Bacterial endophthalmitis (see the image below) is an inflammatory reaction of the intraocular fluids or tissues caused by microbial organisms. Bacteria may gain entry into the eye via corneal or scleral trauma (surgical or accidental) or hematogenously. If not properly treated, bacterial endophthalmitis can result in complete vision loss and persistent ocular pain.
Bacterial endophthalmitis. Hypopyon, 3 days after phacoemulsification.
Signs and symptoms
The clinical presentation depends on the route of entry, the infecting organism, and the duration of the disease. In general, patients complain of the following:
A red eye
Deep ocular pain
Bacterial endophthalmitis is classified on the basis of routes of entry (ie, exogenous or endogenous).
Disease from exogenous sources includes the following:
Acute postoperative (< 6 wk postoperative)
; usually occurs 2-10 days after surgery
Delayed onset or chronic pseudophakic postoperative (>6 wk postoperative)
Filtering bleb associated
Posttraumatic– History of trauma is present, and infection usually progresses rapidly
On physical examination, general findings in bacteria endophthalmitis are as follows:
Visual acuity decreased below the level expected
Anterior chamber cells and flare
Fibrin membrane formation
Loss of red reflex
Retinal periphlebitis if view of fundus possible
Specific physical examination findings are as follows:
Delayed onset or chronic cases– Occasionally, a white plaque within the equator of the remaining lens capsule
Filtering bleb associated– A purulent bleb is seen occasionally with areas of necrosis in the sclera from the use of antimetabolites
Posttraumatic– Evidence of penetrating trauma is seen with the possibility of an intraocular foreign body
Endogenous– Patients may appear systemically ill
See Clinical Presentation for more detail.
Perform culture and sensitivity studies on aqueous and vitreous samples to determine the type of organism and antibiotic sensitivity.
If endogenous bacterial endophthalmitis is suspected, a systemic workup for the source is required, with cultures of blood, sputum, and urine.
Anterior chamber tap
Vitreous biopsy: A 23-gauge vitrectomy cutter may be used if available
For anterior chamber taps, a 30-gauge needle on a tuberculin syringe is used to obtain a 0.1-mL sample under topical anesthesia through the limbus. For vitreous taps, a sub-Tenon or retrobulbar block with lidocaine with epinephrine is given, and a 21-gauge needle on a tuberculin syringe is used to obtain an adequate vitreous sample of 0.1-0.2 mL.
Perform B-scan ultrasound of the posterior pole if view of fundus is poor
Typically, choroidal thickening and ultrasound echoes in the anterior and posterior vitreous support the diagnosis
Occasionally, another source of inflammation other than or in addition to bacteria, such as retained lens material, may be seen
The ultrasound also provides a baseline prior to intraocular intervention and allows assessment of the posterior vitreous face and areas of possible traction
Rarely, a retinal detachment is seen concurrently with endophthalmitis
Other imaging studies
In traumatic cases, a CT scan may show thickening of the sclera and uveal tissues associated with various degree of increased density in the vitreous and periocular soft tissue structures. For possible endogenous cases, imaging modalities to rule out potential sources of infection include 2-dimensional echocardiography and chest x-ray.
See Workup for more detail.
Bacterial endophthalmitis is an ocular emergency, and urgent treatment is required to reduce the potential of significant visual loss.
All patients should have therapy consisting of the following
Intravitreal and topical antibiotics
Topical steroids (eg, ophthalmic prednisolone, dexamethasone, triamcinolone)
Cycloplegics (eg, atropine ophthalmic)
When the inflammation is severe, systemic and periocular therapy may be used in non–cataract-induced, delayed onset, filtering bleb–associated, and posttraumatic endophthalmitis. In endogenous endophthalmitis, systemic, topical, and possibly periocular therapy is usually required.
Vancomycin – For patients who cannot receive or have failed to respond to penicillins and cephalosporins or have infections with resistant staphylococci; Assaad et al showed that vancomycin was effective against 99.6% of gram-positive bacterial endophthalmitis isolates tested
; Ahmed et reported that intravitreal, rather than intravenous, vancomycin is necessary for the treatment of bacterial endophthalmitis.
It is not necessary to monitor vancomycin levels when administered via intravitreal injection.
Ceftazidime – First-line choice for intravitreal gram-negative coverage; ceftazidime was effective against 100% of gram-negative bacterial endophthalmitis isolates in a study by Assaad et al
Amikacin – Second-line choice for intravitreal injection for gram-negative coverage
Ciprofloxacin/ofloxacin/levofloxacin/moxifloxacin/gatifloxacin ophthalmic – Fluoroquinolones with activity against
Pseudomonas, streptococci, MRSA,
S epidermidis, and most gram-negative organisms; may have limited activity against anaerobes
Surgical intervention is usually performed urgently; however, elective surgery may suffice in delayed-onset cases. Indications for surgical therapy include the following:
Acute pseudophakic postoperative– When the presenting vision is light perception or worse
Delayed onset or chronic postoperative– If marked inflammation or a subcapsular plaque is identified, surgical removal is required
Filtering bleb–associated– If marked inflammation is present
Posttraumatic– If marked inflammation or rapid onset occurs
See Treatment and Medication for more detail.