Bilateral visual loss in a patient with endocarditis

Abstract

A 72-year-old woman with a history of a mitral valve repair and treated hypertension came to hospital in July, 2012, with a 10-day history of lethargy, myalgia, and anorexia. She had become increasingly unwell on the day of admission with fever and rigors. She was brought to hospital by ambulance. During transport she complained of painless loss of vision in both eyes, without preceding ocular symptoms. When examined in the emergency department she was febrile, tachycardic, and hypotensive. A soft pansystolic murmur was noted but there were no embolic events. Visual acuity was no light perception in either eye. She had minimal conjunctival injection. The pupils were non-reactive, the red refl exes were absent, and cloudy media obscured views of the fundi. The patient was resuscitated and treated with intravenous antibiotics. Slit lamp examination showed keratic precipi tates, microcystic corneal oedema, and severe cellular activity in the anterior chamber. The anterior segment infl ammation and bilateral cataracts precluded fundal examination. The ophthalmic assessment was suggestive of bilateral endogenous endophthalmitis. A vitreal aspirate and blood cultures grew Streptococcus agalactiae. Trans oesophageal echo cardiogram showed 1·2 × 0·9 cm mitral valve vegetations and 1·9 × 1·3 cm tricuspid valve vege tations. Contrast-enhanced CT of the brain was normal. A diagnosis of defi nite infective endocarditis was made with the modifi ed Duke criteria (one major, three minor criteria). Increasing erythema and swelling of the eyelids, conjunctival injection, and a right hypopyon developed over the next 48 h (appendix). During the next 3 weeks she remained intermittently febrile despite appropriate intravenous and intravitreal antibiotics. Repeat echo cardiogram showed stable appearance of the mitral valve but an increase in the size of the tricuspid valve vegetation and severe tricuspid regurgitation. The patient had mitral and tricuspid valve replacements. Histology showed mitral and tricuspid valve endocarditis and the mitral valve annulo plasty ring was also aff ected. Gram stain showed Gram-positive cocci but cultures were sterile. The postoperative course was uncomplicated. The patient’s vision had not improved when she was seen for follow-up in December, 2012. Sudden, simultaneous, bilateral visual loss is rare and has a restricted diff erential diagnosis (panel). The only anatomical site at which the visual pathways meet is at the optic chiasm; so bilateral visual loss from a lesion at any other site must be accounted for by bilateral, simultaneous pathological change. In the context of endocarditis, bilateral occipital lobe infarction can occur from an embolus to the basilar artery. In our patient, sudden visual loss was caused by endophthalmitis. Endophthalmitis refers to infl ammation, usually from infection, aff ecting the vitreous cavity, retina, and uvea. Exogenous endophthalmitis, which is more common than endogenous endophthalmitis, arises as a complication of eye surgery, periocular infections, and trauma. Endogenous endophthalmitis is the result of haematogeneous dissemination of a systemic infection, such as endocarditis, pneumonia, and soft tissue infections, to the eye. Staphylococcus aureus and strepto cocci are the most commonly implicated organisms. Fungal endophthalmitis is an important metastatic complication of candidaemia in immuno suppressed patients. The diagnosis of endogenous endophthalmitis requires a high degree of suspicion. A delay in diagnosis is common in patients presenting with visual symptoms and only subtle manifestations of systemic infection. Blood cultures are more likely to be positive than vitreous aspirates. The management is focused on treatment of the systemic infection with intravenous antibiotics, with or without intravitreal antibiotics. Vitrectomy or enucleation may be required after failure of medical therapy. The visual outcome is poor, with 80% of patients left with a visual acuity of light perception or worse in the aff ected eye. Endogenous endophthalmitis should be considered in the diff erential diagnosis of patients presenting with acute visual loss, particularly in the context of a known or suspected systemic infection.