Fungal Endophthalmitis Treatment & Management

Updated: Sep 20, 2018
  • Author: Lihteh Wu, MD; Chief Editor: Hampton Roy, Sr, MD  more...
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Treatment

Medical Care

In vitro, minimum inhibitory concentration (MIC) data do not always correlate with in vivo MIC values. Therefore, these should only be used as a guideline.

The following drugs are used in treating of fungal endophthalmitis:

  • Amphotericin B

  • Fluconazole

  • Ketoconazole

  • Miconazole

  • Flucytosine

  • Itraconazole

  • Caspofungin

Systemic amphotericin has been the treatment of choice because of its broad-spectrum coverage; however, the penetration of the vitreous cavity is poor. Doses of 5- to 10-mg intravitreal amphotericin have been used. Retinal toxicity has been reported in animal models at these doses. Fluconazole and flucytosine have good intraocular penetration, but Candida species show high resistance to flucytosine.

A new systemic treatment is voriconazole; when administered orally or intravenously, it has good intravitreal concentrations. Intravitreal administration of voriconazole also seems safe without evidence of retinal toxicity with concentrations up to 25 mg/mL.

The echinocandins (caspofungin, micafungin, and anidulafungin) are newer agents that exert their antifungal activity by inhibiting D-glucan synthase, an enzyme involved in fungal cell wall synthesis. Because mammalian cells lack a cell wall, it also represents an ideal and specific target for antifungal therapy. Echinocandins exert antifungal activity against Candida and Aspergillus species [21]

In a double-blind multicenter trial of 239 patients, caspofungin was found to be equally as effective as amphotericin B in the treatment of candidemia. Patients were infused with either amphotericin B (0.6–1 mg/kg/d) or caspofungin as a single loading dose of 70 mg with a daily maintenance dose of 50 mg. In this cohort of patients, 7 patients with endophthalmitis were included and the endophthalmitis resolved in all 7 patients. Unfortunately, the authors failed to mention whether or not these 7 patients received caspofungin or amphotericin B. Significantly fewer drug-related adverse events occurred in the caspofungin group than in the amphotericin B group. [22]

Gauthier et al reported a case of Candida endophthalmitis that failed treatment with caspofungin because of its poor penetration into the vitreous cavity. [23] Given its limited vitreal penetration, the role of echinocandins remains to be determined in fungal endophthalmitis.

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Surgical Care

The advent of pars plana vitrectomy has improved the treatment results of fungal endophthalmitis.

The advantages of pars plana vitrectomy are that it provides material for culture, removes viable organisms and inflammatory end products from the infected vitreous, and provides intravitreal access to antifungal agents (eg, amphotericin B).

Vitrectomy and intravitreal amphotericin B should be considered in those cases of endogenous fungal endophthalmitis where the disease is progressing despite initial therapy with an appropriate systemic antifungal agent.

As a general rule, moderate-to-severe vitreous involvement requires vitrectomy because most systemic antifungals have poor vitreous penetration.

Endogenous fungal endophthalmitis without evidence of disseminated disease can be treated successfully with vitrectomy and intravitreal amphotericin B.

Given the narrow therapeutic range of amphotericin B, it should not be given in a gas-filled eye.

Some authors have advocated the use of 400 µg of intravitreal dexamethasone as an adjuvant.

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Consultations

Because endogenous fungal endophthalmitis is frequently an ocular manifestation of a systemic disease, the patient requires a multidisciplinary approach.

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Prevention

Once a positive fungal culture is obtained, the patient should be started on systemic antifungals. At the same time, an ophthalmologic consultation should be obtained. In 2 different studies using this protocol, the incidence of endogenous fungal endophthalmitis was reported to be only 3-9%.

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Long-Term Monitoring

Patients should receive follow-up care as needed. Optical coherence tomography (OCT) may assist in the follow-up of patients with fungal endophthalmitis. A small retrospective case series of 12 eyes of 7 patients showed two patterns of posterior segment involvement of fungal endophthalmitis. Fifteen eyes demonstrated chorioretinal infiltration on OCT imaging, whereas 5 eyes showed inner retinal/retinal vascular infiltration without choroidal involvement. The presence of optic nerve edema, epiretinal membranes, and subretinal fluid was also noted. Upon successful treatment, these OCT abnormalities resolved. [24]

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Further Inpatient Care

Many patients with fungal endophthalmitis are hospitalized. Patients may require intravenous medications.

Two dilated ophthalmic examinations should still be considered, even in asymptomatic patients with fungemia. [25]

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