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Query: UMLS:C0022568 (keratitis)
 5,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Travelers to West, central and eastern Africa as well as to selected areas of Latin America are at risk for infection with Onchocerca volvulus. Infection with this tissue nematode may cause chorioretinitis and keratitis, and it is responsible in endemic areas for blindness in millions.1 In addition to ocular manifestations, it can produce a distressing pruriginous dermatitis or subcutaneous nodules. Clinical manifestations vary according to the parasitic load, previous immunity, and duration of infection.1 Infection is initiated by inoculation with larvae during the bite of the Simulium black fly. Once in the connective tissue, larvae mature to filiform adults and may remain in tissues for years, with the clinical manifestations being produced by the inflammatory reaction to dying parasites. Female adults produce large amounts of microfilaria that migrate through skin and connective tissue; once an infected host is bitten, the infectious larvae develop again in the female Simulium black fly and the life cycle is completed. Transmission is from person to person, and may occur even after a relatively short exposure.2 Although infection of travelers with O. volvulus is rare, according to the Centers for Disease Control and Prevention, 46 new cases of onchocerciasis were diagnosed in the United States in 1994 (Dr. David Addis, personal communication, June 1996). We describe the case of an expatriate who became infected with O. volvulus and we review the treatment and recommendations for prevention of this parasitic infection.
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PMID:Onchocerciasis in an expatriate living in Cameroon. 981 71

The modern local antibiotics, such as the aminoglycosides and quinolones, are very successful in treating infectious conjunctivitis and keratitis. More notably in some Third World countries, however, suppurative keratitis is found in more than half of the infectious disease cases caused by Fusarium species. Here, of course, treatment should be antifungal. The emergence of some problematic microorganisms is related to contact lens wear. Pseudomonas, for example, have the ability to adhere to contact lenses and thus form microcolonies, which are protected by biofilm that predisposes to infection. Acanthamoeba infections of the cornea are a direct consequence of inappropriate or inadequate disinfection of contact lens systems. Occasionally the diagnosis of herpes simplex manifestations of the outer eye can be very difficult. Even more confusing is the delayed appearance of zoster manifestations, such as pseudodendrites, particularly in cases of zoster sine herpete eruptione. The polymerase chain reaction is of particular value in demonstrating the presence of varicella zoster DNA. Although infectious disease of the outer eye remains common, the incidence and complications have increased because of frequent use of antimicrobial agents. In the under-developed areas of the world, however, infections are still very common, are frequently caused by fungi, and are the cause of serious ocular complications. In the Western World infectious eye disease does not seem to be a major diagnostic or therapeutic point at present. Some organisms that have been in the environment all along, however, have emerged in the past half century as a major problem. Thus, in the past years a number of new techniques in diagnosis as well as new insights in pathophysiology and new developments in treatment have emerged that are of interest.
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PMID:Infectious diseases of the conjunctiva and cornea. 1016 42

Human immunodeficiency virus (HIV) infection is associated with a wide spectrum of systemic and ocular infectious diseases. Little is known about its association with herpes simplex keratitis (HSK) in this geographical region (South India). A retrospective study was undertaken to analyze this association in a cohort of 30 virologically proven recurrent HSK cases. Laboratory methods included herpes simplex virus (HSV) isolation, HSV antigen detection and tear secretory IgA or HSV DNA detection while commercial ELISA kits detected HIV infection. The rationale behind the HIV screening was to assess the role of HIV with increased HSK recurrences. Confirmed HIV seropositivity was 16.7% in recurrent HSK cases as against 3.3% in the matched first-episode HSK cases (p < 0.05, Fisher's exact test). Our observations on the features of herpetic keratitis in HIV-proven patients, though based on a small number of cases, raise the question whether the immunological abnormalities associated with HIV/AIDS may affect the clinical course of HSK.
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PMID:Influence of human immunodeficiency virus status on the clinical history of herpes simplex keratitis. 1096 47

The unique structure of the human eye as well as exposure of the eye directly to the environment renders it vulnerable to a number of uncommon infectious diseases caused by fungi and parasites. Host defenses directed against these microorganisms, once anatomical barriers are breached, are often insufficient to prevent loss of vision. Therefore, the timely identification and treatment of the involved microorganisms are paramount. The anatomy of the eye and its surrounding structures is presented with an emphasis upon the association of the anatomy with specific infection of fungi and parasites. For example, filamentous fungal infections of the eye are usually due to penetrating trauma by objects contaminated by vegetable matter of the cornea or globe or, by extension, of infection from adjacent paranasal sinuses. Fungal endophthalmitis and chorioretinitis, on the other hand, are usually the result of antecedent fungemia seeding the ocular tissue. Candida spp. are the most common cause of endogenous endophthalmitis, although initial infection with the dimorphic fungi may lead to infection and scarring of the chorioretina. Contact lens wear is associated with keratitis caused by yeasts, filamentous fungi, and Acanthamoebae spp. Most parasitic infections of the eye, however, arise following bloodborne carriage of the microorganism to the eye or adjacent structures.
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PMID:Fungal and parasitic infections of the eye. 1102 63

