Treatment of Post-Endophthalmitis After Intravitreal Injection
First-Line Management
The recommended treatment for post-endophthalmitis after intravitreal injection is immediate vitrectomy combined with intravitreal antibiotics, specifically amphotericin B deoxycholate (5-10 μg/0.1 mL) or voriconazole (100 μg/0.1 mL), plus systemic antifungal therapy. 1
This aggressive approach is essential because:
- Endophthalmitis that extends into the vitreous results in worse visual outcomes than chorioretinitis without vitritis 1
- Early intervention is critical to preserve vision and prevent permanent damage to ocular structures
Treatment Algorithm
Step 1: Immediate Diagnostic Procedures
- Perform a diagnostic vitreal tap for culture and sensitivity testing
- Obtain samples before administering antimicrobials to maximize diagnostic yield
Step 2: Intravitreal Antimicrobial Therapy
For fungal endophthalmitis:
- Administer intravitreal amphotericin B deoxycholate (5-10 μg/0.1 mL sterile water) OR
- Administer intravitreal voriconazole (100 μg/0.1 mL sterile water or normal saline) 1
For bacterial endophthalmitis:
- Administer broad-spectrum intravitreal antibiotics based on the most likely pathogens
Step 3: Surgical Intervention
- Perform pars plana vitrectomy to:
- Decrease the burden of organisms
- Remove fungal or bacterial abscesses inaccessible to systemic agents
- Obtain diagnostic material for culture 1
- Improve drug distribution within the eye
A 2021 study showed that immediate vitrectomy with intravitreal antibiotics performed within 6 hours of presentation resulted in significant visual acuity recovery in most patients with post-injection endophthalmitis 2.
Step 4: Systemic Antimicrobial Therapy
For fungal endophthalmitis:
- For fluconazole/voriconazole-susceptible isolates: Fluconazole (loading dose 800 mg, then 400-800 mg daily) OR voriconazole (loading dose 400 mg IV twice daily for 2 doses, then 300 mg IV or oral twice daily) 1
- For resistant isolates: Liposomal amphotericin B (3-5 mg/kg IV daily), with or without oral flucytosine (25 mg/kg 4 times daily) 1
For Aspergillus endophthalmitis:
- Voriconazole administered systemically is recommended 1
Duration of Treatment
- Treatment should continue for at least 4-6 weeks 1
- Final duration depends on resolution of lesions as determined by repeated ophthalmological examinations
- Regular follow-up with an ophthalmologist is essential to monitor response
Special Considerations
Vitrectomized Eyes
- The half-life of both amphotericin B and voriconazole is shortened in vitrectomized eyes
- Repeated intravitreal injections may be required 1
Macular Involvement
- Sight-threatening lesions near the macula require more aggressive treatment with intravitreal injections to ensure prompt high levels of antifungal activity 1
Collaborative Care
- Decisions regarding antifungal treatment and surgical intervention should be made jointly by an ophthalmologist and an infectious diseases physician 1
Pitfalls and Caveats
Delayed intervention: Prompt recognition and treatment are critical for preserving vision. Any delay can result in irreversible vision loss 3.
Inadequate sampling: Vitrectomy provides superior material for culture compared to needle aspiration, allowing for proper antimicrobial selection 1.
Relying solely on systemic therapy: Poor penetration of many antimicrobials into the vitreous necessitates direct intravitreal administration 1.
Inappropriate antimicrobial selection: Treatment must be tailored based on culture results when available. Empiric therapy should cover the most likely pathogens based on clinical context.
Insufficient follow-up: Regular ophthalmological examinations are essential to monitor treatment response and adjust therapy accordingly.
The evidence clearly supports that immediate vitrectomy with intravitreal antimicrobials, followed by appropriate systemic therapy, offers the best chance for visual recovery in patients with post-injection endophthalmitis 2.