The eye in systemic sepsis

Abstract

-Metastatic or endogenous endophthalmitis (EE) is a serious consequence of systemic sepsis. It is defined as intraocular infection resulting from haematogenous spread of organisms in which the initial focus of infection is at a site distal to the eye. A red/sore eye in a patient with a known septic focus needs urgent attention as EE can be a major cause of visual loss. Early diagnosis and treatment are associated with better visual outcome. This article focuses on the two main causes of EE, namely bacterial and fungal infections, and also briefly mentions dissemination of cytomegalovirus to the eye in immunocompromised patients. Although conscious patients may notice an ocular problem, unconscious or very sick patients may not; vigilance by medical staff in looking for early signs of this is extremely important.KEY WORDS: candida, ciprofloxacin, cytomegalovirus (CMV), endophthalmitis, floaters, hypopyon, red eye, retinal infiltrates, retinitis, septicaemia Endogenous fungal endophthalmitisFungal sepsis is identified most frequently in hospitalised patients who are seriously ill. Endogenous fungal endophthalmitis (EFE) occurs in 28-45% of patients with candidaemia 1,2,3 and is the most common form of endogenous endophthalmitis (EE) 4 . Patients usually present with floaters and decreased vision, unilateral or bilateral. Onset is often insidious; in its early stages EFE can be asymptomatic 2 , but if left untreated can have devastating consequences for visual function. Therefore, regular screening of high risk cases is undertaken in many centres 5,6 . High risk characteristics include those listed in Table 1. CandidiasisCandida albicans is the most common pathogen causing EFE and in some series is the causative agent in 85-99% of all cases 6,9 . Non-albicans candida spp are important as aetiological agents 10 because fungaemia with these species is associated with a higher incidence of endophthalmitis than with C. albicans 11 . Other causes of EFE in descending order of importance are Aspergillus fumigatus, cocciodioides, cryptococcus, fusarium, histoplasmosis and paecilomyces 4 .Diagnosis of ocular candidiasis. The clinical diagnosis of ocular candidiasis is largely made on the ocular appearance 8 . The organism typically causes inflammation in the choroid and retina, with subsequent spread into the vitreous cavity 8 . The ophthalmoscopic appearance is of one or more creamy-white, usually round and sometimes elevated retinal lesions, often sited in the posterior pole of the eye (Fig 1). They may vary in size from small pinpoint lesions to two-disc diameter in width 8 . If the vitreous is involved, multiple clumps may form ('puff balls') (Fig 2). Thread-like strands may connect these, producing a so-called 'string of pearls' appearance. Ocular lesions can indicate otherwise occult deep tissue fungal infection and are useful indicators of systemic candidiasis 12,13 . Although autopsy studies have demonstrated a high incidence (78%) of ocular involvement in patients with candidaemia 12 , the eye can be the ...

Ocular Complications of Endocarditis

“…(30) If a large septic embolus pass through the www.intechopen.com central retinal artery and disseminates throughout the retina, retinal necrosis and ischemia may occur. (30) This allows the microorganisms to quickly invade the vitreous and further the anterior segment, causing inflammation of intraocular tissues (panuveitis) that may be mixed-up a non-infectious inflammatory disease. (31) Similarly, in cases of fungal endophthalmitis a localized inflammatory reaction surrounding a small nidus of fungi forms in the inner choroid, breaks through Bruch's membrane into the retina forming a microabscess and spreads into the vitreous cavity.…”

“…(30) They establish a septic focus that can develop in the retina prior to breaking into the vitreous. (30) The infectious embolus is usually in proximity to the retinal vessels. (30) If a large septic embolus pass through the www.intechopen.com central retinal artery and disseminates throughout the retina, retinal necrosis and ischemia may occur.…”

“…(30) The infectious embolus is usually in proximity to the retinal vessels. (30) If a large septic embolus pass through the www.intechopen.com central retinal artery and disseminates throughout the retina, retinal necrosis and ischemia may occur. (30) This allows the microorganisms to quickly invade the vitreous and further the anterior segment, causing inflammation of intraocular tissues (panuveitis) that may be mixed-up a non-infectious inflammatory disease.…”

“…(30) Destruction of intraocular tissues may be due to direct invasion of the organism and/or from inflammatory mediators of the immune system. (30,31) In any type of endophthalmitis, bacteria are introduced into the intraocular environment, encountering a site of immunological inactivity. (30) The intraocular environment is termed an "immune privileged site", devoid of inflammatory mediators and cells present that would otherwise fight infection.…”

“…(30,31) To invade ocular tissues and produce infection the organisms must cross the blood-ocular barrier either by direct invasion (septic emboli) or by changes in vascular endothelium caused by substrates released during infection. (30) They establish a septic focus that can develop in the retina prior to breaking into the vitreous.…”