Post-Traumatic Endophthalmitis

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Disease Entity

Disease

Post-traumatic endophthalmitis involves infection of anterior and posterior segment of the eye after a traumatic open globe injury.

It is a devastating complication of ocular trauma and accounts for one-third of all infectious endophthalmitis cases irrespective of the cause. This infection is reported in approximately 1 in 100 penetrating eye injuries. The infection rate is higher in presence of intraocular foreign bodies (IOFBs) especially if contaminated with organic matter.

Etiology

The infectious micro-organism enters the eye through the open wound during trauma. Most of the cases of post-traumatic endophthalmitis are bacterial, usually gram-positive organisms - Staphylococcus, Streptococcus, Enterococcus and Bacillus species; 10% –15% are due to gram-negative organisms mainly Pseudomonas aeruginosa and some species of Enterobacteriaceae; 10-30% are polymicrobial. High incidence of Bacillus infections are seen in the setting of IOFB or soil contaminated wounds. Candida species, Aspergillus and Fusarium are fungal entities that have been identified in chronic indolent cases.

Risk Factors

Factors that may increase the risk of infection in open globe eyes include:

  • Delayed primary repair of open globe injury by greater than 24 hours
  • Retained Intraocular Foreign Body (IOFB)
  • Contaminated injury with soil, rural or organic matter
  • Ruptured Lens Capsule
  • Large wound size
  • Vitreous prolapse through the open globe wound

Diagnosis

It can be difficult to diagnose early infection immediately after open globe injury due to trauma related disrupted ocular tissue and inflammation. Detailed history regarding the nature of the injury is important. Detailed anterior and posterior segment examination should be performed. Ultrasonography of the eye or CT of the orbit may be needed, in presence of media opacity, to evaluate for presence of an IOFB.

Signs

  • Eyelid edema
  • Conjunctival injection with Chemosis
  • Purulent discharge
  • Corneal edema
  • Anterior chamber reaction with Hypopyon +/- fibrin membranes
  • Vitritis
  • Possible periorbital erythema and proptosis


Symptoms

Symptoms can range from mild to excruciating pain, photophobia, tearing and decreased vision. Pain may be out of proportion to the injury. The worsening of symptoms and progression of infection depends on the type and virulence of infecting organism.

Diagnosis can be very difficult in early infection in traumatized eyes. Symptoms and many signs of infection overlap those of traumatic injury. However, increasing pain with hypopyon and vitritis suggests an infection until proven otherwise. It is important to distinguish bacterial from fungal infection since the treatment is different. The patient with a fungal infection may just have mild discomfort and worsen slowly and may not start for weeks after the initial injury. These should be suspected in tree branch or vegetable matter injuries. Infections due to bacteria especially Bacillus on the other hand (in IOFB cases or soil contaminated cases) have a rapid onset and progression to panophthalmitis with severe pain and inflammation.

B-scan is needed to evaluate for vitreous opacities, IOFB and status of retina and choroid. CT scan should be performed to evaluate for retained IOFB if the history is suspicious.

Cultures should be obtained from the wound, vitreous and possibly anterior chamber for identification of aerobic, anaerobic bacteria and fungus. Gram stain, KOH preparation of vitreous sample and blood and chocolate agar should be plated. Samples should be cultured on Sabaroud’s dextrose for fungal organisms. Only 70% of vitreous cultures usually yield positive results. PCR assays of vitreous for identification of bacterial and fungal strains should be considered.

Differential diagnosis

  • Post-traumatic non-infectious inflammation
  • Phacoanaphylactic endophthalmitis

Treatment

Emergent admission to the hospital for emergent localized ocular treatment and systemic antibiotic treatment.

