Bacterial endophthalmitis
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Sara Mehrsefat, M.D. [2]
Overview
Bacterial endophthalmitis means bacterial infection inside the eye, involving the vitreous and/or aqueous humors. Most cases of endophthalmitis are exogenous, and organisms are introduced into the eye via trauma, surgery, or an infected cornea. Endogenous endophthalmitis occurs when the eye is seeded via the bloodstream. Patients usually have symptoms from their underlying systemic infection, but sometimes present only with eye symptom.
Historical Perspective
Classification
Based on how infectious agents generally gain access to the posterior segment posterior segment of the eye, bacterial endophthalmitis may be classified into:[1][2]
- Exogenous bacterial endophthalmitis
- Acute post-operative bacterial endophthalmitis
- Delayed post-operative bacterial endophthalmitis
- Post-traumatic bacterial endophthalmitis (following a penetrating injury of the globe)
- Endogenous bacterial endophthalmitis
Pathophysiology
Exogenous bacterial endophthalmitis
Pathogenesis
Acute post-operative bacterial endophthalmitis occurs within 1 week following ocular surgery. It is an ocular inflammation resulting from the introduction of an infectious agent, most commonly coagulase-negative staphylococci, into the posterior segment of the eye. Nearly every type of ocular surgery, such as cataract (approximately 90% of all cases), glaucoma, retinal, radial keratotomy, and intravitreal injections, may be able to disturb the eye globe integrity and contaminate the aqueous humor and/or vitreous. Preoperative topical antimicrobial agents can decrease colony counts in the tear film, but they do not sterilize the area. The exact low rate of clinical infection following eye surgery (despite the relatively high prevalence of microorganisms in the eye) is not fully understood. It is thought that low rate of clinical infection following surgical procedure is explained by combination of low inoculum levels, low pathogenicity, and the innate ocular defenses against infection.[1][2][3]
Post-operative bacterial endophthalmitis may also occur weeks to years following surgery. It presents as a low-grade inflammation in the anterior chamber. The exact pathogenesis of delayed postoperative bacterial endophthalmitis is not fully understood. It is thought that delayed post-operative bacterial endophthalmitis is caused by either sequestration of low-virulence organisms introduced at the time of surgery or delayed inoculation of organisms to the eye through wound abnormalities, suture tracks, or filtering blebs. Propionibacterium acnes is the most common microorganism encountered in delayed post-operative bacterial endophthalmitis. [1][2]
Post-traumatic bacterial endophthalmitis occurs following penetrating ocular injuries. Following penetrating injury, the eye globe integrity disturbed. Penetrating ocular injuries are accompanied by infection at a much higher rate compere to ocular surgery. The broad prevalence range is due to factors such as:
- Presence of an intraocular foreign body
- Delay primary globe repair
- Location and extent of laceration of the globe
Post-traumatic endophthalmitis associated with a greater variety of organisms. The most common isolated organisms include Gram-positive Staphylococcus epidermidis and Streptococcus (as a part of the normal skin flora and regularly contaminate open wounds). Bacillus cereus is ranked second and some cases are polymicrobial.[2][4]
Gross Pathology
On gross pathology, eyelid swelling, eyelid erythema, injected conjunctiva and sclera, hypopyon, chemosis, and mucoprulunt dischage are characteristic findings of exogenous bacterial endophthalmitis.
Microscopic histopathological analysis
On microscopic histopathological analysis, infiltration of polymorphonuclear leukocytes or chronic inflammatory cells (depending on the duration of the inflammation) and destruction of ocular structures are characteristic findings of bacterial endophthalmitis.
Endogenous bacterial endophthalmitis
Pathogenesis
Endogenous endophthalmitis is typically the result of hematogenous spread from a distant infective source, such as urinary tract infections, liver abscesses, meningitis, catheters, and illicit injection drug use. Endogenous endophthalmitis is commonly associated with immunosuppression or procedures that increase the risk for blood-borne infections, such as diabetes, HIV, malignancy, intravenous drug use, transplantation, immunosuppressive therapy, and catheterization. Under normal circumstances, the blood-ocular barrier provides a natural resistance against invading organisms. Following bacteremia, the blood-borne organisms permeate the blood-ocular barrier by:[1][2][5]
- Direct invasion (septic emboli)
- Change in vascular endothelium (caused by inflammatory mediators released during infection)
Gross Pathology
On gross pathology, findings in endogenous endophthalmitis may be similar to those in infections of exogenous origin.
Microscopic histopathological analysis
On microscopic histopathological analysis, infiltration of polymorphonuclear leukocytes or chronic inflammatory cells (depending on the duration of the inflammation) and destruction of ocular structures are characteristic findings of bacterial endophthalmitis.
