Post-traumatic Infectious Endophthalmitis Ghanbari MD 1391:03:25.

Post-traumatic Infectious Endophthalmitis

Ghanbari MD1391:03:25

FRIENDS …. OR FOES …..?

CORNEA & RETINA

The extent of wound

Described as: • Zone I : limited to the cornea

and limbus; • Zone II : Involves the anterior

sclera within 5 mm from the limbus;

• Zone III : Involves sclera posterior to 5 mm from the limbus

• An open globe injury is a full thickness laceration of the cornea and/or sclera, either penetrating (one entrance wound) or perforating (an entrance as well as an exit wound).

• Post-traumatic infectious endophthalmitis is an uncommon but severe complication of ocular trauma.

Incidence and epidemiology

• Post-traumatic endophthalmitis comprises approximately 25--30% of all cases of infectious endophthalmitis

• The reported incidence of endophthalmitis following open globe trauma ranges from 3.1% to 11.9% of open globe injuries in the absence of an IOFB.

• The incidence in cases with an IOFB ranges from 3.8% to 48.1%, with higher infection rates reported in eyes with retained IOFBs contaminated with organic matter from a rural setting.

Signs and Symptoms

• Pain ,• Decreased visual acuity,• Photophobia, • Tearing, • Pain with eye movement.

• Pain from trauma may be distinguished from that of endophthalmitis if it is out of proportion to the degree of injury.

Clinical signs of infection

• Purulent exudate from the site of injury,

• Eyelid edema, • Chemosis, • Corneal edema, • Hypopyon,

Other signs

• Severe anterior chamber inflammation(e.g., fibrinoid response);

• Vitritis or vitreous opacification; • Retinitis ;• Periphlebitis.

RAPD

• Inflammation that progresses slowly following primary repair may be indicative of fungal endophthalmitis.

• These patients usually have minimal discomfort in contrast to the intense pain associated with bacterial infection.

• The clinician should consider the diagnosis of endophthalmitis in all eyes with a history of trauma as the time between the injury and the onset of symptoms can be highly variable.

• Signs and symptoms of endophthalmitis may occur days, weeks, months, and even years after the injury.

Diagnosis:

• Symptoms of extreme pain with hypopyon and vitritis indicate an infection until proven otherwise.

• If the signs are subtle, diagnosis can be difficult.

• An increase in inflammation with increase in pain and vitritis should prompt an investigation for endophthalmitis.

• During the initial assessment of all types of penetrating ocular trauma, especially if there is a suspicion of endophthalmitis, the eye should be Evaluated for the presence of an IOFB.

• Unfortunately, media opacities, hypopyon, fibrin membranes, vitritis, vitreous hemorrhage, and/or traumatic cataract can make it difficult to visualize an IOFB directly.

• Plain radiography and computed tomography scans are then used to detect IOFBs.

• In order to detect small objects by computed tomography, the cut width should be less than 2 mm.

B-scan ultrasound

• May be used to help locate radiolucent foreign bodies such as glass or plastic.

Risk factors for the development ofpost-traumatic endophthalmitis

• Retained IOFB, • Lens rupture, • Delayed timing of primary repair,• Age greater than 50 years, • Female gender, • Large wound size,• Location of wound, • Ocular tissue prolapse,• Placement of primary intraocular lens (IOL), • Rural locale.

• The composition of the IOFB may play a role in infection;

Non-metallic IOFBs may have a higher risk of endophthalmitis.

• Delayed primary repair, especially more than 24 hours, is considered to be a risk factor for post-traumatic endophthalmitis in the absence of an IOFB.

Nature of Trauma

• Organic vs Inorganic Injury;• Penetrating vs Perforating

Injury;• High- vs Low-velocity Projectile

Injuries;• Wound Site;• Intraocular Tissue Prolapse.

• Posterior scleral lacerations commonly are associated with vitreous and uveal prolapse. Traditionally, the presence of intraocular tissue prolapse through the open wound has been thought to increase the risk of endophthalmitis through enhanced exposure to infecting organisms.

Factors affecting visual prognosis

• The visual prognosis in traumatized eyes with endophthalmitis is extremely poor.

Factors affecting visual prognosis

• The presence of an RAPD, • Perforating injury, expelled lens, • Corneoscleral wound (vs corneal

wound),• Retinal detachment at the time

of injury.

