophthalmitis. Experimental results on the effectiveness of intravitreal steroids during bacterial endophthalmitis also vary. Intravitreal dexamethasone/antibiotic combinations have been shown to be effective Citation[86,87] or ineffective Citation[72,88,89] in reducing inflammation during experimental bacterial endophthalmitis. Intravitreal prednisolone/antibiotic combinations were also ineffective in reducing inflammation during experimental Bacillus endophthalmitis compared with that of intravitreal antibiotics alone Citation[73]. Although there is a lack of definitive evidence for either position, corticosteroids (i.e., dexamethasone at 0.4 mg) are commonly used in conjunction with antibiotics for the treatment of endophthalmitis.
Vitrectomy
In severe cases of endophthalmitis, vitrectomy is often used to remove dead bacteria, damaged tissue, the inflammatory milieu and other toxic substances from the interior of the eye. Clearing the posterior segment facilitates recovery and maintenance of transparency and vitreal diffusion, leading to faster recovery of vision. Microincision vitrectomy surgery, including 23- and 25-gauge vitrectomy, is often described as being minimally invasive. However, since vitrectomy remains a complicated intraocular surgery despite technical improvements, the procedure is not without some risk Citation[90,91].
Vitrectomies became a more acceptable adjunct to endophthalmitis treatment following the Endophthalmitis Vitrectomy Study report demonstrating that endophthalmitis patients with visual light perception experienced a threefold increase in 20/40 vision when vitrectomies were performed Citation[92]. Varying theories exist for the success of vitrectomies in endophthalmitis cases with light perception vision. Results from clinical pars plana vitrectomy studies suggest that this type of surgery may induce blood–ocular barrier breakdown, allowing systemically administered antibiotics to enter more easily Citation[93,94].
Intravitreal antibiotics with immediate vitrectomy have been recommended for post-traumatic endophthalmitis cases with retained intraocular foreign bodies (IOFBs) Citation[19,95]. Early administration of vancomycin and ceftazidime, and prompt vitrectomy to remove the contaminating IOFB, resulted in a 53.5% improvement in vision, while 40% of patients experienced a decrease in vision with the same treatment Citation[19,95]. Prompt vitrectomy has been shown to improve the visual outcome of endophthalmitis following noncataract ocular surgery and the visual outcome of endophthalmitis following cataract surgery where infections were initially refractory to treatment Citation[96]. For endogenous endophthalmitis, vitrectomy also contributed to improvements in visual outcome, but only when vitrectomy surgery was performed early during infection Citation[97]. The majority of clinical reports agree that vitrectomy performed in conjunction with the proper intravitreal antibiotics should be initiated immediately in severe cases of endophthalmitis. This degree of aggressive therapy is critical to a successful visual outcome, especially in those endophthalmitis cases involving IOFBs.
The majority of recent experimental studies on the benefit of vitrectomy for endophthalmitis have tested the efficacy of vitrectomy in experimental fungal infection models Citation[98,99]. For bacterial endophthalmitis, vitrectomy can be an efficient technique to remove dead organisms, tissue and cellular debris, and damaging toxins and other substances that are not affected by antibiotic or anti-inflammatory drug activity. Newer office-based sutureless vitrectomy systems may prove to be useful, but are not yet indicated for the treatment of endophthalmitis. To date, few experimental studies have analyzed the effectiveness of vitrectomy for the treatment of bacterial endophthalmitis. However, given the need for clarity of the posterior segment in facilitating healing following infection, further studies assessing the benefits of this surgical procedure are warranted.
Prevention
The most effective therapy for endophthalmitis is prevention. Sterile technique during all phases of surgery is paramount. Care must be taken in preventing contamination at each preparation step during any type of ocular surgery, including preparation of outpatient intravitreal injections. Povidone–iodine preparation of the eye and the use of proper prophylactic antibiotics and antiseptics is important. New therapies are being investigated for both prophylaxis and treatment. Biodegradable scleral plugs impregnated with antibiotic, antiviral and anti-inflammatory drugs have been tested for extent of sustained drug release in vitroCitation[100,101]. The safety and cost–effectiveness of intracameral antibiotics have also been reported, but their penetration into the posterior segment remains an open question Citation[102,103]. The use of antibiotics in the irrigation and infusion fluid is also an option. Careful attention to instituting preventative measures prior to surgery is important in reducing the potential for infection.