Causes
Post-operative Bacterial Endophthalmitis
Post-operative endophthalmitis has been reported following nearly every type of ocular surgery. Common causes of post-operative bacterial endophthalmitis include:[2][2]
- Gram-positive bacteria (95%)
- coagulase-negative staphylococci (70%)
- Staphylococcus aureus (10%)
- Streptococcus (9%)
- Enterococcus and mixed bacteria (5%)
- Gram-negative bacilli (6%)
Delayed Post-operative Bacterial Endophthalmitis
Common causes of delayed post-operative bacterial endophthalmitis include:[2][1]
- Propionibacterium acnes (most common)
- Streptococcus species
Post-traumatic Bacterial Endophthalmitis
Common causes of post-traumatic bacterial endophthalmitis include:[2][1][4]
- Streptococcus
- Bacillus cereus
- Polymicrobial
Endogenous bacterial endophthalmitis
Common causes of endogenous bacterial endophthalmitis include:[2][1][5]
- Gram-positive bacteria
- Staphylococcus aureus
- Bacillus cereus (primary bacterial cause in intravenous drug abusers and are most likely seeded from contaminated injection paraphernalia and drug solutions)
- Gram-negative bacteria
Differentiating Bacterial Endophthalmitis from Other Diseases
Bacterial endophthalmitis must be differentiated from:[2][1][6]
- Fungal endophthalmitis
- Post-operative inflammation
- Intraocular foreign body
- Acute retinal necrosis
- Keratitis (interstitial)
- Uveitis
- Hyphema
- Toxic anterior segment syndrome (TASS)
- Vitreous hemorrhage
- Autoimmune disorders (Ankylosing Spondylitis, Spondyloarthropathy, acute complications of Sarcoidosis, and HLA-B27 Syndromes)
Epidemiology and Demographics
- Post-operative bacetrial endophthalmitis accounts for approximately 60000 cases per 100,000 cases of exogenous endophthalmitis.[7]
- Endogenous endophthalmitis is a rare disease that tends to affect immunocompromised patients and patients with chronic disease.
- Endogenous endophthalmitis accounts for approximately 5000 to 10000 cases per 100,000 cases with endophthalmitis.[8]
Prevalence and Incidence
- The incidence of post-traumatic endophthalmitis was estimated to range from 3.300 to 30,000 per 100,000 individuals with penetrating ocular trauma.[2][4]
- The incidence of post-traumatic endophthalmitis was estimated to range from 1,300 to 61,000 per 100,000 individuals with intraocular foreign body.[2][4]
- The incidence of endogenous endophthalmitis is estimated to be 50 cases per 100,000 hospitalized patients.[2][4]
Age
- Post-operative bacterial endophthalmitis (following cataract surgery) commonly affects patients older than 85 years.[2]
- Patients of all age groups may develop endogenous bacterial endophthalmitis.[7]
Gender
- Exogenous and endogenous bacterial endophthalmitis affects men and women equally.[2]
Race
- In East Asian populations, liver abscess caused by Klebsiella pneumoniae is the source of 60% of cases of endogenous endophthalmitis.[5]
Developed countries
- In developed countries/United States, post-cataract endophthalmitis is the most common form bacterial endophthalmitis.
- In developed countries/United States, the incidence of post-operative bacterial endophthalmitis was estimated to be 100 to 300 cases per 100,000 individuals who have ophthalmologic operations (mostly cataract).[7]
Risk Factors
Post-operative bacterial endophthalmitis
Common risk factors in the development of post-operative bacterial endophthalmitis include:[2][9]
- immunosuppressive therapy
- Secondary intraocular lens placement
- Lens implants made of polypropylene (Prolene) instead of polymethyl methacrylate
- Vitreous contamination following cataract surgery (break in the posterior lens capsule)
- Implantation of an intraocular lens without a heparinized surface
- Diabetes
- Wound dehiscence or leak
- Age ≥85
- Eyelid abnormalities (blepharitis, conjunctivitis, cannuliculitis, lacrimal duct obstructions, and contact lens wear)
Post-traumatic bacterial endophthalmitis
Common risk factors in the development of post-traumatic bacterial endophthalmitis include:[2][4]
- Retained intraocular foreign bodies
- Delay in repair more than 24hours
- Disruption of the lens
Endogenous bacterial endophthalmitis
Common risk factors in the development of endogenous bacterial endophthalmitis include:[2][1][5]
Screening
Screening for bacterial endophthjalmitis is not recommended.
Natural History, Complications, and Prognosis
Natural History
Most cases of bacterial endophthalmitis present with reduced or blurred vision, red eye, pain, and lid swelling. Bacterial endophthalmitis is a medical emergency. If left untreated, It may lead to panophthalmitis, corneal infiltration, perforation, and ultimately permanent vision loss.