Medical therapy

  • Systemic broad spectrum antibiotics are initiated immediately using vancomycin 1 g q12h and ceftazidime 1g q8h. Addition of clindamycin (300 mg every 8 hours), amikacin (240 mg q8hr) or gentamycin 80 mg q8hr should be considered in severe cases suspicious for Bacillus (history of IOFB) or anaerobic bacteria. Systemic fluconazole (200 mg BID) or more recently, voriconazole (200mg BID) is recommended intravenously for fungal infections.
  • Perform expedited vitreous biopsy with empiric intravitreal vancomycin 1mg/0.1ml and ceftazidime 2.25 mg/0.1ml injections in cases where emergent pars plana vitrectomy cannot be performed.
  • Initiate fortified topical vancomycin (50 mg/ml) with ceftazidime (100 mg/ml) every hour


Medical follow up

  • Inhospital stay of 3-5 days for intravenous antibiotic treatment with daily follow-up for clinical examination and B-scan of the vitreous cavity is recommended.
  • Once hypopyon resolves and vitritis improves, the antibiotics are switched to the oral route and the patient is discharged from the hospital. Oral fluoroquinolones (e.g. Ciprofloxacin 750 mg q 12 hr) are widely used for bacterial infections and oral voriconazole (200 mg BID) for fungal infections.
  • Semiweekly to weekly follow-ups with B-scans are performed until the infection fully resolves.


Surgery

  • Immediate pars plana vitrectomy (PPV) with intravitreal antibiotics is the mainstay of treatment for post-traumatic endophthalmitis. Bacterial and fungal cultures of undiluted vitreous are ordered. For mild suspicious cases of traumatic endophthalmitis, intravitreal antibiotics (without vitrectomy) with vitreous cultures can be considered. Emergent removal of intraocular foreign bodies, if present, should be performed.
  • Empiric intravitreal vancomycin 1mg/0.1ml and ceftazidime 2.25 mg/0.1ml injections are given during PPV. Avoid aminoglycosides for gram negative coverage due to high risk of retinal toxicity. If history of IOFB is elicited, suspect Bacillus. B. Cereus is resistant to cephalosporins and has a rapid deterioration of infection. In severe cases where Bacillus is suspected, a meticulously prepared low dose gentamycin 40ug intravitreal injection may be considered in eyes with average volume vitreous cavity with no choroidal detachment. Intravitreal corticosteroid (dexamethasone, 0.4 mg / 0.1 ml) may be *Consider amphotericin (5 ug/0.1 ml) or voriconazole (50-100 µg in 0.1 ml) intravitreal injection if vegetable matter contamination is suspected. Use of intravitreal corticosteroids is not recommended if fungal infection is suspected.


Surgical follow up

  • Daily follow-up until marked improvement of infection noted. If no improvement is seen in 48-72 hours, repeat the intravitreal antibiotics As infection improves, vitreous debris may worsen. Vitreo-retinal tractional bands may progressively form especially if a limited vitrectomy was performed initially due to media opacity. Possibly repeat vitrectomy may be required for debridement and to repair traction RD.

Complications

  • Vitreous hemorrhage
  • Recurrent endophthalmitis
  • Retinal tears
  • Retinal detachment
  • Choroidal Detachment
  • Drug induced retinal toxicity
  • Cataract
  • Secondary glaucoma


Prognosis

Visual prognosis is poor and depends on the virulence of the infecting organism, presence of retinal detachment, timing of treatment, and the extent of initial injury.

Primary prevention

  • Expedited closure of the open globe wound
  • Expedited removal of IOFB
  • Use of intravitreal antibiotics in cases of IOFB


Additional Resources

References

  1. Bhagat N, Nagori S, Zarbin MA. Traumatic endophthalmitis. Survey of Ophthalmology. Forthcoming.
  2. Essex RW, Yi Q, Charles PG, Allen PJ. Post-traumatic endophthalmitis. Ophthalmology. 2004 Nov;111(11):2015-22.Meredith TA. Posttraumatic endophthalmitis. Archives of ophthalmology. 1999 Apr;117(4):520-1.
  3. Peyman GA, Lee PJ, Seal DV. Endophthalmitis: Diagnosis and Management. London, England: Taylor & Francis; 2004: pp 90-91.
  4. Soheilian M, Rafati N, Mohebbi MR, Yazdani S, Habibabadi HF, Feghhi M, et al. Prophylaxis of acute posttraumatic bacterial endophthalmitis: a multicenter, randomized clinical trial of intraocular antibiotic injection, report 2. Archives of ophthalmology. 2007 Apr;125(4):460-5.