Summary
Endophthalmitis can be a rapidly blinding complication of ocular surgery, trauma to the eye or systemic infection. In reviewing and comparing results from various clinical and experimental reports regarding the efficacies of different endophthalmitis therapeutic regimens, it is clear that no single universal therapy exists that is highly effective for all cases of bacterial endophthalmitis. Variables involved in the nature of the pathogen itself, routes of entry into the eye and underlying medical conditions greatly confound the situation, resulting in severe cases of bacterial endophthalmitis that are difficult to manage and refractory to treatment. Variables in dosing regimens in humans and different animal models also prevent solid conclusions from being drawn regarding the best treatment regimens for this disease. However, rapid diagnosis and treatment is critical, even though identification by culture may not be immediately available. Identification of the more virulent organisms is preferable to identify pathogens capable of rapidly destroying the eye. Intravitreal antimicrobial therapy is a preferred route in terms of delivering high levels of the appropriate drugs directly to the site of infection. The use of anti-inflammatory agents remains controversial. Vitrectomy, implemented as an adjunct in moderate or severe cases, effectively clears the vitreous of toxic and inflammogenic substances. Intravitreal injections and vitrectomy are not without risk, however, and their use must be carefully considered in light of the potential for significant vision loss if these regimens are not used. The key to successful therapy for endophthalmitis is rapid sterilization of the posterior segment and arrest of potentially harmful inflammation, while concurrently limiting risks associated with penetration of the eye by injections or surgery. Future design of better and/or novel therapeutic regimens that achieve these goals is critical to successfully combating this blinding disease.
Expert commentary
A review of the current state of endophthalmitis therapy and management indicates that, while most cases of endophthalmitis are successfully treated, those cases that are refractory typically result in significant vision loss. The difficulty in devising a successful universal therapeutic strategy for endophthalmitis lies in the variations in conditions during which these infections occur. Translating the results of experimental studies to improving therapeutic regimens in the clinical setting is also difficult owing to the absence of variations that may not always be included in experimental models. In the context of bacterial endophthalmitis, intravitreal administration of antibiotics can sterilize the eye. The effectiveness of anti-inflammatory drugs in arresting inflammation during endophthalmitis remains an open question. Neither of these types of drugs target toxic factors synthesized by the organism; factors that can irreversibly damage fragile retinal tissue. Vitrectomy is the only current therapy to approach the elimination of toxic factors, theoretically removing all vitreal contents in order to clear the infection and begin the healing process. It is clear from experimental and clinical studies that instillation of potent antibiotics into the eye as soon after infection as possible is the best strategy, but this must be evaluated by clinicians in terms of the risks involved with intravitreal injections.
Five-year view
Although potent broad-spectrum antibiotics are available for the treatment of ocular surface infections, the use of these antibiotics is more critical for endophthalmitis because of the potential for rapid and irreversible vision loss once these infections commence. Improvements in therapeutic outcome of endophthalmitis will depend upon faster identification of the infection itself and rapid and aggressive intervention. Diligence in proper training and prevention of contamination in the ocular surgery setting will decrease the number of postoperative cases, as will the use of intravitreal antibiotics upon presentation of post-traumatic injuries that may include contamination of the posterior segment.
Key issues
• Bacterial endophthalmitis is an infection and inflammation of the posterior segment of the eye that can rapidly evolve into a sight-threatening situation.
• During endophthalmitis, bacteria enter the posterior segment following trauma, surgery or from spread into the eye through the bloodstream from a distant focus of infection.
• Most topical and systemic antibiotics cannot penetrate into the eye fast enough or in high enough concentrations to be effective during endophthalmitis.
• Intravitreal administration of antibiotics ensures delivery of high concentrations directly at the site of infection.
• Experimental and clinical studies disagree on the effectiveness of anti-inflammatory drugs in affecting inflammation during endophthalmitis.
• Vitrectomy removes vitreal contents which, during endophthalmitis, may include bacteria, bacterial products, inflammatory cells and other toxic factors that may damage the retina.
• Improvements in the clinical outcome of endophthalmitis depend largely upon faster identification of the infection, and rapid and aggressive intervention.
• Prevention of contamination in the surgical setting will decrease the number of postoperative cases of endophthalmitis.
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Severe bacterial endophthalmitis: towards improving clinical outcomes
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Activity Evaluation: Where 1 is strongly disagree and 5 is strongly agree
1. A 72-year-old, black woman developed bacterial endophthalmitis following cataract surgery. Which of the following statements about her condition is most likely correct?
□ A Bacterial endophthalmitis is an infection of the anterior segment of the eye
□ B Bacterial endophthalmitis almost never causes irreversible vision loss
□ C Eye surgery is not a known risk factor for bacterial endophthalmitis
□ D Prevention of contamination in the surgical setting should help reduce the number of postoperative cases of endophthalmitis
2. Which of the following statements about the role of topical and systemic antibiotics and anti-inflammatory drugs is most likely to apply to the management of the above-described patient?
□ A In most cases of endophthalmitis, useful vision can be retained if proper treatment is started quickly
□ B Topical or systemic antibiotics are usually effective
□ C Anti-inflammatory drugs are definitely indicated
□ D Fluoroquinolones are the mainstay of treatment
3. Which of the following statements about the use of intravitreal antibiotics and vitrectomy is most likely to apply to the management of the patient?
□ A Intravitreal injection of antibiotics ensures delivery of high concentrations directly at the site of infection
□ B Experimental studies have suggested that immediate vitrectomy is the best approach
□ C Removing vitreal contents may impede healing of bacterial endophthalmitis
□ D Intravitreal injection and vitrectomy have no known risks