We report the isolation of Ewingella americana from the conjunctivae of a 38 year old female physician with keratoconjunctivitis associated with the use of soft contact lens. The patient was treated successfully with topical ciprofloxacin. The source of the infection remains unknown. All contact lens cleaning materials used by the patient were sterile. Since the patient was a physician, and this organism has been recorded as a cause of nosocomial infections, we checked whether cases of Ewingella americana had been reported, but none were identified. We have identified 39 bacterial species, 27 fungi, 4 viruses, 7 protozoa, 4 helminths, and 2 arthropods which rarely have been associated with keratitis or conjunctivitis. Infectious diseases specialists and ophthalmologists must be aware of the many different causes of this illness, including Ewingella americana. This organism is a rare bacterial cause of keratoconjunctivitis not previously reported in Brazil. It should be added to the list of unusual cases of external eye infections.
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PMID:A case of keratoconjunctivitis due to Ewingella americana and a review of unusual organisms causing external eye infections. 1106 58

Cat scratch disease (CSD) is a common infectious disease, however, its association with disciforme keratitis is a previously unreported ocular complication. With the use of the 16S rDNA-PCR technique with subsequent DANN sequencing on corneal material obtained by corneal scrape we were able to identify Bartonella henselae in an unusual form of disciforme keratitis.
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PMID:Disciforme keratitis caused by Bartonella henselae: an unusual ocular complication in cat scratch disease. 1107 Oct 35

Infection with the parasitic nematode Onchocerca volvulus can lead to severe visual impairment and blindness. In an effort to characterize the molecular basis for the inflammatory response in the cornea, we have developed a murine model for O. volvulus-mediated keratitis in which parasite antigens are injected into the corneal stroma of sensitized mice. This model reproduces the two main clinical features of human disease, corneal opacification and neovascularization. Histological analysis of corneas from these mice reveals a biphasic recruitment of neutrophils and eosinophils to the central cornea, along with a small, but persistent number of CD3+ cells. In this review, we present evidence that production of antigen-specific T cell and antibody responses are essential for development of O. volvulus keratitis, and we propose a sequence of molecular and cellular events that lead to migration of inflammatory cells to the cornea and to loss of corneal clarity.
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PMID:Immune mechanisms in Onchocerca volvulus-mediated corneal disease (river blindness). 1112 54

Neutrophils are thought to be involved in many infectious diseases and have been found in high numbers in the corneas of patients with Acanthamoeba keratitis. Using a Chinese hamster model of keratitis, conjunctival neutrophil migration was manipulated to determine the importance of neutrophils in this disease. Inhibition of neutrophil recruitment was achieved by subconjunctival injection with an antibody against macrophage inflammatory protein 2 (MIP-2), a powerful chemotactic factor for neutrophils which is secreted by the cornea. In other experiments, neutrophils were depleted by intraperitoneal injection of anti-Chinese hamster neutrophil antibody. The inhibition of neutrophils to the cornea resulted in an earlier onset and more severe infection compared to controls. Anti-MIP-2 antibody treatment produced an almost 35% reduction of myeloperoxidase activity in the cornea 6 days postinfection, while levels of endogenous MIP-2 secretion increased significantly. Recruitment of neutrophils into the cornea via intrastromal injections of recombinant MIP-2 generated an initially intense inflammation that resulted in the rapid resolution of the corneal infection. The profound exacerbation of Acanthamoeba keratitis seen when neutrophil migration was inhibited, combined with the rapid clearing of the disease in the presence of increased neutrophils, strongly suggests that neutrophils play an important role in combating Acanthamoeba infections in the cornea.
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PMID:Exacerbation of Acanthamoeba keratitis in animals treated with anti-macrophage inflammatory protein 2 or antineutrophil antibodies. 1129 16

The genetic structure of a population of Pseudomonas aeruginosa, isolated from patients with keratitis, endophthalmitis, and contact lens-associated red eye, contact lens storage cases, urine, ear, blood, lungs, wounds, feces, and the environment was determined by multilocus enzyme electrophoresis. The presence and characteristics of virulence factors were determined by restriction fragment length polymorphism analysis with DNA probes for lasA, lasB, aprA, exoS, exoT, exoU, and ctx and by zymography of staphylolysin, elastase, and alkaline protease. These analyses revealed an epidemic population structure of P. aeruginosa, characterized by frequent recombination in which a particular successful clone may increase, predominate for a time, and then disappear as a result of recombination. Epidemic clones were found among isolates from patients with keratitis. They were characterized by high activity of a hitherto-unrecognized size variant of elastase, high alkaline protease activity, and possession of the exoU gene encoding the cytotoxic exoenzyme U. These virulence determinants are not exclusive traits in strains causing keratitis, as strains with other properties may cause keratitis in the presence of predisposing conditions. There were no uniform patterns of characteristics of isolates from other types of infection; however, all strains from urinary tract infections possessed the exoS gene, all strains from environment and feces and the major part of keratitis and wound isolates exhibited high elastase and alkaline protease activity, and all strains from feces showed high staphylolysin activity, indicating that these virulence factors may be important in the pathogenesis of these infectious diseases.
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PMID:Epidemic population structure of Pseudomonas aeruginosa: evidence for a clone that is pathogenic to the eye and that has a distinct combination of virulence factors. 1155 72

A 35-year-old man was diagnosed with Mycobacterium abscessus keratitis in the left eye 3 weeks after bilateral laser in situ keratomileusis (LASIK). Infection in the right eye developed 6 weeks after surgery. Despite aggressive treatment with topical amikacin and clarithromycin and oral clarithromycin, the infection progressed in both eyes. To improve antibiotic penetration, the LASIK flap was removed in both eyes. Culture positivity was prolonged; however, after 8 weeks of intensive topical antibiotics, the infection was eradicated. The final best corrected visual acuity was 20/30 in both eyes.
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PMID:Bilateral Mycobacterium abscessus keratitis after laser in situ keratomileusis. 1197 73


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