- Acute bacterial post-operative endophthalmitis may occur within hours to few days after surgical procedures. Symptoms include fever, decreased vision, red eye, and eye pain. If left untreated, it may developed to permanent vision loss.
- Delayed post-operative endophthalmitis may occur several weeks or month after surgery and often include less virulent bacteria.
- Posttraumatic endophthalmitis may occur within hours after the trauma or up to several weeks after injury. Symptoms include decreased vision, pain greater than expected, lid swelling, and corneal ring ulcer. If left untreated, it may developed to permanent vision loss.
- Endogenouse bacterial endophthalmtis presents with eye symptoms (pain and blurred vision) rather than symptoms of their underlying infection. If left untreated, it amy developed to permanent vision loss.
Complications
Prognosis
Endophthalmitis is one of the most devastating diagnoses in ophthalmology. The prognosis of bacterial endophthalmitis, whether of exogenous or endogenous origin, is often poor. Early diagnosis and treatment with antimicrobial therapy are fundamental to optimize visual outcome.[2][10]
Post-operative bacterial endophthalmitis caused by any type of streptococci is associated with very poor visual outcome. Post-operative bacterial endophthalmitis caused by coagulase-negative staphylococci (cause milder endophthalmitis) is associated with better visual outcome than strepcocci. Overall, 50% of eyes with post-cataract endophthalmitis recover 20/40 vision, and 10% are left with no useful vision.[1]
Post-traumatic bacterial endophthalmitis is associated with particularly very poor visual outcome. Only 22% to 42% patients with post-traumatic bacterial endophthalmitis obtain a final visual acuity of 20/400 or better.[2][11]
Diagnosis
Diagnostic Criteria
History and Symptoms
Physical Examination
Laboratory Findings
Imaging Findings
X Ray
CT
MRI
Ultrasound
Other Imaging Findings
Other Diagnostic Studies
Treatment
Medical Therapy
Surgery
Prevention
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 Durand ML (2013). "Endophthalmitis". Clin Microbiol Infect. 19 (3): 227–34. doi:10.1111/1469-0691.12118. PMC 3638360. PMID 23438028.
- ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 2.13 2.14 2.15 2.16 2.17 2.18 2.19 2.20 Kernt M, Kampik A (2010). "Endophthalmitis: Pathogenesis, clinical presentation, management, and perspectives". Clin Ophthalmol. 4: 121–35. PMC 2850824. PMID 20390032.
- ↑ Keay L, Gower EW, Cassard SD, Tielsch JM, Schein OD (2012). "Postcataract surgery endophthalmitis in the United States: analysis of the complete 2003 to 2004 Medicare database of cataract surgeries". Ophthalmology. 119 (5): 914–22. doi:10.1016/j.ophtha.2011.11.023. PMC 3343208. PMID 22297029.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 Essex RW, Yi Q, Charles PG, Allen PJ (2004). "Post-traumatic endophthalmitis". Ophthalmology. 111 (11): 2015–22. doi:10.1016/j.ophtha.2003.09.041. PMID 15522366.
- ↑ 5.0 5.1 5.2 5.3 Wong JS, Chan TK, Lee HM, Chee SP (2000). "Endogenous bacterial endophthalmitis: an east Asian experience and a reappraisal of a severe ocular affliction". Ophthalmology. 107 (8): 1483–91. PMID 10919895.
- ↑ American Academy of Ophthalmology/eyewiki (2014) http://eyewiki.aao.org/Endophthalmitis Accessed on July 20, 2016
- ↑ 7.0 7.1 7.2 Aaberg TM, Flynn HW, Schiffman J, Newton J (1998). "Nosocomial acute-onset postoperative endophthalmitis survey. A 10-year review of incidence and outcomes". Ophthalmology. 105 (6): 1004–10. doi:10.1016/S0161-6420(98)96000-6. PMID 9627649.
- ↑ Jackson TL, Eykyn SJ, Graham EM, Stanford MR (2003). "Endogenous bacterial endophthalmitis: a 17-year prospective series and review of 267 reported cases". Surv Ophthalmol. 48 (4): 403–23. PMID 12850229.
- ↑ Taban M, Behrens A, Newcomb RL, Nobe MY, Saedi G, Sweet PM; et al. (2005). "Acute endophthalmitis following cataract surgery: a systematic review of the literature". Arch Ophthalmol. 123 (5): 613–20. doi:10.1001/archopht.123.5.613. PMID 15883279.
- ↑ Mamalis N (2002). "Endophthalmitis". J Cataract Refract Surg. 28 (5): 729–30. PMID 11978440.
- ↑ Affeldt JC, Flynn HW, Forster RK, Mandelbaum S, Clarkson JG, Jarus GD (1987). "Microbial endophthalmitis resulting from ocular trauma". Ophthalmology. 94 (4): 407–13. PMID 3495766.