Virulence of Microorganisms

• Cases of traumatic endophthalmitis that involve Bacillus cereus, either as the sole causative agent or as one of many, have a very high risk of progressing to a final visual acuity of NLP.

• Eyes with Gram negative rod infection also tend to lose vision quickly.

• Fungal infections can be difficult to diagnose, which delays the treatment. Surprisingly, good vision can be achieved in the fungal cases.

• On the other hand, Staphylococcus epidermis, which is the most common organism noted in such infections, is not as virulent as Gram-negative or Bacillus infections, and many more eyes achieve a final visual acuity of 20/400 or better if the nature of the injury permits them to do so.

Characteristics of Intraocular Foreign Bodies

• 1) Structural damage induced by the IOFB

• (e.g., retinal tear);• 2) Vehicle to deliver infectious

agent(s); • 3) Chemistry of the IOFB (e.g.,

pure copper is very inflammatory).

Vitreous Tap or Biopsy

• Once the diagnosis of post-traumatic endophthalmitis is suspected, a vitreous tap or biopsy should be done promptly so that the specimen can be sent for Gram stain, culture, and KOH stain.

Managementa. Treatment guidelines for posttraumatic

endophthalmitis

• Intravitreal Antibiotic Therapy:

• For initial therapy, intravitreal vancomycin hydrochloride (1 mg/0.1 ml normal saline) and ceftazidime (2.25 mg/0.1 mL normal saline) unless the patient is allergic to the medication(s).

• Currently, vancomycin is the drug of choice for Gram-positive organisms including Staphylococcus and Streptococcus species.

• The half life of vancomycin in the vitreous of infected rabbit eyes is long (38 -54 hours).

IV Antibiotic Therapy

• There are several options for intravenous antibiotic therapy

• One vancomycin intravenous (1 gram every 12 hours in patients with normal renal function)

• Ceftazidime (1 gram every 8 hours).

• Additional treatment with intravenous clindamycin (300 mg every 8 hours) can be considered in a scenario when vancomycin is contraindicated

• Or if Bacillus or anerobic infections such as Clostridium are suspected.

• Topical antibiotics are almost always used with intravitreal antibiotics for endophthalmitis treatment in an attempt to increase the antibiotic concentration in the eye.

• Topically administered antibiotics have poor penetration into the vitreous cavity.

• Fortified topical antibiotics may be used while awaiting culture results and include vancomycin hydrochloride (50 mg/mL) with ceftazidime (100 mg/mL) every hour.

• Fortified gentamicin sulfate or tobramycin (14 mg/mL) can also be used with cefazolin sodium (50 mg/mL) if vancomycin and ceftazidime cannot be used

Topical and Subconjunctival Antibiotics

• Subconjunctival administration of antibiotics can lead to therapeutic levels especially in the anterior chamber.

• This approach can be used in patients where frequent drops cannot be administered.

Subconjunctival injection

• Vancomycin hydrochloride: (25 mg/0.5 mL of normal saline) • Ceftazidime: • (100 mg in 0.5 ml of normal

saline)

Steroid Therapy

• Theoretically, concurrent administration of corticosteroids may be beneficial in bacterial endophthalmitis to control both inflammation- and infection-related tissue injury.

Treatment of Post-traumatic FungalEndophthalmitis

• The most common organism reported in posttraumatic fungal endophthalmitis is Candida albicans.

• Fusarium and Aspergillosis also have been reported frequently in this setting.

• Intravenous amphotericin B combined with intravitreal amphotericin B is the most common treatment regimen used in this setting.

• The intravitreal amphotericin dose is 5-10 g in 0.1 mL.

• Intravenous amphotericin B can be given at a dose of 1 mg/kg of body weight, assuming normal renal function.

Role of Vitrectomy

• In addition to appropriate antibiotic treatment, some clinicians feel that it is also important for patients with post-traumatic endophthalmitis to undergo early therapeutic vitrectomy.

Special Considerations with IOFBs

• Prompt surgical management is imperative if a patient presents with clinical signs and symptoms of post-traumatic endophthalmitis with an IOFB.

Goal

• PPV • IOFB removal, • Debridement of the infected

vitreous, and• Intravitreal antibiotics injection. • IOFB culture.

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