Treatment of Endophthalmitis
Immediate Empiric Antibiotic Therapy
For bacterial endophthalmitis, intravitreal vancomycin 1 mg/0.1 mL combined with intravitreal ceftazidime 2.25 mg/0.1 mL is the recommended first-line treatment, administered immediately after diagnostic vitreous tap. 1, 2, 3
Bacterial Endophthalmitis - Intravitreal Antibiotics
The cornerstone of treatment is intravitreal injection of antibiotics, which achieves far higher intraocular concentrations than any systemic route 3, 4:
Vancomycin 1 mg/0.1 mL - covers all Gram-positive organisms including methicillin-resistant Staphylococcus epidermidis and Staphylococcus aureus, which are the most common pathogens in post-surgical endophthalmitis 2, 3, 5
Ceftazidime 2.25 mg/0.1 mL - preferred over aminoglycosides for Gram-negative coverage due to lower macular toxicity risk 2, 3
Critical pitfall to avoid: Subconjunctival injections alone are ineffective and should never replace intravitreal administration 1, 5. The intravenous route does not achieve therapeutic intraocular levels for bacterial endophthalmitis 5.
Role of Systemic Antibiotics in Bacterial Endophthalmitis
- NOT routinely recommended for exogenous bacterial endophthalmitis (post-surgical, post-traumatic) 4
- Required for endogenous endophthalmitis (bacteremic seeding): IV vancomycin 15-20 mg/kg every 8-12 hours plus third-generation cephalosporin 6, 4
Surgical Management
Pars plana vitrectomy is indicated when:
- Vision deteriorates to light perception or worse 6
- Severe vitritis with significant inflammatory debris 1
- Macular involvement threatening vision 1
Vitrectomy removes infectious organisms and inflammatory debris, and is sight-saving in severe cases 1, 6. However, note that vitrectomy shortens the half-life of intravitreal antibiotics, potentially requiring repeat injections 7.
Fungal Endophthalmitis Treatment
Candida Endophthalmitis
Treatment algorithm based on severity and organism susceptibility:
For Chorioretinitis WITHOUT Vitritis:
Fluconazole-susceptible isolates: Fluconazole 800 mg loading dose, then 400-800 mg daily OR voriconazole 400 mg IV twice daily for 2 doses, then 300 mg twice daily 7
Fluconazole-resistant isolates: Liposomal amphotericin B 3-5 mg/kg IV daily ± flucytosine 25 mg/kg four times daily 7
For Endophthalmitis WITH Vitritis or Macular Involvement:
Systemic therapy PLUS intravitreal injection PLUS consider vitrectomy 7:
Systemic: Liposomal amphotericin B 5 mg/kg IV daily ± flucytosine 25 mg/kg four times daily 7
Intravitreal: Amphotericin B deoxycholate 5-10 μg/0.1 mL sterile water OR voriconazole 100 μg/0.1 mL sterile water/normal saline 7
Vitrectomy: Strongly recommended to remove fungal abscesses and decrease organism burden 7
Important consideration: Echinocandins achieve poor ocular penetration and should NOT be used as monotherapy for endophthalmitis, despite being first-line for candidemia 7. Voriconazole serum trough levels should be monitored to maintain 2-5 μg/mL 7.
Aspergillus Endophthalmitis
IV amphotericin B plus intravitreal amphotericin B deoxycholate plus pars plana vitrectomy 7, 1:
- Intravitreal amphotericin B following diagnostic vitreous tap 7
- Alternative: Voriconazole administered intravitreally and/or systemically 7
- Vitrectomy is sight-saving by removing bulk of organisms and inflammatory debris 7
Duration of Therapy
Bacterial endophthalmitis: Continue until clinical resolution, typically requiring repeat injections if no response to initial therapy 4
Fungal endophthalmitis: Minimum 4-6 weeks, with final duration based on repeated ophthalmologic examinations documenting lesion resolution 7, 1
Diagnostic Requirements Before Treatment
Obtain vitreous tap for culture before initiating antibiotics 1:
- Provides definitive microbiological diagnosis 7
- Vitreous culture superior to aqueous tap 7
- Essential for endophthalmitis of unknown origin 7
Monitoring and Follow-up
- All candidemic patients require dilated retinal examination by ophthalmologist early in therapy, especially those unable to communicate visual symptoms 7
- Repeated ophthalmologic examinations mandatory to assess lesion resolution and determine treatment duration 7
- Direct macular involvement indicates poor prognosis for visual acuity recovery 7, 1
Special Populations and Complications
Cavernous Sinus Involvement (Panophthalmitis)
If cavernous sinus thrombosis suspected 6:
- Immediate contrast-enhanced MRI/CT to confirm diagnosis
- IV vancomycin 15-20 mg/kg every 8-12 hours plus third-generation cephalosporin
- Anticoagulation with heparin for minimum 3 months
- Urgent neurosurgery consultation
Immunocompromised Patients
Consider fungal pathogens including Aspergillus and Pythium species, requiring broader antifungal coverage 6.