Endophthalmitis caused by fungal infections may be either endogenous or exogenous. Exogenous fungal endophthalmitis is uncommon in North America and Europe. In contrast, in tropical regions such as India, fungi account for up to one-fifth of culture-positive cases following surgery or trauma. Endogenous fungal endophthalmitis is rare regardless of setting and typically occurs in either severely immunocompromised patients with persistent fungemia or otherwise healthy intravenous drug users following transient fungemia. Clinical presentation is often subacute, and the diagnosis is typically delayed for weeks. Aspergillus (Fig 11-17) and Fusarium are the most commonly identified causative species. Fungal keratitis may also progress to endophthalmitis, most typically when caused by Fusarium. Treatment is frequently difficult and typically involves vitrectomy, intravitreal injection of amphotericin B (5 μg/0.1 ml) and/or voriconazole (0.1 mg/0.1 ml), and systemic antifungal therapy. Two-thirds of patients with fungal endophthalmitis lose useful vision.
Yeast (Candida) endophthalmitis
Endogenous yeast endophthalmitis is most frequently caused by Candida species. Affected patients frequently have previously used indwelling catheters or have undergone long-term antibiotic treatment or immunosuppressive therapy. Many also have a history of hyperalimentation, recent abdominal surgery, or diabetes mellitus. The initial intraocular inflammation is usually mild to moderate, and yellow-white choroidal or chorioretinal lesions may be single or multiple (Fig 11-18). Subretinal infiltrates may coalesce into a mushroom-shaped white nodule that projects through the retina into the vitreous. Exogenous Candida endophthalmitis is rare.
Figure 11-17 Color fundus photographs of endophthalmitis caused by infection with Aspergillus species. A, Features present include mild vitritis, a diffuse macular chorioretinal lesion with subretinal and subhyaloid hypopyon, intraretinal hemorrhage, and papillitis. B, Same eye 2 months after treatment shows macular scar, preserved overlying retinal vessels, and temporal optic nerve head pallor. Final visual acuity was 20/400.
(From Weishaar PD, Flynn HW Jr, Murray TG, et al. Endogenous Aspergillus endophthalmitis. Clinical features and treatment outcomes. Ophthalmology. 1998;115(1):60.)
Figure 11-18 Color fundus photographs of endogenous yeast (Candida) endophthalmitis. A, Note the vitreous infiltrates in a “string-of-pearls” configuration. B, Photograph shows a patient with endogenous endophthalmitis before treatment. C, After treatment with vitrectomy and intravitreal amphotericin B, the endogenous endophthalmitis shown in B was resolved.
(Courtesy of Harry W. Flynn, Jr, MD.)
The diagnosis of Candida endophthalmitis is usually made according to the history, clinical setting, and presence of characteristic fundus features. Intraocular culture specimens are best obtained during pars plana vitrectomy, because it is difficult to culture the localized vitreous clusters of fungus from specimens taken via diagnostic vitreous tap. After completion of the vitrectomy, intravitreal injection of amphotericin B or voriconazole at standard doses is usually performed.
The ophthalmologist should seek consultation with a specialist in infectious diseases to evaluate the patient for systemic disease and assist with treatment planning. If the macula is not involved, visual prognosis after treatment is generally good. Focal chorioretinal lesions are often successfully treated with systemic medications alone. Intravenous fluconazole and voriconazole penetrate the eye well and have been used to treat focal lesions.
Oude Lashof AM, Rothova A, Sobel JD, et al. Ocular manifestations of candidemia. Clin Infect Dis. 2011;53(3):262–268.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.