Bacterial and Fungal Endophthalmitis

Abstract

Endophthalmitis is a severe eye infection that may result in permanent loss of useful vision in the affected eye. Most cases are exogenous and occur as a complication of cataract surgery, an intravitreal injection, or penetrating ocular trauma. Endogenous endophthalmitis results from hematogenous seeding of the eye by bacteria or fungi, but bacteremia or fungemia may be transient and patients may present without symptoms of systemic infection. Nearly all endophthalmitis patients present with decreased vision, and some also have eye pain. Eye examination usually reveals a hypopyon and intraocular inflammation. Diagnosis is clinical, supported by cultures of the vitreous and/or aqueous or by blood cultures in some endogenous cases. Molecular diagnostic techniques have been used in research laboratories for pathogen identification in endophthalmitis and offer the possibility of rapid diagnosis, including in culture-negative cases. Intravitreal injection of antibiotics is the most important component of treatment; some cases also benefit from surgical debridement of the vitreous by a vitrectomy. The visual outcome depends partly on the pathogen: coagulase-negative staphylococcal endophthalmitis has a better prognosis than does streptococcal endophthalmitis, for example. Endophthalmitis is a medical emergency, and prompt diagnosis and treatment are essential for saving vision.

Keywords: Candida endophthalmitis; bacterial endophthalmitis; bleb-related endophthalmitis; endophthalmitis; endophthalmitis prophylaxis; fungal endophthalmitis; keratitis-related endophthalmitis; postoperative endophthalmitis; posttraumatic endophthalmitis.

FIG 1

A hypopyon is seen as a layer of white blood cells in the aqueous in this eye with endogenous S. aureus endophthalmitis. (Republished from reference with permission of Springer.)

FIG 2

Fungal endophthalmitis from Scedosporium. Note the “clumped” appearance of the intraocular inflammation. (Republished from reference with permission of Springer.)

FIG 3

Vitreous sampling by needle aspirate (A) or vitrectomy (B).

FIG 4

Gram stain of an intraocular sample demonstrating abundant pigment granules but no organisms. Pigment granules usually appear purple on Gram stain (a) and can be mistaken for Gram-positive cocci unless the fine-focus knob is rotated back and forth, which shows the hyperrefractile (coppery) color of the pigment granules (b).

FIG 5

Endophthalmitis resulting from extension of Alternaria keratitis. Note the irregular borders of the corneal infiltrate and satellite lesions, both typical of mold keratitis.

FIG 6

Endogenous Candida albicans endophthalmitis following illicit injection drug use. A vitreous aspirate was culture negative, so a vitrectomy was performed, and this yielded the diagnosis. Note white lesions overlying the retina, typical of endogenous fungal endophthalmitis.