Endophthalmitis

Endophthalmitis is severe intraocular inflammation involving the vitreous and aqueous, usually infectious. It is a sight threatening emergency, and untreated virulent infection can destroy the eye within 24 to 48 hours.

Exogenous causes:

• Postoperative: cataract surgery (0.04 to 0.1%), glaucoma surgery with bleb leak, intravitreal injection (0.02 to 0.05% of injections)
• Post-traumatic: 4 to 13% of open globe injuries, up to 30% with a retained foreign body
• Contiguous spread from keratitis

Endogenous disease (2 to 15%) results from bacteremia or fungemia. Organisms:

• Coagulase negative staphylococci (about 70% after cataract surgery)
• Staphylococcus aureus, streptococci, enterococci, Gram negative bacilli
• Bacillus cereus after trauma (fulminant)
• Cutibacterium acnes and fungi in delayed onset disease (over 6 weeks)
• Candida and Klebsiella in endogenous disease

Risk factors: diabetes, immunosuppression, posterior capsule rupture, wound leak, intravenous drug use and indwelling lines. Outcome depends on presenting acuity and the organism.

• Falling vision and increasing pain 1 to 6 days after surgery, red eye, eyelid swelling
• Hypopyon (about 75%), vitritis, absent red reflex, corneal edema, retinal periphlebitis
• Fungal disease: slower course, fluffy white lesions and "string of pearls" vitreous opacities
• Endogenous: fever, systemic source, may be painless
• Red flags: hypopyon, afferent pupillary defect, rapid decline, light perception only

• Clinical diagnosis, followed by immediate sampling.
• Vitreous tap or biopsy (0.2 to 0.3 mL by needle or vitrector) and aqueous (0.1 mL) before antibiotics, for Gram stain, culture and broad range 16S PCR.
• Systemic evaluation for endogenous disease: two sets of blood cultures, urine culture, echocardiography, chest imaging, glucose and a search for a focus (endocarditis, liver abscess).
• B-scan ultrasound when the view is poor, to show vitreous opacities, choroidal thickening and retinal detachment.

Differentials: toxic anterior segment syndrome (onset within 24 hours, no vitritis), postoperative uveitis, retained lens material, vitreous hemorrhage, intraocular lymphoma.

Treat the same day without waiting for culture results.

Postoperative and post-traumatic bacterial disease:

• Intravitreal vancomycin 1 mg in 0.1 mL and ceftazidime 2.25 mg in 0.1 mL, in separate syringes with separate needles, immediately after sampling. Repeat at 48 to 72 hours if worsening.
• Presenting acuity of hand movements or better: tap and inject. Light perception only: immediate pars plana vitrectomy with intravitreal antibiotics.
• Intravitreal dexamethasone 0.4 mg in 0.1 mL can be added after antibiotics.
• Topical fortified vancomycin 50 mg/mL and ceftazidime 50 mg/mL hourly for the first 24 to 48 hours, atropine 1% twice daily and prednisolone 1% every 2 hours.
• Oral prednisolone 1 mg/kg daily for 5 to 10 days from 24 hours after antibiotics when bacterial infection is confirmed.

Fungal disease:

• Intravitreal voriconazole 100 micrograms in 0.1 mL, or amphotericin B 5 micrograms in 0.1 mL, with vitrectomy.
• Voriconazole 400 mg orally twice daily on day 1, then 200 mg twice daily (or 6 mg/kg intravenously twice on day 1, then 4 mg/kg twice daily) for 6 weeks. Monitor liver enzymes and visual symptoms.
• Candida: fluconazole 800 mg load, then 400 mg daily for 4 to 6 weeks.

Endogenous bacterial disease: intravenous vancomycin 15 to 20 mg/kg every 8 to 12 hours plus ceftazidime 2 g every 8 hours for 2 to 4 weeks, intravitreal antibiotics, and treatment of the source.

Delayed onset (Cutibacterium acnes): vitrectomy with capsulectomy and intravitreal vancomycin. Intraocular lens exchange for recurrence.

Children: vancomycin 15 mg/kg every 6 hours intravenously. Intravitreal doses are the same as for adults.

Prevention: povidone iodine 5% to the conjunctival sac for at least 3 minutes before surgery and 30 seconds before injection, intracameral cefuroxime 1 mg in 0.1 mL at the end of cataract surgery, and eyelid and wound care.

Review daily in the first week. About half of promptly treated eyes reach 20/40 or better. Counsel on early return with pain or reduced vision.